Mop Top Robinias & Weeping Mulberries – pruning standard trees

What do you do when you are faced with the daunting task of pruning a weeping mulberry or a Mop-Top Robinia or any other standard tree for that matter? Well, firstly take a deep breath because it’s not as hard as first appears. Secondly, there are some simple tricks you can use which will lead to success, and finally, you can’t do much damage that can’t be fixed by new growth, except to prune below the graft!

A gorgeous weeping Mulberry

I believe that pruning can be easier if you know what type of plant you have and how it grows, so to begin with, let’s look at what a standard plant is. Basically, it’s one plant grafted onto another at a desired height. The ‘rootstock’ is the host plant, and will usually be in the same plant family as the ‘graftee’.

For example, the Mop Top Robinia, with the botanical name Robinia pseudoacacia ‘Umbraculifera’ is grafted onto the Black Locust tree, Robinia pseudoacacia. The latter suckers and is becoming an environmental nuisance, so to enjoy the benefits of the lovely Robinia’s color and foliage, a rare dwarf form of Robinia (Robinia umbraculifera) was grafted on. This results in a small tree that will naturally grow into a dense round ball that is environmentally friendly and will never grow more than 4-5 metres tall.

There are several benefits to grafting;

The rootstock is usually very hardy, easy to propagate, and quick growing. This means that hard to grow species, perhaps with specific soil requirements, can be grown more easily, such as roses and grafted natives.

With seed grown stock there is always going to

Weeping standard grevilleas, using groundcovers. Photo courtesy of the Weeping Grevillea Nursery, Victoria

be genetic diversity, so that each plant in a batch of seedlings will be slightly different from another. When plants are grafted using plant material from one source, this diversity is overcome. This means that each Mop Top graft taken from one mother plant is genetically cloned and has an identical head, making formality easier.

Grafted plants will grow to the height of their host rootstock, ensuring uniformity and control. This also means that a low-growing plant, such as a groundcover, can be elevated to a higher status!

Mop Top Robinia ready for a trim

So let’s get down to the business of pruning a standard. My examples here the Mop-top Robinia and the standard weeping Mulberry, as the guidelines are basically the same. I prune in winter when both have lost their leaves, so you can see what you’re doing, but you can always give them a trim at other times.

 

The tree on the right is half done.

1. Cut out all dead, ailing, and twiggy branches. Gee that was simple!

2. Cut all other branches off by 2/3rds. This may sound drastic, but there is more to come.

3. Shape the remaining branches. At this point you need to make decisions about which are staying and which are going. Cut off all branches that cross over others in an inconvenient way. Choose your most attractive, strong, healthy, and favourite branches, and clear away the rest. When pruning a weeping standard, cut just below an outward facing bud, so the tree doesn’t start growing towards the centre.

Give yourself a pat on the back for a job well done, pour yourself a cup of your favourite tea and put your feet up – it’s a tiring job!

The pruning complete

The happy couple – fully recovered!

Just a few additional notes…

I don’t always give weeping mulberries or Mop-Tops a severe prune – some years they just need a little trim. However, if you have one that hasn’t been pruned for some time, it may be just what it needs to revitalize and send out some new vigorous growth.

If you are pruning a flowering tree, a weeping cherry for example, find out when it flowers first. If you prune just before it flowers, there goes the reason you probably bought it – the flowers!  If it already has a good shape, just trim neatly, like a good haircut.

And just like after a haircut, your plants will regrow!

Cheers and happy pruning,
Amanda


79 thoughts on “Mop Top Robinias & Weeping Mulberries – pruning standard trees

  1. Gina says:

    We have pruned our mop tops very hard this year and hubby is concerned they won’t be as bushy this year. They gave fabulous shade over a fernery area and now of course this is exposed to the sun.
    How much will they regrow do you think. They were pruned a bit harder than your photo.
    Your input to our query is appreciated. Thanks.

  2. Amanda Reynolds says:

    Hi Gina,
    Thanks for your query. I have seen mop tops pruned VERY severely (at McDonalds) and they seem to bounce back quite happily. If they are in good soil, they should recover well, particularly if you fertilize with a slow release fertilizer and mulch. Hope this helps and happy gardening.
    Cheers
    Amanda

  3. Sarah says:

    Hi Gina,
    When we purchased our house 4 or 5 years ago there were two mop tops already in the front yard about 2-3 meters from the house. In the last week or two we’ve noticed some suckerings coming through. When we had a closer look at these, we saw that the roots of the mop tops are actually running straight under our house. We are now concerned about damage to our foundation. Would you recommend removing the trees?
    Regards,
    Sarah

  4. Amanda says:

    Hi Sarah,
    Thanks for your query. The Mop Top Robinia is a combination of a dwarf form of robinia grafted onto the Black Locust tree, Robinia pseudoacacia. The Black Locust can sucker and become quite a nuisance, and in Australia, it is not recommended to plant it close to pipes and foundations.
    As this is the rootstock for your Mop Top Robinias, I do think that 2-3 meters from the house is too close. If you choose to remove the trees, you will need to ensure that the rootsock is also removed or poisoned, as removing the graft (the top part of the tree) will give the rootstock the chance to sucker more.
    I hope this helps and please contact me if you need any further clarification.
    Cheers
    Amanda

    • Amanda Reynolds says:

      Hello John,
      Thanks for your question. The grafted plant on the top is a dwarf form of Robinia, which if planted by itself would only be about 1 metre high. The growers who first grafted and named the standard ‘Mop Top’ chose this form as a good seller for landscapers. The graft can be any height you choose, even at ground level. I would guess that the present height of the graft is a commercial choice.
      Hope this answers your question.
      Cheers,
      Amanda

  5. David says:

    Hi Amanda,
    We have recently discovered some insects (mainly Earwings) in the trunk of our mop top trees. Do you think the pruning may help kill them?
    Also, we are always worrying, once pruned, it may take many years for the mop top trees growing up to today’s flourishing, what do you think?
    Thanks again!
    David

  6. Amanda Reynolds says:

    Hi David,
    Thanks for your questions. Firstly, can you see any damage from the insects? If not, perhaps the insects in the trunk are not harming your tree, and you don’t have to worry. However, if they are concering you, you might like to try the organic solutions for earwig control on the website. I wouldn’t prune too close to the trunk as this may shock your tree and encourage the rootstock to grow from the base.
    Secondly, it is natural to worry that your Robinias will not grow back. However, the photos in the post show a severe pruning and lush regrowth in the same year – within 6 months in fact. I can be sure of this as I did the pruning and took the photos myself. To give your trees the best chance of recovery, ensure that they are fertilized and mulched in spring and autumn, and watered well in summer.
    I hope this answers your questions. Please feel free to contact me again if you have any further enquiries.
    Happy gardening,
    Amanda

  7. Ernest Ralton says:

    Hi Amanda ,
    I read your notes with interest & have a few comments to make . When removing Mop Tops completely I have found it best to poison the tree , wait until completely dead & the remove . Ive tried cutting them down , stump grinding etc & they always seem to succor.
    one year I did a normal hard prune for a client & for no apparent reason one in the row completely died off on one side , it took 2 years to come back. cheers E

    • Amanda says:

      Hi Ernest,
      Thanks for your great comments. Robinia rootstock certainly is persistent, and your method of removal I think is the best.
      I’m glad your clients moptop came back eventually too.
      Cheers, Amanda

  8. Keith Daniells says:

    Hi Amanda. The Mop Tops in our garden have not been cut back in at least 8 years. I have read your article but I would like a little more info on a couple of things, I live in the Wimmera region of Victoria where rainfall is not as often as one would like. It is dry. Two things is it safe to cut back hard on well developed trees and is now, March, a time when it can be done. Is there anything I should watch for during and after cutting and what do you suggest re feeding the tree.
    With thanks, Keith,

    • Amanda says:

      Hi Keith,
      Thanks for your comment.
      Firstly, it’s fine to prune well developed trees, but if you are worried, you don’t have to cut back as hard as I have done in the article photos. You could try a light prune this year, such as cutting by 50%, and when you feel more confident, prune more next year. It is still important to prune dead or diseased material, both for the health of the tree and to allow light and air to flow.
      Secondly, I usually prune in winter when the trees have lost their leaves. This is so I can see more clearly what needs to be cut, and so the tree, being dormant, has more chance of a good recovery in spring. I certainly would recommend waiting for the season to break, so the tree is deeply watered.
      Thirdly, when pruning, ensure that your tools are clean and sharp, and always try to make a clean cut, so no damage is done to the tree. I usually fertilize my whole garden in autumn after rain, and again in spring as the soil is warming up. This is because plants find it difficult to take up nutrients when soil is either dry or cold.
      I hope this helps and good luck with the pruning.
      Cheers,
      Amanda

  9. Jillian Govan says:

    Hi Amanda,
    I live in Ontario, Canada. 26 years ago I planted a Weeping Mulberry, (no fruit) tree which we hardly pruned and which grew to 15 or 16′ and became very unruly. I had a local lawn/property maintenance guy come to help clean up my garden (I am not at all knowledgeable in plant care). In November last year he sawed off the top of the mulberry tree to what I now realize was below the grafting, and I was left with a single 4′ stump all winter. He assured me it would grow back out of the top of the stump. However, this is not happening and I just seem to be getting what I guess are suckers. I have pinched off the suckers growing on the lower part of the trunk hoping to encourage growth on top but nothing is happening on the top. I’ve just let a few suckers grow around 2/3rds up the stump. When I called the guy to find out what I should be doing with this situation, he told me to take off those bottom leaves and that he had done this many times before and new growth would be coming out of the top. In your opinion is it possible for new branches to grow out of a solitary stump, or has in fact the tree been killed off? Any thoughts would be gratefully appreciated.

  10. Amanda Reynolds says:

    Hi Jillian,
    Many thanks for your comment to the post. Sadly, I’m not convinced that your weeping Mulberry will recover, as it should have shown some top growth from the graft in Spring. The fact that the rootstock is growing strongly would point to this too.
    When pruning grafted standards, it is essential to prune above the graft, leaving several strong solid branches (as in the completed pruning photo in the post), even if these are quite short. If these are not there, I would suggest that the tree has been pruned too severely.
    If the graft has indeed been killed, you would have a couple of options. The first would be to remove the plant completely, as the rootstock will vigorously take over without the graft, which seems to be happening already. The second would be to allow the Mulberry rootstock to grow – it may be a fruiting variety, but it will definitely grow into a very large tree, which may not suit you.
    I am so sorry that you may have lost your tree, but wish you all the best in your garden.
    Cheers,
    Amanda

  11. Pam Hill says:

    Amanda
    I had an unruly mop top and last fall it was drastically cut back with main branches being left at top of the main trunk. For the new growth and shape.
    I have not seen any growth and am worried it is dead.
    Should it take a year or so to come back?
    I have seen others Cut back more drastic then mine and they seem okay.
    My other mop top, while a tad unruly was not trimmed back and it is slow to produce growth as well, but is growing.
    I see no signs of damage to the trunks by insects.
    Thank you for any insight on this.

    • Amanda says:

      Dear Pam,
      Thanks for your inquiry. If you have had a warm spring, I would expect your mop top to have sent out some growth by now. It should not take a year to recover, I’m sorry to say. However, if you are living in the Northern Hemisphere and it’s only been 6 months or so, you may have a chance.
      If you are not in a hurry to give up on it, I would suggest giving it some fertilizer and mulch and give it another month or two to see what happens. If it has been damaged by creatures or disease, it may be on the roots.
      Another way of checking if it’s died is to look for suckers. If the top hadn’t survived, the rootstock would have sent up growth from below the graft. If this hasn’t happened, then either the whole plant has died, or it still has a chance to come back.
      Hope this helps,
      Amanda

  12. Barry Pilton says:

    Amanda.
    I would like to transplant a weeping mulberry tree it’s almost 2mts tall, this is the second year since I planted it. I want to move it to a better location, hope you help me.
    Regards Barrry

    • Amanda says:

      Hello Barry,
      Thanks for your question. As it is a large tree, you will need to take a bit of care when transplanting.
      Firstly, the best time to transplant it is when it is dormant – winter or early spring.
      Secondly, prune the top of the tree as per the article – this helps the tree by reducing the amount of transpiration or water loss while it recovers.
      Thirdly, dig around the base of the tree at the drip line, cutting through all the roots. The drip line is where the leaves spread to before pruning. Do this a couple of weeks before moving it- this will encourage the tree to make new roots close to the trunk.
      When moving the tree, try to get as much soil around the roots as possible, to preserve the root ball as much as you can. It will probably be very heavy, so have someone to help if possible. The best way is to lift the tree onto a sheet or tarpaulin and drag it to the new hole if it’s not too far.
      Lastly, dig the new hole twice the size of the root ball, adding organic matter and mixing it into the existing soil. Water in well and fertilize when the tree starts to make new growth. Good luck with your moving!
      Cheers,
      Amanda

  13. Gavin says:

    Hello Amanda. I live in Canberra and carried out a first hard prune on my mop top robinia in July. Poor thing hasn’t shown the Slightest sign of lift and we are experiencing a warm September. Have I done something wrong?

  14. Amanda Reynolds says:

    Hi Gavin,
    Firstly, sorry for the delay in replying, but we are moving the nursery and only just catching up!
    I’m not sure why it wouldn’t be shooting if you’ve had a warm spring, but by the look of the weather reports for Canberra you’ve had a particularly cold winter. It may just be starting to wake up, and the soil will still be cold, which will impact on growth. I’m also not sure if you’ve done anything wrong as I don’t have a photo of the prune, but as long as you haven’t pruned below the graft, you have probably done the right thing.
    Keep waiting – it may well surprise you and reward you with a lovely ‘mop’.
    Cheers, Amandda

    • Gavin says:

      Thank you Amanda. Do you mind terribly if I send you an email photo of the mop top ? I would really appreciate your advice. Thank you again. Gavin.

      • Bronwyn Allan says:

        Hi Amanda
        I also live in Canberra and my mop top which is 8 years old has only been pruned this year for the first time. I employed an arborist to do the pruning as the tree is very large. He cut it back severely , just like your photo, but unfortunately still no sign go regrowth. I have noticed all the mop tops in our area are shooting so I am getting concerned, any other tips

      • Amanda Reynolds says:

        Hi Bronwyn,
        I’m not sure what is happening with your moptop but as I emailed to Gavin, I wonder whether the extra cold weather in your city had burned off any new tender shoots that had tried to come through? Sometimes when a plant shoots in spring, a frost can damage the new growth and burn it so it dies. If the plant is strong and healthy, it will shoot again later. The start to spring has been quite erratic and some nights have dropped a lot in temperature, so that may be the problem. I have some plants in the nursery that have shot, been burned and shot again.
        As you have employed an arborist to do the initial pruning, I also feel you could legitimately ask them to return to have a look at your tree. They may have some further clues.
        Hope this helps.
        Cheers,
        Amanda

  15. Murray Vallance says:

    Hi Amanda
    I prune my Moptops right back every year and they come back very nicely and admired by the passers by.
    This year they are very slow sprouting and there is some sort of wood weavils/caterpillars and a lot of the dead wood.
    I believe these might have been there for sometime now as there is a lot of dust in amongst the branches.
    It looks like a caterpillar and is probably 10/12mm long with a clear body and black head.
    Your comments please as to how to eradicate
    Thanks
    Murray

    • Amanda Reynolds says:

      Hi Murray,
      Thanks for your comment and query. It is quite difficult to diagnose a problem with plants, particularly as there may be more reasons for the Mop-top’s problems than meets the eye. For example, the caterpillars may be there because the plant is stressed or diseased, or they may be causing the problem. It’s also risky to suggest a remedy without knowing what the caterpillar is.
      My suggestion would be to take the offending beasts to a knowledgeable nursery or a botanic gardens near you. They could identify it and suggest a treatment.
      As for managing the trees themselves, I would suggest 3 things –
      1. Remove as many caterpillars as you can and keep an eye on them recurring.
      2. Remove all the dead wood, dust and debris – this will get rid of places for the caterpillars to hide.
      3. Fertilize, water and mulch all the trees to give them the best chance of recovery.
      I would do all this as well as what is suggested to you by someone who can identify the caterpillars. In doing so, you can encourage the trees to return to health and lessen the chance of the critters returning.
      Hope this helps and your Mop-tops are being admired again soon!
      Cheers,
      Amanda

      • Murray Vallance says:

        Thanks Amanda
        Looking at it now there appears to be borer in some of the dead wood.
        Opening some of them up I have discovered some brown lavae
        Can I spray for these and should I wait until it is in leaf?
        Murray

      • Amanda Reynolds says:

        Hello Murray,
        I’m sorry but it’s very hard to make suggestions about pest control without seeing the pest in situ, so I would highly recommend taking the larvae into a nursery or botanic gardens for identification and suggestions on control. Pest management can be very precise and it is important to know what you are trying to eradicate, and the specifications of what you will be using.
        Hope this helps,
        Cheers,
        Amanda

  16. Rose Percy says:

    Hello. I have a line of moptops that I am trying to grow into a hedge to screen a house in front. The neighbours have pruned the branches on their side of the fence so that side is flat rather than rounded. So I have decided to do the same on our side of the fence. My problem now is that the tops need “flattening off”. But they have started sprouting as is spring here in the South Island of NZ. If I prune while sprouting, will it kill the trees? Will I have to wait until next winter? Thank you for your great column! I’ve enjoyed reading all the questions and comments. Regards, Rose.

    • Amanda Reynolds says:

      Hi Rose,
      Thanks for your query and your kind comments.
      Sounds like you have a bit of a Mohawk mop top! It will be fine to prune now – you will just have more foliage to deal with. The main reason for pruning in winter is that it is easier to see what you are doing, and the plants are dormant so it’s not so much of a shock. If you are worried, you could just give them a lighter prune than the sides and do a harder prune in winter.
      However, if you feed, water and mulch to keep them healthy, they should be fine.
      Happy pruning,
      Amanda

      • Rose says:

        Thank you for your prompt reply Amanda. Love the scenario that my moptops are now Mohawks! Haha! We have pruned the tops off now, and we are hoping the Mohawk Robinias will now form a hedge to screen the house in front! It will be interesting to see what happens! Rose.

  17. Laura Mac says:

    Hi there,
    I moved in to a new house in Winter and there were 3 bare mop tops along the fence. Now that it’s Spring (I am in Australia), the trees are full of beautiful leaves; it’s been amazing to watch how big they’ve gotten in only a matter of 8 weeks or so!
    However, the leaves are now dropping considerably. It hasn’t affected the trees’ aesthetics at all but there are leaves everywhere. Summer hasn’t even started yet, surely now is not the time for the trees to shed leaves? I can’t find anywhere that this is a problem in Spring for these trees…
    Also, I planted a vegetable garden a few metres from the trees. Nothing is growing and suckers from the mop tops have just started coming up throughout the garden. How would you suggest I get rid of them? The soil here has a bit of clay. The trees are only 5 metres from my bedroom window; do I need to dig them out? I hope not, as they are beautiful!
    Hope you can help!
    Laura

    • Amanda Reynolds says:

      Hi Laura,
      Thanks for your query. I’m not sure what part of Australia you are from, but many areas are having very inconsistent and variable weather at the moment – where we live we have had one day of 33C followed by a night of 3C! This variability can cause plants to do odd things, such as lose their leaves out of season. Moptops don’t generally have a habit of losing their leaves in spring, but it may be the weather if yours has been unpredictable. As long as the trees have a good canopy and the leaves are green and healthy, I wouldn’t be too concerned.
      As for the suckers, some roots of the Moptops may have been damaged in digging and the rootstock will see this as an opportunity to grow, particularly if you have improved the soil for the vegies. The suckers belong to the very robust rootstock, the Black Locust tree, Robinia pseudoacacia. These must be removed, preferably by pulling out rather than pruning off, as this will only increase growth. You will need to be consistent, as the rootstock will take any chance it can and will need to be removed as soon as you see it. You cannot poison the suckers, because the whole tree will die, as the rootstock feeds the grafted top.
      As for the vegies, the rootstock of the Moptops is far reaching and hungry, so the vegies may not have the best chance so close. Can you site the vegies in another part of the garden?
      If you want to keep the trees and don’t mind dealing with the suckers, you won’t have to dig the whole tree out. However if the suckers become a real problem, the moptop graft starts to lose vigor and/or you really want to grow the vegies in that spot, you may need to do so. If you choose to get rid of the moptops, you will need to dig out what you can and poison the stump to remove all of the rootstock.
      All the best with whatever you decide.
      Cheers,
      Amanda

      • Laura says:

        Thanks for your reply. The weather has been up and down here (I’m in Adelaide, and I’ve just noticed you are too; I must come check out your stall at the Fullarton Markets one weekend….!)
        The vegie garden is not dire, the basil and parsley are going well enough so I’ll dig out the rest and just have a garden full of basil and parsley–nothing wrong with that!
        Thanks again for the advice
        🙂

  18. Amanda Reynolds says:

    Glad I could help Laura. A garden full of basil and parsley sounds like heaven! Would love to see you at Fullarton sometime.
    Cheers,
    Amanda

  19. Keith Daniells says:

    Hi, our mop tops were in place when we bought the house. I believe they are at least 8 – 10 years old. I have cut a couple of them back very hard, probably the first time for them and now they are coming back with thorns. Have I ruined the tree?

    • Amanda Reynolds says:

      Hi Keith,
      Thanks for your inquiry. I am sorry to say but I think you may have pruned your mop tops back to the rootstock. The very attractive Mop Top Robinia, with the botanical name Robinia pseudoacacia ‘Umbraculifera’ is grafted onto the Black Locust tree, Robinia pseudoacacia, which has many thorns in it’s natural state. Without it’s graft, it will revert to this form.
      It’s difficult to be sure without seeing them in person, so you may like to get another opinion before going further.
      If you have more mop tops, it may be wise to cut them back only to half in the winter, to ensure you retain the graft.
      Hope this helps and happy gardening.
      Cheers,
      Amanda

      • Keith Daniells says:

        Thanks for the info Amanda, not really what I wanted to know 🙂 but I did expect it. So what happens now? What happens if I leave it as is and just let it grow? Or should I remove it all together.

      • Amanda Reynolds says:

        Hi Keith,
        Sorry I couldn’t give you better news!
        I would definitely remove the rootstock, as it will take over completely given the chance.
        I have written a comprehensive reply below to Lisa, as she has a similar problem. I think this will help you also, but if you need further clarification, please don’t hesitate to contact me again.
        Cheers,
        Amanda

      • Keith Daniells says:

        Hello again. I have noticed that the new growth are not all growing back with thorns in fact it is not the dominate growth. So I am removing the thorned growth as I find it in the hope that Mop Top will outgrown the Black Locust. Hope that makes sense to you 🙂 Will keep you informed as to the end result if you like……

  20. Lisa says:

    Hi, I removed a Robina mop top in July and planted a new small tree in there in October. However, over the past few weeks I noticed little branches and leaves growing around the new plant which I thought were weeds. I tried to kill them with weed killer but after having a close look it turns out that the leaves were of mop tops.
    The person who removed it told me that the remaining roots would die away on its own but it hasn’t. Would you please give me your advice how to kill it completely and what sort of poison for the remaining roots?

    • Amanda Reynolds says:

      Hi Lisa,
      Thanks for your query. Unfortunately what is growing back is the rootstock, the Black Locust tree, Robinia pseudoacacia. This is a very persistent variety which will take every opportunity to grow.
      To remove the rootstock completely I think it would be best to poison the tree, wait until completely dead & the remove. This is also the advice of Ernest (comment above).
      If you choose to do this, I would remove the new tree you have planted – sorry about that, but poisoning the rootstock would probably also poison the new tree through contamination in the soil.
      I’m not sure what your location is, but I use a tree and blackberry killer mixed with kerosene here in South Australia. I use a paintbrush and neat mixture rather than spraying. Paint any leaves or green plant material and score any roots or shoots and let the poison soak into any hard wood. This directs the poison onto the rootstock only and minimizes any residue to the soil or other plants. You would also need to dig out as much plant material as possible when the rootstock is definitely dead.
      Only when you are sure that the rootstock has died should you replant the other tree – this may take several months. Otherwise you will always be fighting back the rootstock.
      Before you plant anything in the area, please make sure to revitalize the soil by adding compost, fertilizer and mulch, so you give any replacement plants the best start.
      Hope this helps,
      Cheers,
      Amanda

      • Lisa says:

        Hi Amanda,
        Thank you for your advice and your time to reply to my question. My place is in Adelaide. As you advised me I bought a 250ml bottle of tree & blackberry killer as well as kerosene. Just wondering how much of kerosene do I need to mix into the killer? Looking forward to your reply 🙂

  21. Amanda Reynolds says:

    Hi Lisa, I use a half/half mixture for blackberries and bush weeds and it works well. I paint it on the stem straight after I cut it for maximum seepage into the plant. If you have a large stem greater than about 5mm, you could also cut into the stem to enable more of the poison to take effect. Using this method, I don’t need to spray so it makes the mixture go further and doesn’t harm anything else.
    Hope this helps.
    Cheers,
    Amanda

    • Lisa says:

      Hi Amanda,
      I have been poisoning the remaining rootstocks with the tree & blackberry killer and kerosene that you recommended to me. But there are too many rootstocks under the ground and they have already grown over my neighbour’s garden. It is impossible to poison all rootstocks in the ground unless using a machine like dingo to dig all my garden up to expose all the roots. Every week I see new leaves coming out from new spots. Someone suggested me to use butcher salt to kill all rootstocks as I don’t have any other plants. Also I was advised I won’t be able to have any plants or trees in the future which I don’t mind if I can completely kill them. Would you be able to let me know if this would really work?

      • Amanda Reynolds says:

        Hi Lisa,
        I’m so sorry to hear that you are still having such a problem with your troublesome rootstock. The Black locust is certainly persistent! As you live in Adelaide, the best idea may be for you to ring me on 0428833949 and have a chat. Or you could visit me at the Fullarton Market, which is on the 4th Saturday of the month from 9 – 1 at the Community Centre, Fullarton. Cheers, Amanda

  22. Jase says:

    Hi Amanda a friend of mine has offered me 5 mop tops as they are building a deck where they are going to go.
    So I cant wait until they go dormant unfortunately.
    They are only a couple of years old.
    I am a bit scared on how to do it and if they will survive.
    Any tips would be fantastic

    • Amanda Reynolds says:

      Hi Jase, so sorry about the delay in replying but was having problems with my computer!
      Thanks for your inquiry about moving the moptops. I’m not sure where you are writing from, but the basic steps for moving large shrubs and trees are as follows:
      1. Prepare the holes they are to go into with good soil, a little fertilizer and water well. If you can, dig the holes twice the size of the rootball of the plant you are moving. and then loosen the soil of the hole a little bit more. If they are being planted in clay, you might like to add some gypsum, if in sandy soil, add organic matter. I usually mix compost with the natural soil when I plant.
      2. Prepare the plants to be moved – it the moptops are only young, the canopy will indicate roughly how far the roots will extend. Cut the roots with a sharp spade at least 1/2 a metre from the trunk. Then prune the top of the tree to the same size. This is because you need to reduce the amount of water the plant can potentially lose from the leaves. If it’s not possible to move such a large (and heavy) rootball, trim both the roots and canopy to what you can manage and give the tree lots of care. At this stage, water well.
      3. Choose a cool day and take your time. This will be a big job, and the more time and care you take, the more success you will have.
      4. When moving the trees, try not to damage the roots too much or the grafted canopy. Most people use a large tarpaulin or heavy cloth, moving the tree onto it, then onto the transport, then to the new home.
      5. Plant carefully in the new holes, watering well. You could also give them a weak solution of seaweed fertilizer too.
      Watch them over the next few weeks. They may lose some of their leaves, especially if we have a burst of warmer weather, but just make sure they don’t dry out without flooding them.
      My great grandfather, a great nurseryman and botanist, used to say that you could move anything at any time – I’m not quite sure if that’s true, but it’s certainly worth giving it a go!
      I hope that’s given you some ideas on how to do it, and I wish you all the best success with the move. Please don’t hesitate to contact me again if you need any further information.
      Cheers,
      Amanda

    • Amanda Reynolds says:

      Hello Jay,
      Thanks for your question. I don’t know of any non-suckering substitute unfortunately. The pseudoacacia was chosen because of it’s compatibility with the dwarf moptop robinia and it’s vigorous growth habit which regrettably includes it’s suckering nature! It would certainly improve the nature of the beast if an alternative could be found.
      Cheers and happy gardening,
      Amanda

  23. Louise Comey says:

    Hi Amanda
    I was hoping yo may be able to give me some advice regarding my moptop. I have 2, I believe they are 20+ years old. I have pruned them back successfully for the last 7 years. Sadly, I have noticed that one has developed significant wood rot/ it seems to have borers. This has resulted in the trunk becoming quite ‘loose” and beginning to tip (that was how I first noticed a problem). I have just cut the heavy stumps from the top of the tree to lighten the weight and remove any danger should it fall, but I am wondering if there is any hope of the tree recovering (will it regenerate roots and stability) or is it too late? I am in Adelaide. Thank you kindly Louise

    • Amanda Reynolds says:

      Hi Louise, Thanks for your inquiry. I’m sorry to say that I really think that you might need a qualified arborist for this one. It’s always possible that trees can recover from pest or disease attack, but without seeing the tree, it would be very hard to say what is causing the problem or what is the best remedy. The rootstock is a very hardy and vigorous one, so if treated it may recover.
      Can I suggest asking a tree specialist at the Botanic Gardens? If they can’t help, they may know of someone qualified in tree care to help.
      Best wishes with your moptop,
      Amanda

      • Louise says:

        Thank you very much Amanda
        Greatly appreciate you taking the time to reply.
        I will follow this up further and fingers crossed it recovers
        Kind regards
        Louise

    • Amanda Reynolds says:

      Hello Lionel,
      Thanks for your inquiry. Yes it is possible, but you will get the rootstock, not the moptop, which means you will have very robust plants with lots of thorns. If this is what you would like, it’s very easy – just dig up any suckers that have good roots on them and pot them on. The robinia rootstock is usually grown from seed, so that the grower can get a uniform and strong plant that has one main stem for grafting later. Growing from suckers means that your plants may be multi-stemmed and not uniform in shape.
      I hope this helps,
      Cheers,
      Amanda

  24. Annika says:

    Hi Amanda,
    I have 2 mop top Robinia’s, around 4 meters apart. One is strong and beautiful, and the other has started turning yellow (leaves), the trunk is now slightly leaning and turned more of a blackish colour, and the foliage is becoming very sparse.
    (Can I please send you a photo? And where to?)
    They are so gorgeous, I’m hoping I can get it to survive.
    Thanks Amanda…
    Annika

  25. Annika says:

    Hi Amanda,
    I have 2 mop top Robinia’s, around 4 meters apart. One is strong and beautiful, and the other has started turning yellow (leaves), the trunk is now slightly leaning and turned more of a blackish colour, and the foliage is becoming very sparse.
    (Can I please send you a photo? And where to?)
    They are so gorgeous, I’m hoping I can get it to survive.
    Thanks Amanda…
    Annika

  26. Annika says:

    Hi Amanda,
    I have 2 mop top Robinia’s, around 4 meters apart. One is strong and beautiful, and the other has started turning yellow (leaves), the trunk is now slightly leaning and turned more of a blackish colour, and the foliage is becoming very sparse.
    (Can I please send you a photo? And where to?)
    They are so gorgeous, I’m hoping I can get it to survive.
    Thanks Amanda…
    Annika

  27. Annika says:

    Hi Amanda,
    I have 2 mop top Robinia’s, around 4 meters apart. One is strong and beautiful, and the other has started turning yellow (leaves), the trunk is now slightly leaning and turned more of a blackish colour, and the foliage is becoming very sparse.
    (Can I please send you a photo? And where to?)
    They are so gorgeous, I’m hoping I can get it to survive.
    Thanks Amanda…
    Annika

  28. Annika says:

    Hi Amanda,
    I have 2 mop top Robinia’s, around 4 meters apart. One is strong and beautiful, and the other has started turning yellow (leaves), the trunk is now slightly leaning and turned more of a blackish colour, and the foliage is becoming very sparse.
    (Can I please send you a photo? And where to?)
    They are so gorgeous, I’m hoping I can get it to survive.
    Thanks Amanda…
    Annika

  29. Annika says:

    Hi Amanda,
    I have 2 mop top Robinia’s, around 4 meters apart. One is strong and beautiful, and the other has started turning yellow (leaves), the trunk is now slightly leaning and turned more of a blackish colour, and the foliage is becoming very sparse.
    (Can I please send you a photo? And where to?)
    They are so gorgeous, I’m hoping I can get it to survive.
    Thanks Amanda…
    Annika

  30. Amanda Reynolds says:

    Hi Annika,
    Thanks for your query. I’m not sure what might be wrong, but you are welcome to send a photo to greenplatypusgardens@gmail.com. Also, please let me know where you are living and what the garden, soil, location and climate are like where you are. I hope I can help.
    Cheers,
    Amanda

  31. Carolyn says:

    Hello
    My weeping mulberry is very lush on one side but the other side pretty much just grows straight down so I have a half round tree!!! (Hope that makes sense!!) how do I prune it so that the flat side becomes more rounded?

  32. Carolyn says:

    Hello
    My weeping mulberry is very lush on one side but the other side pretty much just grows straight down so I have a half round tree!!! (Hope that makes sense!!) how do I prune it so that the flat side becomes more rounded?

    • Amanda Reynolds says:

      Hi Carolyn,
      Thanks for your inquiry. I’m not sure if I understand correctly, but I’ll have a try!
      It might be that the tree has been pruned so that the buds above the prune cut point downwards instead of outwards. If you were to prune below a bud that has a definite outward direction it might help. In that way when the branch grows from the bud, it heads towards the sky rather than the ground. I hope my reply makes sense!
      All the best with your pruning and please contact me again if you have any further questions.
      Cheers,
      Amanda

  33. Robin says:

    Hi, great info! I have just pruned my weeping mulberry and happy with the results fingers crossed. We made some large cuts, would you suggest painting anything on the surface of the cut? Also I have a few Robinias but not the weeping type, probably a Robinia tree, do I prune these at all? Thanks in advance.

  34. Amanda Reynolds says:

    Hi Robin,
    So sorry for the delay in replying – we’ve had trouble with the internet! Thanks for your inquiry and well done for having a go at pruning your mulberry. I don’t usually paint anything on the cuts but if you are concerned, please feel free to do so. I find plants very resilient if they are healthy, and they tend to close the cuts themselves quite successfully.
    In regard to your Robinias, I prune trees only if needed. I suggest all pruning using the following guidelines:
    D – prune any dead, diseased or dying branches.
    F – time your pruning to improve flowering or fruiting – Robinias flower in spring/summer, so I would prune after flowering, particularly to deter the seedpods from forming.
    S – prune for shape & size – this is very important for your Robinias, but one that will depend on your personal preference. Robinias grow large and strongly, so may need a good prune now and again.
    They are also renowned for suckering, so please take care and if they start to do so, you may need to remove them – sorry, but they can be very vigorous!
    I hope that’s been helpful – please don’t hesitate to write again if you need further information.
    Cheers and happy gardening,
    Amanda

  35. Marg says:

    I was thinking of planting a Mop Top next to our shed but after reading comments about suckering and thorns have decided against that idea. We have a garden space of just over a metre wide between the shed and lawn and want to plant a not too tall deciduous tree/shrub that would hide the shed in late Sping, Summer but lose its leaves in Winter so that the lawn gets some sun. With the roots we have Adelaide clay soils to consider and shed foundation and lawn. Do you have any idea what plant would be good. 6 metres from it we have a very tall gum tree.

    • Amanda Reynolds says:

      Hello Marg, Thanks for your inquiry – sorry about the delay in replying. There are quite a few options regarding trees/shrubs for your spot. With trees, you may have problems with roots in such a small space, but if the lawn and shed are coping with a tall gum tree that may not be an issue.
      My suggestions would be a tall, slim tree such as Pyrus calleryana ‘Capital’, (Manchurian pear), Prunus cerasifera ‘Oakford Crimson Spire’ (Flowering plum, burgundy leaves) or Lagerstroemia indica x l. fauriei ‘Sioux’, (Crepe myrtle, upright with bright pink flowers). Your choice would depend on colors you like and whether you want bright flowers. All of these will grow up to 5 metres tall.
      There are a few deciduous shrubs I would suggest – Viburnum opulus sterile (Snowball tree, white flowers), Forsythia x intermedia (border forsythia, yellow flowers) and Cotinus coggygria (Smoke bush, purple leaves). All of these grow to 3m tall.
      All of these plants would grow in Adelaide’s clay soil and would give you interest throughout the year, either in leaf color, flower color or autumn color.
      Hope this helps, and happy gardening.
      Cheers, Amanda

  36. Alysha Hack says:

    Hi Amanda,
    I have recently purchased 3 mop tops to put along our back fence as privacy from the house behind. I spoke with the nursery where we purchased the about putting them in planter boxes.
    We have a sewer line that runs right under where we want them, so therefore they cannot be planted in the ground. We are going to build boxes and understand that restricting the roots with restrict the mop top but we’re hoping they will still get big enough to provide some privacy and shade in summer 🙂
    I was hoping you might have some advice regarding how big we should make the planters so as to ensure we still get good growth on top. Also any recommendations on fertilisers for them? And are you aware of any specific rules for caring for trees in planters?
    Thanks a bunch!

  37. Amanda Reynolds says:

    Hi Alysha,
    Thanks for your inquiry.
    When growing plants in planter boxes, there are several things to consider. Firstly, remember that you are providing everything the tree needs to survive and thrive, as it won’t have access to the natural soil.
    1. Assuming you won’t be having to move the boxes, make them as large as you can, with plenty of drainage.
    2. Use the best possible potting mix, not natural soil.
    3. You will need to provide all the nutrition, so ensure that you fertilize regularly.
    4. Make sure the trees are watered adequately and not allowed to dry out.
    When I plant large shrubs or trees in planters, I use the best potting mix I can find – I know this can be costly, but using the best means you won’t have to do it again if the plant doesn’t grow very well.
    Add fertilizer to the soil when you plant – I use a slow-release fertilizer such as Rapid Raiser or Osmocote, which gives the plant continuous food for a couple of months. Repeat this feeding every season, either by topdressing with slow-release or liquid feeding with a soluble fertilizer such as Seasol.
    Water regularly, making sure that the top 2 centimetres of soil is damp. Don’t overwater, but this shouldn’t be a problem if your planters have good drainage.
    All the best for your mop-top planter adventure!
    Cheers and happy gardening,
    Amanda

  38. Lisa says:

    Hello,
    I live in regional Victoria, Australia and I plated two Mop Tops about 8 metres apart about 18 months ago. In Spring they both developed new growth but one went on to develop into a beautiful big Mop Top and the other just seemed to stop growing and still only has sparse new growth. The growth seems quite dehydrated. There is a lot of soil in the clay but when I put it in I did dig a very large hole and turn it all over. I think I’m going to have to dig it up and mix Gypsum through. Should I just buy a replacement tree? Or could this one come back?

  39. Lisa says:

    Hello,
    I live in regional Victoria, Australia and I plated two Mop Tops about 8 metres apart about 18 months ago. In Spring they both developed new growth but one went on to develop into a beautiful big Mop Top and the other just seemed to stop growing and still only has sparse new growth. The growth seems quite dehydrated. There is a lot of soil in the clay but when I put it in I did dig a very large hole and turn it all over. I think I’m going to have to dig it up and mix Gypsum through. Should I just buy a replacement tree? Or could this one come back?

  40. Lisa says:

    Hello,
    I live in regional Victoria, Australia and I plated two Mop Tops about 8 metres apart about 18 months ago. In Spring they both developed new growth but one went on to develop into a beautiful big Mop Top and the other just seemed to stop growing and still only has sparse new growth. The growth seems quite dehydrated. There is a lot of soil in the clay but when I put it in I did dig a very large hole and turn it all over. I think I’m going to have to dig it up and mix Gypsum through. Should I just buy a replacement tree? Or could this one come back?

  41. Lisa says:

    Hello,
    I live in regional Victoria, Australia and I plated two Mop Tops about 8 metres apart about 18 months ago. In Spring they both developed new growth but one went on to develop into a beautiful big Mop Top and the other just seemed to stop growing and still only has sparse new growth. The growth seems quite dehydrated. There is a lot of soil in the clay but when I put it in I did dig a very large hole and turn it all over. I think I’m going to have to dig it up and mix Gypsum through. Should I just buy a replacement tree? Or could this one come back?

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