Rootwork on Leptospermum Petersonii - Lemon scented tea tree

[Bevo]

Hi, new to posting here, if there's already a good answer for this somewhere I apologize.. I tried the search and couldn't find any solid answers.

So I just recetly pruned back the foliage on my Leptospermum Petersonii and it seems to be doing fine so far. I removed easily half of what was on there. Now I'm wondering how long I should wait, what time of year is best, and how much of the root mass I can safely remove each time I do rootwork. Cheers.

[Ryceman3]

I have repotted these in late summer with good results… around February for me in Melbourne.
When you work on trees/repot etc often has a lot to do with your location. To make it easier for others to offer advice it would be good to add that to your profile.
Nice trunk.

[shibui]

L.petersonii has been among the most resilient Leptos I have tried. I've root pruned real hard sometimes - up to 3/4 off and they just keep growing.
I usually root prune in late spring as temps warm up (October - December) but I suspect it could be done any time of year in warmer places.

Also tolerates hard pruning as they are happy to sprout new buds on old wood. I often get shoots from the base of the trunk without even trying.
The only fault I've found is they are a but sensitive to cold temps. They survive our winters but don't look too good coming into spring here.

[Bevo]

I have repotted these in late summer with good results… around February for me in Melbourne.
When you work on trees/repot etc often has a lot to do with your location. To make it easier for others to offer advice it would be good to add that to your profile.
Nice trunk.

Neat, so a bloke from around the Blue Mountains tells me he gets them sprouting up all over the place on his property and has quite a few as bonsai, he cautioned me that they do tolerate root work but not to push my luck.. I'm wondering how much is a sensible amount to prune off? I'm in Canberra so we get pretty cold winters. I'll update my profile, thanks for letting me know, and cheers for the compliment on the trunk movement.

[Bevo]

L.petersonii has been among the most resilient Leptos I have tried. I've root pruned real hard sometimes - up to 3/4 off and they just keep growing.
I usually root prune in late spring as temps warm up (October - December) but I suspect it could be done any time of year in warmer places.

Also tolerates hard pruning as they are happy to sprout new buds on old wood. I often get shoots from the base of the trunk without even trying.
The only fault I've found is they are a but sensitive to cold temps. They survive our winters but don't look too good coming into spring here.

Ok wow, have you ever lost any root-pruning them that hard? If I were to reduce the root-mass right now by 3/4 only a few weeks after pruning the foliage really hard do you think that would be a wreckless move?

Also, on your point about them not looking too good coming out of winter, this is only my experience and I only have the one Lepto, but going into winter it was super bushy, and I had the pot sitting on the ground and it pushed out with super vigorous growth coming into spring and looked great. I'm not worried about the roots getting too damp on the ground because I've been told they live in clay swampy locations.

[Rory]

If you’ve cut back the foliage heavily a few weeks ago, I would not be messing with the roots now. It’s just gone through a massive change and will be in all new push-mode to produce a new entire flush of growth all over the tree. I wouldn’t be touching the roots, as you’ll completely throw the tree into chaos so soon after a heavy cutback.

Most Lepto varieties I have root-pruned have been pretty hardy. I’ve happily removed 3/4 of the roots off of nursery material with no dramas. The key is to do it when the tree is healthy and bushy and growing strong, like mid or late spring, but it all depends on your location. Neil and many experts are like Superman when it comes to root removal, in that they go super hard for great success, and they have a tonne of material to repot. Provided the tree survives, it is much wiser to go hard initially. I sometimes don’t have the courage that they do, and probably stick with a 50% root removal on my older material. But they will get better results quicker. My results will take longer. But if it’s a first attempt, you might as well go somewhat hard, because you don’t want to spend years on the root reduction slowly over time only to discover the roots are a nightmare in tight. And this can often lead to root rot and other problems, which is why the best approach is to go hard initially and concentrate more on separating the roots at the first instance rather than the mindset of reduce, reduce, reduce.

But having said that, I have many Leptospermum brachyandrum that I have removed probably 80-85% of the roots at the first root prune, and had no dramas. From experience, Leptos will probably drop all leaves if the root prune was too much for the remaining foliage. But they’ll usually shoot all over from the trunk in 3-4 weeks or so.

Having said that however, there are species of Lepto you would not attempt a 3/4 root reduction with however. But even my hardiest Leptos, I wouldn’t do a root prune so soon after removing most of the foliage like on yours.

Lepto don’t seem to be bothered so much by having wet feet. But not constantly wet. But after a root prune, the best care is to make sure you water again when the tree needs it. It will significantly reduce the water uptake, so when you do finally do a root prune, remember to just monitor it and water it when it gets dryish but not bone dry. But in the first 3 weeks after a root prune, DO NOT let the roots dry out.

….. oh and one more thing.
From my experience with Leptospermum, their roots are highly susceptible to damage from a strong jet spray with the hose. The roots easily get stripped and will die off if your hoses jet stream is too strong. You can do this on the outer areas fine, but when you get in close and work your way inwards, reduce the strength and spend more time physically separating them. There’s nothing worse than spending an hour reducing the roots, to then quickly rush the most important part and have it stripped of the outer protective layer.

[Bevo]

If you’ve cut back the foliage heavily a few weeks ago, I would not be messing with the roots now. It’s just gone through a massive change and will be in all new push-mode to produce a new entire flush of growth all over the tree. I wouldn’t be touching the roots, as you’ll completely throw the tree into chaos so soon after a heavy cutback.

Most Lepto varieties I have root-pruned have been pretty hardy. I’ve happily removed 3/4 of the roots off of nursery material with no dramas. The key is to do it when the tree is healthy and bushy and growing strong, like mid or late spring, but it all depends on your location. Neil and many experts are like Superman when it comes to root removal, in that they go super hard for great success, and they have a tonne of material to repot. Provided the tree survives, it is much wiser to go hard initially. I sometimes don’t have the courage that they do, and probably stick with a 50% root removal on my older material. But they will get better results quicker. My results will take longer. But if it’s a first attempt, you might as well go somewhat hard, because you don’t want to spend years on the root reduction slowly over time only to discover the roots are a nightmare in tight. And this can often lead to root rot and other problems, which is why the best approach is to go hard initially and concentrate more on separating the roots at the first instance rather than the mindset of reduce, reduce, reduce.

But having said that, I have many Leptospermum brachyandrum that I have removed probably 80-85% of the roots at the first root prune, and had no dramas. From experience, Leptos will probably drop all leaves if the root prune was too much for the remaining foliage. But they’ll usually shoot all over from the trunk in 3-4 weeks or so.

Having said that however, there are species of Lepto you would not attempt a 3/4 root reduction with however. But even my hardiest Leptos, I wouldn’t do a root prune so soon after removing most of the foliage like on yours.

Lepto don’t seem to be bothered so much by having wet feet. But not constantly wet. But after a root prune, the best care is to make sure you water again when the tree needs it. It will significantly reduce the water uptake, so when you do finally do a root prune, remember to just monitor it and water it when it gets dryish but not bone dry. But in the first 3 weeks after a root prune, DO NOT let the roots dry out.

Mate. That is an exceptional response. I don't even know how to respond to all of that but please know that I super appreciate it. I also checked out your profile and I'm part-way through reading your post on Trialling Australian Native trees as bonsai.. amazing work man, outstanding stuff.

Edit: That advice on not blasting the entire root ball potentially just saved me some heartache too! That's exactly what I would have done, and I've done it with other trees without a problem. You're an absolute legend, I oughta buy you a beer or something

Edit 2: while we're here, I have a Melaleuca Swamp Paperbark and plan to get a bunch more, I really love their bark and their foliage.. anyway, are their roots similar in that you can reduce up to 3/4 of the root mass without a problem if done correctly at the right moment, and with a vigorous tree? Also, would I have to be careful blasting the root-mass of the Swampy too?

[Rory]

Haha, beer and bonsai is the greatest marriage of all time.
What works for some, may not work for others. I've lost so many trees through trial and error throughout my time, but for me I have found that with most Australian Natives you will generally get better success by leaving a lot of the foliage on the tree, right after doing a root reduction. Place the tree right back into the same level of sun, and keep the roots watered for the next 3-4 weeks, species dependent. The only exception to this would be genus that are susceptible to root-rot... with those you want to only rewater when the mix needs it... regardless of whether you've just done a heavy root prune or not.

Edit 2: while we're here, I have a Melaleuca Swamp Paperbark and plan to get a bunch more, I really love their bark and their foliage.. anyway, are their roots similar in that you can reduce up to 3/4 of the root mass without a problem if done correctly at the right moment, and with a vigorous tree? Also, would I have to be careful blasting the root-mass of the Swampy too?

I assume you mean Melaleuca ericifolia. They are very hardy and Swamp Melaleucas should tolerate a heavy root removal yes. I have grown them a long time ago and they tolerated a substantial root prune. But the possums loved this species so much that I gave up on them. But nearly all Melaleuca will tolerate heavy root removals.

But with that variety, don't let the roots get dry, you can happily keep them on the wetter side. You can happily re-water the roots even if you don't think the mix will dry out by the next day. Personally, with all my Melaleuca I like to keep the roots sprayed with water throughout the entire repot.

[MikeK]

L. petersonii has been among the most resilient Leptos I have tried. I've root pruned real hard sometimes - up to 3/4 off and they just keep growing.
I usually root prune in late spring as temps warm up (October - December) but I suspect it could be done any time of year in warmer places.

Agreed ... for a healthy tree, I've removed 80% of the root ball (from a 330mm black plastic nursery pots into a shallow bonsai pot in one go) with no noticeable impacts. Same as Neil ... I do it when it's nice and warm (I'm looking for avg daily temps > 22).

I also keep it in a shallow water tray for a 3-5 days after the reduction (the only time I use a water tray ... max 7 days post large root reduction)

Personally, I would not be doing this after a large foliage reduction ... I'd be letting it recover from that first.