Master Discussion: Summer and Fall Collecting and Repotting

[a0kalittlema0n]

I've been trying to do research on this topic for awhile now, but I've never personally collected in the Late Summer/Fall. I have read stuff from Walter Pall, Harry Harrington (https://www.bonsai4me.com/AdvTech/ATquercus rootpruning and repotting.htm), and others about collecting at this time of year, and from my understanding I think Randy Knight collects from Spring constantly through Fall (different places for varying reasons such as a change in climate in collected area and where he houses them). I've read all over about this, but I'd love to get a solid discussion about this in one place rather than scattered all over different threads on different sites. I'm going to post information from everything I can find between Reddit, Mirai, BonsaiNut, etc. and then tag those involved in that discussion.

What I'd love to know more about from those who have collected is details. For deciduous, did you defoliate, did you leave leafs on, which species, where did you collect from, where do you live, how was the rootball when it came out, did you cutback root significantly or keep as many fine roots as possible, did you cutback the foliage to balance with roots, was it easily removed from its place in nature or was it a hard dig, yardadori or yamadori, aftercare that it was given, was it in a greenhouse, was it in full shade, did you mist or fertilize, did you place it on the ground if you potted it up (Randy Knight mentions this as paramount in survival), what medium was it planted in, etc. The list goes on, but the more information we can put together the better we can collectively understand the success of this technique of collecting outside of Spring (which is the more commonly practiced belief among most).

Also this video

was very informative. At the 11:45 marker Mauro Stemberger talks about a "resulgen area"? (I couldn't understand what he was saying...) and he mentions that it has a somewhat better ability to push small roots and that it is common in Olives and Oaks. He says they almost collect no roots with the Oak he is talking about. He mentions that the cells of the wood are very active and that is part of the reason they re-root so well. This area is within the first 10-15cm from the base of the trunk.

Species that tend to like it from what I read (with tags with some of those who were successful): Larch, Ponderosa Pine, Tamarack, White Pine, Crape Myrtle, Hornbeam, Beech, Sweetgum (Late season to Summer), Linden @petegreg, European Hornbeam @petegreg, Scots Pine @petegreg, Norway Spruce @petegreg, Bald Cypress, Oaks, American Beech, American Hornbeam, Chinese Elm, Box Elder, Vine Maple @Arcto

Here are some interesting quotes I read while searching:

This is a 2 year old thread. However, Harry Harrington has a recent article in Bonsai Focus magazine about Autumn collecting. He says the success rate is higher, but you need to be able to protect the tree from frosts. In Autumn most trees are going into their biggest phase of root growth. Also, as temperatures go down the tree needs less water. When you collect in spring the tree has to grow new roots and put out foliage at the same time. Also, temperatures are rising and leaves are opening, so the tree starts to need more and more water soon after you've reduced its roots. It helps if the tree still has leaves when you collect in Autumn. This produces hormones that trigger root growth. Walter Pall and the book Modern Bonsai Practices also recommend collecting and repotting in Autumn. This idea is still new and controversial.

If you can't provide frost protection, then collect in Spring.

Any tree that you can collect with sufficient foliage is best collected in late summer. The foliage will trigger hormones for root growth. The trees will soon go into their strongest phase of root growth and temperatures are getting cooler. In spring newly collected deciduous trees have to put out new leaves and grow new roots at the same time, which they may not have enough energy reserves for. Walter Pall recommended this in his recent maple repotting thread. I've had most success collecting many trees this time of year. Hornbeam, Elm, Beech, oak, etc. I like to keep the pots submerged in water for a couple of weeks if collecting at this time of year with foliage. Makes complete sense to me. This is only true if you can provide frost protection for collected trees.

@peterbone

No, I wouldn't say collecting in spring and fall are equally advantageous. I have done both, but unless there's a compelling reason I stick with a season of January 1 through March 31 for the bulk of the work. Sweetgum is collected after first flush, April through June works really well and better than in dormancy. You can lift Chinese elms after they come out, just defoliate. I've had worse luck with them in the dead of winter or prior to budding. Oaks can be collected later in the year, into summer, but not too late. Also defoliate (this is true for all deciduous when in leaf).

I've been told that the procedures are different for CA Live Oaks than for my FL Live Oaks....honestly the advice from adamaskwhy is all I can truly take as gospel, because I know he's talking about the same specie in the same enviro!
I'd never had luck collecting an Oak til this past fall, when I collected one (on adam's advice) because, after the rainy season, there's optimal # fine/feeder roots under the trunk - I collected one that I'd trunk-chopped earlier in the year and it's still alive now thankfully, though it's a Laurel not Live (I really dig the deep grooving in Live Oak bark, gives a much more dramatic aged appearance!)
I agree on experimentation but jesus it's tough putting in the time only for it to be a failure, right now I'm in the "collect a ton" mindset so, come spring / growing-time, I'll at least have some that've made it!!

Interesting Links:

Late summer repotting

Spruce # 87 It's called 'late summer repotting' Never ever fall! Summer is until mid-September. But that's already LATE. I have repotted a huge spruce yesterday with Thomas. Now starts the repotting time until first week of September. You have to watch two things. General health of tree. Do not...

www.bonsainut.com

https://capebonsaikai.co.za/index.p...to-pot-what&catid=49:species-notes&Itemid=228 (Flip 6 months for Northern Hemisphere)

Articles – Bonsai4Me

bonsai4me.com

As more is discussed more will be added to the initial post.

List of people to tag: @M. Frary @Johnathan @Zach Smith @joe Dupre @Garveycm @Poink88 @Txhorticulture @aml1014 @johng @sorce @Forsoothe! @Walter Pall @Gustavo Martins @leatherback

 

[Atom#28]

Following VERY closely

 

[Mike Hennigan]

Nice, waiting for the wisdom to roll in. Harry Harington just published an article on fall collecting on his website that was previously published in Bonsai Focus last year. Link here:

Articles – Bonsai4Me

www.bonsai4me.com

I would probably try it if I had some overwintering structure that I could keep trees anywhere close to 32 degrees. But as I mulch mine in in the backyard right now, I can’t imagine NY winter would be too forgiving for fall collecting.

 

[petegreg]

Well I voted NO, I've collected few trees in mid summer, I think in July during their so-called summer dormancy. It could possibly be done later in warmer areas, but I'm in zone 6a, winters can be bad (I'm with Mike mentioning some good overwintering structure) and these temperate continental summers are not tree friendly on my balcony recently at all. Yes, I've lost quite enough trees in last two years. But they were after recovery and not all (summer) collected. So I think I can't be helpful here.

 

[Cattwooduk]

Not done any collecting in autumn/fall yet but have my eye on a couple of trees I didn't get this spring. Now I've moved house and have 4x the garden space I had before plus a nice big green house I'm eager to get back out and try collecting some more at this time of year.
Useful thread to have, that Harry Harrington post is really good and seems it's probably ideal time now to get out and start diggin!

 

[Jorow99]

The one and only tree I've collected in fall was a bare rooted ponderosa from a crack in Colorado. Still alive, but not close to fully vigorous.

 

[BrianBay9]

I've collected lodgepole pine and ponderosa pine in spring and fall in Colorado. My success was slightly higher in spring, but both were around 80%. The aftercare was the same. The trick is to pick the right trees. I've had success in fall with elm and pyracantha, but they're so tough it probably doesn't count.

 

[wireme]

I used to have a raised bed full of highly decayed sawdust and granite particles. Fall collected trees went into it and stayed a couple or few years until recovered. It wasn’t that big and I only had it for a few years before moving so not a large number of trees but every one of them lived. Those were old conifers or Junipers. I wouldn’t feel great about going out and digging a tree right now and stuffing it into a pumice box for winter but if I still had that bed I would be very confident.

 

[a0kalittlema0n]

The one and only tree I've collected in fall was a bare rooted ponderosa from a crack in Colorado. Still alive, but not close to fully vigorous.

Details please!!! Where and how was it overwintered? Was it in full shade, how long? Have you fertilized since then? How long ago did you collect it? What makes you say it isn't vigorous?

I've collected lodgepole pine and ponderosa pine in spring and fall in Colorado. My success was slightly higher in spring, but both were around 80%. The aftercare was the same. The trick is to pick the right trees. I've had success in fall with elm and pyracantha, but they're so tough it probably doesn't count.

I'm assuming you brought them back to CA where you live? How was the climate different from when it was collected? Did it experience any shock from the change? Was it at alpine height where you collected it? Explain what you mean in picking the right tree, I know that is true of collection as a whole, but how does that apply specifically to Fall collection vs Spring collection? How long did they take to "recover" and be vigorous again? Did you fertilize at all? What was the aftercare that it was given? Potted up, in pumice, replanted in ground for winter? What was your winter care like?

I used to have a raised bed full of highly decayed sawdust and granite particles. Fall collected trees went into it and stayed a couple or few years until recovered. It wasn’t that big and I only had it for a few years before moving so not a large number of trees but every one of them lived. Those were old conifers or Junipers. I wouldn’t feel great about going out and digging a tree right now and stuffing it into a pumice box for winter but if I still had that bed I would be very confident.

Interesting. If you aren't a Mirai Live subscriber you haven't seen this video, but Randy Knight discusses having a coarse sawdust bed on top of landscaping fabric (to keep roots from growing into ground) and uses this shaded area as a "danger tree" area. He also mentions that being in Portland-ish area that he has never seen a tree drown in sawdust. He also suggests putting all deciduous trees into sawdust first and by doing so he saw survival rates of deciduous collected material skyrocket into 95%+. Talks about how he used to field grow trees and lose a ton of deciduous when digging them until he did the sawdust method.

Thanks for adding to the knowledge

 

[RobertB]

I’ve collected all times of the year. It all depends on how you do the aftercare and over winter. There is plenty of info around to learn about. Don’t try and pull the best tree at first. Get it down then pull. If in doubt, collect during best time of year.

 

[Johnathan]

Ha! I was about to post somewhere like this a few days ago. I also watched that collecting lecture by Mauro that @a0kalittlema0n posted a few times now over the last week or two.

I'm going to collect my first landscape juniper this weekend. It'll also be the largest tree that I attempt so far in my bonsai lifetime.

I've been on the fence about collecting it, going back and forth about Spring vs Fall. The Mauro video says spring for conifers, my buddy who subscribes to Mirai (I dont) but he told me that Ryan says Junipers in fall... and he collects ERC in fall (I know) .. but #1 the homeowner is going to be selling so I don't want to miss out on the chance. #2... the research that I've come across seems to suggest that common juniper (which I'm guessing this is) tends to shoot new roots in late summer/ fall. So I hope this will help out.

I don't really have access to a custom growbox for it, so I'm probably going to just use either a very large Monrovia container or even a storage bin if necessary. Obviously I'll cut down the sides of whatever I use and try to secure the tree as best as possible so it doesn't move.

It'll be planted in something that's probably 90% DE and 10% Pumice. Reason is, because I don't have much pumice, and summers here in OKC easily hit 100s so I prefer DE as a many soil particle.

As far as aftercare, I'm going to sit it somewhere that doesn't really get any direct sunlight at all and should be protected from most winds. It's a small area maybe 5-7 feet between the house and the fence.

Of course I have collected elm in the heat of summer, but like @BrianBay9 said I don't think they really count

 

[Arcto]

In Central Oregon, spring was my go to time. Fall collecting didn’t work as well for 2 reasons. 1. The fine volcanic soil turned so dry that digging rootballs successfully without them disintegrating was very difficult. 2. Hard freezes came early, all plants were dormant by late September. My aftercare setup was not geared for late season recovery. Here in western WA, I’m in arguably one of the best places to experiment with fall collecting and root work. We don’t typically see freezing temps till well into November. Cool days with frequent precipitation really lowers the stress issues on collected plants along with an extended period for root growth.

 

[BrianBay9]

I'm assuming you brought them back to CA where you live? How was the climate different from when it was collected? Did it experience any shock from the change? Was it at alpine height where you collected it? Explain what you mean in picking the right tree, I know that is true of collection as a whole, but how does that apply specifically to Fall collection vs Spring collection? How long did they take to "recover" and be vigorous again? Did you fertilize at all? What was the aftercare that it was given? Potted up, in pumice, replanted in ground for winter? What was your winter care like?

OK, lots of questions. First, I lived in Colorado at the time. Trees were collected at about 7000 ft, and I lived at about 5500 ft elevation so they weren't that far off. I collected in the spring well into June because my spots still had snow cover until then. I would start again around October.

Picking the right tree for me meant finding that one in a hundred, or one in a thousand tree growing in a rocky ridge in a pocket in stone, but not locked tight into the cracks and crevasses. Such a tree, when rocked by the trunk, shows movement of the entire root ball around it. I might spend days looking for a tree, but I never spent more than 15 min getting a tree out - expose the root ball and cut one or two support roots. The tree went from a natural stone pocket to a box with very little trauma. I took off whatever native soil that came off easily and left the rest.

After care was burying the roots and the box in a bed of pea gravel on the north side of my house, protected from the wind, and misted regularly. I didn't do anything for at least a year, waiting until the tree showed strong growth to let me know it was ready. After that, I waited until the following year to mess with it. Some trees took only one season to get going. Some took three years.

 

[Johnathan]

Oh and I'm also very interested in learning more about this "resulgen area" as @a0kalittlema0n called it (I couldn't make it out either) but it's definitely a game changer when it comes to collecting Oaks.

 

[Jorow99]

Details please!!! Where and how was it overwintered? Was it in full shade, how long? Have you fertilized since then? How long ago did you collect it? What makes you say it isn't vigorous?

We put it into the smallest custom box it could fit in with a little bit of the natural soil, but mostly BonsaiJack mix. I would have used pumice if I had any. I don't think I put it in shade at all, just straight out in the fall sun. In the winter I left it on the ground to the outside of the pile of all my trees with some leaves on the sides of the box (not the top). It did pretty well I think, didn't lose any branches like some of my other trees did. I haven't fertilized a whole lot. I will probably start going heavier on the fertilizer from now on since summer is almost over. It'd not vigorous because each bud only put out a few needles this spring, and some of them aren't even as long as they should be.

 

[TN_Jim]

Here’s a pile of dead trees for various reasons beyond seasonal collection. I won’t get into that here and do not support summer/fall collecting....but that lone elm I pulled out of the muck of a construction site last year, planted in ground, bare rooted as seen in basket, moved...has some fight in it...

I voted no in this poll, because from what I understand in my region, collecting working, stressed, or newly dormant material is the pursuit of ignorance and lack of experience testified here and elsewhere.

Go collect some wild evergreen or deciduous material in such time (lower Florida and privet excluded) post it, and we can all watch it be weak or die. I only ask, commit to following up next year.

 

[TN_Jim]

Ha! I was about to post somewhere like this a few days ago. I also watched that collecting lecture by Mauro that @a0kalittlema0n posted a few times now over the last week or two.

I'm going to collect my first landscape juniper this weekend. It'll also be the largest tree that I attempt so far in my bonsai lifetime.

I've been on the fence about collecting it, going back and forth about Spring vs Fall. The Mauro video says spring for conifers, my buddy who subscribes to Mirai (I dont) but he told me that Ryan says Junipers in fall... and he collects ERC in fall (I know) .. but #1 the homeowner is going to be selling so I don't want to miss out on the chance. #2... the research that I've come across seems to suggest that common juniper (which I'm guessing this is) tends to shoot new roots in late summer/ fall. So I hope this will help out.

I don't really have access to a custom growbox for it, so I'm probably going to just use either a very large Monrovia container or even a storage bin if necessary. Obviously I'll cut down the sides of whatever I use and try to secure the tree as best as possible so it doesn't move.

It'll be planted in something that's probably 90% DE and 10% Pumice. Reason is, because I don't have much pumice, and summers here in OKC easily hit 100s so I prefer DE as a many soil particle.

As far as aftercare, I'm going to sit it somewhere that doesn't really get any direct sunlight at all and should be protected from most winds. It's a small area maybe 5-7 feet between the house and the fence.

Of course I have collected elm in the heat of summer, but like @BrianBay9 said I don't think they really count

Why? Sure you can collect junipers in late summer, but why? I highly recommend you start with material you don’t have your heart set on.

 

[a0kalittlema0n]

I’ve collected all times of the year. It all depends on how you do the aftercare and over winter. There is plenty of info around to learn about. Don’t try and pull the best tree at first. Get it down then pull. If in doubt, collect during best time of year.

Could you enlighten me on the info that there is plenty of "around"? Also explain what your aftercare is for differing species. The details are what we're trying to tease out here to educate as many as possible. Please and thank you.

I don't really have access to a custom growbox for it, so I'm probably going to just use either a very large Monrovia container or even a storage bin if necessary. Obviously I'll cut down the sides of whatever I use and try to secure the tree as best as possible so it doesn't move.

It'll be planted in something that's probably 90% DE and 10% Pumice. Reason is, because I don't have much pumice, and summers here in OKC easily hit 100s so I prefer DE as a many soil particle.

As far as aftercare, I'm going to sit it somewhere that doesn't really get any direct sunlight at all and should be protected from most winds. It's a small area maybe 5-7 feet between the house and the fence.

Of course I have collected elm in the heat of summer, but like @BrianBay9 said I don't think they really count

Thanks for the details, let us know how it goes and any following up would be great. Remember also you can mist junipers and they can absorb a significant amount of water through the foliage to help recovery.

OK, lots of questions. First, I lived in Colorado at the time. Trees were collected at about 7000 ft, and I lived at about 5500 ft elevation so they weren't that far off. I collected in the spring well into June because my spots still had snow cover until then. I would start again around October.

Picking the right tree for me meant finding that one in a hundred, or one in a thousand tree growing in a rocky ridge in a pocket in stone, but not locked tight into the cracks and crevasses. Such a tree, when rocked by the trunk, shows movement of the entire root ball around it. I might spend days looking for a tree, but I never spent more than 15 min getting a tree out - expose the root ball and cut one or two support roots. The tree went from a natural stone pocket to a box with very little trauma. I took off whatever native soil that came off easily and left the rest.

After care was burying the roots and the box in a bed of pea gravel on the north side of my house, protected from the wind, and misted regularly. I didn't do anything for at least a year, waiting until the tree showed strong growth to let me know it was ready. After that, I waited until the following year to mess with it. Some trees took only one season to get going. Some took three years.

Thank you for the details. I think you make a good point about the 1/1,000 trees. Lifting a tree like you described sounds more similar to moving a nursery container plant to another pot, which is obviously doable at any time. This no doubt helps survivability in all collecting situations. Did you mist regardless of species? I've heard that it doesn't do too much for pines, but I'm not a huge pine lovers myself.

We put it into the smallest custom box it could fit in with a little bit of the natural soil, but mostly BonsaiJack mix. I would have used pumice if I had any. I don't think I put it in shade at all, just straight out in the fall sun. In the winter I left it on the ground to the outside of the pile of all my trees with some leaves on the sides of the box (not the top). It did pretty well I think, didn't lose any branches like some of my other trees did. I haven't fertilized a whole lot. I will probably start going heavier on the fertilizer from now on since summer is almost over. It'd not vigorous because each bud only put out a few needles this spring, and some of them aren't even as long as they should be.

Ponderosa put in full sun. Left on the ground is how I would probably go if I didn't have other means to protect my trees. Thanks for the info.

Here’s a pile of dead trees for various reasons beyond seasonal collection. I won’t get into that here and do not support summer/fall collecting....but that lone elm I pulled out of the muck of a construction site last year, planted in ground, bare rooted as seen in basket, moved...has some fight in it...

I voted no in this poll, because from what I understand in my region, collecting working, stressed, or newly dormant material is the pursuit of ignorance and lack of experience testified here and elsewhere.

Go collect some wild evergreen or deciduous material in such time (lower Florida and privet excluded) post it, and we can all watch it be weak or die. I only ask, commit to following up next year.

Thanks for the photos of your dead trees, but I'm not sure why that is relevant. Can you go into more details about why you're so vehemently opposed to late summer / fall collecting? You essentially say that it is ignorant and due to lack of experience, but I would say plenty of people more experienced than any of us (Mauro, Walter Pall, Randy Knight, Harry Harrington, etc.) continually pursue this with consistent success. I'm not saying your opinion is wrong (Ryan Neil doesn't love the idea himself...) but I'm curious as to your logic behind your opinion. As you say, it may be a terrible idea for your climate or whatever, just curious.

As for the last portion of your post, if you look through the threads here you'd see exactly what you're asking for...

 

[peterbone]

What I'd love to know more about from those who have collected is details. For deciduous, did you defoliate, did you leave leafs on, which species, where did you collect from, where do you live, how was the rootball when it came out, did you cutback root significantly or keep as many fine roots as possible, did you cutback the foliage to balance with roots, was it easily removed from its place in nature or was it a hard dig, yardadori or yamadori, aftercare that it was given, was it in a greenhouse, was it in full shade, did you mist or fertilize, did you place it on the ground if you potted it up (Randy Knight mentions this as paramount in survival), what medium was it planted in, etc. The list goes on, but the more information we can put together the better we can collectively understand the success of this technique of collecting outside of Spring (which is the more commonly practiced belief among most).

I voted yes. However, I also collect in Spring. It depends on the tree. The main factor being if I can collect with foliage or not. For trees collected in Summer / Autumn:

- No, I don't defoliate. You must collect with foliage in late summer / Autumn because this is what triggers root growth.
- Native deciduous species such as Hawthorn, Blackthorn, Hornbeam, Elm, Beech, Field Maple, Spindle, Birch.
- I live in South East UK. We have mild winters but I'm also able to provide frost protection for collected trees.
- I try to keep as many fine roots as possible but most of the time get very little due to the clay soil we have here.
- I cut back the foliage a little if there's a lot.
- Removing from the ground is normally not easy.
- I will remove most of the soil from the roots but not wash them.
- For trees collected in late summer with green leaves I will pot them up and submerge the whole thing in water for a few weeks. In the shade.
- For trees collected in Autumn I will place in a bag for humidity. They'll stay there until the leaves have fallen or even for the whole winter and following Spring.
- I protect from frost over winter in a polytunnel or my shed.
- Last year I used large grain pumice with Sphagnum moss and some bark, which worked well even for difficult species with not much roots.
- I plant in the smallest pot possible that can contain the rootball. I make sure that no roots are at the bottom of the pot in the perched water table.
- I mist before leaf fall and new leaves in Spring.
- I use anti-transpirant spray on the foliage before leaf fall and in Spring.
- I use Rhizotonic or home made Willow water but can't say if it helps or not. Watered into the soil and as a foliage spray.
- I don't fertilise until new shoots are growing strongly in early Summer. If not growing strongly my mid summer I will give very small amounts.
- Trees not growing strongly my mid summer stay in clear bags or the polytunnel and are kept in a shaded area. Sprayed daily.
- I won't water weak trees much. Maybe once a week to keep the soil damp but not waterlogged.

 

[Shibui]

Mild winters here too so I can collect almost year round. I don't have access to really old trees for collection. Most are ferals from roadsides and farmland, others saved from garden makeovers and demolition sites.
Olives and azaleas can be collected any time of year here.
Hawthorn (feral) have survived late winter, spring and autumn collections.
Many of our Australian natives survive better when dug in warmer weather - late spring and early summer.
Deciduous exotic species are dug from leaf fall right through to bud burst.
I shake off most of the field soil when digging trees and they go straight into my normal bonsai potting mix.
Also cut most roots back short enough to fit into a pot. Usually cut thick roots back quite close to the trunk so there's room for new roots to grow and still fit into a bonsai pot eventually.