I’m moving some fruit trees in 5 gal containers to a sunnier area. Some of them have rooted through the bottom of the container into the soil and I’d like to know the best way to deal with these roots. I seem to have two choices, to cut off the roots just below the container…or to try to gently dig up/loosen the root(s) for a foot or two of length and try to bury these roots where I end up moving the tree/container to.
The trees in question are a dwarf Algerian mandarin(2-3 yrs old), a Souvenir du Congres Pear, and some others. I’m running into this problem often since I have a lot of fruit trees in containers and have more trees than places to plant them.
No help here just wanted to say I had the same problem and I went ahead and planted most in my backyard last winter. If you have any space remaining for planting you could cut the pot apart and dig out the roots and plant the ones with larger roots extending outside the pot. Good luck, Bill
I have a bearing age tree nursery with many trees in pots that I encourage to send roots out of to save water and allow some root to be placed in real soil when I transplant them. I do this even though the literature usually recommends discarding such trees- which to me is completely nuts.
I carefully dig such trees to save as much root as possible and use a razor knife and hand pruner to remove the pot it the roots don’t easily slip through the holes. Sometimes I will have 5’ stretches of root that I protect while moving with wet sheets wrapped in plastic. I will extend planting holes with trenches to accommodate such roots so I don’t need a 10’ diameter planting hole.
I consider escape roots a blessing, but it deprives the potted tree the usual benefit of transplanting well when trees are in leaf.
Pears are the only species that doesn’t respond especially well to this method. With them, the more root in actual soil or planting medium the better. I seldom move them bare root and keep as much root in their pots as possible.
Here is my experience with the subject. Our local grower (a former commercial orchardist in the California fruit industry) grows in 5 and 15 gallon pots. He ends up having alot of larger trees in 15’s that have large escaped tap roots that bury themselves despite the landscape fabric he has them sitting on. When he sells these trees he just cuts those roots off at the bottom of the pot. My impression of how these trees do after being put in the ground is poor. They seem to take at least one year, sometimes two to recover from it and resume growth. I believe (tho I have no proof) that when a tree has these escape roots down in the actual soil, that it mostly abandons the ones in the pot in favor of a much better situation down in actual soil. So when they are cut, its pretty devastating to the tree. The larger the tree the worse off it is. So alan’s advice about careful digging out the tap root and keeping it wet I believe is sage advice.
Our solution for this grower has been to simply not buy his stuff in 15’s. His containerized stuff in 5’s doesnt have any excaped roots and once planted will have explosive growth. So much so that they will within a year outpace the size of anything planted at the same time in 15’s.
I have two Carmine Jewel bush cherries in pots. I’m going to leave this one outside. The other is tucked away already in the garage. If the outside one dies, no big deal, both will flower and fruit next spring. The roots have some through the pot and are in the ground, the pot will not move! I tried moving it, and it’s not budging. Hardy to z2b they say add two zones in containers, so 4b, I’m in zone 6a, it should be fine.
I have a lot of observational experience on this and I don’t think that roots ever abandon any area they inhabit, except when they actually die. If the potting soil drys out the fine roots will die- same thing if real soil dries out. If the potting medium becomes too wet in the bottom of the pot the roots will die there- same thing with real soil. When conditions improve- fine roots sprout out again.
Native trees (in climates with a winter) do the most vigorous growing of fine root in the spring where conditions are best- near the surface where it warms up first and there is plenty of oxygen to go with the moisture. As the season heats up and conditions gradually tend to become drier more active growth occurs further down the soil profile.
There are always parts of the soil that are more conducive to growth at any given time and that is where most growth of fine, absorptive root occurs. Fine roots come and go.
Anyway, that’s how I read what is going on. If the potting medium maintains good conditions for root growth- there will be root growth there- even if there are roots growing into actual soil. In Arizona best temperatures might be hard to maintain during the hot months, even if you kept the medium moist. In hot regions there isn’t much root growth in real soil right near the surface during the summer months- this is variable from species to species, of course, and all have their ideal soil temp for maximum growth.
Maybe abandon wasnt the right word. But its easily discerned which trees have escape roots in this nursery that im referring to, they are the trees twice as large as the others. No need to lift a pot to check. So maybe they dont abandon the roots in the pot but they certainly are heavily benefited by the escaped roots. At least in our hot environment. And are also injured badly by having them cut.
Most of my potted trees, I tried to drill the holes from the bottom sides instead of underneath the pots for drainage and that will eliminate issues with escaped roots going into the soils. I have had that problem in the past but l have learned from it and modified the pots.
The roots in the pot become inactive in a dry climate as soon as the soil in the pot dries out. In a sense the roots in the pot are very much abandon when they no longer function to absorb water. I’ve got 20+ potted figs like that now. I need to repot if I’m going to cut off the escaped roots.
I wasn’t really debating your comment so much as expanding on it. I move so much bare root material every season and have for many seasons. Trees in my nursery are usually planted bare root and then dug up and either put in pots, grow bags or set in wider spacing in soil again to be dug up bare root again in a few years as 2"+ diameter trees. They are then moved to permanent locations.
I’ve also done a great deal of digging in soil occupied by the roots of native trees at all times when the soil is thawed.
What I’ve seen contributes to how I manage transplanting trees as much as what I’ve read and thought my observations might be useful to anyone else engaged in transplanting trees. .
i usually try to estimate how much of the ‘escaped’ roots were damaged or severed after uprooting, and then prune at least the same mass of branches(or if i want to save the branches, prune at least the same amount of mature leaves). I usually get rid of branches located at disadvantaged portions of the tree, thus serving a dual purpose. And if only trimming leaves(and if branches are prone to sunburn), i apply some protection–aluminum foil or paint.
root mass-to-stem/leaf mass ratio should always be tilted heavier on the roots
most pertinent approach to illustrate this would be the scenario of sawing down a tree to a stump(with at least a node, thus having destroyed >99% of all the above-ground parts of the tree) Stump and roots will not die and will easily re-establish strong growth with that one itty-bitty node that it has.
conversely, and hypothetically, if we were to severe just 70-80% of a tree’s roots, and leave the full-canopy of branches and leaves undamaged, that tree will die outright.
btw, the mandarin might suffer more if it the current cold temps at this time of year have not caused leaf drop(even though they are not deciduous), while the pears will do much better if they already have shed all leaves.
Well I don’t have that much experience, but I have dug up an in ground tree and it had massive roots (2nd leaf), IMHO bare root trees are missing well over half maybe 70% of their roots already. I’m also not sure how much of the top needs to be removed if any. Nobody removes 70%, yet that much of the roots are missing. If a tree is 6 foot tall, it should have feeder roots 6 feet long.
When I moved the tree I didn’t cut any of the top, except for normal pruning to shape tree. It fruited fine the next spring. No dieback either. I did damage the roots while moving no doubt. I kept the rootball as large as possible, any bigger and I would not be able to move the tree without help.
it depends on the drought tolerance of the trees, 70% root loss will definitely be lethal where am at during summer(at 113F and ~zero humidity), especially those species which cannot be propagated via cuttings. 70% loss almost equates to a cutting.
btw, when trees are dormant, they don’t lose much water since it is through the foliage where majority of water loss occurs, on top of the cold weather which prevents vaporization of water.
so dormant trees have the luxury of “selective” growth(of nodes), come spring, that only a certain number of nodes will develop, as the plant would rather support fewer nodes with scant resources/limited root activity.
Carl Whitcomb would beg to differ with you. His experiments seem to contradict the previously conventional assumption that a balance of top to root accomplished by removing branches at transplanting increases the survival of trees. He found no clear correlation and recommends only pruning for form.
I think there may be some variability on this depending on the species and the reserve energy in any given tree (also the humidity and temps during first growth after transplant)- but branch removal is not something I automatically do during transplanting. It is often estimated that over 90% of the functional root system of a plant is destroyed during most transplants. This is because most of the absorbing roots dry out in the process.
Trees simply pull back on photosynthesis, closing stomata until new root is developed. They also grow smaller leaves when coming out of dormancy to reduce evaporation.
Here too, and we hardly ever get above 90F, we should more often, the last couple of summers have been extremely cold here. I moved the tree while dormant. What you can do with trees while dormant is amazing. The tree showed no signs of stress at all. The tree was over 6 foot tall, the roots were a lot longer than that! Numerous 6 foot strands running in every direction, what a PITA to dig up!
reason i proposed removing branches is because it is a faster way to get rid of active foliage, hence the dormancy and root-to-foliage ratio scenario i brought up earlier.
for transplantation survival intent, 90% root death is quite untenable if not also removing some foliage, especially in very hot areas with low humidity, so yes, as you’ve mentioned, there is variability depending on species, and will have to add that variablility depends on time of year and location one is transplanting.
quite amazing i agree! And it well explains the relative vigor of the tree, since it was already primed by last year’s growth and food storage in what remains of the roots. Additionally, distribution of moisture could be realigned , since the plant could allocate its resources to just a select number of nodes, and sending out smaller leaves for the meantime, if viable active roots are still scant.
I believe that there are also energy reserves in branches that may be transferable to root growth. This may partially explain the lack of benefit of removing top to balance loss of roots.
However, if branches contain fruiting or any seed producing parts these can pull energy from root production. The tree must “decide” whether to expend energy on seeds or on roots- pretty much an existential dilemma. Immature trees don’t have this issue and can put all energy in saving the tree. Whitcomb performed all his experiments on immature trees, I believe.
Fruit trees and their rootstock have been bred for early production (maturity).
most definitely. Some plants we could propagate by cuttings have an ample amount of reserves, such as roses and figs. Whenever we strike some lignified stems from figs or roses as cuttings, we are compelled to trim all its regular-sized foliage to minimize transpiration losses(since those leaves were accustomed to the luxury of being supported by the fully-operational sapwood system and roots), and the cuttings are then obliged to sprout tinier leaves, to allow some photosynthesis(while minimizing water loss), at least while waiting for roots to develop.
extreme examples of specialized stem storage would be begonia rhizomes, potato spuds, etc which are stems, anatomically speaking. These are so easily propagated.