you can definatly trim the roots if your plants are root bound. i wouldnt do it until it needs it for sure though, no point to stress the tree for nothing. just read the guides here and u'll do fine just dont forget to trim the top at the same time or the reduced root system wont be able to provide enough nutrients to the foliage. also dont fertalize for about 2 weeks after this will encourage the new roots to grow out in search of nutrients.

This might be an exception to the don't fertilize "rule"; if you prune the top and the roots, trying to retain a 4:! ratio by weight of tree to root, fertilization (weakly weekly) would maintain the balance. BTW... Zone 10.. why are these plants not in the ground?

Clm, your information is simply not true. Pruning the top to compensate root loss is very counterproductive for a woody plant. All of the energy needed to produce new roots comes from photosymthesis. Top pruning can put a root pruned plant way behind in the rejuvenation process.

Root pruned container plants recover very rapidly in a porous medium, responding with a new flush of feeder roots, which will vastly increase the surface area for absorption in a matter of days. But only if the top hasn't been chopped.

H., the usual time to root prune is at the onset of spring growth. Many of us root prune when we repot to freshen the potting medium.

Thank you for the replies.

They've been in the container for two years so I think it's time. They did fruit heavily this year. Roots are popping out of the bottom, and in one case where the container was on soil, the roots dug into the soil!

John, they're not in the ground because there are really old trees around, and tree roots are ample just a feet below, so nothing really flourished after the first year of planting as I've learnt. Containers do much better!

The winters here are very mild, so I was thinking I should prune because the mild temperatures would reduce the stress.

H

rhizo as far as i know it works both ways. roots need leafs and leafs need roots. if you dont want to trim the top im sure thats fine but i would expect to see a significantly higher amount of leaf drop then if you didnt.

as john mentioned, try to retain a 4-1 ratio

I expect no leaf drop, lol. As a matter of fact, if the tree in question is overdue for an up poting or root pruning, a flush of new top growth is the likely result. It's a benefit to the tree. Prune the top when needed....prune the roots when needed. Just not at the same time.

If the top is pruned at the same time as the roots, a plant will take energy reserves FROM the roots TO the top in order to replace the lost energy (carbs) factories.

Plants are not able, physiologically, to regenerate roots and shoots at the same time. Or at least not very well. They need manufactured energy in order to undergo cell division, to repair damage, to recover from insects or disease....even to fend off pests in the first place, to produce flowers, fruit, and seeds.

If the factories are reduced, as well as the root surface area .....a plant must remetabolize stored energy from someplace else, usually the roots.

That puts the plant in a very vulnerable mode, prone to pest invasion and disease infection.

The practice of top reduction to compensate for root pruning is outdated. As science has allowed us to delve deeper into how plants actually work, we must change old habits. Hopefully, we keep learning as we go.

I might add, as well, that root pruning of containerized plants is something that has been practiced for centuries.

Thank you guys for the input and the long explaination. Makes a lotta sense when you know the science behind it.. Thanks again!