Hi
I have a relatively large lemon tree in a relatively large pot (24 inch diameter x 24 inches high). After a few years of trying, I seem to be able a keep the plant relatively happy and actually bare fruit. (Blossoms smell awesome!). The plant is more of a bush than a tree. However the plant and pot is just too big and for our small home. Is it possible to repot into a smaller pot and trim back the plant size? Lots of info on repotting from smaller to larger pots, but not much on repotting from larger to smaller pots. Thxs
Hello, thanks for contacting the Toronto Master Gardeners about your tree.
First off, kudos for keeping a lemon tree healthy – and getting it to bear fruit at that, since they can be finicky and fruit is often a bonus.
Keeping it a manageable size given your space constraints is understandable and a good idea. However, it’s advisable to reduce the container size gradually: too much might send the plant into shock. Reduce the pot diameter by about 2″ each time and then give the plant several months to adjust. The best time for repotting/pruning is just before or just as the plant breaks dormancy in the late winter/early spring (i.e. in your case pretty soon). If you must reduce the pot size again, wait until the plant has finished setting buds, flowering and fruiting as this period is when the plant uses most of its energy reserves. That energy store needs to be replenished.
You can prune the bottom branches and/or oldest and/or widest ones close to the main stem/trunk to make it into a smaller, tree-shaped form, and also cut off the ends of the widest branches to shape. Remove any crossing branches that are rubbing against each other. Diseased/dead branches can be pruned out at any time.
Separate and spread out the roots carefully and then prune out the thickest/largest and oldest roots with a sharp knife or saw sterilized with rubbing alcohol or hydrogen peroxide to avoid spreading disease. A plant takes up most of its nutrients and water through fine feeder roots, whereas the large roots are used for anchoring and stability – fine for when the plant is in the ground, but not necessary in a container. Pruning out the old roots will keep the plant from getting root-bound and cause it to put out more of the feeder roots, producing a healthier specimen. In fact, it is a good idea to do this in general for containerized plants every two to three years. Also remove and refresh the old soil with new potting soil with some compost mixed in (two parts potting soil (containing perlite and peat moss) to one part compost is a good ratio).
With both stems and roots, a good rule of thumb is to remove no more than 25-30% at a time — again, to avoid shock.
Click on the links below for root pruning pot-bound plants – your approach for reducing the size of your lemon tree is roughly the same, except that your goal is also to prune the outermost roots to reduce the size of the root ball.
Root-Pruning a Pot-Bound Houseplant – Laidback Gardener
Root Pruning Container Plants – FineGardening
See here for general pruning techniques for trees and shrubs:
Pruning trees and shrubs | UMN Extension
Pruning Trees & Shrubs (ncsu.edu)
And finally, for lemon tree care and pruning specifically, check out these previous questions and answers on our website, and these other links and a YouTube video:
Lemon Tree Care* – Toronto Master Gardeners
Lemon Tree – Toronto Master Gardeners
Growing citrus indoors | UMN Extension
Cutting Back Lemon Trees – Learn When And How To Prune A Lemon Tree (gardeningknowhow.com)
How to Prune a Lemon Tree Using Tree Science as a Guide – Bing video (YouTube)
Good luck. I hope your tree will thrive and bear fruit for years to come.
April 27-2022