I would love to get opinions on the best time of year for re-potting. I live in California (zone 9) and leave my citrus outside during the winter, although occasionally they need some protection from frost.

On one hand I would think fall because the tree roots could begin to incorporate themselves into the new potting soil prior to the 1st spring growth spurt.

On the other hand, perhaps spring is the best because the roots would just be beginning to also grow more rapidly.

Thoughts...

Thanks,

-Brett

I don't think time of year makes that much difference. I would try to do it between flushes, so you don't have a major demand for water to support the new flush.

I repot winter, spring, summer, fall - a.m or p.m.

The best time to transplant a containerized tree is when the roots have filled the container. If the tree is not transplanted at this time, the roots have no where to go except circle around and around the container. Therefore one should not wait 4 to 6 months until fall or spring to arrive. The growth of the tree's root system, followed by the scion's vegetative growth, occur in cycles lasting approximately two months for each.. First the roots develop new growth, lasting approximately 2 months, then the foliage growth period starts which also takes a couple months. After which the entire cycle starts over again and again and again. So you see there is no one time of the year that is "best". I have transplanted citrus trees in every month of the year. The important point is not when, but how to transplant. - Millet

I have a question then: what about transplanting with fruit on the tree? I am now a big believer in the CHC/peat moss combo and have 5 trees that are still in the soil I bought them in. They are getting roots all over the place and they need to be repotted. The only thing is they all have a bunch of fruit on them about including lemons that are close to done and oranges and grapefruits about baseball size. Do I have to worry about transplant shock hurting the fruit or should I just repot them now?

Thank you so much for your valuable advice.

-Brett

Brett,

I whole heartedly second Millet's advice that you repot when you need to; you do not wait. That being said, however, if you repot in the fall be extra careful to not damage the roots. I repotted several trees late last fall. They didn't seem much worse for wear through the winter, but as the weather warmed and the trees awakened from dormancy, I observed significant leaf drop. The root damage didn't impact the trees much when they went dormant for the winter, but the weak root systems didn't have a chance to recover before becoming saturated during the winter. Had I repotted earlier in the season, so that the root system would have healed before dormancy, I believe the trees would have recovered sooner with less leaf drop. Of course the less damage you inflict when repotting, the better off your tree will be regardless of season. When repotting a root-bound tree that has adhered itself to compacted soil, it is difficult to avoid damaging the roots to some extent. Perhaps I use too much water pressure trying to rinse out every bit of old soil that I can, but I think allowing too much to remain causes bigger problems in the long run. Which kind of brings us back to -- don't wait!

Kent