The northeast has gone thru an exceptional heat wave which has caused tremendous growth on all of my potted citrus. Daily watering was required. The heat has resulted in tremendous flowering on kumquats and limequats.With the high humidity, the weather simulated the southeastern US conditions.They have grown so much that my big problem will be finding room indoors during the winter. I always have a hard time pruning them back. [][url=http://www.freewebproxy.com/][img]http://www.freeimagehosting.net/t/2zyue.jpg[][/url]

Hmm I am not that far south of you and mine didn't change much during the heat wave these past couple weeks. I have been getting tons of blooms but it started at the end of June and is just now finishing up. I got my trees this year, though, so their schedule might be off from being greenhouse grown elsewhere, transported to PA, and re-potted.

There are many reasons why a citrus tree grows and flowers. Extra heat producing growth??? Maybe yes, maybe no. If the containers temperature was above 95 F, there would be very little, to no growth at all for a citrus tree. - Millet

I Live in Michigan, last week was so HOT AND MUGGY!!! All my Container Citrus really put out lots of new growth. I'm surprised they did anything, my Key Lime Has tons of blossoms since last February. Temp has dropped to 59 with the passage of cold front, hope they don't go into shock!!

Damn Nicky. Do you have stock on Monrovia?

No stock in Monrovia. Just lucky to purchase used Monrovia pots from a local nursery. They make the citrus plants look more attractive since the pot designs are consistent.
http://imageshack.us/a/img694/8740/35eu.jpg

I mention one further point. Citrus trees do not automatically flush because of one incident of nature occurs. A period of new leaf flush will not start until the root growth following the last flush has first occurred and has been completed. Only then the next leaf flush cycle can start once again. Until that happens, heat , sun, long day, light, or nutrition can not cause the next flush of leaves. I think it is probably just a coincidence that the hot weather and the growth flush came at the same time. - Millet

One comment, you mentioned that no single condition will produce new growth, but I have noticed that when the temperature difference between night and day is 15-20 degrees F, either flowering starts or new growth begins. This has happened at my latitude on Long Island, NY especially when evening temps are 65F and day temps reach 80F. I believe this replicates a Mediterranean type climate.http://imageshack.us/scaled/thumb/203/g5e3.jpg

nicky, thanks for your comment. It is comments like the one you posted above creates discussions of interest for member of the forum. I really don't believe temperature differences between day and night has anything to do with the causeation of a citrus to flush and bloom. Day and night temperatures in Florida do not have drastic temperature swings, and Florida citrus can be expected to produce a new flush every two months +- during the growing season. Day and night temperatures in the tropics are just a couple degrees different, and a tropical citrus tree can have up to 5 growth flushes per year. When a container, or in ground citrus tree is properly cultivated a citrus tree can be expected to flush about every two months. However, a citrus tree, especially lemons, can be made to bloom by withholding water, but not by fluctuating the temperature. If temperature swings between day and night worked, then one could have as many growth flushes as they wished, and could even make the tree to flush during the winter months. Unfortunately, temperature differentiation is not one of the causes of new growth. - Millet