Quote:
Originally Posted by tommyg
Richard feel free to start your own thread on your topic. I would like to continue discussing kumquats and meyer lemons on this one.
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Yes, we are all discussing containerized citrus here. The last post was regarding Lisa's (
fmu65) question on fertilizer concentrations. Her other question was:
Quote:
Originally Posted by fmu65
Anyway, because I am big on research, can you recommend any books that address growing citrus (especially in containers)? Thanks again for your help. My biggest fear with this meyer lemon is the lemons will get to a certain size and then just fall off, as I have had many people tell me happens with citrus in containers.
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For references, I would point you at a succession of textbooks and research papers. However, there is a course taught on Citrus at UCR which is available through extension. Our very own member here
GoAngels recently took this course so perhaps he can point you at the course materials.
The two main challenges in growing citrus and other fruiting trees indoors are: (1) supplying enough energy via light in the correct spectrum to the plant -- think of the leaves as solar panels, and (2) getting supplying enough potash in relation to nitrogen so that the plant can "service" the fruit.
For light you need between 55 watts/sq.ft. to 75 watts/sq.ft. in the 6500 Kelvin spectrum for a period greater than 7 hours per day. 9 hrs per day is sufficient. Hopefully you have some natural sunlight enveloping the plant and a very cheap light meter that measures watts (not lumens) can tell you what the contribution is. Then of course you need to make up the difference with supplemental lighting: the CF65K (compact fluorescent 6500 Kelvin) bulbs work well as do a bank of 4-foot 6500K fluorescent bulbs.
For nutrients, you would like the nitrogen (N) to potash (K) ratio to be about 1 N to 2/3 K, and the phosphate (P) to be the lowest. There are many fertilizer products in all shapes, types, and sizes from many suppliers that do this. These formulas are all examples: 3-1-2, 6-2-4, 9-3-6. If you walk into a big box store you'll likely see (among other things) an organic Citrus food that is 8-6-8 and an organic Palm food that is 8-4-8. Well, the first one is a little high in P, but the second is a pretty good choice. It's a bit more K than the plant will use but at least it meets the plants need. In the water-solubles you will see 20-10-15 which again is not quite the 1 to 2/3 ratio, but pretty darn close.