I heat the roots to about 70-80 F. The foliage I heat to about 80-100F. I foliar feed as the roots don't need much water and provide additional lighting.

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Plants on the floor level get light and the heat warms the root above to about 80F. The lights above the citrus provide heat such that it is about 80F at the root zone and 100F at the top. The trees grow very well.

If you click on the picture you can get into my photobucket tropical displays. All my pics are publicly viewable and you can see many other setups that might work for your situation.

Your lemon tree looks great and in need of additional light. The root heat could be provided by a plant heating pad.

Poncircusguy:

What type of bulbs are you using?

Also, is your setup just for overwintering?

Mike

As long as that pot has drainage holes, it should survive the Winter in that soil mix - it's a fairly small volume of mix for a tree of that development.

The only issue I see is that the tree needs to be fertilized. That is how a Meyer tells you that it has been hungry for a while. More frequent fertilization will halt the yellowing of older leaves, although it will not cause those yellow leaves to green again - they're goners.

Give the tree as much light as possible.

Josh

I am using compact fluorescent at 18 watts to 23 watts. with a temperature range from bright white to daylight. on the citrus floor and warm white to bright white on the ground floor. My choice on bulbs is made by sales.

All the pieces are precut and take about 2 hours to assemble and 1 hour to disassemble. It is used for the citrus trees and starting other seed trees to give them a 4 month jump on spring. The ground level is for vegetable starts in spring and growing greens in winter holding pepper plants from 1st frost till the some 50 peppers ripen.

The 2 plant you see in the bottom are pepper plants ripening their peppers. At this time I am bout to start harvesting greens. march i'll start my pepper and egg plants for smummer