Yes, but know that 55F (13C) is also the dormant temperature for foliage. By keeping a greenhouse at a lower than 55.4F will still reduce or stop any growth of your tree. - Millet

Oh Ok, will keep an eye on both air and root temp closely and try and match the two, its only for a while as a few more weeks the night time temp will be above 10C I guess.

Inspected the tree last night, it has quite a few buds and leaves trying to grow, think it will hold in there, hope so!!

Any idea why the end of the branches are dying?

Still a bit worried about my tree's Millet, I have them in the greenhouse now on a heat mat, roots roughly 60-75F, but they still lose leaves, it appears like lots of new leaves are appearing but yet its still dropping.

Is there anything you recommend? My small clementine tree has dropped all of its fruit, and is now losing leaves also. They are all potted in equal grit, orchid and citrus compost, and in terracotta pots, Im not overwatering. Could it be a shock thing? Moving from one place to another? It does get quite hot in there during the day, possibly about 80F ish?

If it's hot in there --80's, you shouldn't need a heat matt.

Trouble is over here the night temp is between 5C and 10C, by the time the sun gets up I doubt the roots are warm enough. Once the night temps heat up a bit I will move them all outside.

Why would the ends of my branches die?

Hi
I ran into a lot of problems with my lemon trees this winter. I do think so if it was the cool soil, but I think that underwatering caused a lot of my leaf drop.... I dont think the soil wants to dry out at all, is this a possibility for you?


Frank

I have repotted in citrus compost/orchid compost/grit, it seams better drainage, I guess I will have to wait a few weeks to see if it improves.

On the subject of aerobic, our company here in the UK has an aerobic digestion plant, breaks down all waste food from supermarkets and turns into fetiliser. Last time we had it tested the nitrogen came out in 3 figures, its nice rich stuff, I cover my allotment in it.

Would it do my citrus trees any good?

Phillip, I think you have the terms mixed up-- aerobic means with air or oxygen, anerobic is without oxygen. Nitrogen fixation happens in an anerobic environment-- mostly in plant root nodules. Most sewage digesters cycle between aerobic and anerobic conditions to convert N back to atmospheric N--the aerobic conditions break down proteins and convert ammonia to nitrate. Then the anerobic conditions make the bacteria use the Oxygen in nitrate to continue to break down carbon and in the process they convert NO3 to N2.

Actually, farmers often add a product called Nserve to prevent the conversion on ammonia to nitrate so that the nitrate can't be converted back to N2.

You are correct if you meant nitrification-- that is an aerobic process. Nitrogen fixation is the process by which plants like legumes convert atmospheric N to fixed nitrogen that can be used by plants--that process is anaerobic ( I misspelled that earlier) and it generally requires Molybdenum.

The nitrification process you mentioned is also important in aquariums-- without it ammonia from waste will build up and kill the fish, but farmers actually try to inhibit the process so that they do not loose their fertilizer.

Actually I was a chemist for 25 years before I got my doctorate in Marine Science. Element cycling is a major theme in marine science, N, P, C, S, O, Fe, Mn even most of the trace elements.

Citrus roots supply the tree with water, but without soil oxygen they cannot do so. Citrus root supply the tree with nutrients, but without soil oxygen they cannot do so. Citrus roots supply the tree with a firm anchor in the soil, but without soil oxygen they will die and so cannot do so. Many people blame over watering with killing their tree, but in reality what actually kills the tree when it is over watered or the roots are flooded, is the lack of oxygen. A growth medium for citrus should have a 25 - 35 percent drainable pore space. When a CHC growth medium is used it is almost impossible to over water. - Millet

Phillip, no your answer was correct. - Millet