GROWING TROPICAL FRUITS IN NORTHERN COOL TEMPERATE LATITUDES.

IS IT POSSIBLE TO WATERPROOF GROW LIGHTS TO ELIMINATE ELECTRICAL HAZARD WHEN OPERATING IN A HIGH HUMIDITY ENVIRONMENT?

I like to keep humidity levels high (at least 90% relative humidity) in my indoor mylar foil-lined plastic grow tent. My carmabola, avocado, sapodilla (as featured in the photo), citrus and soursop (all grown from seed, since I find grafted plants impossible to import into the UK, especially from Florida) have put out an abundance of new growth since I maximised the humidity. I've never had fungal problems, but if I did, I would spray the affected areas with a very weak hydrogen peroxide or copper sulphate solution.

The humidity is so high that there is a lot of condensation. This poses an obvious safety risk when using electrical equipment, such as grow lights. However, my growlights, which consist of two T5 HO fluorescent units (each rated at 216 Watt, 16,600 lumens, 6500 Kelvin) are mounted outside my grow tent, which eliminates the electrical hazard, but light can still penetrate the clear PVC plastic of the grow tent. Mylar foil surrounding the T5 units and the grow tent maximises light availability to the plants.

Is there any means of proofing a fluorescent, LED or HID light fixture against high humidity and condensation so that they would be safe to use in the humid environment of my grow tent? Can humidity- and condensation-proof HID, LED or fluorescents be purchased?

Do you think that my two current T5 units, which are run simultaneously, can generate enough light to induce not only flowering and fruit set, but also ripening/maturation? I live in a cool temperate climate (England, UK, latitude: 50 degrees 52' N) and plan to move many of my containerised tropicals (except ultra-tropicals, such as my soursop) outside from mid-April until late September. I overwinter them indoors.

I intend to buy a grafted 'Keitt' mango and Canistel ('Fes' or 'Bruce'- which is better for container culture?). Both will spend their lives in 30 litre size (equivalent to 7 US gallons?) containers. Do I stand a chance of obtaining fully ripe, edible fruit from them in my climate, and with my current T5 light set-up?

I've noticed that the light from my T5 fluorescent units only registers on my light meter when in close proximity, yet the supposedly weak sunlight of the March sunset gives a very strong reading!

On a different matter, I have a tiny, tiny 4 month old allspice (pimenta dioica) seedling, which is barely more than 1cm tall. It has hardly grown at all ever since it germinated- 4 months ago!. Is this extremely slow growth typical of seed-grown allspice? Could it be due to weak genetics of this particular seed? Out of 40 seeds, two germinated. One died, and I have one left, which I don't want to lose, since subtropical allspice shrubs/small trees are impossible to obtain here in England. Temperature inside my grow house is sultry 32 degrees Celcius when my T5's are on (they do emit some heat, which has a tendency of driving away moisture from the leaves of humidity-loving tropicals when it is too close to them).

Gary

This post was edited by GarryGreenfingers on Wed, Mar 19, 14 at 10:54