By William Mills
In my house the last sunlight reached my backyard in early October with no more expected until March in the early spring. An upstairs window still gets a few hours a day when the sun shines. It is useful to make a map of your plants’ home detailing which times of the year natural sunlight can be expected and for how many hours.
Last year I had just spent £40 on a lemon tree and really didn’t want to lose it over the winter months so I thought I would experiment with artificial lighting. First I purchased a light meter which are available on the internet and from garden centres costing less than £10.
I soon discovered that ordinary tungsten light bulbs don’t emit enough rays to help my plants. However a 50 watt halogen spot lamp made a lot of difference. So did fluorescent strip lights in the kitchen. After a few days it’s possible to notice the plant growing towards this new source of light.
Next I researched hydroponic lights finding a bewildering array to choose from, with it becoming clear many are unsuitable for domestic use. A normal household bulb uses up to 100 watts (w) of electricity per hour. Some specialist hydroponic lights use 600w and 1000w bulbs. These need a transformer like metal control box which is both heavy and gets extremely hot posing both a fire and injury risk. I didn’t feel they were right for my home and more appropriate for commercial horticulture.
I bought a Maxibright 250w Compact Fluorescent Lamp complete with all fittings for £80 which proved simple to rig up in my kitchen. A time clock switches it on for four hours a day between 10am and 2pm to augment the limited winter natural daylight, and is enough to help the lemon tree flower in December. A kilo watt hour (kwh) costs around 15p, so for five months until the sun appears over next door’s roof the electricity is cheaper than buying replacement plants in the spring from the garden centre.
As soon as the shortest day is past, the artificial light should be left on an extra 30 minutes a week bearing in mind in gets lighter between December and June at an approximate rate of two hours extra a month.