Tip of the Week  #11

This is probably one of the most misunderstood aspects of bonsai cultivation.  There are many different types of bulbs available today.  They are good for many different things, but few will give long term successful results with bonsai.   Because of the amount of heat most bulbs give off, all but fluorescent bulbs have proven impractical for bonsai use.  Fluorescent bulbs are cool burning.  They don't dry the foliage or the soil.   They are also the most economical to use.   There are a number of different types of fluorescent tubes, but the only ones I have found to work over long periods of time are those classified as "Full Spectrum".  (You'll find information and specifications on Full Spectrum Bulbs in our Product Catalog, under "Supplies").   The best way I've found is to set the fixtures up on a 24 hour timer.   To give the trees a sense of the changing seasons, deduct 15 minutes a week from the cycle until late December, then add 15 minutes a week until late June.  If your bonsai are under the lights year round, they will get 12 hours daily in December, and 15 hours daily in June.  That's close to the normal light cycle in most parts of the U.S.A.  The bulbs should be no more then 15 inches from the top of the shortest bonsai.  The tallest can be almost touching the bulb(s).  If there is too much height difference, either use more then one fixture, or make a platform to raise the shorter bonsai.  It's a good idea to hang the fixtures with large-link chain, so you can add & remove links to change the height of the fixtures.  If you move your bonsai from indoors to outdoors as weather permits, get them out as early in the spring as your climate permits.  Trees get a protective coating on their foliage similar to suntan in people.  If they go from artificial light to strong summer sun, the results could be disastrous.  With a little common sense, experimentation, and the right bulbs, you'll find indoor growing a pleasurable extension of a great hobby.