Home > Begonian > Volume 68 (May/June 2001, pages 94 - 95)
by Jim Hannah
Our home isn't exactly the greatest when it comes to
good windows for growing plants. Years ago we set up a table and some
fluorescent lights in the cellar in self defense. We've used this rig
since then for growing a wide variety of plants and for starting seedlings
for outdoor spring planting. Most recently, we've used it for begonias.
Hopefully, our new greenhouse will take over most of the functions of the
lights. But meanwhile, the of light table is still a great place for
starting seeds and growing some of the low light plants; we may never do
away with it entirely.
The basic table's nothing more than a framework of 2
by 4's with a half inch thick 4 by 8 foot plywood top. The top is 38
inches above the floor. It has proven to be a comfortable height. We added
a low rim and covered the top with a couple of layers of thin plastic
sheet to contain dirt and liquids. We use standard I1 by 22 inch no-hole
black plastic trays to further confine any messes. Some random boards we
had lying around were used to make a storage platform under the top.
Light is provided by standard two tube 'shop light'
fixtures. They're set up in a row above the table. We spaced them a foot
apart originally and haven't changed anything since. Each fixture is
'responsible' for a 1 by 4 foot strip of growing area. The tubes are
ordinary 40 watters. We haven't used the tubes developed specifically for
light gardens. That doesn't say that they're not worth the money -- just
that we don't use them ourselves. The lights are controlled by a timer.
The normal cycle is 14 hours on and 10 hours off. The temperature range is
from 55 degrees F in the winter (lights off) to about 90 in the summer.
Under the lights it probably gets over 100 degrees in summer. Under the
lights it probably gets over 100 degrees in summer.
One little trick we discovered has worked well. In any
light garden, you have to adjust the height of the fixtures from time to
time. Our table is set up with the long side against a wall. 'Nuff said.
We solved the problem of getting to the wall ends of the lights by putting
screw eyes to the ceiling and running cords through them to the lights.
Little pulleys can be used, too. They're easier on the cords. We put
cleats in convenient positions to make tying the cords off a cinch. We use
the same system for the front ends of the lights, too. If putting screw
eyes in the ceiling isn't your cup of tea, you can make a little framework
for them above the table. Either way, just be sure that you can raise the
lights to a sufficient height. The light adjustment system should permit
the bottoms of the lights to be at least 24 inches above the table
While you won't normally set them that high for
growing, there'll be times when you'll want them up and out of the
Now let's get back to begonias. Our experience thus
far has been that successfully growing begonias under fluorescent lights
is simply a matter of the choice of plants. Some types are happy under
fluorescent lights and will flourish. Others will not, either because they
need more light or because they just grow too tall. For example, we've had
little success with the Semperflorens. While many of the Semp varieties
are listed in seed catalogs as partial shade plants, their light needs
seem to be greater than our setup provides.
You can also pretty much rule out begonias which grow
taller than about a foot or so. This eliminates most of the cane-like and
shrub begonias. Even though many of them are reasonably happy with the
light strength, they'll grow way too tall way too fast. The cultivar B.
'Down Home' grew beautifully for us and even flowered abundantly, but
we had to keep chopping it off to control it. For us, there's something
sad about a plant that's not allowed to grow to itsnormal size. (What?
Huh? Yes, we do love Japanese bonsai. I guess we're just not very
So what can you grow? Leading the list are the smaller
rhizomatous and Rex begonias. There's a huge variety available in leaf
size, shape, and coloration in these two groups alone. A great plant to
start with is B. masoniana, the Iron Cross begonia. It fits its
name and has an iron constitution as well. There are many others.
I wish I could personally add tuberous begonias to the
list of light garden plants, but to date we've only used our setup for
starting the Nonstops from seed for outdoor use. They did quite well up to
the point where they were ready to ship outdoors, though. It might well be
possible to grow the tuberous begonias through their full cycle under
lights. We just haven't tried it yet. A well grown tuberous begonia in
flower is an awesome sight.
There there's a whole group of small begonias of
various types which either require or thrive in terrarium conditions --
very high humidity and warmth. These are made to order for fluorescent
light gardens. You can easily construct some sort of clear-sided enclosure
for them. We've even used clear plastic wrap and coat hanger wire in a
pinch. B. lymansmithii was grown from seed and chugged along very
happily in an enclosure under the lights. There are many others you can
try. The ABS Seed Fund can help you keep your costs to a minimum.
Got a nice seed starting tip from Mr. Collard in
Canada. He uses soft margarine or other similar plastic containers. First,
though, he cuts out most of the center of the lid. Then, when he's ready
to cover the container, he stretches clear plastic wrap over the tube and
uses the modified lid as a clamp. Simple and effective.
See you next time. Write if you get the