Sunlight:
You may have
read that the plants do not like direct sunlight. Again this is
true, but not to the extent that the plant is a shade lover, - as
some would suggest. In fact, in my experience, the plant likes as
much light as it can possibly get without getting too much direct
sunlight.
Venetian blinds on a south facing window will protect
them from excess, otherwise ideal is if you have a window that
gets just a little morning or evening sun. Ensuring enough light
will encourage growth and the production of rich dark green leaves.
Artificial Light:
I’m having success growing under artificial light. In order to get
more winter growth, and because of a general lack of suitable window space, I set up some plants in a windowless utility room. These have lights on a timer-switch
(16hrs on, 8hrs off) and are growing well.
I’ve heard of and seen fluorescent strip lighting being used by other
people, but I’ve simply used ‘energy-saver’ bulbs in standard light
fittings. These are in effect mini fluorescent lights anyway.
The plants (mostly youngsters in 10cm pots) are between 25cm to 100cm away
from the light sources. I originally suspended a total of four lights above the plants,
kind of one at each end of two parallel ‘shelves’ of plants. This
worked okay but since then I've added an extra light above the middle of the
lower shelf, so that this shelf has three lights, and I have extended, as can be
seen in the photograph below, with more plants (and another light) included in an area at the back
of the shot (in front of a mirror)
The ‘shelves’ consist of
just over a dozen or so plants on each
shelf, - each shelf about 1.5m in length, 0.4m wide.
As you can see, one set of plants is slightly further away (lower down) from the light
sources, so there is quite a range of distances from plant to light, but all plants
are growing well and it's been so successful that I've extended into other
cupboards.
The total light bulb wattage was originally 96 watts, consisting of 2 x 25
watts (1200 lumen each) plus 2 x 23 watts (I assume proportionally less lumens
for the lower wattage), with later another 18 watts added above the middle of
the lower shelf, and a further 25 watts for the inclusion of more plants (in
front of the mirror at the back). - Quite bright over all, each bulb >= 100w
ordinary bulb equivalent (an ordinary 60w bulb outputs ~700 lumen), but without
producing too much scorching heat (or using too much power). Of course,
you wouldn't need this many lights for fewer plants.
Considering that there is no need to mimic direct sunlight, I would argue
that expensive high
power lamps are not necessary. However, you do want to get a bright crisp
light. Note that some energy-saver bulbs advertise themselves as producing
an especially 'warm', 'soft' or yellow light. These are to be avoided if
possible.
Like I say, I don't believe specialist high power lighting is
absolutely necessary, but one of my plant recipients
has been experimenting [...]
Note that another way to use artificial light would be by a window, i.e. to supplement
natural winter light rather than completely replace it.
24hr Artificial Light
I tried this as an experiment with a few plants at the beginning of January
2002. Apparently it can work with some plant species to increase growth
rates. I stopped after 8 weeks. I wanted to re-arrange my set-up and
this included reclaiming the cupboard space that was being used. During
the 8 weeks the plants did grow, but did not appear to be growing any faster
than those under the 16hr on 8hr off set-up. I have to say the the 16hr on
/ 8hr off plants did look healthier too. If anyone else has done a similar
experiment I'd be interested to hear about it, particularly if they've done it
for longer than a couple of months.