Culture. African Violets under the hand of man have been vastly improved and 
diversified and many new colors and forms have been produced. New species have been 
discovered. They have also adapted themselves to somewhat different conditions from 
those found in nature. 
The advised range of temperatures for winter is 60° at night and 70° daytime. — 
They might do a little better at 10° higher but that is uncomfortable for people in winter 
clothing and summer brings about 10° increase, in our living rooms. 
The plants do not like sudden changes nor great changes. A nearly even temperature, 
within a limit of 12° between high and low is better. They are bound to have a 
greater range sometimes and if not more than about 15°, they are unlikely to lose their 
flowers. Loss of flowers is the first evidence of something wrong. This may result from 
sudden changes, drafts, too high a temperature in summer and in winter it may result 
if temperature goes much under 60° for more than an hour or two. Or it may result 
from too low relative humidity. This should be 40 to 60%. 
African Violets grown at a congenial temperature are usually killed if subjected to 
lower than 40°. Therefore it is impossible for us to send you plants by mail in winter, 
to a cold climate. In favorable weather we can usually send to warmer sections of the 
south. Express is safer. Nor do we ship on very hot days in summer. We plan to ship 
so that they do not arrive to you on a week end and thus remain in a carton a day or 
two longer. 
Watering. Do not use cold water. The water should be near the room temperature 
and never over 10° lower or higher. Most of our watering is done by spraying with a 
hose. The plants need to have the foliage sprayed and it does not spot the foliage if no 
sun falls on the foliage before they dry off. The interval between waterings should be 
long enough to permit the top soil to become slightly dry. Do not use pots that have no 
hole at bottom for drainage. Use sub-irrigation infrequently. We prefer regular pot 
watering rather than use of wicks. 
Good ventilation is needed by all plants but Saintpaulias do not like drafts. Slow 
movement of air currents are more conducive to their comfort. 
Soil formulae. Plants have a considerable tolerance and do well in a wide variety 
of soils. They should be at least mildly acid in reaction and a type that will drain easily 
and quickly. Heavy clay soils, therefore, are not good. 
We use about one half oak or redwood leaf mold and one half sandy loam or good 
loose garden loam. To this is added enough Sponge Rok or coarse sand to make the soil 
gritty and aid drainage. Fine screened peat is as good or better than leaf mold. 
If you are unable to supply your own soil mixture, the best we know about is 
Black Magic which we list under supplies. We believe this may be stretched and really 
improved if one should add an equal portion of very gritty sandy loam and fine rotted 
leaf mould. But if added, you must sterilize this addative in the oven to get rid of 
soil bacteria and nematode. 
Fertilizers. We use only Spoonit and recommend it to be applied once a month, on 
a day following watering. See our listing under Garden Supplies. 
Sun exposure. Most of the advice one receives over-emphasizes shade. Lack of 
sufficient light intensity is one of the most frequent causes of non-blooming. All shade 
plants need a certain amount of modified sunlight to make them flower. In the winter, 
the sun is at a low declination. Its rays must pass thru several times the thickness of 
atmosphere penetrated at noon in the summer when the sun is directly above or at 
“high declination.” Very little shading is needed on the greenhouse in winter. Treated 
thus, our plants bloom profusely all winter. Very likely, plants in a south window, 
anywhere in the north temperate zone, in winters, will be sufficiently shaded on the 
brightest days by a thin muslin curtain. It may not even be needed at all and on days of 
less than maximum intensity remove the shade. 
But summer sun is much stronger. One must give more shade. It should not, 
however, be too heavy. The color of the foliage will tell you what they can endure. 
When healthy plants have light, yellowish foliage they probably receive too much sun. 
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