Growing African Violets on a Windowsill
Growing African Violets on a windowsill is quite common practice - they require little space, some sunlight or artificial light, proper air humidity, occasional watering etc. It sounds like much, but it is not - once you get habit of having them, it will be very easy to take care of them.
Proper Light Conditions on a Windowsill
African violets can tolerate various light conditions, but correct amount of light for African violets is around 10.000 to 12.000 lux.
For example, living rooms have around 50 - 100 lux, sunrise or sunset on a clear day is around 400 lux, but full daylight (not direct sun) is around 10.000 - 25.000 lux and direct sunlight is between 32.000 - 130.000 lux.
Too much sunlight can damage your plants - if you want to be sure, using light-meter check light intensity on your windowsill during morning, midday and in the evening.
During summer, depending on the window orientation, you will probably have to provide some shade to your African violets, especially if you have windows facing south.
These photos were taken during summer - window is facing south and during the day, light intensity behind the glass can reach up to 100.000 lux - not recommended for sensitive plants, like African violets. One can clearly see shades for light protection and, after all, some decoration :o)
During autumn and winter, remove shades and check light intensity - if you provide enough warmth to plants, they will grow and bloom even if light level is suboptimal.
If you notice that your plants are not developing properly during winter, consider some artificial growing light to combine with weak sunlight - these lights can be found in various sizes, just be sure to read the manual.
Proper Temperature Conditions on a Windowsill
During summer, plants on a windowsill, behind shades and in the air-conditioned room can have perfect growing conditions. Temperatures around 25°C (77°F) are suitable for both humans and African violets, unless plants are on the path of cold air from AC unit - this can be very harmful to African violets, but also to many other plants. Cold air from AC units can be very cold (below 15°C - 59°F) and sudden changes in temperature can damage, even kill sensitive plants.
Just to be sure, protect African violets using some decorative curtains - these curtains will protect plants from cold air from AC units, but also from any draft that can be present in the room.
During winter, be sure that leaves don't touch window glass - they can be much colder than air in the room and this cold can kill leaves. One of the best ways to protect plants is putting baking paper between plants and window glass - it is more transparent than ordinary paper and it is more durable. Of course, if you have enough space, put your plants at least 2-3 cm (1 inch) away from the glass.
For more general information about light and temperature requirements, feel free to visit Light and Temperature article (article opens in the new window).
Proper Watering and Humidity
There are no special requirements when growing plants on a windowsill or somewhere else. Nonetheless, there are few things to consider:
- during summer, even in air-conditioned rooms, temperature next to the window can be little bit higher than in the rest of the room, especially if you have plants between windows (even with shades) and curtains. This would require watering plants more often.
- during winter, situation is opposite - temperature between windows and curtains can be lower. These plants require less watering than one would expect.
The fastest and the easiest whey of checking if your plants need watering is by simply pushing your finger into the growing soil:
If you notice that soil is soggy and wet - don't water it. If you notice that some soil particles are sticking to your finger and that soil is more or less humid, don't water it for day or two. If you notice that soil is dry - water it immediately.
Water used for watering plants should be at room temperature and preferably, at least, one day old. Stale water will not 'shock' the plants and chloride and fluoride content in such water is relatively low.
To increase humidity around African violets and to have stale water when need it, I keep my watering can next to my plants. Having such amount of 'open' water is not the cleverest idea due to possibility of spilling it accidentally, but so far, so good :o)
Seriously, if you have kids or pets running around, avoid having any open pots or cans with water - they will sooner or later be flipped over.
For more general information about this topic, feel free to check Watering and Humidity article (link opens in the new window).
Plants and Pots - Shapes and Sizes
Size of the pots and planted African violets are determined by width of your windowsill. Great thing about African violets is that they generally grow very well in ordinary plastic 10 cm (4 inch) pots and if you have miniature African violets, even smaller pots can be used.
Rounded pots or squared/rectangular boxes - I have them all and they all have their pros and cons:
- since sunlight on windowsill comes generally from one direction, it is easier to rotate rounded pots. After every watering, you can rotate your pots and thus stimulate it to grow symmetrically - and you rotate it how much you think is necessary avoiding contact between leaves and window glass. And if you have rectangular boxes as growing pots, there are only two possible positions - four if you use squared boxes.
- squared/rectangular boxes have more growing soil per plant, which is not so important for African violets, but if you are planning on growing, for example, small windowsill herb garden, it is something to consider. Also, having more soil per plant, means watering less often.
There are other possible issues - potting soil, fertilizers, pest and diseases, etc - regarding growing African violets on a windowsill, but they are just as same as growing African violets elsewhere...