Potting and Growing Medium for African Violets
African violet soil - potting and growing medium - must mimic conditions that African violets have in nature and must provide them with water and macro and micronutrients for their growth and blooming.
Conditions that good African violet soil must satisfy:
- good drainage - African violets are sensitive to soggy conditions around root system which can rot in such environment and kill plant. Good African violet soil must have good drainage so that any excess water can easily exit pot through drainage holes.
- pH levels - African violet soil must have pH around 6.0 - 6.5 which is slightly acidic. This pH factor enables African violets to take nutrients from the soil and keeps root system healthy. You can check pH factor using small testing kits that can be bought at garden centers, although we have rarely seen that people had problems with pH, even with homemade soil mixes.
- good water and mineral retention - African violets have very fine root system that in contact with soil particles takes water, macro and micronutrients and transport them to the rest of the plant (primarily to the leaves). If soil lacks important nutrients, plants don't have proper conditions to grow and will not bloom the way they can and should. Good drainage and good water retention are two different things, so don't mix them - good African violet soil should have both good water retention and good water drainage.
- aerated soil - African violets like plenty of air around roots. When you water the plants, water fills those air pockets and when water is drained out of African violet pots, new and fresh air enters into the soil and around the roots.
When potting and repotting your African violets, it is important to have good soil. If you are going to mix your own African violet potting mix, than you should mix one third of potting soil, one third of peat moss and one third of perlite or vermiculite. Some people also add sand, which is good for drainage and provides air around roots, but sand doesn't retain water or nutrients well. If you are going to use used soil or soil from garden, sterilize it in the oven - at around 80-85°C (180-185°F) for some 30-40 minutes. Remember that melting point of expanded polystyrene is around 120°C (250°F) and under no circumstances you should reach or go above that temperature when sterilizing potting soil that has perlite in it.
You can buy special African violet soil in small bags at garden centers and some superstores. This type of soil is optimized for African violets and in most circumstances, it is sterilized. If you are buying African violet soil, buy sterilized one, and plant your African violets in new pots (ceramic, plastic) or use old pots, but wash them thoroughly with, for example, diluted bleach solution and after that with plenty of soap and warm water.
Note: when buying African violets potting mix, some bags can have gnats and other pests inside, even if the potting soil was sterilized during manufacturing process. If you notice any pests in your freshly opened bag of potting soil, either throw it away (after being refunded) or try to sterilize the soil in the oven - be careful, some manufacturers add ingredients that don't react the best way on higher temperatures. Long story short, if you see pests in just opened bag of soil, don't use it.
Also some manufacturers add small gel bag or ball inside the potting soil to keep moisture and other soil parameters within claimed range - if you have children or pets, keep them away from these gel bags/balls.
Recommended African Violet Potting Mix
It is hard to pinpoint 'the best' potting mix for African violet plants. Growing healthy and blooming African violets depends on many things, with potting mix being just one them.
However, choosing proper one can help significantly.
Long story short - growing medium must slightly acidic, it must retain moisture and minerals well, must be well aerated and must be pests free.
Buying certified growing medium for African Violets and other indoor flowering plants is sometimes the best way to go. Such growing medium can be bought in garden centers and online shops.