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. Which soil mix will you choose, depends on many things, but some of recommended ones that can be purchased online are given in the following list.
This is 1-1-1 equal blend of 100% Canadian Peat Moss, A3 Course graded Vermiculite and Course graded Perlite. It has no fertilizers added. Mixture is very even and of uniform size - very light and airy.
Espoma AV4 4-Quart Organic African Violet Potting Mix
This is all natural potting mix for African violets and other houseplants. It is formulated to help retain moisture and to aerate soil and promote root growth. Good potting mix, but if you have strong blooming plants, after 4-5 weeks of repotting, consider adding some fertilizer to the pots.
24 Cups of Organic Worm Castings for Your Garden and House Plants by VermipostPro
Organic worm castings are something in between of organic fertilizers and rich potting soils. This mix should be added to 'old' potting soil to improve it's quality in numerous ways - it is very hard to over-fertilize plants and cause root burns, it promotes root health and prevent roots to rot, it feeds plants for longer period of time (2-3 months), it is great for number of indoor and outdoor plants.
Since worm castings reduce the acid-forming carbon in the soil and increase the nitrogen levels in the soil, if you notice any problems with African violets not blooming, consider adding some phosphorous - it is vary rare, but it is good to know :o)
Miracle-Gro 0044607-323 African Violet Potting Mix
This is specially formulated African violet peat moss and perlite potting soil mix with a slightly acidic pH. It improves existing soil and can be used as new soil. This potting mix is enriched with Miracle-Gro Plant Food that feeds plants up to 3 months.
Note: Some people claim to have problems with pests using this soil. Well, commercial bagged potting soil should be sterilized and free of pests - when potting any plant, if you notice any pest in the soil, don't use it, throw it away. Better safe than sorry ....