African Violets in Gritty Mix or 5:1:1
I mentioned this in one of the soil threads, but have more questions, so wanted to make it a dedicated thread.
I am convinced that many of the problems that many growers have with AVs is because of the very wet peat based soil we all use to grow them. I filled three, 3 oz Solo cups (often used to start leaves) each with gritty mix, 5:1:1, and a typical AV mix of 1:1:1 peat, vermiculite and perlite.
I added 15ml of water to each and mixed well. Then, I added 25ml more water to each. I had holes punched in the bottom and I let them drain.
The gritty mix drained 11 ml, the 5:1:1 drained 10 ml, and the 1:1:1 drained no water.
I believe that most of us who get good results have learned how to manage this slow soil mix, but that it's not optimal. But, I'm relatively new to this and I don't know much about the other components and how they might affect AV culture. Some of my fellow AV growers think I'm crazy to entertain that the 1:1:1 isn't the best mix. Mostly, I think they believe that the alternatives will cause problems.
So, I need some help and knowledge from all of you who know more about these components than I.
First, the bark. The criticism I've heard is that it's too acid and that it will decompose quickly, taking the pH too low, causing problems with ferts. I do not think the bark will decompose that quickly, but I don't know what happens when bark decomposes. Does it create a more acid environment? From my research, AVs can take a pH from about 5.5 to about 7. In that range, many people say that there are better sweet spots - say, 6.5-7 vs 5.5-6 - so there isn't agreement, but I think we can safely say they will grow in anything in that range.
As the pH drops, there are problems with availability of some ferts, if I am remembering what I've read here correctly. When I measured the pH of the soil solution here at my home, the gritty mix was about 6.5 and the 5:1:1 was 5.6. This was without anything added, such as lime.
Now, AVs should be repotted at least annually, and some as often as 6 months, so if you repot that frequently, will the decomposition of the bark cause problems?
Next is the question of fertilizer. Everything I'm reading points to AVs being no different from any other plant in that a 3:1:2 ratio is a good ratio. Given that preferred pH of the plant and the both the gritty and the 5:1:1 mix, would any changes need to be made in the fert?
My last question is about watering. Many AV growers do not top water. They use wicks to bring water in (not as a way to encourage drainage). Or they use capillary mats. Either way, they are bottom watering.
I seem to recall Just-a-Guy remarking that he needed to alter the 5:1:1 to wick to the top, but this was in a taller container. Most AVs are in shallow depth containers. Can anyone think of anything that might need to be changed in order to wick or capillary mat water either of these soil mixes?
Also, because these are wicking upward, is there anything special that needs to happen to avoid salt accumulation? They are not getting flushed each time they are watered. Will how often they should be flushed vary based on the mix or should that not matter?
I have about 16 leaves rooted and in the process of growing baby plants. I plan on taking plants of the same variety, from the same leaf, and growing them in each of the three mixes to compare. I also will do another experiment with fertilizer, comparing a traditional AV fert, but haven't figured out what soil mix to use. I don't want too many variables....Oops. I just looked at my AV fert. I bought a 20-5-10. It's a bit more N than a 3:1:2 ratio, but is darn close. Guess I won't be testing that unless I buy one of the other ferts that are sold for AVs.