AV Decline - Oyama Pots
I had a couple of African Violets that I placed in an eastern windowsill. I purchased them last summer and they looked fantastic and were blooming beautifully for quite a while. At some point I purchased Oyama pots. A couple of months after replanting in Oyama (mixing 1 part vermiculite, 1 part perlite, 1 part AV soil (all standard Home Depot grade)) following the Oyama instructions, they started to slowly decline. They continue to put out healthy leaves in the center, but the outside leaves kept getting black and rotting. There has been no flowering in months. Now some of the plants are getting big spots on the leaves, although they continue to put out new leaves from the center.
I also noticed this decline as it got colder outside. I wonder if they fact they were sitting right next to the window was too cold for them? I live in S. Louisiana so it doesn't get very cold, but I don't really run the heat very often either.
I also noticed that the soil in the Oyamas was staying pretty wet. So I went and purchased a good quality 1-1-1 soilless mix from Amazon. It recently was delivered and its seems great. Nice big fluffy chunks of verm and perl. So I go to replant in the Oyamas with the new soil and I am noticing the water is draining VERY slowly because the perlite is clogging the drainage holes. I did an experiment and filled the Oyama with just the soilless mix and it drained better that way then the perlite alone did. Do I need to buy coarse or horticultural grade perlite to put in the bottom of the Oyama planters? It seems like my problem was that my AVs were staying too wet because the perlite was clogging the drain holes? The Oyama instructions don't mention needing to purchase any special type of perlite.