I'd be very interested (after the fact) what 'soil' mixes others have used to fill permanent containers. After 2 years, I finally planted 3 large permanent containers alongside my driveway. (6 wheelbarrows full). I had expected to find the perfect container soil mix at a reputable soil company down the highway. What they recommended was 50% fish compost and 50% compost. Come again? I know it wouldn't take many years before that would decompose and that the 'soil' level in the containers would continually drop. Been there, done that. So, what I did, was buy a lawn dressing mix made up mainly of sand and compost (whatever that is). I added steer manure and very well composted bark mulch. Top dressed the containers with my own compost laced with red wiggler worms. I put about 4 inches of rotting fir bark on top of the drainage holes to help prevent too much mix from coming out. (Aesthetics only.) Hoping for the best but time will tell. Your comments would be much appreciated . . . it's not too late to start over with a better mix if necessary.
Some relevant points are: How large the containers are What you are planning to grow What proportion of the finished mix is organic material
How large the containers are: 24-inch diameter on top; height 17 inches. (H: ~42cm x D. 61cm) What you are planning to grow: I have planted a Nandina domestica 'Gulf Stream' in each of 3 pots. I know the pots are larger than they need to be at this point but I already had them and don't want to buy more, smaller ones. I chose the Heavenly Bamboo because it's good in sun, keeps a compact size, is fairly attractive and, most important, is not too appealing to deer. Also, the pots are near a tap so they'll be easy to water. What proportion of the finished mix is organic material: At least 50%, probably more. I noticed that the container mix the plants were growing in looked like shredded sawdust. What do you think?
