Organic container mix

bower · May 3, 2021

IIRC the organic certification here required container mix to be at least 50% compost. I always use about 1/3 fresh compost in reusing old mix.

I have often used a bit of dried/pelleted chicken manure product as a general amendment, and I found it boosted production. I dig some lime in as well.

I use about 6 oz scoop of bone meal mixed into the planting hole for 5 gallon containers for N and P. Maybe 8 oz for larger fruited in larger containers. That is enough P for them to set a nice crop of fruit.

I use kelp meal (dried crushed kelp) as my K source. A scoop or two for 5 gal. If I had lots I sometimes use more.

The coarsely crushed kelp may actually help with moisture retention in the containers, but loses that value over the season as it is completely consumed.

Any time I wanted to keep the plants going over an extended season, I had to use liquid fish ferts after the main crop starts to ripen, because although the plants loved a bit more of that chicken manure, scratching it into the surface always made them grow a mat of roots right there on top.

I don't know if you're near a beach, but it is worth a run if you have a truck to fill up. Kelp is really easy to crush if you get it to the right dryness. I used to chop it up wet and what a job that was. Now I just pick a dry day, spread it out in the sun and wait until it is so crisp it crumbles in my hand. It picks up humidity from the air, so damp weather is no good for that, it will stay in large rubbery pieces no matter how you work it. Tomatoes that touch root against a large clammy piece of kelp in the mix will probably complain at transplant time (leaf gestures), but they do get over it in a day or two. My friend bought kelp meal by the sack for the farm, and that was a nicer product, finer ground, if you can get it. Expensive for something we think of as "free" but maybe not if you count the labor. Then again you may have a mill for that which would speed things up, if so it would be a nice product to offer your clients.

May 3, 2021	#5
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,794	IIRC the organic certification here required container mix to be at least 50% compost. I always use about 1/3 fresh compost in reusing old mix. I have often used a bit of dried/pelleted chicken manure product as a general amendment, and I found it boosted production. I dig some lime in as well. I use about 6 oz scoop of bone meal mixed into the planting hole for 5 gallon containers for N and P. Maybe 8 oz for larger fruited in larger containers. That is enough P for them to set a nice crop of fruit. I use kelp meal (dried crushed kelp) as my K source. A scoop or two for 5 gal. If I had lots I sometimes use more. The coarsely crushed kelp may actually help with moisture retention in the containers, but loses that value over the season as it is completely consumed. Any time I wanted to keep the plants going over an extended season, I had to use liquid fish ferts after the main crop starts to ripen, because although the plants loved a bit more of that chicken manure, scratching it into the surface always made them grow a mat of roots right there on top. I don't know if you're near a beach, but it is worth a run if you have a truck to fill up. Kelp is really easy to crush if you get it to the right dryness. I used to chop it up wet and what a job that was. Now I just pick a dry day, spread it out in the sun and wait until it is so crisp it crumbles in my hand. It picks up humidity from the air, so damp weather is no good for that, it will stay in large rubbery pieces no matter how you work it. Tomatoes that touch root against a large clammy piece of kelp in the mix will probably complain at transplant time (leaf gestures), but they do get over it in a day or two. My friend bought kelp meal by the sack for the farm, and that was a nicer product, finer ground, if you can get it. Expensive for something we think of as "free" but maybe not if you count the labor. Then again you may have a mill for that which would speed things up, if so it would be a nice product to offer your clients.