Raised Garden bed compost question

Asked June 21, 2020, 3:49 PM EDT

I started a raised garden bed in my yard. Started with putting down cardboard and added about 8 inches of the free leaf mulch from Tacoma Park city. I mixed some perlite and some bagged garden soil in the bed. Maybe 75% leaf mulch to 25% perlite/soil mix. All garden plants that I direct seeded or transplanted are stunted and pale green (not deep greed, especially snap peas), no big leaves, etc. I'm thinking maybe the leaf mulch wasn't fully composted. Is the bagged Leafgo a fully cured compost to add directly to garden? If I start again for a july - first frost veggie garden, would you recommend just starting adding on top of the leaf mulch beds or mix other materials in? Could add a mix of peat moss and leafgro, maybe add in some of my own clay dominated garden soil? I'm trying to avoid buying 20 bags of garden soil from home depot.

Montgomery County Maryland

1 Response

Hi- you are probably correct that the leaf mulch was more like leaf fragments than compost. Microbes that digest organic matter have been using the available nitrogen to do their jobs, leaving your plants short of nutrients.

A good approach at this point would be to add a 50:50 mixture of bagged Leafgro (yes, it is fully composted and ready to add to the garden) and your clayey garden soil (if it's possible to dig up the top 2-4 inches from around the raised bed or some other spot). The amount to add depends on the depth of your bed, budget, and ease of using available garden soil. A 4-6 inch addition would not be excessive. Use a garden fork to gently incorporate the Leafgro/garden soil mix with the existing contents. You can then begin planting- don't forget to fertilize.
https://extension.umd.edu/hgic/topics/soil-fill-raised-beds
https://marylandgrows.umd.edu/2020/05/15/vegetable-plants-to-gardener-feed-me-and-ill-feed-you/
Jon