Is there a way to standardize soil block size for all seed sizes?

Ed Bronner

Soil blocks are starting to interest me for starting my seedlings. The biggest issue is that different seedlings have different space requirements. Small seeds like most herbs and cole crops can be started in small volume starters, while large seeds like squashes, beans, and tomatoes require more room.

My current methods waffle between a 1 1/2 inch seed germination tray and Poindexter's (?) modified cup system. Many of the seedlings are requiring potting up before they are ready for the garden.

The commercial soil block systems seem to require potting up; the 3/4 inch for germination, move into the 2 inch and then 4 inch as they grow. There is even saw a 5 cell 1 1/2 inch blocker.

Thoughts are leaning towards using 2 inch blocks for everything avoiding a rapid need to pot up and find more space.

Is anyone else just trying to standardize or are there other considerations (germination rates)? Is there a guide to how much starter volume is need for the different seed types and how long they can grow before transplanting?

Thank you for any input.

gardneto76

I currently have the 2 inch block maker. Anything smaller than that seemed like it would just creat more work for me when blocking up to the next size. Even at that size the blocks occasionally crumble on me. For larger faster growing plants that Either don’t transplant well, or I feel to lazy when planting will go into larger plastic pots. I do consider germination rate and growth rate when planting my seeds.