If it takes more than sixteen seeds to make up an inch, you're dealing with really small seeds. Seeds from the cole family (kale, cabbage, tat soi, broccoli, etc.) are notorious for this. The packet says it has over a hundred, but you struggle to end up with 20 viable plants. Seed sowers don't work, you can't pick up just one with your fingers, and often only tweezers are the only way to separate the resulting crowd of seedlings.
... and often tweezers are the only way to pick up one seed at a time to plant it or put it on a homemade seed tape! This is the only way I've found to successfully plant really small seeds.
Step 1: What You Need
This is what you need to do this:
- really small seeds, such a kale, tat soi, or cabbage
- tweezers: a longish set made from thin stainless steel work the best
- a white saucer to hold the seeds (and you can see them against the white!)
- a place to put the seeds (seedling tray, seed tape, a cold frame)
I took these picture from a session of planting tat soi in a cold frame. Additional things I found useful:
- a dibble for marking out sectors to aid spacing and help me keep track of what I planted
- a stool for sitting on so I could be close to the planting surface
Step 2: Set Up for Outdoors Planting
I smoothed the planting surface down, crumbling clods, and removing things much larger than the seeds.
This space is roughly a 21 inch square. I divided it in quarters by making lines with the dibble.
The best thing I found for making the half inch depressions required for the seed was that handy implement, a finger.
You can use this set up for planting a seedling flat as well.
Step 3: Lay Seed and Cover
Now gather your patience and set your saucer of seed by your work area.
Use the tweezers to pick up a seed and lay it in a depression. Work across a row and down the rows. You can see from the photo that the flattish depression from your finger prevents the seed from slipping into the soil -- it's always easy to see what's still empty.
Once a quarter is filled, smooth the soil over the seed and lightly tamp it down. Now it's clear that that quarter has been done.
Think good thoughts about your seeds, conscientiously water them (but don't overwater -- just enough to maintain damp!), and enjoy seedlings that will be easy to transplant and thin (if you have to!).