Gardening with small children in an exercise in letting go of any tidy gardening habits you may have had in the past. When letting a toddler help you out, you are likely to get thick masses of seedlings growing together. Rather than fighting it and trying to grow things in straight lines, I find it easier to let them sow to to their hearts content and then do some damage control at the the thinning phase.
Radishes, beets, kale, chard, lettuce and greens are all good candidates for this method. The greens are edible, the seeds are plentiful, and the seedlings are delicious. It’s especially easy if you’re growing in a container.
We’ll do this a few days in a row once the seedlings reach a few inches in height. Going through your patch of sprouts pull or cut every second one. I then give them a quick rinse and let them stand in a jar of water. they’ll last quite a few days on a windowsill like this. Tonight we’ll have tiny red russian kale on our pizza along with a salad of radish and beet greens. Delicious! and the toddler will eat it right up while proclaiming “I grow the seeds!”.