My best method to date involves a bit of combining of methods.
- I use an unfertilized seeding soil well moistened for all seeds but I use a big enough container to put good lightly fertilized potting soil in the wells first and dampen well. I then put in about 1/2-3/4" of the well moistened seed soil and pat it down.
- For littler seeds I scratch the surface and drop on 1-2 seeds per sector. For larger ones I add enough seeding soil to cover the seed the required amount--the depth of 1 seed.
- I water the whole tray when done seeding and set on a tray to catch the moisture and cover with bubble wrap or in a plastic bag or under a clear dome and set in a warm enough place to germinate the seed.
- I watch the flats and wait for the seed to pop out a leaf. I do not water from the top as a general rule. Soaking from the bottom works better and makes for stronger longer roots.
- I generally use a misting of fish oil in water on the seedlings weekly as they grow and most of them get blown on to strengthen their stems. You can use a small fan as well. You can also use weak compost tea.
- Once they are up and have at least a set of leaves I move them to the greenhouse most of the year. It is lightly shaded part of the day and gives them better air circulation but does increase their water consumption.
- I try to get plants up to several leaves before they go to the garden. I lose fewer this way and have room to grow them and up-pot them when needed.
Growing herbs and tomatoes from rooting a cutting takes a bit of planing and has been hit and miss for me this year. Most herbs do well if you pinch off a length of a growing tip and drop the stem in either wet sand or just water and wait for roots to appear. Once they have roots move to wet potting soil and decrease watering to bottom only. Tomatoes can be rooted by breaking off suckers from the plant and dropping them into a cup of water. I take a piece about 6" long and strip off the leaves at the bottom if there are any. I use rainwater or purified water for this. In a couple of weeks the roots will be big enough to transplant into a pot then the garden. Sweet potatoes can be done this way as well.