Johnny's Selected Seeds has a nice overview article about the pros and cons of several different seed-starting methods. This post is mainly a review of that article.
I started the thread to invite people to share their favorite indoor seed-starting methods, resources, tips and gotchas. (*)
http://www.johnnyseeds.com/t-s...
- "traditional" 1020 trays and plug flats
- 20-row seed flats then potting up quickly
- biodegradable pots like "Cowpots"
- soil blocks - air pruning of roots! (with video)
(Johnny didn't mention starting seeds on
paper towels or coffee filters, in plastic bags or other humidity enclosures, as suggested by Dr. Deno. Then pot them up one or more times before transplanting outdoors. I use coffee filters cut to fit the bottoms of stacking, nestable glass bowls. I use up a lot of space, but it let's me inspect them all very easily.)
Johnny didn't even mention what I think of as the "traditional" way to start seeds indoors, namely broadcasting seed thinly over a
seed flat, then "pricking out" the seedlings and potting them up
as soon as any true leaves appear. Or at least before the roots get too tangled.
I started to like this seed-flat method when I realized that I could use the big inserts from an 1801 tray (18 cells, 3"x3") or 2401 tray (24 cells, 2"x3") as
mini-seed-flats to start 18 or 24 different varieties in one 1020 tray. Then, DUHH, it sank in that I could use a simple 4" square pot as a seed flat if I filled it shallowly.
I still get queasy when I untangle tiny naked baby roots, but they seem able to survive it.
I liked their suggestion for starting lettuce in 200-cell flats, but they start 2-4 seeds in each cell! Then they cut all but one.
They start tomatoes and peppers in 20-row flats, then pot up to rigid 50-cell square plug trays. I would have thought those were pretty small for tomato seedlings! Maybe I keep them in pots too long, but I've carried trays of tomato seedlings back indoors at night, for as many as tyhree weeks.
Johnny's uses a bleach substitute for sanitizing plastic trays ("Oxidate", with Hydrogen Peroxide and Peroxyacetic Acid) . I guess I should consider using peroxide instead of chlorine bleach. Actually, after I clean trays outdoors with a sprayer and scrubbing, I often run them through part of a dishwasher cycle.
(*)
I think of there being four main ways of starting seeds:
1. Direct sow in the final spot outdoors (maybe with floating row cover or polyfilm)
2. Sow outdoors in a cold frame / seed bed, then transplant
3. Sow outdoors in a jug, then transplant (winter-sowing)
- - 3.a - - classic potting-soil-WS with drain holes and vent holes to let air and a little rain in
- - 3.b - - Jonna-style WS with sealed containers and coarse vermiculite.
4. start indoors, (maybe pot up), then harden off then plant out
