Planting Lettuce from seed in a greenhouse
Printer-friendly versionI planted Brocclli and Lettuce at the same time and the lettuce did not come up, any tips.
Agree with zacman, give your seeds the right amount of time. If after an appropriate amount of time your seeds still have not shown then it's probably time to analyze the situation.
Most lettuce cultivars should come up in 6 to 10 days at 65-70 degrees. Most also need light to germinate properly. If you have the seed trays too hot, or the seed to deep that might explain the lack of germination. If you cover the seed at all it should be with a very light coat or better yet with a small covering of vermiculite. That will keep the seed moist but still let some light get to the seed.
Right on Drew. I developed this procedure from various internet sources when I first started sowing lettuce: Sow the seed thinly, and very very shallow in a 20-row seed tray, then put it in the house (70°± day and night) under a 24" two-bulb fluorescent fixture hung about 4" above the seed tray, keeping the lights on 15 hours a day. The seed sprouts in 3-5 days, and using Johnny's seeds, I estimate I've consistently seen 90% germination across several varieties of leaf lettuce. You also have to keep the seed mix consistently damp during germination. A couple of days after the seeds sprout, I move the seed tray to the greenhouse where the temp is kept at 58°, unless the sun is out and warms the greenhouse higher. When it has its first true leaves, I transplant lettuce to 38-cell trays until it is warm enough to put the trays outside (consistently 40°plus at night). This procedure is a lot more work than just sowing seed in the garden after it warms up, but for the hobbyist, you can get some trophy lettuce by going this route
Sorry, I meant right on psiler. Also, the 58° greenhouse temp is not a magic number for lettuce; I keep the greenhouse at this temp for tomatoes.
I am curious what kind of tomatoes (i.e., Cabernet, Early Girl, etc.) you grow that will make fruit at 58 degrees?
Thanks for the advice, I live in eastern Va. the nights are still cold.( 25-40 ) I did put them at the same depth as the brocclli, this may have been one mistake of many. I plan to replant this weekend, the old ones would have been in for 12 days. I have them on a heat mat with out a therm., and a self made dome over them to keep heat in.
allen, the lettuce seeds might have been too hot. I'm on a laptop and can't access my lettuce info, but if I remember correctly, a soil temp much above 80 really slows down germination, and above 85 or 90 virtually stops germination.
Great advice everyone! Allen, if you're soil is too warm certainly consider at least a thermometer or, even better, a t-stat for your prop mat.
I took the advice and the second time around was a charm. 300 Brocclli and lettuce later I am starting 150 tomato and pepper plants. Thanks from Va. I also just finished a project at the local school of a raised bed for the kids ( k-5 ) to use my donated plants and plant there own garden. My local steelworks local helped with the sponsership.
There could be many reasons. You do not say when you planted the seeds. Broccoli will come up sooner than lettuce - i.e., can come up from 5-8 days or so, while lettuce may not show for two weeks.