Thursday, November 06, 2008

Growing lettuce in FLA

From a post over on the Florida Forum of GardenWeb... my thoughts on salad greens in FLA:
i direct-sowed a bunch of lettuce in september but nothing came up (but the brassicas all came up--broc, collards, rocket). christine (happly_fl_gardener) probably correctly diagnosed the problem as soil fungus, and the small seeds couldn't germinate. (maybe dusting them with fungicide or soaking them in a bit of weak need might have helped.) in the past, i've always direct-sowed my lettuce, but typically i don't plant it until mid-november or later.

at the beginning of october i sowed a bunch of red sails lettuce (from tony--thanks!) in a large windowbox in a mostly-soiless mix, and they all germinated. i've also got a bunch of jericho lettuce going in windowboxes...

anyway, long story short, i learned some things: soil's just to microbiologically active when temps are above, say, 80 here in florida. little seeds (like carrots, parsley, lettuce) don't germinate because they rot or are rendered otherwise sterile. if you want to start lettuce early, i think a soil-less or nearly so mix is necessary. if you want to direct sow, then wait until things cool down--evening temps below 60.

5 comments:

mary said...

Interesting. I sowed lettuce in September in a soiless mix and am now harvesting heads every day. I also planted lettuce (mesclum, Ruben's red romaine, and Jericho) in mid-October in a raised bed w/ storebought top soil in it. All of it has sprouted. I seem to recall direct sowing arugula, it all sprouted. Maybe arugula is more disease resistant.

Anonymous said...

I direct sowed arugula in 'organic potting mix' in early october. It came up but most of it seems to be stuck at the size they were 3 weeks ago. No idea what went wrong...

emily said...

I've been covering my seeds with burlap until they sprout, that's really improved germination.

Anonymous said...

Wow. Sorry about your luck. I am in Orlando and have directly sowed many types of salad greens and they have all been coming up and doing well, even in 80 degree temps. New Zealand spinach, Oak leaf lettuce, Red Flame lettuce, a generic lettuce mix, Bok Choy, Collards, Swiss Chard... Pole beans are growing crazy, a few cabbages, Better Boy tomatoes and 100 cherry tomatoes, Also a couple mild peppers and English Peas.

Mark said...

Some types of lettuce exhibit what's referred to as thermal dormancy and won't germinate very well, or at all, at soil temps above 75 degrees. The Bibb types do much better at warmer soil temps, followed by the Cos or Romaine type and then the leaf varieties which generally need the lower soil temps. Another thing to be carefull with is the sowing depth. The seed should be covered, but it also needs light to germinate, so plant at a depth of 1/8 -1/4 inch. I sow into 50-cell trays and transplant to the garden after 3-4 weeks. Seeding into trays gives you much more control over planting depth, they're esier to thin to single plants and you can germ the more heat sensitive varieties in the house or a shaded area.