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Why are my lettuce leaves curling?

Posted by chele519 5 (My Page) on
Mon, Mar 28, 11 at 19:39

I have a few different varieties of lettuce planted but only some of the leaves seem to be curling up. These were just planted 6 days ago and sprouted 4 days ago. The Bibb lettuce isn't curling at all so I don't know if it is normal for looseleaf varieties. I don't know exactly what is growing in these trays because it is a mixed package, they are supposed to be looseleaf though. I read that lettuce roots are shallow and to keep it moist but I don't know if I overwatered, the temps in the basement are ranging from 50-60 but if it were due to temps being too cool, I would think the others would be having issues too. The Bibb lettuce was planted 1 week before the looseleaf. Can anyone tell me what's going on?




Follow-Up Postings:

RE: Why are my lettuce leaves curling?

Are the Bibbs the bottom lot? If so the variety is not the only difference - they are also in net pots rather than cells, so they have different growing conditions. It looks as if the compost in the cells is cracking away from the sides of the containers. This implies it is too dry. I'd put the cells into a shallow container of water and leave until the surface of the compost looks wet. Then drain thoroughly. The lettuce basically looks fine, just a little thirsty. 50 - 60 is not too cool for lettuce.

RE: Why are my lettuce leaves curling?

Thanks, I did water them Sunday afternoon and I took these Monday afternoon so I was afraid to water too much. How frequently do seedlings normally need to be watered? I'm new to doing this inside so I have a lot to learn. I'll water them now and see how they do.

yes the Bibbs are the bottom picture but I also have some in 6 packs and those aren't curling either.

RE: Why are my lettuce leaves curling?

Another question regarding temps of seedlings, I know lettuce likes it cool but peppers and tomatoes like it warmer. My peppers just sprouted and I will be starting tomatoes in a couple weeks. I am growing everything in my basement where the overnight temps now are staying at 50 without the heat on.

How do you manage growing vegetables with different temperature requirements in the same room? Since the peppers just sprouted a few days ago and not all of them have germinated yet, I left them on the heating mat since it is so cool in the basement. Once more have germinated I was going to remove them from the heat, since the room is only 50-60, I dont' think the mat will fry them.

Should they come off the mat now or is it a good idea to leave them on? I am picking up one of those wire shelving units at Sam's later this week so would it be best to put some material around the peppers to keep them warmer while leaving the lettuce open since they prefer cool?

RE: Why are my lettuce leaves curling?

I think they are watered perfectly. peat will pull away from the sides. It is just the nature of the beast. I dont think there is any reason for concern the lettuce looks great!

Watering should only be done when teh top 2/3 is dry. It is so much harder to fix overwatered then underwatered. if you check them everyday, it should be easy to monitor them.

In regards to temps. I grow all my veggies at the same temp, around 60-70*. You could use the top shelf of your rack you are getting for peppers and your tomatoes, becuase the heat from your lights will rise and then keep your lettuce on the bottom.

It is not too big of a deal as long as they stay in the 50-75* range, they will be fine, well, they have alwyas been fine for me : )


RE: Why are my lettuce leaves curling?

Growing plants with different temp requirements isn't really that hard. You just need to understand microclimates, and what different temperatures are going to do to your plants.

Yes, peppers and tomatoes are "warm-loving" plants. BUT, that is what they need to set fruit or to germinate. Once they are germinated, growing them in cooler conditions 55-65 degrees will not do them any harm, in fact, it is probably a benefit. They will grow slowly, so they will be stout and strong. The distance between each set of leaves will be very small. That is actually very beneficial. Also, by growing them in a cooler environment, they will have a much easier time adapting to outside conditions (specifically, night time) when you harden them off and plant them outside. The ground will be significantly cooler than the air when you plant them out, and if the difference in temperature for the roots is that great there will be a greater amount of transplant shock. Keeping it all cooler while growing under lights is a good idea. Just be sure that the temp doesn't drop below 45 degrees.

Another good plan, even in a cool environment, is to blow a fan on them for several hours per day to give them a "wind" condition. This will also help the plants to grow stronger stems and prevent "legginess". Leggy plants are ones with thin, weak stems that easily fall over and large distances between branches.

RE: Why are my lettuce leaves curling?

Thanks for the info, too late on watering them though, I did it this morning before work after seeing the first reply. How do you tell when the top 2/3 is dry? THe containers are a little small to stick a finger down in there, I'm afraid I'll disturb roots or something. The top layer did feel dry, some of them soaked it up faster than others but it probably wasn't dry that far down. I think some of the peat on the sides is from when I first planted them, I filled the trays and then once I watered, it mostly sank down but some was still around the edges.

I have been blowing a fan on them each evening for a couple hours but when I saw them curled up like that I turned it off thinking it was too strong even on low. I've also been turning on the heat when it drops down to 50 to bring it up to 55-60. Should I stop doing that?

I will use your suggestion for the rack. I didn't think the lights would make a difference. They aren't hot to the touch and I put the thermometer in the basement right next to a tray under the lights and it didn't seem any different than 6 ft away.

I know the Bibb in the pellets doesn't quite have any true leaves yet, they are just starting to come up, but, should I thin those out now? They seem a little crowded to me. What about if 2 seedlings came up right next to each other? Do you snip one off or wait until they are bigger? My peppers just germinated 4 days ago but in 2 of the cells, seeds sprouted right next to another one.
Thanks for all the help.

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