I actually have this problem when I grow my lettuce outside as a winter crop. I've been following a suggestion that I saw a few years ago on a cooking show. I crisp mine up by soaking it in the sink (or in a bowl) of icy cold water and white vinegar. It probably only takes 1/4 to 1/3 cup per gallon of water, but the vinegar really helps the lettuce crisp up.

Tell me about how you grow your lettuces. I grow the same varieties you do and I'm getting mixed results. Do you scatter a few seeds together in the same cube of rockwool, or do only use one seed per cube?

Sorry to take so long to reply.

I'll try your approach; it makes sense to me. And if I add vinegar while soaking the lettuce, maybe I won't need it for the salad?

My raft/floating system can only handle about 24 plants. When things are going right, I will be harvesting from all 24, but half of them are about three weeks behind. When the new seedlings are big enough to move to the raft, I remove the oldest batch, and then transplant new batch.

Re. planting seeds, I briefly soak 1" rock wool cubes and then add two seeds to the hole in each cube, put them in tray with a 1/4" of water in tray, and then I put tray in a relatively dark and cool place. The seedlings are visible in four or five days. In most cases, both seeds germinate.

My problem, that maybe you can help me with, is leggyness. I have read that the problem is due to lack of light, which might make sense in the winter. Anyway, as soon as seedlings show themselves, I have been exposing them to about 18 hours of light--close up. I can see no difference. The good news is that after they droop a few days, the stalks seems to beef up. However some of plants will still be drooping when I transplant them, but eventually they come out of it.

Thanks for your suggestion.

Denny

When you say the lettuce goes limp it sounds like you're talking about the harvested leaves, not the plants the leaves came from. Is that correct?

Because if the plants go limp that's not a great sign but if they perk back up that's alright.

If it's the harvested leaves the simple fix is to soak them in cold water. I don't use vinegar and it works fine for me that way. Fold up a paper towel in a ziplock bag along side your lettuce if you want to store it, and get as much air out of the bag as you can without crushing the leaves. That'll keep it crisper longer. You can also bring them back after storage by soaking in water again.

hydroponica,

Yes, I'm talking about harvested leaves. Thanks for your insight.

Are you growing lettuce hydroponically? If so, what method are you using?

Denny

I've been growing it for about a year indoors using DWC. I added a link below to my blog, if you go back through it you can see what I've been up to. I just use a basic DWC and it works great.

I'm planning to grow my next crops in smaller modular containers so that I can grow a lot more plants and harvest younger leaves more frequently. Still DWC but with a twist.

Here is a link that might be useful: My blog