Scott, a few days of 90 degree heat and lettuce gets bitter, then it bolts, or goes to seed. I don't believe local farmers grow much lettuce accept for some who grow for farmers markets.

The last 2 years I've grown 'jericho,' a romaine type with excellnt taste. Last year I grew it into Aug without a problem. Simpson elite also does well in the heat and is a very tasty variety.

I've just started another batch of lettuce seeds indoors to take me into Sept- Oct. It's too hot outside for good germination.

You can get jericho through the site below for the price of seeds and a $2 S&H fee. They ship promptly too....or have for me.

Here is a link that might be useful: Kitchen Garden Seeds

When do you plant and have you tried planting it earlier? Lettuce prefers the cooler soil and air temps of very early spring and will even tolerate a light frost. We plant it in mid to late February here - buttercrunch, Simpson, and romaine. As peggy said, once any heat develops, bitter lettuce quickly follows.

Dave

I agree....hot weather equals bitter lettuce.

This year I'm growing 'Jericho' and so far pretty darn tasty! If I can get them thru August like peggy I'll be estatic :D

Vera

Vera, I think you'll be very pleased with jericho. I like it better than many other romaines I've grown. I grew over 12 types of lettuce this spring and only simpson and jericho have bolted. I't been pretty awful hot here though we did have some relief the last week.

Good luck!

Try Butterhead lettuce it stays sweet longer and resists bolting for longer than most other types.

Yep. Hot weather, full sun = bitter.

I harvested all of mine a week ago and don't plan to try to grow anymore until the end of August. Minnesota isn't exactly a sweltering hot kind of place in the summer, but I haven't had edible lettuce anytime but May and September. This year we had a mild start to June so it lasted a little bit longer than usual, but that's not to be depended on.

I was growing butterhead too, so maybe that helped. Previous years I did black seeded susan and it turns bitter FAST.

read here

http://forums2.gardenweb.com/forums/load/cornucop/msg061553588832.html?39

Included are links to a big test.

Nevada and Jericho seem good. Nevada is better than Jericho apparently. Jericho is a big romaine. Nevada is a Batavia lettuce.

Also try other greens for your salad in the heat of the summer. we discuss that also.

Here is a link that might be useful: Lettuce

Butterhead and Bibb types seem to keep better. I have some growing in the shade of a tall branching oleander tree and also toss some shade over the top late in the day when the sun hits it.

We haven't been in the high-80/90's yet, however, so maybe another few weeks will tell the tale.

Bejay

We get lots of threads about bitter lettuce on this forum, here is a link to an older one

Here is a link that might be useful: Thread: Bitter Lettuce In The Fall

The thread which reviews several varieties of red lettuce has 3-4 links to trials which evaluate the level of bitterness among different lettuce cultivars.

Here is a link that might be useful: Bitterness Links in Red Lettuce Thread

In the baby leaf lettuce thread, I review several cultivars for bitterness.

Here is a link that might be useful: Thread: Baby Leaf Lettuce

Thanks for everyones help. I will try the varieties suggested and I guess live with store bought lettuce for now. Next season I'm going to try to figure out how to give a portion of the garden access to full sun but lower the temp somewhat. Any ideas?

I have encountered the bitter lettuce wall as well. I had many types growing and had plenty of excellent lettuce early, but it has gotten exceedingly hot here of late and it has just about all bolted. Several exceptions are "Concept" a Batavian type and "Red Sail" a red leaf. I have sense ordered some varities that I have seen recommended here. They are:
Winter Density
Tropicana
Jericho*
Nevada*
Anuenue
New Red Fire*
and Mizuna*
Most of these (with the *) have come highly recommended by "Korey" the lettuce king.
I have also rigged up an old canopy frame and old sheets into a shade area from the afternoon sun. I hope that it works as I really love my summer salads.

I live in Eldersburg, MD (15 minutes down the road from you) and I planted romaine lettuce that was wonderful for about 4 days. The problem was that we had only 1-2 weeks between frost and 90 degrees. From what I've seen and read you just can't grow lettuce like that. I plan to plant 8 or 9 different types of lettuce in September (see the types recommended in the other posts) and see what I can get before it frosts and kills them. I don't know how successful shading will be, we don't have any of that in our yard. The other suggestion that I have seen is to grow them in large pots that can be started very early (March) indoors and then taken outside when the temps are right...this way when the temps get too high, you can move them to shade or back inside under a grow light. We don't have space in the house for all of that, so I will try a fall harvest, but may stick to store bought.

I did not read the entire post so forgive me if this has been mentioned already.

What you might try if you have been taking the lettuce from the garden to the table is putting it in the refrigerator for a while before eating. Start overnight 1st that will surely make a difference, then try working back to a couple hours to suit your taste.

Hope That Helps (HTH),
Gumby_CT

I live just SW of Frederick and I've grown lettuce out in temps well below freezing in the spring and fall. In fact, one year I planted it out in Feb in a cold frame made of straw bales and storm windows. I was harvesting lettuce before April 1.

That year I learned that if you start lettuce seeds in Dec, even under lights...they grow very, very slowly:) Which is why I took a chance and planted them as small transplants in Feb. Temps went done in the low 20's and the lettuce would freeze solid. Then it would just melt away when the sun rose. No slugs or flea beetles to content with, lol!

I grew 22 types of lettuce this spring and only the jericho hasn't bolted. And we've had 95 degree days consistently for days on end and jericho is growing in full sun.

I harvested my Tom Thumb lettuce last night. I had grown it under lights, and it was just starting to get a stem (hence my decision to harvest it). I found the leaves to be more bitter than I remember, and then I discovered that aphids had gotten into it. But once I rinsed off the aphids and drowned the lettuce in raspberry vinagrette, it wasn't half bad.

I just bought some seeds for the heat resistant and summer lettuce that's supposed to grow in summer sun and heat. Anyone tried that?

Wash, dry, and store the leaves in the refrigerator for a day or two. Much of the bitterness will disappear.

if you wash before the refrig make sure it is dry or it will turn to mush