The first thing is how old is the raised bed, if it was the first year then things should improve the second year with the addition of more compost. I added 4-5 inches to mine in the fall after the first year and the improvement was dramatic. It will settle and fit within the bed during the growing season. On the lettuce I would say watering. Iceberg takes a lot of water an inch a week just don't cut it for me. An adult seems to need an inch of water every other day when I grow it in the square foot bed. I think any intensive bed is going to require constant consistent watering for any greens.

Curt

First off, Mel's Mix holds water very well. Both vermiculite and peat moss hold water as one of their primary functions. They also drain well, so that may be what you're seeing.

Never grew iceberg so can't say if it's simply water or a nutrient deficiency. If you used a diverse compost though, nutrients shouldn't be a problem. Good luck!

I finally found the PERFECT moisture holding mix!

I have 2 raised beds for veggies totaling 100 sq ft, one for pineapple and several for annuals...(I'm lucky, my hubby's a master mason, so I get hundreds of pavers that hold my plants like gangbusters!)

Back to water retention. Last year, I found something called Gro-Bric(s) that I would trade my kids for...okay, I don't have kids, but if I did, lol... These bricks are literally the size of a standard clay brick. I put one in a 5 gallon bucket, pour 2 quarts of warm water w/fish emulsion fertilizer over it.

In about 20 minutes, I flip the now monstrous brick (think of a marshmallow in a microwave), break up any chunks and pour another quart and a half of the fertilizer mixture over it again. This makes 2.5 gallons. Three of them make 2 cubic feet (this time, think giant peat moss bag). They're made from 100% ground coconut husk (coir), and hold 5x their weight in water.

I have not had to water my veggie garden except for twice since November, and have had steadily producing beds this whole time. They're like the jiffy peat pellets, only on a grand scale...and they're not peat, lol.

I've had no cracking on my tomatoes (Cherokee purple, Champion, Roma, Early Girl and Better Boy) or carrots (Danver). I use it with straight sand (Fl indigenous soil really) for my berries, use it for ALL of my cuttings, for transplanting my loquats (which used to shock badly, but not now) and as a mulch for my azaleas (I mix in sulfur and it gives a steady release).

The best part is...even if you don't wear garden gloves, this stuff won't make your hands dirty! It just brushes off!

I'm in LOVE with these things! The moisture retention is so good that without fail, straight seeded veggies are germinating within 5-7 days!!! I put in carrots on the 22'nd...today, (26th) at least a dozen are showing their pretty faces! Southern peas (field peas) like crowder, purple hull, blackeye, all came up within 5 days last season...I was stunned.

Never again will I try to find the "perfect" mixture for water retention. Best stuff in the world! I get mine from Spray-N-Grow... love their tomato cages too, they "give" in strong winds and I use them for not only tomatoes, but anything I can get to vine, including sugar baby watermelons. Last night, we had 80+ mile an hour gusts (tornado touched down east of us) and my sugar snaps did just fine on those cages. They bent and swayed, but are upright and sturdy today, as are the peas!

I'm sure it can be purchased elsewhere, however, that company has so many common sense gardening items that I just buy them by the case.

Lettuce: I don't grow Iceburg...don't like it. I grow loose leaf lettuces, so I can't help you there.

Sorry for the long post, but this stuff is AMAZING!
Hope it helps!
Deanna

deannac ~ Do you use the brics alone or do you mix them in with compost, vermiculite, etc?