How to fertilize lettuce for large size

[jbclem]

The lettuce I grow never gets to the large size that I can buy in the market. I wonder what the organic lettuce growers are doing? Are they fertilizing constantly, or in high concentrations (of N), or is it more in the soil. My soil is sandy/silty, and it takes a lot of compost to get it anywhere near looking good and fertile. I'm growing in raised beds, and also in containers(the container mix is different, of course). But I'd like to get the raised bed lettuce Romaine and Prizehead growing to large sizes.

Any suggestions from the green thumbs out there?

John

[bower]

Hi John,
I've tried a couple of different ferts for lettuce in containers. Had some chicken pellet manure which I read somewhere was the best, but it didn't grow up the lettuce as big or fast as the bone-and-blood meal. That's what I'm using now, just mixed into the subsoil with a clean layer on top. The mix itself is mostly compost.
I think I often end up with smaller than average vegetables because of spacing. Even in my raised beds, it's just not rich enough and deep enough to supply that many plants with all the water and nutes they need. At my friend's organic farm, the soil is great, it's also deep, doesn't require fertilizer often other than compost, and the row spacing is generous. The plants get all they need and are really bumptious. I think it's all the root space that makes the difference too.

[Cole_Robbie]

I just bought a bag of fertilizer that claims to be made for leafy greens and lettuce. The npk is 18-2-17.

[Tormahto]

Would growing Cracoviensis solve your problem?

[bower]

I'm going to admit that I never had any luck with Parris Island Cos. We grew that a number of times and they got bitter before they got large iirc. I had better size with Coastal Pride Romaine. I think that's the bigger one I've grown. Sherwood is my favorite romaine for taste so far, but it's a small head by nature. Got Monte Carlo going at the moment which is nice and vigorous and seems more cold tolerant than most, as regards how fast it is coming on. The other romaine I've grown is Red Romaine. Gorgeous plant but very slow growing, it's a 70 day variety not fast and early, but they do get to a good size with lots of patience. Rouge d'Hiver is soft and not much of a rib, we mostly used it to cut and come again so not much to say about the heads.

[MissS]

I think that temperatures and full sun help quite a bit. I have planted lettuce for years and always have great results. Paris Island Cos is grown every year and grows just fine. I add a sprinkling of bone and blood meal just prior to planting and work it in as soon as the soil can be worked. Then plant seeds every two weeks for all my lettuce until the heat sets in and makes things bolt. Some years the lettuce season here is quite short other years I can get good crops all summer. The only lettuce I don't grow is Iceberg's.

[PNW_D]

I recall reading/hearing somewhere - perhaps Charles Dowding - the closer you plant the smaller the lettuce

[ddsack]

No one has mentioned the importance of lots of water. Sweet lettuce needs to grow fast, so along with a fert, it needs to be watered much more often than most crops if you don't want bitter lettuce. I have sandy soil in my raised lettuce bed, so unless we get rain or a stretch of cloudy weather, I often hand water my lettuce every day in the summer.

[Shule]

No one has mentioned the importance of lots of water. . . .

It seems like mulch should help a lot, too.

[Growing Coastal]

One observation I made last summer on the lettuce I grew in large pots.
I covered the pots with fine mesh netting to keep the sparrows off the lush lettuce. It did well with blood meal and other nutrients.
A lot of aphids developed on the lettuce leaves because the wasps and other predators could not get at the aphids. When I lifted the cover they came in and cleaned things up.
I would use something with larger holes that flying insects could get through. The lettuce sure thrived under the covering. Maybe the slight shade helped with our extraordinarily hot summer last year.

[jbclem]

I've been looking around for Coastal Pride Romaine, but all I've seen are Coastal Star Romaine, and that one only at two seed companies so far (Johnny's and HossTools). Bower, could you have mixed up the name or are there two versions of the Coastal Romaine in Canada?

As far as spacing goes, my plants are definitely close together. So I will try one plant in a five gallon container as a test. At the same time, the butterhead lettuce (Maule's Pennsylvania Butter) I'm growing, very close together, may not be huge, but are large enough to produce plenty of leaves for cutting, many more than the Super Red Romaine does.

Watering wise, I was trying to get that right...going back after the first watering had soaked in, and watering again and sometimes a third time. But we had a very good rainy December last year (10 inches) and it was notable how the lettuce picked up. So I might need to add some peat or some water holding substance to the raised bed soil to go along with my watering. My sandy/silty soil is not holding moisture for more than a few days.

[ddsack]

No one has mentioned the importance of lots of water. . . .

It seems like mulch should help a lot, too.

Mulch is great if you can use it. My lettuce bed gets dappled shade for part of the day and is a slug magnet. Mulch provides a perfect hiding place during the day for harboring the slugs which emerge towards evening to ravage the lettuce leaves, so I can't use it. I hand pick all I can find and bury them in a hole away from the garden -- I think I have slug zombies coming back up. I bought a box of slug pellets last season, but kept forgetting to put them out. I guess partly because I'm not sure how they work, and how toxic they are. My lettuce bed is in a woodsy area, so there are always new slugs moving in to replace the others.

[Tormahto]

No one has mentioned the importance of lots of water. . . .

It seems like mulch should help a lot, too.

Mulch is great if you can use it. My lettuce bed gets dappled shade for part of the day and is a slug magnet. Mulch provides a perfect hiding place during the day for harboring the slugs which emerge towards evening to ravage the lettuce leaves, so I can't use it. I hand pick all I can find and bury them in a hole away from the garden -- I think I have slug zombies coming back up. I bought a box of slug pellets last season, but kept forgetting to put them out. I guess partly because I'm not sure how they work, and how toxic they are. My lettuce bed is in a woodsy area, so there are always new slugs moving in to replace the others.

Collar and mulch. A band of fert under the mulch and outside the collar may be overkill, but then that's what you probably want.

[bower]

@jbclem you're right. I checked my seed box, it's Coastal Star.
@ddsack the slug bait is non toxic to people or pets. The active ingredient is some form of iron that slugs can't digest, wrapped up in a bait they can't resist. It does seem to work, but temporarily. Like you I have an infinite supply of woodsy habitat slugs. I tend to avoid mulch for the same reason. Wider spacing and well weeded helps when plants get bigger - probably because the robins get down and pick off the daring slugs.