Wednesday, March 23, 2011

Growing Lettuce in Kihei

 
A Baby Mesclun Mix

 Lettuce is a cool season green that grows best in Kihei when planted in the late fall through early spring. In my opinion, the night time temps are the most important factor in growing lettuce successfully. If they're too warm, germination may be low or non-existent and the plants may bolt early in their growth cycle. 

A Baby Romaine Mix

Growing lettuce as cut and come again baby greens is perhaps the best method for achieving good results. Seeds are sown densely and if some fail to germinate it's not normally noticeable.The lettuce is ready to begin cutting in just a few weeks.

If you create your own mesclun mixes, I suggest not adding kale seeds into the mix as kale grows large leaves much faster than lettuce. Mizuna and other small mustard greens work well in a mix with lettuce seeds.

Bronze Arrow
Looseleaf

I've trialed more varieties of lettuce than I can remember, looking for lettuces that will grow as individual plants in our warm climate. So far, Bronze Arrow, Green Romaine and Tango have been the most heat tolerant but Bronze Arrow doesn't produce much bronze or red pigment in the leaves.

New Red Fire
Looseleaf
 
Mascara
Oakleaf 

Many of the red lettuces need cooler weather in order for the red to develop. The winter temps fluctuate and my results with the red lettuce varies each year. New Red Fire and Mascara developed some red and violet variegation.
 
Merlot (top)
Looseleaf
 
At least Merlot has consistently produced deep red-violet leaves.

Tango
Oakleaf

For individually planted lettuce, I've found that looseleaf, oakleaf and romaine are more heat tolerant than batavian or butterhead. I've yet to grow a butterhead variety that actually formed a head. Lettuce tends to bolt early. Most of the full heads I've harvested have been on the smaller side and this is due to our warm climate.

Individually planted lettuce seems to grow larger in full sun but will grow in partial shade.

A Baby Lettuce Mix at 10 days

All of my lettuce is grown in containers. For cut and come again baby lettuce, I plant seeds in an 8 in x 30 in container with a soil depth of 5 inches. For individual lettuce, I plant in a container with a soil depth of at least 7 inches.

I fill the container with an organic potting soil amended with OMRI azomite and green sand. After the lettuce has been growing for 3 to 4 weeks, I begin watering it with liquid fish emulsion every 2 weeks.


Another container I use for lettuce is a 3 ft x 2 ft x 7 in all purpose utility tub that I purchased at Kihei ACE Hardware for about $22. I drilled holes in the bottom and each fall when I plant lettuce I fill it with fresh potting soil amended with OMRI azomite and green sand. In this container I grow rows of small lettuces.

 
Densely Planted Rows of Lettuce

I plant the seeds in rows that are spaced about 4 inches apart and gradually thin the seedlings to 5 per row. I've been able to grow this lettuce in partial shade - it's in full sun until 12 pm, diffused sunlight through the early afternoon and shade in the late afternoon. It's a great way to trail a number lettuce seeds at the same time.


Slugs, snails and the cabbageworm are pests that affect lettuce and many other salad greens. I keep lettuce covered with a tulle especially from mid-November through February when the cabbageworms are active. For more information see my post on Cabbageworms. Slugs will bury themselves in the soil and are hard to find once the lettuce starts growing.

Heirloom lettuce seeds are widely available. Many of the local garden centers have lettuce seedlings available throughout the year.
 
After some experimenting, I've been able to grow a few lettuce and salad green seeds successfully during the summer months:


12 comments:

  1. Lettuce (wilted with slimey leaves) was $2.98 a head in our local market today!!! I am so glad I garden. Your lettuce looks wonderful and I would gladly pay $2.98 for it!

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  2. Aloha Jane,
    Beautiful lettuces! I too grow mesclun mixes as they are so easy to grow. In Mililani, the cabbage moths are still around in late March! I agree about the white flies--they wreak havoc on a lot of my plants. Will try some Natural Farming techniques to see if they work--I will keep in touch. Corliss

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  3. Hi Lynda! Slimey lettuce doesn't sound to appetizing! My lettuce season is sadly ending and yours should be starting soon and then I will be wishing for lettuce!

    Hi Corliss! I still have those horrid white moths too but they seem to have stopped mating as the last cabbageworm I found was during the 1st week of March. I've had significant problems with an assortment of moths this winter and I need to try and ID them as there are some lure products available.

    I used to use those yellow sticky cards for white flies but they didn't seem to make a dent in the population! Right now I'm on a neem spraying campaign and if that reduces the white flies I'll let you know.

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  4. Beautiful lettuce Jane. It must be a real challenge to grow in your climate. The Forellenschuss Romaine is absolutely beautiful! I purchased Freckles Romaine seeds this year and I am very excited to try them.

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  5. I tend to grow loose leaf and romaines too, but that is because those are the ones I love eating the most. Lettuce is so easy here except at the height of summer. It must be so hard to grow there.

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  6. Hi Robin! Freckles might be the same as Forellenschuss - it looks so similar in the catalog photos. It's one of the few that will grow beyond the baby stage in my climate so it might grow well in the summer where you live.

    Hi Daphne! It took me a few years to figure out when to grow lettuce and what would grow. I tried so many seeds that were noted to be bolt resistant and heat tolerant but they weren't, at least not here.

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  7. thanks for the great tips, I did put fertilizer in my pots and they seemed to do ok.

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  8. Hi Tonja! I should edit that part as it may be misleading. The best germination I've had with lettuce has been with new FoxFarm soil and green sand. I hope your lettuce is doing well. The night time temps have been cool and maybe they'll last a bit longer and give us more time to grow lettuce.

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  9. JANE!! :) can tell us more about your strawberries near New Red Fire Loose Leaf Lettuce

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  10. Hi Natalie! My strawberry plants did okay during the winter and early spring but many of them perished in the hot summer sun. Strawberries grow really well all year in full sun at the higher elevations on Maui. If you live in Kihei I certainly wouldn't discourage you from planting them.

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  11. Mahalo for the very informative and helpful tips on your site and introducing me to Bountiful Gardens (trying to grow chickweed and miner's lettuce in cooler mountainside area, no success yet). My regular lettuces (except oak leaf-types) are suffering from sporadic yellowing, rotting leaves with black and white spotting on each head. Aphids? Cabbage worms?

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    1. Mahalo for your appreciation! Without seeing photos I don't know. Cabbageworms just munch the leaves and drop their poop all over the plants. I've found that successful lettuce depends on the planting dates which differ widely due to the diversity of climates in the islands. It took me a few years to figure out the right months to plant in Kihei and that's why I developed a blog to help other gardeners in my climate.

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