Lettuce is a very popular vegetable, and can be grown spring through fall in the Tahoe Basin. Lettuces come in a wide variety of reds and greens and can add a beautiful element to an edible garden. Many varieties can be harvested on an as-needed basis, making for a very convenient source of fresh vegetables come mealtime. Additionally, lettuce readily grows directly from seed, making for an easy and affordable addition to a vegetable garden.
Types of Lettuce
- Crisphead Lettuce - grows in a dense cabbage-like head, the most iconic example being Iceberg Lettuce.
- Batavian / Summer Crisp lettuce features curlier leaves forming a head and is relatively slow to bolt, so good for mid-summer plantings.
- Butterhead or Bibb lettuce is a much looser head forming lettuce with more delicate leaves. Often sold as living lettuce in grocery stores.
- Romaine or Cos lettuce features sturdy, upright leaves—often the lettuce used in a Caesar Salad.
- Leaf Lettuce grows without forming a head. Gardeners can harvest leaves as they mature—generally from the outermost leaves of the lettuce plant.
- Celtuce / Stem Lettuce, as the name implies, is grown for both the stem and leaves. Often used in Chinese cooking, it tastes similar to hearts of palm, asparagus, and/or celery.
Variety Selection
Early and late season, many varieties of lettuce can be grown in the Tahoe Basin, though early season seedlings will likely need to be started indoors to ensure seeds remain at a proper germination temperature (60-75F.) During this timeframe, consider cold-hardy lettuce varieties that will be more likely to survive a freeze. Some varieties (including Black Seeded Simpson, Salad Bowl, Winter Density, Winter Marvel, and Arctic King per University of Maryland research) will even over-winter when established late-fall.
For mid-summer sowing, varieties that are slow to bolt perform better—our intense sunshine can cause lettuce to go to seed quickly. Using shade cloth or planting in partial sun can also help stave off lettuce going to seed too soon.
Varieties known to grow well in the Tahoe Basin:
- Buttercrunch (Bibb)
- Nevada (Leaf/Batavian)
- Jericho (Romaine)
- Merlot (Leaf)
- Oak Leaf (Leaf)
- Parris Island (Romaine)
- Red Cross (Bibb)
- Red Sails (Leaf)
- Salad Bowl (Leaf)
- Sierra (Leaf/Batavian)
- Summer Bibb (Bibb)
- Summertime (Head)
Varieties that are especially frost-tolerant (good for early and late season growing):
- Arctic King (Bibb)
- Australe (Bibb)
- Black Seeded Simpson (Leaf)
- Salad Bowl (Leaf)
- Winter Density (Bib/Romaine)
- Winter Marvel (Bibb)
How to Grow
For springtime crops, start seeds indoors or under a cold frame, as seeds germinate best from 60-75 degrees Fahrenheit. Lettuce seeds requires light to germinate, so seeds should be sprinkled on the soil surface and gently watered in.
Plan to harden off, then plant out after the threat of hard freeze has past, though lettuce often survives light spring freezes. After the last frost date, lettuce seeds grow well when direct seeded into a prepared planting bed. Succession planting, i.e. staggering the date you plant, will give you a more steady stream of harvestable lettuce (versus lettuce that all matures at the same time.)
Lettuce requires compost-enriched, nutrient-rich moist soil. Amend soil with compost and a slow-release nitrogen fertilizer upon planting, and additional side-dressing or liquid fertilizer when the heads of head varieties begin to develop. Leaf varieties often don’t require a second dose of fertilizer, but keep an eye on growth, as yellowing of older leaves can indicate nitrogen deficiency. Of the various crops you grow, lettuce generally requires more frequent but less deep watering due to its relatively shallow root system.
As the weather warms and sun gets more intense, lettuce is more likely to bolt, or turn its production to seed, sooner than you can harvest its leaves before they turn bitter. Growing in less direct sunlight or installing shade cloth can help extend your harvest window.
As with all young tender edible plants, lettuce is well-loved by birds, rabbits, and other vertebrate pests. Physical barriers such as wire fencing or hoop houses installed with shade cloth can be effective—the latter helping lettuce not bolt too soon. Refer to the UC IPM website to help troubleshoot other pests.
Container Size
Lettuce has relatively shallow roots, so for container gardening wide, 6” deep pots work well. Head and Romaine lettuce pots should be 12” deep.
How to Harvest
For head varieties, and Bibb varieties you want to develop into a head, you’ll let grow until the head is mature (often indicated in days based on variety planted.)
For all non-head varieties, harvest leaves from the outermost part of the plant as needed. Harvesting this way is especially convenient in that you can pick exactly what you need, letting the plant grow for future meals. Leaves can be harvested until the plant begins to set flowers, i.e. bolts, at which time the lettuce becomes bitter due to a spike in milky sap (lactucarium) production. When picking leaves you’ll likely notice a milky-like substance at this time. Once lettuce is too bitter, you can decide whether to let the lettuce set seed which you can use again, or pull and plant more for harvest in as soon as a few weeks.
Another method of harvesting is to employ a ‘cut and come again’ strategy - harvesting with scissors the top of the plant (yielding something akin to a baby spring lettuce mix seen in grocery stores). Leave at least 1” of growth from the existing plant, and it will continue to send up additional leaves. Depending on conditions gardeners usually get 3-4 harvests this way.