Let Us Grow Lettuce!
Part-full sun (5-8 hours/day)
1/8 - 1/4 in (.3-.6 cm)
4-12 in (10-30 cm) depending on type
1-2 in (2.5-5 cm) per week
Heavy nitrogen feeder
Thrives in Spring and Fall
Types of Lettuce | How to Plant | When to Plant | Planting Time | After Planting | Harvest and Store | Troubleshooting
Know Before You Grow - Essential Information You Need to Have a Shot at Success
No spring or fall garden is complete without a variety or two of lettuce!
Nothing says kitchen garden quite like lettuce! Whether you are a longtime salad enthusiast or an occasional side salad dabbler, give the humble lettuce a place in your garden – let me show you how!
Timing: Lettuce is a fast growing cool-season crop that grows best in both spring and fall.
Difficulty: I would consider lettuce about medium difficulty mostly because there are some specific logistics to be aware of to be successful.
Essential Crop Info:
Two main varieties: Leaf and head lettuces have different growth habits and pros and cons. I always view leaf lettuce as a bit easier to grow because it grows faster and can be harvested multiple times throughout the season.
Lettuce Bolts in warm weather: Once warmer weather hits, the plants form a center stalk, produce flowers, and get a bitter taste.
Setting up For Success - The basics of how to get a successful harvest
Pick the right type for you
Leaf Lettuces
Examples: Red leaf, Mesclun
Grow faster with many varieties maturing in 45-55 days
Are typically harvested in a “cut and come again” fashion
Tend to be more cold than heat tolerant
Cheryl’s take – pretty easy to grow
Head Lettuces
Examples: Romain, Butterhead, Bib, Cos
Take longer to develop with most needing 55-80 days to mature
Typically harvested as a whole plant
Tend to be more heat than cold tolerant
Cheryl’s take - the hardest to grow
Batavian Lettuces (a.k.a. Summer Crisp or French Crisp)
Examples: Muir, Nevada, Concept, Sierra, Cherokee Red
50-65 days to maturity
Are typically harvested in a “cut and come again” fashion but can be either
This type of lettuce breaks the rules of traditional head and leaf varieties because it is both heat and cold tolerant. It can geminate in soil temperatures around 80°F / 27°C and VERY slow to bolt. The shapes of the different varieties vary but they are generally somewhere between a head and leaf growth habitat.
Cheryl’s take – probably the easiest to grow
Leaf Lettuce
Head Lettuce
Use the information above to plan out what works best for you. There is also a wide variety of tastes and textures so don’t hesitate to try out several. Those Batavian lettuces aren’t always defined as a separate type but I wanted to mention them because of their temperature tolerances. Definitely worth a try, especially if you would enjoy lettuce year round like I do.
How to plant
I almost always recommend growing lettuce from seed even if you have never grown from seed before. I’ve laid out the pros and cons of each option below:
Pros for Seeds / Cons for Transplants
Variety: Infinitely more varieties are available from seeds than transplants.
Cost: Seeds are far more cost effective especially since they direct sow easily so you don’t necessarily need a seed starting setup. (While purchasing 1 transplant from a nursery typically costs about the same amount as purchasing a head of lettuce from the grocery store.)
Timing:
Often, nurseries don’t start selling vegetable transplants until Memorial Day and by that time, it’s almost too late (at least in my area) to maximize my lettuce growing potential.
Growing from seed allows you to grow in the fall (which is PRIME lettuce growing time) when most nurseries are done selling vegetable transplants.
Succession planning: Lettuce is a GREAT candidate for succession planting (more on that later) which is best achieved when growing from seed.
Pros for Transplants / Cons for Seeds
Effort: Less time and effort are needed for transplants
When to plant
Lettuce presents a golden opportunity in many climates to grow in both the spring and fall but timing is everything and procrastination can really have significant consequences. Let’s get you set up success!
Your mission in planting lettuce is to plant early enough in the spring or late enough in the fall to grow and harvest all between 32°F / 0°C and 80°F / 27°C.
I always recommend becoming aware of your last expected frost date in the spring and your first expected frost in the fall. In the US, this is estimated based on your zip code. You can find this information by using the frost date calculator on the Farmer’s Almanac Website. This information will serve you well throughout your gardening journey so I recommend you write it down.
Temperatures above about 80°F / 27°C trigger lettuce plants to form a flower stalk and transfer sugars toward that production (this process is referred to as “bolting” or “going to seed”). This transfer of sugar within the plant renders the actual leaves bitter and inedible. On the opposite side of the temperature spectrum, temperatures below about 32°F / 0°C will kill most lettuce varieties. While some varieties provide a little grace within these limits, these temperature ranges are a good guide for most situations.
With all that in mind, planning is key. The table below provides the temperature specifications as well as some timing to help with planning. Remember though, your seeds and plants only care about soil and air temperatures. The timing provided is to help you as a grower to plan ahead but I always recommend keeping that 80°F / 27°C - 32°F / 0° range in mind so you can make decisions based on your current weather patterns.
| Method | Soil Temperatures | Air Temperatures | Timing Before Last Spring Frost | Timing Before First Fall Frost |
|---|---|---|---|---|
| Germinating seed indoors | 40–75°F / 4–24°C Optimal: 70–75°F / 21–24°C |
45-80°F / 7–24°C | 6-4 weeks* | 15-13 weeks* |
| Direct Sowing | 40–75°F / 4–24°C | Nighttime temps are consistently above 40°F / 4°C | As soon as soil is workable (right around last frost)* | 8 weeks* |
| Transplanting outdoors | At least 35°F / 1.5°C | 45-80°F / 7–24°C | 2 weeks | 11-7 weeks* |
* These are estimated times to start. If succession planting (see below), start a new round every 2-3 weeks.
Succession Planting
Succession planting means planning to grow several batches of the same or different plants over time. There are many strategies for various crops, and lettuce is a great option to start with, even if you're new to it.
Because lettuce doesn’t have very good storage potential, you wouldn’t want a huge bounty all at once. Starting a new batch of seeds about every 2 weeks should provide you with an extended harvest window.
“I’ll always recommend growing lettuce from seed even if you’ve never grown from seed before”
Planting Time - Set the Plants up Right from the Get-go!
Prep The Soil
Because it is fast growing and shallow rooted, lettuce ends up being a heavy feeder meaning it will take a lot of nutrients from the soil and likely needs additional nutrients added throughout its growing season to live up to its full potential. Set it up right from the start by adding a good 2 inches / 5cm of compost to the planting area. I also generally recommend adding a high phosphorus fertilizer (like Fish Bone meal) at planting time for almost all crops to help them quickly establish a healthy root system. A balanced granular fertilizer will do just fine though if you don’t have a high phosphorus one on hand.
A high Phosphorus fertilizer will help establish a strong root system
Spacing and Depth
Plant spacing will depend on the type you are growing. Leaf type varieties can be planted as closely as 4 in / 10 cm apart while head lettuces should get 10-12 in / 25-30 cm between each plant.
Lettuce seeds need light to germinate so cover them very lightly with only 1/8-1/4 in / .3-.6 cm of soil. Transplants should generally be planted in the ground at the soil level of the transplant itself.
Companion Planting
Without going into too much detail on companion planting itself, (I’ll save that for another article), lettuce is an excellent crop to slip into blank spaces throughout your garden. It thrives on some shade, doesn’t take up too much space, and can often be harvested before neighboring crops reach their full size.
Lettuce planted alongside carrots and onions.
Mulching
Because of the shallow root system, lettuce only has access to the top layers of soil which heat up and dry out the fastest. I always recommend mulching your whole garden but if that’s not in the cards for you, I urge you to at least mulch your shallow rooted crops like lettuce. You would be amazed at how much just a little mulch maintains the soil moisture and temperature (among other things) for your crops. Mulch can be anything organic like non-treated grass clippings, dead leaves, wood chips, straw, pine needles, etc.
Containers
Because of their shallow root systems, lettuce is a great candidate for growing in contains with at least 6 inches / 15 cm of soil. You will need to keep in mind, however, that the soil in containers dries out faster than that in raised beds or in ground so you will really need to stay on top of you watering. Also, don’t hesitate to add mulch to your containers for the same reasons mentioned above.
Lettuce works great in containers
After You Plant - Taking Care of Your Plants While They Are Growing
Watering
Did you know that lettuce is 95 – 96% water? When growing your own, you’ll need to provide all that water. It’s generally recommended to ensure that lettuce gets 1-2 in / 2.5-5 cm of water weekly. In addition to ensuring there is enough water to take up, keeping the soil moist will also keep it cool, which is important for this cool-season crop!
Fertilizing
Lettuce is obviously prized for its green leafy growth. To best support that, lettuce needs lots of nitrogen. To optimize the potential growth of your lettuce, supplementing the soil with a high nitrogen fertilizer, like blood meal, can go a long way. There are lots of organic and synthetic options out there. Just look for a fertilizer with a higher first number in the ratio (like 12-0-0, 5-2-2, 6-4-0, etc.) and follow the package instructions with typical applications about every 2-3 weeks.
Fertilize with Nitrogen to maximize growth potential.
Harvest and Store
How and When to Harvest
Lettuce can’t really be harvested too early. As soon as you have leaves, they are edible although you likely want to maximize their size for optimal harvest. Depending on the type and variety, full size heads or leaves can take anywhere from 55 – 130 days to develop. What you don’t want to do, however, is harvest too late. As mentioned earlier, warmer temperatures (above 80°F / 27°C) can cause the lettuce to bolt resulting in bitter tasting leaves. Because this is mostly irreversible, I generally keep an eye on the extended forecast and if temps are going to raise above that, I will do one of two things:
If it’s only a day or two in the low-mid 80’s (no higher than 29°C), I’ll do what I can to provide shade for the plants, water really well, and be sure that I have a good layer of mulch intact. In most cases, this will help the plants make it through the warm spell.
If it is going to be over 80°F / 27°C for more than just a few days or over 85°F / 29°C, I will just harvest what I have. Better to have a smaller harvest than a waste with bitter, inedible leaves.
Lettuce can also be harvested in 2 different ways:
Cut and come again: Most leaf lettuces fall into this category. Using this method, you harvest the outer, larger leaves as you want to use them. If you leave the center ones intact, they will continue to grow, allowing you to harvest multiple times throughout the growing season.
Single cut: This describes most head lettuce varieties. With this method, as it sounds, you wait until the head of lettuce reaches a mature size and then harvest the entire head at once.
Storage
The storage potential for lettuce isn’t great. If treated optimally, 1-3 weeks is about the expected survival length before you end up with slimy salad. Here are some points to help maximize the storage potential of your lettuce
Harvest in the morning or coolest part of the day
Don’t pre-chop or rip prior to storing
Wash well in cold water
Dry off the leaves really well after washing then wrap loosely in paper towels to prevent too much moisture collecting in a single area
Store in a lettuce crisper or Green Bag in the crisper drawer in the refrigerator
What Could Possibly Go Wrong?
Pest and Disease
Lettuce definitely has its share of pests out there happily feeding on your luscious leaves. I’ll go through the most common ones in my experience. In most cases, there are a variety of ways to combat them. I will mention a few that I have personally found or heard to effective but please note, I have not seen or done it all. I have also witnessed MANY cases of certain remedies working for some gardeners but not others. Your garden will always be unique for you so do your research, try different things, and don’t get discouraged. You will always be working with nature.
Slugs
Slugs love lettuce. Their tell-tale damage is irregularly shaped holes in the leaves. Because they are primarily nocturnal, I suspect slugs are the culprit when I see holes chewed in the leaves but don’t see any worms or other potential suspects during the day. Your best chance to see them in action is in the morning or on a cloudy or rainy day on the underside of the leaves. Some methods of control include:
Commercially available slug bait like Sluggo or Slug Magic
Beer (yup, not kidding)
Laying a wooden board along the soil (to lift up during the day and remove the slugs that are clung to the bottom)
Diatomaceous Earth, or DE
There’s a lot to say about slugs and each of these methods. For my take on methods of control and/or prevention, check out my article devoted to all things slugs!
Aphids
I almost always get aphids on my lettuce but have never personally had a major infestation destroy my crop. Aphids are tiny insects with long piercing mouth pieces that suck sap out of plants. Because of their size and the fact that they don’t leave visible damage, it can be hard to spot them at first especially because the varieties that often affect lettuce are a perfectly incognito shade of green. Aphids can be controlled by:
Removing by hand (or just squished if you don’t mind)
Spraying off with a garden hose (most sources tell you that aphids can’t climb back up onto the plants once knocked to the ground)
Treating with numerous sprays. My favorite organic option is a solution of 1 Tbsp / 15 mL castile soap to 2 cups / 500 mL of water.
Regardless of your method of control, repeat every few days to stay on top of their aggressively multiplying life cycle.
Rabbits
If you notice tears starting along the outer leaves, suspect rabbits. Left long enough, they will chomp down your whole plant. There are a number of commercial sprays and other products to repel them, all with various efficacy in my opinion. I feel like I have tried them all and just ended up going with fencing or cloches. They can fit through holes just 2 in / 5 cm in diameter though so keep that in mind while trying to keep them out.
Missed Your Planting Window or pushing the limits
I’ve covered the ideal temperatures for lettuce to thrive but what if you procrastinated a bit or want to test the limits? Here are a few tactics to help support a potential harvest:
Plant more heat tolerant varieties such as the summer crisp series
Keep plants shaded with shade cloth
Keep plants mulched and well-watered
Lettuce Bolted
As mentioned earlier, warm temperatures can cause lettuce to bolt which results in bitter leaves. This is mostly irreversible but in some cases, if caught early, dropping the lettuce in ice cold water and then in a green bag in the refrigerator for 24 hours could potentially remove enough of the bitterness. It won’t always work but worth a try!