Lettuce is one of the few crops in Missoula that rewards you for being impatient. While you are waiting on tomatoes and peppers to wake up, you can be cutting salad greens. Most of them tolerate cool weather, a few even shrug off a light frost, and the whole group grows fast enough that you can plant again every couple of weeks and never run out.
The catch is heat. Lettuce and most salad greens are cool-season crops, which means they do their best work in the cooler parts of spring and fall. Once Missoula hits its July stretch of hot afternoons, a lot of these plants turn bitter and shoot up a flower stalk. Knowing how to work around that is most of the battle.
When to Plant Salad Greens in Missoula
You can start much earlier than you might think. MSU Extension recommends putting cool-season crops in the ground about two to three weeks before the average last spring frost, which in Missoula lands around May 19. That puts your first planting in late April or the first few days of May, depending on how the weather is behaving that year.
Lettuce seed germinates in cool soil that would stall a tomato. It will sprout once the soil is in the 40s, though it comes up faster and more evenly when the soil is closer to 60. Young lettuce also takes a light frost without much complaint, so an early planting is a low risk. If a hard freeze is coming, throw a row cover or an old sheet over the bed overnight and pull it off in the morning.
The bigger move is to keep planting. A single April sowing gives you one wave of lettuce and then it is gone. Instead, sow a short row every two weeks through spring. This is called succession planting, and it is the difference between a glut of lettuce in June and a steady supply from May into summer.
The Greens Worth Growing Here
Leaf lettuce is the easiest place to start. Loose-leaf types like oakleaf and red and green leaf varieties grow quickly and let you pick outer leaves while the plant keeps producing from the center. You get weeks of harvest off a single planting instead of one head and done.
Romaine and butterhead types form looser heads and take a little longer, but they handle our cool nights well and have better texture than most leaf lettuce. If you want a crisp head lettuce, give it your earliest spring planting so it matures before the heat arrives.
Spinach is the cold champion of the group. It germinates in genuinely cold soil and grows fast in spring, but it bolts earlier than almost anything once days get long and warm. Plant it early, harvest it hard, and do not expect it to last into midsummer. Many Missoula gardeners get a better spinach crop in fall than in spring for that reason.
Then there are the greens that fill the gap when lettuce struggles. Arugula grows fast and adds a peppery bite, though it bolts quickly in heat too. Kale and Swiss chard are the workhorses. Both are technically cool-season but far more forgiving of summer than lettuce, and chard in particular will keep going from spring until a hard fall freeze. If you want something in the salad bowl all season, these two carry you through July and August when the lettuce has given up.
Keeping Greens Going Through the Heat
When a lettuce plant bolts, it stretches upward, the leaves turn bitter, and that is more or less the end of it. You cannot reverse it, but you can delay it. A few things help in a Missoula summer.
Afternoon shade is the most useful trick. MSU Extension notes that lettuce and spinach actually do fine with some shade during the day, so a spot that catches morning sun and gets relief from the hot afternoon will hold your greens longer than a fully exposed bed. If you do not have a naturally shady spot, taller crops like pole beans or trellised cucumbers can throw shade onto a lettuce row planted on their east side.
Steady water matters just as much. Greens have shallow roots and dry out fast, and heat stress plus dry soil is what pushes them to bolt. Water deeply and keep the bed evenly moist rather than letting it swing from soaked to bone dry. A layer of straw or another light mulch around the plants keeps the soil cooler and holds moisture between waterings, which is worth a lot in our dry July weather.
Choosing heat-tolerant and slow-to-bolt varieties helps in the hottest part of summer, and seed packets usually say which ones those are. But honestly, the most reliable strategy is to lean into the calendar. Grow most of your lettuce in spring and fall, lean on kale and chard through the worst of the heat, and start a fresh round of greens in August for a fall harvest once the nights cool off again.
A Fall Crop Is Worth Planning For
A lot of people plant salad greens once in spring and forget about them. Our first fall frost is usually around September 22, and lettuce and spinach planted in mid to late August have plenty of time to size up in the cooling weather. Fall greens often taste better than spring ones because they mature in steady cool temperatures instead of racing the heat. Mark a reminder for yourself in late summer so you do not miss the window.
If you want a garden plan built around your specific yard, your sun exposure, and a planting schedule that keeps greens on the table from spring through fall, that is exactly the kind of thing I help Missoula gardeners sort out. Take a look at the vegetable garden consulting page and get in touch if you would like a hand.