Very Hardy vegetables will withstand freezing temperatures and hard frosts without injury. They can be planted as soon as the ground can be prepared. Spinach and lettuce seeds may even be broadcast on late snows over soil prepared in fall. Frost Tolerant (semi-hardy) vegetables can withstand light frosts.
How cold can lettuce seedlings get?
How to Grow: Lettuce is a cool-weather crop that thrives in the temperature range 60-65 degrees F, and if thoroughly hardened, most varieties survive temperatures as low as 20 degrees F. Cold-adapted varieties survive much lower temperatures.
How cold is too cold for lettuce?
Lettuce is considered “hard frost hardy,” which means it can withstand frosts below 28 degrees. If the frost continues unabated, however, the cell walls may form ice, and the plant actually freezes. Freezing is irreversible and will kill a lettuce plant.
Can lettuce survive a frost?
Lettuce can usually tolerate at least a couple of hard frosts, especially if you’ve taken steps to harden off the seedlings and keep the soil warm. A light freeze is defined as any time temperatures are in the 28 to 32°F range, and a hard freeze occurs below 28°F.
Can I plant lettuce seeds before last frost?
Most cool season crops, like cabbage, broccoli, lettuce and many others, can tolerate a light frost and will grow best when sown a couple weeks before your last spring frost. Some, like peas and spinach, are so cold-hardy they can even be planted “as soon as the ground can be worked,” as many seed packets say.
How do I protect my lettuce seedlings from frost?
HOW TO PROTECT PLANTS FROM FROST
- Lay a pane of glass, held up by small pots, over low-growing plants.
- Relocate outdoor potted plants somewhere warmer, such as on a verandah or under the house.
- Save old net curtains, bed sheets and shadecloth for emergency overnight protection.
When can I plant lettuce seeds outside?
Lettuce seeds germinate best in the cooler temperatures of spring or fall. If it’s too hot, they won’t germinate. So, the best time to plant lettuce seeds is as soon as the ground is workable in very early spring, or once the temps start to cool down in late summer or early fall.
Does lettuce need warmth to germinate?
Depending on its variety, lettuce seed can germinate when the soil temperature is 35 to 80 degrees Fahrenheit. The ideal soil temperature for germination though, is 70 to 75 F. In cooler temperatures, germination takes longer. When temperatures are warmer than 70 to 75 F, lettuce seed may not germinate.
Do you soak lettuce seeds before planting?
You can soak your lettuce seeds before planting to encourage faster germination. Put them in clean water and let them sit for a day or so before planting. However, this is not required – as long as the growing medium is moist and warm, the lettuce seeds should germinate well.
Can I grow lettuce in the winter?
Growing lettuce in winter is easier than you think! The key is to select frost-tolerant varieties and pair them with a season extender like a cold frame, mini hoop tunnel, or polytunnel.
Can spinach seeds survive frost?
Very Hardy vegetables will withstand freezing temperatures and hard frosts without injury. They can be planted as soon as the ground can be prepared. Spinach and lettuce seeds may even be broadcast on late snows over soil prepared in fall. Frost Tolerant (semi-hardy) vegetables can withstand light frosts.
Will lettuce seeds germinate in cold weather?
Lettuce seed will germinate at 35°F, but optimum germination is 70 to 75°F. If the plants are sufficiently hardened, they will withstand freezing. Repeated exposure to subfreezing temperatures, however, can seriously injure or kill the crop.
Can I plant lettuce seeds in January?
January is a great time to plant seeds directly into the garden or in flats or pots to produce transplants. Garden lettuces can be divided into three classes based on habit of growth – leaf or loose-leaf types, semi-heading types, such as butterhead and romaine (or cos), and heading or crisp-head types.
Do I need to cover my lettuce for frost?
Butterhead, romaine, and leaf lettuce typically make it through a 30-32℉ (0 – -1℃) degree frost unharmed, while red leaf and iceberg lettuce may be damaged at that temperature. Always protect your lettuce from frost when temperatures dip below 32℉ (0℃).
Should I cover my lettuce seeds?
Direct sowing lettuce seeds
Don’t sow the seeds too deeply as they need light to germinate. Cover them with a thin layer of soil.
Will frost hurt seeds in the ground?
If sown in the ground, cold hardy seeds should survive this weekend’s freeze without damage. Though air temperatures are predicted to drop into the teens, soil temperatures will remain much warmer thanks to the ground’s ability to store heat.
Do I need to cover lettuce seedlings?
Growing lettuce from seed in late summer may require generous artificial shade to help cool the soil for germination. Once days become cooler, the shade can be removed to give plenty of sunlight to young lettuce plants. Lettuce grows best in loose, cool soil with good drainage.
Can I sow lettuce seeds in February?
Hardy crops that are usually grown outdoors can be sown under cloches or in the soil beds of a greenhouse or polytunnel. They will romp ahead and give welcome fresh produce at a lean time of year: Lettuce. Carrots.
Can I plant lettuce seeds straight into the ground?
If sowing in the ground, prepare the soil by digging in lots of well-rotted garden compost beforehand. This helps to prevent lettuces bolting or running to seed in hot or dry weather, especially in light soils. Sow seed thinly along a moist, 1cm deep drill (trench), made by pressing a bamboo cane into the soil.
Do lettuce seeds germinate in the dark?
Light is required for some lettuce seeds to grow. When seeds fail to germinate in the dark, they’re called “photosensitive” or “photodormant.” Once they do emerge, to grow a field of lettuce with heads that are all relatively the same size (uniform), the seedlings must all spend an equal amount of time in the sun.
When should I start lettuce seeds indoors?
For a jumpstart on the spring garden, start lettuce seeds indoors 3 to 4 weeks before your area’s last hard frost — which is around 28 degrees overnight.