Bolting in lettuce is triggered by warm weather and the long days of summer, usually when the daytime temperatures climb above 75°F and nighttime temperatures are over 60°F. After bolting, lettuce leaves will taste bitter and grow slowly.
What temp is too cold for lettuce?
Lettuce may cope with light freezing and even one or two hard freezes, but once the thermometer reads 25°F or below, the plants are in danger. That level of cold causes ice to form in the plant tissue, regardless of the amount of moisture in the air.
What causes lettuce to bolt?
Bolting, when the plants shift from leafy growth into flower production, is caused by a number of factors including high temperatures, long daylight hours, and less moisture – in essence – summer. Lettuce does offer a few clues when it’s about to bolt.
How long does it take for lettuce to bolt?
Plants grown on short days bolted about 135 days after planting, compared with about 90 days for plants on long days, and neither short-day nor long-day plants had premature bolting. Thus, total day length and not temperature determined the time of bolting.
Is 40 degrees too cold for lettuce?
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. Seed germinates best at about 75 degrees F.
Will lettuce survive a freeze?
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 I stop my lettuce from bolting?
Give your lettuce a break from full sun. Grow pots of lettuce on a porch or patio that gets some shade, plant it in the garden under taller plants, like corn, or use a shade cloth over your lettuce bed. Regular watering can also help delay bolting.
Is it safe to eat bolted lettuce?
Can You Eat Bolted Lettuce? Yes, you can eat bolted lettuce but you probably won’t want to. Once lettuce begins to bolt it starts producing compounds called sesquiterpene lactones. They are the plant’s natural defense mechanism to ward off pests so that it can successfully produce seeds.
Can bolted lettuce Be Saved?
This is my favorite thing to do with the bolted lettuce in my garden. Instead of pulling the plants out by the roots, simply cut the tops off and leave the roots intact. The stump will resprout when temperatures cool later in the season and go on to produce a second crop of lettuce in the late summer or fall.
Does all lettuce bolt?
Many lettuce varieties are classed as long-day plants, meaning that they automatically start to bolt when there are more than 14 hours of daylight. Other lettuce plants react in the same way when the right temperature has been reached. However, some lettuce plants flower prematurely.
How can we prevent bolting?
How can bolting be prevented?
- Plant in the right season.
- Avoid stress.
- Use row cover or plant in the shade of other plants to keep greens and lettuce cool as the season warms.
- Cover young broccoli or cauliflower plants and near-mature bulbing onions during a cold snap to protect them from bolting.
What do you plant after lettuce bolts?
For most gardeners, the best vegetables to plant after lettuce are bush beans, which germinate fast in warm soil and produce heavily in late summer. Other good veggies to plant after lettuce include carrots, cucumbers, squash or a second sowing of basil to carry you through the summer.
Should I cover my plants at 39 degrees?
Frost protection should be removed every day, but row covers can remain in place for weeks or months. When the weather begins to dip, it can affect the plants and shrubs. Plants at 39 degrees can begin to feel the chill and require a cover just to be safe.
At what temperature should you cover your plants at night?
Cover Plants – Protect plants from all but the hardest freeze (28°F for five hours) by covering them with sheets, towels, blankets, cardboard or a tarp. You can also invert baskets, coolers or any container with a solid bottom over plants. Cover plants before dark to trap warmer air.
Will 45 degrees hurt tomato plants?
Is 45 Degrees Too Cold For Tomatoes? A temperature of 45 degrees Fahrenheit (7.2 degrees Celsius) may not cause severe, immediate damage to your tomato plants, especially if you protect them. However, it can cause them to produce less pollen during the flowering stage.
Can you grow lettuce outdoors in 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.
What temperature is too cold for spinach?
Keep the cover on until the weather warms. Optimum growing temperature is 50⁰ F to 60⁰ F, but young seedlings can tolerate temperatures as low as 15⁰ F to 20⁰ F.
When should you plant lettuce?
Sow seeds in the ground 2 to 4 weeks before your last spring frost date or as soon as the ground can be worked. Or, to get a head start, start seeds indoors about 1 month before your last spring frost date. Harden off seedlings for 3 days to a week before setting outdoors.
What is the most heat tolerant lettuce?
Butterhead lettuce is usually known for being among the most heat-tolerant and bolt-resistant of all the lettuce types.
Why is my lettuce growing so tall?
ANSWER: Lettuce plants that suddenly start stretching toward the sky and growing extra tall are likely to be bolting. In the bolting stage, a plant stops focusing so much on producing foliage and starts to turn its attention toward reproduction, sending out a flower stalk that will eventually dry to release seeds.
How do you harvest leaf lettuce so it keeps growing?
Plan to harvest your lettuce leaves in the morning, when they’ll be at their crispest. Cut the outer lettuce leaves about 1 inch above the crown. This protects the crown so the lettuce can continue growing. Cut off the amount of lettuce needed when the leaves reach a length between 3 and 6 inches.