CORVALLIS, Ore. – Not ready to put away your gardening gloves and spade yet? Be brave and plant some cold-hardy vegetables that you can harvest next spring. But dont dawdle.
It’s likely that you will have something to harvest in the spring if you plant cold-hardy vegetables between mid-August and early October, depending on the crop. “.
“Winter gardening is a risky business,” said Jim Myers, plant breeder and researcher at Oregon State University. “It may work one year with a mild winter but not another when the weather is more severe. If you plant cold-hardy vegetables between the middle of August and the beginning of October, depending on the crop, you should get something in the spring. They say farming is a gamble. some years more than others. “.
Cold weather doesnt kill these hardy plants; it simply slows their growth rate. “Growth rate doubles for every 18 degrees rise,” Myers said. However, that rule only works for air temperatures between 40 and 98 degrees. If you plant cold-hardy vegetables between the middle of August and the beginning of October, they might be ready for harvest next spring if they stay alive through the winter without making any more plants.
Myers says that spinach, onions, garlic, leeks, rhubarb, rutabaga, broccoli, kohlrabi, kale, cabbage, collards, Brussels sprouts, corn salad, arugula, fava beans, radish, mustard greens, Austrian winter pea, and turnips are the hardiest vegetables that can handle low air temperatures and heavy frost.
Beets, carrots, parsnips, lettuce, chard, garden peas (before they flower), Chinese cabbage, endive, radicchio, cauliflower, parsley, and celery are some of the semi-hardy vegetables that can handle a light frost in air temperatures between 28 and 32 degrees. For beets, carrots and parsnips, the tops will die but the roots will tolerate lower temperatures. For plants that grow heads, like radicchio and some chicories, the outer leaves may die when it gets cold, but you can peel them off to get to the head inside, which is still healthy.
Myers said that vegetables that are bright red or purple because they have the pigment anthocyanin in them are less likely to rot when it rains in the winter. They include purple-sprouting broccoli, Rosalind broccoli and purple kale.
Myers said that if you live in a part of the state that gets a lot of snow, the fluffy white stuff does double duty as mulch and keeps the soil warm for these tough plants.
No matter where you live in Oregon, “some of the worst problems we have in the winter are with rain rather than temperature,” Myers said. “So keeping plants dry in the rain is very helpful.”
He says to cover the vegetables with high or low tunnels made of metal hoops and clear plastic, which can be bought from companies that sell supplies for greenhouses. To protect plants, you can also use row covers or cloches. To warm the soil use mulch made from yard debris, cardboard or newspaper.
With any luck, you’ll be able to enjoy shelled, juicy fava beans seasoned with salt and lemon juice by March of next year.
Green beans are a warm-weather crop that can’t tolerate frost or freezing temperatures. However, they can withstand cooler temperatures during certain growth stages. Knowing the minimum temperatures green beans can handle will help you know when to plant and how to protect your crop if cold weather is forecasted.
Ideal Growing Temperatures for Green Beans
Green beans thrive in warm conditions. Here are the optimal temperature ranges
- Germination: 70-80°F
- Growth: 60-75°F
- Flowering and pod set: 65-85°F
Temperatures below 50°F or above 95°F can cause issues with germination, growth, flowering, and pod production
Green beans grow best with daytime temperatures around 75°F and night temperatures above 60°F. Consistent temperatures in this range will produce the highest yields.
Minimum Temperature Tolerance
While green beans prefer warm weather, they can tolerate cooler temperatures at certain growth stages:
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Germination: Seeds can germinate at soil temperatures as low as 50°F, but 60-70°F is ideal for quick, uniform sprouting. Temperatures below 50°F significantly slow germination.
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Seedlings: Young green bean plants can withstand light frosts and temperatures down to 40°F for short periods of time. Prolonged exposure below 40°F will damage seedlings.
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Mature plants: Once green bean plants are established, they can tolerate temperatures into the 30s °F before being damaged by cold weather.
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Flowers/pods Green bean flowers and pods are the most sensitive to cool temperatures. Temperatures below 50°F can cause flowers and pods to drop
Protecting Green Beans from Cold
Here are some tips to protect your green beans if colder-than-normal weather is expected:
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Delay planting: If cold temperatures are forecasted, wait to plant until the 10-14 day outlook shows a warming trend.
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Use row covers: Cover rows with fabric row covers, tunnels, or other protections to keep plants warmer. Remove during the day to allow pollination.
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Use cloches: Mini greenhouses called “cloches” placed over individual plants can add several degrees of protection. Make sure to ventilate cloches on sunny days.
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Insulate the soil: Spreading straw, leaves, or other organic mulch over the soil can help retain heat around the plant roots.
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Provide wind protection: Windbreaks, trellises, or supports can shield plants from chilling winds that can damage growth.
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Water judiciously: Avoid overwatering before a cold spell, as wet soil loses heat more quickly than moist soil.
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Harvest promptly: Pick beans as they mature to avoid losing any that get damaged by cold temps. Overripe beans are more susceptible to cold injury.
When to Plant Green Beans
Knowing when to safely plant green beans in spring is key to avoiding cold damage. Here are some tips:
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Wait 2-3 weeks after the average last frost date for your area before sowing seeds directly in the garden.
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If planting transplants, wait 1-2 weeks after the last frost date.
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Monitor extended weather forecasts. Avoid planting if cold temperatures are predicted in the 10-14 day outlook.
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Test soil temperature at planting depth. Wait until it reaches at least 60°F before planting seeds.
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Use a soil thermometer to check temperature at the planting depth. Don’t rely on air temperature alone.
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In colder regions, use black plastic, cloches, or row covers to warm the soil before planting.
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If an unexpected late frost occurs, be prepared to protect young plants using the methods listed above.
Maturity Dates to Avoid Frost
When planning your green bean planting schedule, consider maturity dates so harvest is complete before frost threatens in fall:
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Bush beans: Plant early-maturing bush varieties (50 days or less) with successive sowings for continuous harvest through summer. Avoid late sowings that won’t mature before your first fall frost date.
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Pole beans: Pole varieties need a longer growing season, often 60 days or more. Time plantings so mature beans are ready for harvest at least 2-3 weeks before the anticipated first autumn frost.
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Succession planting: Staggering small plantings every 2 weeks ensures a steady supply without leaving a large crop exposed to frost at the end of the season.
Protecting Late-Season Plants from Frost
If frost threatens before the end of bean harvest, here are some emergency measures to try:
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Cover plants with frost blankets, row covers, sheets, or tarps overnight and remove them in the morning after temperatures warm.
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Provide insulation by mounding soil, compost, or mulch around the base of plants.
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Give plants a deep watering before frost to aid in temperature retention (but avoid overhead watering which can exacerbate frost damage).
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For pole beans, detach vines from supports and allow them to sprawl on the ground, which radiates heat back to the plants.
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Harvest all mature beans promptly so they don’t succumb to cold damage on the vines.
While no method is fail-proof, taking proactive measures can help minimize frost risks and keep your green beans thriving through cold snaps. Paying close attention to the weather, planting timing, and cold tolerance is key to success. With proper care, you can enjoy a bountiful harvest of green beans despite cool temperatures.
Cold Pack Green Beans Canning
FAQ
Can green beans survive 40 degrees?
Can green beans survive a light frost?
What temp is too low for green beans?
Are green beans cold hardy?
Are green beans frost tolerant?
Green or string beans (Phaseolus vulgaris) come in two varieties, bush and pole, and when you are growing them, the green beans’ frost tolerance and temperature requirements are important to note. Beans, in general, are not the most frost-tolerant vegetables, but with a bit of care and knowledge, you can be sure that your bush beans will do well.
What temperature should green beans grow?
Use an inexpensive moisture meter, and keep in the 4-7 range to ensure you’re giving them the perfect amount. The ideal temperature range for growing green beans is between 65-85°F. They are not tolerant of extreme temperatures, either heat or cold. When it falls below that, growth will slow, and frost will eventually kill the plant.
Can green beans grow in cold weather?
Green beans will not usually thrive in cold temperatures like in slightly cooler temperatures. They are considered to be warm-weather crops because they will best germinate anywhere around 70-80 degrees F. While they are likely to tolerate slightly cooler temperatures, it’s best not to begin sowing until the chances of a late frost have passed.
How long do green bean plants live in cold weather?
Though green bean plants can live for more than one year in an ideal climate, they cannot tolerate the cold or extreme heat. High temperatures will cause blossom drop and stop pod development. Cold weather will also stop growth, and frost will eventually kill them.