Last Updated on September 18, 2026

Vegetable Frost Tolerance Chart: Which Crops Survive 32°F, 28°F and Below

Cover tender crops like tomatoes, peppers, beans, squash and basil when the forecast low is 36°F or colder, because frost can form on leaves before the air reaches freezing. Semi-hardy crops like lettuce, beets, chard and peas take a light freeze down to 28°F, and hardy crops like kale, cabbage, collards and Brussels sprouts take a moderate freeze down to 24°F before they need a cover.

Cover at this temperature

The lines come from extension services. SDSU Extension says crops from temperate regions withstand light freezes of 28 to 32°F, cole crops tolerate moderate freezes of 24 to 28°F, and crops from warmer parts of the world cannot take even a light frost. Iowa State University Extension says to act once lows dip to the mid-30s, notes that the National Weather Service issues frost advisories for forecast lows of 33 to 36°F, and says covering typically stops preventing cold damage below about 28°F. Its cold damage guide adds that tomatoes, peppers and beans do not tolerate freezing temperatures below 32°F.

The harvest-first lines sit one step colder than each class can take. Tender crops do not tolerate freezing, so pick them when the low will be 32°F or colder. For hardy crops the line is 20°F, because University of Minnesota Extension lists kale, collards, cabbage and Brussels sprouts as the hardiest crops, down to about 20°F. For semi-hardy crops the line is 24°F: SDSU counts anything under 24°F as a severe freeze, and Utah State University Extension says most row covers give freeze protection only down to around 24 to 28°F.

What to cover tonight

Type in tonight’s forecast low, or tap a preset, and the tool sorts every crop in the chart into harvest first, cover, fine uncovered, or perennial. It works in °F or °C. The example below is a 26°F night, before you change anything.

Look up one crop

Vegetable frost tolerance chart

All 57 crops in the chart, grouped hardy, semi-hardy and tender. The class for each crop comes from the Plan My Garden planner’s crop data, and the notes add crop-specific numbers or advice where an extension service gives them. Filter by class, search for a crop, or print it.

Show All classesHardySemi-hardyTender Find a crop Showing 57 of 57 Print the chart

Sources for the notes: SDSU Extension · SDSU on tomatillos · Iowa State · Minnesota · Delaware · Maryland · Penn State · Penn State on annuals · Illinois · Illinois on annuals · Utah State on celery · Wisconsin on dill · Wisconsin on nasturtium. Sources sort a few crops differently: SDSU puts carrots and spinach with the light-freeze crops and broccoli with the moderate-freeze cole crops, while Iowa State calls carrots and spinach very hardy. When the class and a note disagree, protect to the more cautious number.

These temperatures only tell you what to do once you know when the cold arrives. Enter your zip code in Plan My Garden and it finds your frost dates.

Frost vs freeze

They are not the same thing. SDSU Extension defines a freeze as air at 32°F or below, when water inside plant cells can freeze, expand and rupture the cells. A hard or killing freeze is 28°F or lower. Frost is ice that forms when the air is near freezing, loosely 33 to 36°F, but leaves, soil and other surfaces drop to 32°F. Surfaces cool faster than air, so you can get frost on a night the thermometer never reads 32.

The damage looks different too. SDSU describes frost injury as usually more superficial: bronzed or bleached patches, burned leaf edges, small dead spots. A freeze leaves tissue water-soaked, then limp, brown or black.

The kind of night matters. Colorado State University Extension explains that radiation frosts come on calm, clear nights and usually drop only a few degrees below the damage point, which makes covering worthwhile. Advective frosts arrive with a cold front and can drop far below it, which makes protection questionable.

How long the cold lasts matters

The number on the forecast is only half of it. SDSU Extension notes that a few minutes of frost may cause little harm, while several hours can cause significant injury. Iowa State says plants can be damaged even under a cover at temperatures above 28°F when the below-freezing stretch lasts 5 hours or more. Put the hours in the tool above and it reminds you.

Warm days afterward help. SDSU says warm temperatures after a short cold spell can reverse some injury: pumpkins can take 35°F nights if the days reach 70°F or more. Iowa State points out that a first freeze is often followed by a week or more of warmer weather, which is why covering for one cold night can buy you more harvest.

How to cover plants for frost

Covers work by trapping heat the soil soaked up during the day. Iowa State says coverings trap the radiant heat from the ground, and in Colorado State trials a low, spreading frame was ideal for trapping heat from the soil on a frosty night. Iowa State lists sheets, blankets, towels, tarps, frost fabric and row cover as coverings that work. My fall crop planting guide also suggests old bed sheets, burlap sacks or cardboard boxes, and having frost cloth on hand before the first chilly night.

1. Water the soil around your plants the day before an expected frost. Moist soil absorbs and holds heat better than dry soil, as my fall crop planting guide explains.
2. Cover in the evening as the sun sets, before the temperature drops.
3. Hold the cover off the leaves with stakes, PVC pipe, wire loops or patio furniture (Iowa State). Utah State University Extension warns that plastic touching leaves can freeze them.
4. Take the cover to the ground and weight the edges with bricks or stones so there are no gaps for heat to escape (Utah State).
5. Keep fabric dry. A wet sheet or blanket cools by evaporation and can make it colder next to the plants (Colorado State).
6. Take the cover off the next day once it is above freezing (Iowa State). That keeps the plants from overheating (Utah State) and lets the soil recharge in the sun for the next night (Colorado State).

How much each cover helps

The row cover grades are from University of Maryland Extension. Heavier fabric also lets less light through: 90 to 95 percent for the lightweight grade and 30 to 50 percent for the heavyweight grade. Maryland calls the heavyweight grade useful for covering overwintering crops. Numbers vary by source: University of Delaware expects 2 to 6°F from floating row covers depending on thickness.

For single small plants, Utah State describes homemade cloches made by cutting the bottoms off plastic milk jugs, and rates a cold frame’s protection as medium, a step above a cloche or floating row cover (low to medium). My cold frame tips cover where to put one, venting it on warm days, and adding bubble wrap, row cover or old blankets on cold nights.

Crops that get sweeter after frost

Cold makes some crops taste better. Penn State Extension calls it winter sweetening: through the season these plants store energy as starch, and as temperatures drop they convert some of it to sugar. Carrots, turnips, rutabagas and beets are roots that sweeten with frost, and Brussels sprouts, broccoli, kale and most leafy greens do too. University of Maryland Extension adds that the same starch-to-sugar conversion makes the plants more cold-hardy.

• Root crops: SDSU says they build more sugar once the soil is below 40°F.
• Brussels sprouts: often best after a light freeze, and SDSU suggests harvesting them after several moderate freezes of 24 to 28°F.
• Kale and collards: University of Minnesota Extension says the cooler the fall weather, the better the flavor, until freezing temperatures stop growth. The leaves can be picked and cooked even after they have frozen.

What to harvest before a freeze

SDSU Extension says these have no frost tolerance and should be protected or harvested before even a light frost: beans, sweet corn, potatoes, peppers, eggplant, cucumbers, summer squash and melons. Pumpkins and winter squash may take a very light frost, but it is better to protect them. SDSU adds sweet potatoes, ideally dug before the soil drops below 50°F, and the University of Delaware says to dig them quickly once frost kills the vines, and that the roots suffer damage if the soil drops below 40°F. After digging, see how to cure sweet potatoes.

Some keep ripening after you pick them, so they can come in before they are fully ripe:

• Tomatoes: pick any that are at least mature green, which SDSU describes as changed from deep green to almost turning red. The University of Delaware advises picking ripe, breaker and mature green fruit ahead of a frost. Then see how to ripen green tomatoes indoors.
• Tomatillos: harvest all the fruit, ripe or unripe, before a freeze. Fruit ripens further after it leaves the plant, so store it in its husk (SDSU Extension).
• Cantaloupe: ready when it slips easily from the vine, and it ripens further at room temperature (SDSU).
• Pumpkins: fruit that has started to turn color keeps turning, though it usually will not keep as well as fruit that colored on a healthy vine (SDSU). Delaware notes a light frost kills pumpkin and winter squash vines but leaves the fruit usable; heavier frosts and freezes damage it. To store them, see how to cure winter squash.
• Peppers: they handle a light fall frost better than tomatoes (Delaware). To keep a plant going, my pepper overwintering guide says to start when nights dip below 50°F and bring it in before any frost damage.

Once frost kills the tender crops, cut them at the soil line and leave the roots in, compost the tops, and cover the empty squares with two inches of compost. The rest of the fall list is in How to Prepare Your Garden for Winter.

Find your first fall frost date

This chart is about the crop, not the calendar. To see when frost usually arrives where you live, use the Plan My Garden frost date lookup: enter your zip code and it finds your frost dates, including your first fall frost. In spring, the Seed Starting Calendar turns your last frost date into start-indoors, transplant and direct-sow weeks, and the Seed Germination Temperature Chart covers the soil side.

Quick questions

What temperature should I cover my plants?

Cover tender crops like tomatoes, peppers, beans and squash when the forecast low is 36°F or colder. Semi-hardy crops like lettuce, beets and chard are fine uncovered down to 28°F, and hardy crops like kale, cabbage and collards are fine down to 24°F.

What temperature kills tomato plants?

Tomatoes do not tolerate freezing temperatures below 32°F, and frost can damage them when the low is under 36°F, according to Iowa State University Extension. Pick ripe, breaker and mature green fruit before a frost; SDSU Extension says mature green tomatoes ripen further after picking.

Will a frost kill broccoli?

Usually not. SDSU Extension says broccoli and cauliflower tolerate about 26°F, and this chart has you cover them below 28°F to leave a margin. Cauliflower deteriorates quickly once frozen, according to the University of Delaware, so cut heads that are ready before a hard freeze.

Can kale survive a freeze?

Yes. University of Minnesota Extension lists kale, collards, cabbage and Brussels sprouts as the hardiest, down to about 20°F, and you can still pick and cook kale leaves after they have frozen.

Does covering plants work below 28°F?

Usually not. Iowa State University Extension says covering is typically no longer effective at preventing cold damage below about 28°F. SDSU Extension says hardy cole crops like kale tolerate moderate freezes of 24 to 28°F on their own, and heavyweight row cover, 1.5 to 2.2 ounces per square yard, gives up to 8°F of protection, according to University of Maryland Extension.

Let the planner do the frost math

Frost dates are where every planting schedule starts. Plan My Garden is free to start: enter your zip code and it finds your frost dates, draw your beds, pick kale, lettuce, tomatoes and everything else you want to grow, and it places each plant at square-foot spacing and builds a planting schedule from your frost dates.

Related: Seed Germination Temperature Chart · Seed Starting Calendar · 5 Tips for Using a Cold Frame · Fall Crop Planting · Square Foot Gardening Chart