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Frost & Cold Injury

Frost & Cold Injury

Disorderalso: Frost damage, Freeze injury, Cold injury

Physical damage to plants from freezing or near-freezing temperatures, when ice forms in or around the plant tissue and ruptures the cells. Frost injury is a top cause of lost transplants and ruined harvests at the cold ends of the season, but it often looks worse than it is, and many plants recover from a light frost.

🔎 How to spot it

Look for leaves and shoots that turn dark, water-soaked, and limp within a day or two of a cold night, then dry to brown or black and wilt or collapse. Tender new growth, blossoms, and fruit are hit first, and open flowers may brown and drop. On fruit, watch for sunken, pitted, or streaked areas. The damage appears soon after the cold event, not gradually over weeks.

🥀 Damage it causes

Freezing ruptures plant cells, so frosted tender growth wilts, blackens, and dies, and a hard freeze can kill an unhardened transplant outright or destroy a bloom and the crop it would have set. Damage ranges from a few scorched leaf tips after a light frost, which the plant outgrows, to total loss of a tender crop after a hard freeze.

🔬 What causes it

Cold injury occurs when temperatures drop low enough to freeze water in or around the plant tissue, bursting the cells. How much harm depends on how cold it gets, how long, and how hardy and hardened the plant is: tender, lush, unhardened growth and warm-season crops are most vulnerable, while cool-season crops tolerate frost. Clear, calm, dry nights and low spots where cold air pools raise the risk.

🛡️ Prevent it

Know your frost dates and each plant cold tolerance, and do not set tender crops out until the danger passes. Harden off transplants before planting. When frost threatens, cover plants in the evening with row cover, sheets, or boxes, water the soil beforehand since moist soil holds heat, and use cloches or cold frames for extra protection. Keep tender crops out of low, frost-pooling spots.

🧯 If it is already here

Do not prune frost-damaged growth right away; wait until the weather settles and you can see what truly died, since the plant may push new growth from below. Keep it watered and let it recover. Hosing a light frost off the foliage before the morning sun reaches it can sometimes reduce the damage. For a hard freeze that kills a tender crop, replanting once the danger passes is usually the answer.

💡 Good to know

Frost injury often looks fatal but is not: many plants recover from a light frost, so it pays to wait and see before pulling them. Cool-season crops like kale, spinach, and broccoli shrug off frost that would kill tomatoes and peppers, and a few, like kale, even sweeten after it. Low spots where cold air settles frost first, so where you plant tender crops matters.

🌱 Plants it affects

714 plants in the library can be affected by this problem

Acorn SquashAdirondack Blue PotatoAdzuki BeanAfrican Blue BasilAfrican MarigoldAgapanthusAgeratumAgrimonyAji Amarillo Pepper🍓Albion StrawberryAlice du Pont Mandevilla🥔All Blue PotatoAlmondAloe VeraAmbrosia CornAmerican BasswoodAmerican Beauty Dragon FruitAmerican BeechAmerican PersimmonAmethyst Falls WisteriaAmish Paste TomatoAnaheim PepperAnemoneAngelique TulipAngeloniaAniseAnise HyssopAnjou PearAnnabelle Smooth HydrangeaAnnual VincaApeldoorn TulipApple MintApril Tryst CamelliaArbequina OliveArizona Sun Blanket FlowerArkin CarambolaArmenian CucumberAroniaArp RosemaryArugulaAshwagandhaAsian PearAsian PersimmonAtemoyaAtlantic Giant Pumpkin🥕Atomic Red CarrotAucubaAugust Beauty GardeniaAunt Molly's Ground CherryAutumn Joy SedumAvocadoBachelor's ButtonBalsam FirBalsam PoplarBanana PepperBarbara Karst BougainvilleaBartlett PearBay LaurelBayberryBeach PlumBeauregard Sweet PotatoBecky Shasta DaisyBee Balm🍅Beefmaster TomatoBenarys Giant ZinniaBengal Tiger CannaBetter Boy Tomato🥬Bibb Lettuce🍅Big Beef TomatoBig Boy TomatoBilberryBing CherryBitter MelonBlack BeanBlack Beauty EggplantBlack Beauty ZucchiniBlack Beluga LentilBlack Cherry TomatoBlack CrowberryBlack Currant🍉Black Diamond WatermelonBlack Kabouli ChickpeaBlack Krim TomatoBlack RaspberryBlack Sapote🥬Black Seeded Simpson Lettuce🥕Black Spanish RadishBlack Tartarian CherryBlack WalnutBlack-Eyed PeaBlack-eyed Susan VineBlood OrangeBloomsdale SpinachBlue Bird DelphiniumBlue Bird Rose of SharonBlue FescueBlue Lake Green BeanBluecrop BlueberryBocking 14 ComfreyBok Choy

For educational and informational purposes only. Disease management advice is general guidance drawn from university cooperative extension sources; always identify a problem positively and read and follow the label on any product before use, especially around food crops, children, and pets.