Asked by: Denia Vakulovsky
home and garden landscaping

What temperature can tomato seedlings tolerate?

Last Updated: 13th May, 2020

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Generally, seedlings should not go below 45 degrees Fahrenheit (7 C), and may be killed below 35 degrees (2 C). They can stand temps a bit lower but they almost stop growing until the temp is a bit warmer. Tomatoes grow best between 50F (10 C)and 75F (25 C) degrees.

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Then, what is the lowest temperature tomatoes can tolerate?

Although tomato plants can survive temperatures down to 33 degrees Fahrenheit, they show problems when temperatures drop below 50 degrees F, according to the U.S. Department of Agriculture Research Service.

One may also ask, what temperature can seedlings handle? Keep an eye on the nighttime temperatures in your area as you transplant seedlings outdoors. Some plants, such as onions, can handle freezing temperatures after you harden off seedlings. Other plants, such as tomatoes, will suffer if the temperature goes below 65 degrees Fahrenheit (18.33 degrees Celsius).

Considering this, how cold is too cold for tomato seedlings?

Tomato plants at any age or stage do not tolerate frost. You can generally move young seedlings outdoors when the temperature rises about 45 degrees Fahrenheit. A temperature of 46 F would be warm enough for tomato seedlings.

Is 40 degrees too cold for tomatoes?

Although mature plants might survive light frosts, temperatures below 40 degrees Fahrenheit damage flower and fruit production, making tomatoes perennial only in U.S. Department of Agriculture zones 12 and up. They flower and set fruit best when the air and soil temperatures range between 60 and 70 degrees.

Related Question Answers

Amaya Kuchlin

Professional

What temperature will kill tomato plants?

Tomato plants will survive temperatures down to freezing, so a low temperature of 35 degrees will not kill them. Insulate the plant with sheets or cloches if frost threatens. To ensure plant safety, protect tomato plants any time a temperature of 35 degrees or below is expected.

Laxman Hardt

Professional

What temperature should you cover tomato plants?

The covers can keep the plants in the temperature range of 35 to 40 degrees Fahrenheit if the outdoor air temperature falls to 30 degrees Fahrenheit. Self-watering ground containers can be added protection devices for shielding large tomato plants from frost damage and bloom drops in early spring.

Jaspal Zhirikov

Professional

At what temp should you cover plants?

* Cover plants at night. Covers vary in their insulation characteristics, but they can generally add 3 to 5 degrees to the ambient air temperature, helping to protect plants against freezing temperatures. They can be used on nights where temperatures drop as low as 28 F.

Keiko Merlini

Explainer

At what temperature should I cover tomatoes?

Tall and rangy cherry types can be trained up a trellis or over an arch. Tomatoes grow best when the daytime temperature is between 65 and 85 degrees Fahrenheit. They stop growing above 95 degrees Fahrenheit. If nighttime temperatures are above 85 degrees Fahrenheit, the fruit will not turn red.

Flerida Serrano

Explainer

Can tomato plants grow in pots?

Tomatoes can grow to over 6-8 feet tall and 2 feet across, a half whiskey barrel sized pot is just enough to accommodate the roots for that size plant. Small pots do make smaller plants but that also means a lot less fruit and many of the problems mentioned above.

Kaitlin Baruque

Explainer

When should I put my tomato plants outside?

You don't want to be starting your tomato seeds more than six weeks before nighttime temperatures (either outdoors or in your greenhouse) are reliably above 57 °F (14 °C) although most varieties will tolerate temperatures a little cooler—note emphasis on 'tolerate!'

Yadhira Roselo

Pundit

Should I bring my tomato plants inside?

Tomatoes need full sun and at least eight hours of light to produce any fruit. Temperatures should be in the range of 65 F. One way to preserve your summer tomatoes is to bring them inside at the end of summer. You may be able to save the tomato plants over winter for a period.

Haroun Heydenblut

Pundit

Is 40 degrees too cold for plants?

Houseplants need to be taken indoors before overnight temperatures dip below 45 degrees Fahrenheit. Most tropical plants suffer harm from temperatures below 40 degrees. If the plant is crowding the pot, repot it into a larger container before taking it indoors.

Gigel Pflugerer

Pundit

What happens if you plant tomatoes too early?

Planting too early in cooler temperatures can cause stunted growth, wilting, surface pitting, foliage necrosis and increased susceptibility to disease. Low soil temperatures can stunt plant growth and prevent root development.

Vivas Vrignaud

Pundit

How do you cover tomatoes with plastic?

First, take a clear plastic garbage bag and cut the bottom seam off so you are left with a clear tube. Then place it on the ground over the pepper or tomato plant. Then simply place 4 small wooden stakes into the ground around the plant, on the inside of the bag.

Liliia Majewski

Pundit

Can you grow tomatoes in the shade?

For example, not all tomatoes will tolerate low light, but cherry tomatoes can actually do quite well in the shade. When selecting plants for your shade garden, look for short season varieties of heat loving plants such as tomatoes and peppers.

Coronacion Treurniet

Teacher

Can it frost at 45 degrees?

A rule of thumb: If the dew point is above 45 degrees at sunset then you are probably OK. Below 40 degrees you will probably see a frost if the other conditions are good.

Jayro Jurken

Teacher

What season is tomatoes grown?

Tomatoes run on warmth; plant in late spring and early summer except in zone 10, where they are a fall and winter crop.

Allan Yetman

Teacher

When can I put my seedlings outside?

You can start to harden off your seedlings once they've grown at least two to three sets of leaves. At that point, they're mature enough to move outside. About 7 to 10 days before your seedlings are ready to be transplanted, take them outside and leave them in the shade for a few hours in the morning or afternoon.

Bertina Nadvornizch

Reviewer

Will 45 degrees hurt plants?

Cold weather, even if it doesn't drop below freezing, can harm cold-sensitive plants. Freezes are rare, but frosts can occur at above-freezing temperatures. Even temperatures at 45 degrees for more than several hours can harm some tropical orchids. Heavily water plants before the cold arrives.

Maricela Bartscheerer

Reviewer

What temperature kills Basil?

(0 C.). The herb may not die, but basil cold damage will be in evidence. Keep in mind the cold tolerance of basil and wait until overnight lows are above 50 degrees F. (10 C.)

Candida Paeffgen

Reviewer

Should I cover my seedlings?

Moisten the newly planted seeds with a mister or a small watering can. To speed germination, cover the pots with plastic wrap or a plastic dome that fits over the seed-starting tray. This helps keep the seeds moist before they germinate. When you see the first signs of green, remove the cover.

Voncile Stiefenhofer

Reviewer

Do seeds die if they freeze?

Freezing seeds does not harm them, and can greatly extend their lifespan if done properly. All seed banks freeze their seeds intended for long term storage! Humidity is a greater concern with freezing, as a blast of warm humid air on frozen seeds can damage them.

Nuti Ochsendorf

Supporter

Can seeds grow after being frozen?

Improper freezing can kill some seeds, but other seeds may be less fussy. In fact, many wildflower, tree and shrub seeds actually require a cold period, or stratification, before they will germinate. In spring rising temperatures and moisture will trigger these seeds to sprout.