Some gardeners live in fear of frost. Even as the days begin to warm, a surprise cold snap could mean the end of the road for precious tomatoes and peppers sown too soon. Growers in a handful of tropical areas may not experience such trepidation, but for most gardeners, the fear of frost is alive and well.
There are cold hardy vegetables that can be planted in your garden before, though. In fact, there may be more of them than you think.
Certain cold-hardy plants can survive a light or moderate frost and prosper even if spring temperatures have not quite stabilized. These plants can thrive in cold soil temperatures, compared to their later season counterparts which need a warmer growing medium.
Cold-hardy plants
Carrots
Corn
Peas
Onions
Seed potatoes
Parsnips
Spinach
Turnips
Lettuce
These can all be sown directly into the ground once the soil has thawed enough to be workable.
“Plants like carrots and even corn, they are really hard to transplant and they will germinate right into the soil anyway,” said Wendy Wilber, statewide Florida master gardener coordinator at the University of Florida.
Some long-season seedlings can also be planted before the last frost. Broccoli, beets, cabbage, cauliflower and kale can all be started from seed indoors before bringing them out several weeks before your projected frost-free date. Seedlings should be “hardened off,” or brought outside to face the elements during the day for about a week before you transplant them in order to let the plants acclimate to the elements.
“You’re gradually exposing them to lower temperatures, increased air flow and increased light,” said Kate Garland, horticultural specialist at the University of Maine Cooperative Extension. “Even a week is helpful.”
If you do not start your plants from seed, you can still purchase seedlings from a nursery to plant before the last frost. Just make sure those plants have been properly hardened off as well.
“Ask the nursery staff,” Garland advised. “You can also tell by looking at where they’re stashed. If they’re outside, then they’re probably hardened off, but it’s always good to double check.”
Some perennial crops can be planted before the last frost-free date as well. “Things like asparagus and rhubarb and strawberries, and woody plants like blueberries, raspberries and fruit trees do better if they’re planted a little bit early,” Garland said.
Finding your last frost date
To avoid planting too early, be sure to check the last frost date for your area. You can call your local cooperative extension for the information, but there are a number of online search tools that will provide the projected last frost date based on your zipcode.
The National Gardening Association provides a range of dates and the probability of freezing or below freezing temperatures for each based on data from the National Oceanic and Atmospheric Administration. Dave’s Garden’s search tool does the same with data from the National Climatic Data Center.
Precision can be important when avoiding frost, especially for cold, northern climates. Garland recommends exercising caution.
“I usually set the threshold of 10 percent of having less than 32 degrees,” Garland said. “I’ve gotten my heart broken before.”
Garland said to look at the current weather patterns and projected forecast about a week before you plant as well.
“Curveballs late in the season are common,” Garland said. “It’s really important to look at that ten day forecast before you plant.”
The growing season starts earlier and the risk of a surprise frost late in the season is lower in warmer states, but it is still important to be vigilant.
“We plant quite a lot in January and February, but we don’t plant our spring crops much before [the last frost-free date],” Wilber said. “We’ve had a couple springs where the climate has been very warm up until that last frost date, and then we still get a surprise freeze. One year, we got a freeze on St. Patrick’s Day.”
There are season extenders that can help protect your crops in case of any unexpected cold snaps.
“You may get caught by a light freeze. Be ready, because mother nature is mean and she likes to laugh at us,” Wilber said. “Have your season extenders in place whatever your favorite one is.” Wilber said her personal favorite is a frost cloth to cover plants in case of a cold weather emergency.
Planning your planting before the frost-free date
When exactly you will plant or transplant your crops before the last frost will depend on where and what you plant. For example, broccoli can usually be planted two weeks before the last frost date, while cabbage and collards can go out about four weeks before.
To ensure proper timing, you can use a handy planting calculator like this one from Johnny’s Selected Seeds, or contact your local cooperative extension for more resources.
If you are looking to maximize your yield, Wilber said it is best to have a plan. Keeping track of where you grow which crops also helps you prevent growing the same things in the same spots season after season, which can cause fungal pathogens and insects to build up.
“I recommend folks rotate their crops so they can have a plot plan,” Wilber said. “You can have it in a beautiful garden journal.”
Even though there are lots of options for planting before the last frost-free date, Garland said not to feel pressured to start too early.
“You can plant late and still get a great yield from your garden,” Garland said. “Don’t feel rushed.”
Carrots, corn, parsnips, spinach, turnips, peas, onions, lettuce and seed potatoes can all be sown directly into the ground once the soil has thawed enough to be workable.
Some seeds and plants actually thrive in cooler air and soil and should be planted before the last frost date. This list includes cole crop vegetables, such as kale, broccoli, Brussels sprouts, mustard and collard greens, turnips and cabbage.
Herbs well suited for growing in cool weather are cilantro, chervil, chives, dill, and parsley. Unlike warm-weather summer-grown herbs, cool-weather herbs can be sown directly in the garden a month or more before the last frost in spring for late spring harvest and again in late summer for fall harvest.
You don't have to wait until your last frost date to transplant them into the garden, however, there are some simple steps you'll want to take to protect those new sprouts. We generally like to plant as soon as our soil is workable.
A light frost may cause minimal damage while a severe frost may kill plants. Young, vulnerable plants are much more susceptible to a light freeze, which occurs when temperatures are 29 to 32 degrees Fahrenheit, while mature plants may only suffer from short-term effects.
There are some things you can plant as early as five weeks before the last frost. If you want to get an early start on a vegetable garden, you can seed beets, carrots and peas. Pansies and violas are two annual flowers you can plant five weeks prior to the first frost.
The following seeds can be started indoors 10 weeks before the last frost date: thyme, mint, chives, oregano, artichokes, onions, celery, leeks, and peppers.
Starting in September, it is beneficial to watch the forecast and take note of forecasted low overnight temperatures. Once temperatures dip to the mid-30s °F, it will be necessary to take action by bringing plants indoors, covering plants, or utilizing cold frames and hoop tunnels.
According to Myers, the hardiest vegetables that can withstand heavy frost of air temperatures below 28 include 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 turnip.
Tender herbs need harvesting before the temperature hits freezing and damages the plants. Keep watch on basil, lemon verbena, stevia, lemongrass, calendula, borage, dill, cilantro and other tender plants. Depending on your winter weather, you might need to harvest chives, thyme, mint and parsley before they go dormant.
Japanese Yew. Japanese yew (Taxus cuspidata) is a good choice for an outdoor winter plant because it's an evergreen that keeps its leaves on its branches all winter long. It's drought-tolerant and thrives in both full and partial sun. Hardy to Zone 4, Japanese yews can survive harsh winters.
When To Plant Blueberries. You can plant blueberry bushes at two times in the year—in the fall or in the early spring after your last frost. While you can do either, I'm a bit partial to fall planting when I can, only because there are so many other things to plant in the spring!
Tender (not cold-hardy) vegetables are injured or killed by frost, and their seeds do not germinate in cold soil. They are usually planted at the average frost-free date in the spring. Warm-loving heat-hardy) vegetables are intolerant of frost and cold and require warm soil temperatures for germination and wood growth.
Onions can withstand frosts and moderate freezes, but you must shield them from hard freezes — that is, periods of at least four hours of temperatures below 25 degrees. They can survive temperatures as low as 20 degrees, but not for long.
Onions can withstand light to heavy frosts and moderate freezes, but hard freezes can result in onion damage. Covering the plants with a protective covering or tarp will greatly reduce freeze damage, especially if temperatures are dropping below 20˚F.
All of the vegetables that scream summer – tomatoes, basil, summer squash, peppers, and eggplant – will not survive low temperatures. If it hits 32 degrees F in your garden, these plants will be brown and dead in the morning. (Note: basil can start getting frost damage at 38 degrees F.)
Impatiens: Sow 8-10 weeks prior to the last frost. Warm, moist soil and indirect light are ideal for these flowers. Marigolds: Start 6-8 weeks before the last frost, needing a warm, sunny spot to grow. Begonias: Start about 12-14 weeks before the last frost.
In contrast, perennials (the garden plants that come back year after year), shrubs, and trees can usually withstand a sudden drop in temperature, as long as they are healthy and hardy in your region. A spring freeze might damage developing fruit and destroy flowers, but these plants will survive.
Visible signs of frost damage usually occur within two to three days and include browned, mushy leaves and buds. To protect your new plants, trees and flowers from frost and freezing weather, you'll need to cover them or if you're able to, bring them inside your home or garage to prevent freezing.
Hobby: Calligraphy, Rowing, Vacation, Geocaching, Web surfing, Electronics, Electronics
Introduction: My name is Msgr. Benton Quitzon, I am a comfortable, charming, thankful, happy, adventurous, handsome, precious person who loves writing and wants to share my knowledge and understanding with you.
We notice you're using an ad blocker
Without advertising income, we can't keep making this site awesome for you.
