Is it possible to overwinter tomato plants (zone 9)?
If you’ve ever wondered, Do tomato plants survive the winter? Indeed, it is a resounding yes. Tomato plants are perennials that thrive for many years in their original tropical growing zone. They do not survive the winter outside in frigid areas since they are not frost-tolerant. As a result, most gardeners plant tomatoes as annuals. We plant them in the spring after the danger of frost has passed, harvest them through the growing season, and then uproot and compost the plants as soon as they’ve been killed by freezing temperatures. Tomato plants, on the other hand, may thrive and produce for many years if you put in a little work. In this essay, I’ll show you four different techniques to overwinter tomato plants and maintain them from year to year.
How to keep a tomato plant alive in winter
After putting in tons of effort to grow healthy and productive tomato plants throughout the growing season, it’s always a heartache to watch them succumb to freezing temperatures. Hence, if you want to know what to do with tomato plants in the winter, you must first grasp the significance of time. Starting your tomato overwintering attempts too late diminishes your chances of success. Start thinking about overwintering four weeks before the first forecast autumn frost. In Pennsylvania, I begin planning to overwinter a few tomato plants in mid to late September.
Four weeks prior to your expected first frost, it’s time to think about which one of the four techniques featured below will work for you, your family, and your home. Since not everyone has grow lights or a greenhouse, those approaches may not be suitable for everyone. But most of us have a garage, a basement, or a sunny windowsill, so there’s sure to be an option available for all gardeners. I start preparing my plants after I’ve decided which strategy I want to follow.
How to prepare tomato plants for overwintering
I also start paying close attention to the forecast around four weeks before an usual first frost. If I get an unexpected premature frost and cold weather arrives earlier than expected, I could lose my tomato plants to a surprise freeze, and there go my chances of overwintering them. It’s much better to begin overwintering tomato plants early than to wait too long and get caught with your trousers down!
Prepare plants by keeping them well-watered for at least a few weeks before transferring them. At this period, remove any sick leaves from the plant and inspect for pests. If you discover whiteflies, aphids, caterpillars, or other destructive insects, eliminate them before attempting to overwinter your plants.
If you plan to use one of the first two methods described below and your tomato plant is currently growing in the ground or in a raised bed, you’ll need to dig it up and transplant it into a pot. Utilize fresh, sterile potting soil and attempt to extract as much root mass as possible. Put the pot on a porch or patio for a week to ten days, and make sure it gets frequent thorough watering. If the plant is already growing in a pot, that’s fantastic. Your task is considerably simpler. The transplanting step is optional.
4 ways to overwinter tomato plants
As you will see, the question Can tomato plants survive winter? has a simpler solution than you would imagine. Here are four strategies for keeping your tomato plants safe and healthy throughout the winter months. Employ just one strategy or experiment with all four to determine which one works best for you. Don’t be frightened to try something new; you have nothing to lose. Your tomato plants were going to die from frost anyhow, so why not attempt overwintering them instead?
Method 1: Overwintering tomato plants in your house
When thinking about how to overwinter tomato plants, the most common thought running through a gardener’s mind is, Can I bring my tomato plant inside for the winter? In a nutshell, yes. Tomatoes may be grown inside as houseplants throughout the winter, but they may not produce blooms or fruits if not given adequate light (see section below about how to act as an artificial pollinator if they do produce flowers). This technique is best for determinate tomato plants, dwarf tomato varieties, or those that can be kept compact through regular pinching and pruning.
Can tomato plants survive the winter inside if grown as a houseplant? Absolutely. They do, however, have certain unique needs. The biggest disadvantage of this technique of overwintering is that indoor tomato plants need a lot of sunshine. Well, you may place the pots on a sunny windowsill, but even in the brightest window, they will usually survive the winter with just a few scraggly leaves. Our winter days in the northern hemisphere aren’t long enough, and the winter sun isn’t strong enough, to provide tomatoes with the light they need. If you have a grow light, you should try this approach.
Thankfully, there are many affordable, compact, and high-quality grow lights on the market these days. Floor lamp-style versions integrate perfectly into a room corner. A shelf of LED grow lights works if you have multiple tomato plants to overwinter and they are compact or dwarf types that don’t grow very tall. Keep the lights turned on for 18 to 20 hours every day. Keep an eye out for pests, since they find indoor tomatoes particularly tempting and may feed on the plant’s leaves.
In the spring, gently reintroduce your overwintered plants into the garden by gradually increasing the amount of time they spend outside each day over a two-week period. Afterwards, place them in the garden (or a bigger pot), give them a haircut to half their height, and start watering and fertilizing them regularly. It will let you to have a head start on the growing season and, perhaps more crucially, it will allow you to preserve a favorite variety from year to year.
Method 2: Growing tomato plants in a winter greenhouse
Tomato plants may be readily overwintered indoors if you have a greenhouse and a greenhouse heater. Some gardeners grow their tomatoes in a greenhouse or high tunnel throughout the entire growing season so that when the autumn weather grows colder, they merely have to close up all the vents and turn on the heat in order to protect the plants. The temperature does not need to be too high; anything over freezing will suffice to overwinter the plants. Nevertheless, if you want them to produce blossoms and fruits in the winter, you’ll have to strive for more tropical-like temps throughout year, which may be fairly expensive to attain.
Overwintering hybrid tomatoes like ‘Early Girl’ or heritage varieties like ‘Brandywine’ in a greenhouse is a realistic alternative. Determinate tomatoes and other more compact varieties fit well in tiny greenhouses. You’ll need to use stakes or a cage to support each vine through the winter as their stem growth can become soft and tender in the lower light levels of winter.
If you do want to try to get the plants to produce fruits in the winter, in addition to playing pollinator, you’ll have to add nutrients through the application of liquid fertilizers on a regular basis, perhaps every four to six weeks. But, if you just want to see the plants through the winter, don’t fertilize since it will promote excessive foliage development, which isn’t important during the colder months.
Method 3: Overwintering tomatoes as stem cuttings
This is one of my favorite methods to keep tomato plants alive through the winter. It doesn’t take up much space, and anybody can do it. A jar or plastic container with water and few tomato stem cuttings are all you need.
Cut 3- to 5-inch-long portions of stem from your tomato plants before the first frost. The nicest part of each stem is the tip. Alternatively, you can use the suckers produced at the leaf nodes as your cuttings. Remove all but the topmost leaf or two from each cutting and immerse the cut end in water. Place the pot on a sunny windowsill and label it with the variety name (the brighter the better).
The cutting will establish roots within a few weeks. Your goal for the rest of the winter is to keep the cutting alive by following these steps:
- Every two weeks, take the cutting out of the jar, rinse the roots under running water, and wash and refill the container with fresh water. Return the cutting to the water.
- Cut the top 3 to 5 inches of the cutting every six weeks to create a fresh cutting. To root the fresh cutting, repeat the method described above. You now have two cuts. The original one (with the top removed) will sprout side branches. The second cutting can have its top cut off in another six weeks to make a third cutting.
- About four to six weeks before your last expected spring frost, pot each of the cuttings into a fresh pot of sterile potting soil, planting them as deeply as possible. Place these potted cuttings on a sunny windowsill or beneath grow lights. Turn the pot a quarter turn every day to keep the growth even. If you’ve picked a potting soil that already includes fertilizer, don’t fertilize them.
- Once the danger of frost has passed, slowly acclimate your plants to outdoor growing conditions by following these hardening off instructions. After that, put your rooted cuttings in the garden.
By overwintering tomato plants via cuttings, instead of planting seedlings at the start of the next growing season, you’ll be planting tomato cuttings taken from last year’s plants. This strategy may be used with either indeterminate or determinate tomato plants.
Method 4: Keeping tomato plants in bare-root dormancy for the winter
This old-school way of keeping tomato plants alive over the winter isn’t as widespread as it should be. Maybe the tradition died out as it became simpler to buy fresh tomato seeds or plants each season. Whatever the reason, I would love to see this strategy regain favor. It’s really simple, and best of all, it results in an early harvest. With this method, the answer to Can tomato plants survive winter? is turned into a fun experiment for the whole family.
This technique involves overwintering tomato varieties in a state of dormancy where they have no soil on their roots (bare-root). It can be done in a cool garage, a cold cellar, or a basement that stays barely above freezing all winter long. You may also put the bare-root plants in the fridge as long as the temperature is not too low. Let me walk you through the process of overwintering tomatoes.
- Step 1: Uproot the whole plant just before a frost is forecast. There’s no need to be gentle about the process but do try to keep as much of the root system intact as possible.
- Step 2: Trim each vine down to approximately a foot in length, leaving the plant with just short, naked stems and no leaves.
- Step 3: Remove as much dirt as possible from the roots with a gentle brush or your fingertips.
- Step 4: Form a loose circle of roots by wrapping the roots around your hand. Lay the plant down on a table with the circle of roots sitting on top of a square of cotton fabric or a piece of an old T-shirt with some slightly damp shredded newspaper, sheet moss, or even vermiculite on it.
- Step 5: Cover the roots with gently dampened shredded newspaper, sheet moss, or vermiculite.
- Step 6: Wrap the cotton cloth over the wad of moist paper or moss to hold it in place, and then fasten the entire item around the roots with twine or a zip tie.
- Step 7: Surround the wrapped root mass with a tight layer of plastic wrap or a repurposed plastic grocery bag. If you don’t want to use plastic, waxed cotton will suffice.
- Step 8: Place everything in a brown paper bag and seal it securely. Several plants may be kept together in a single paper bag. (If you try this method, and the plant shrivels up and dies before spring, your environment may be too dry. If this happens, in the future, fill the bag with very slightly damp peat moss to fully surround the stems prior to storage.)
- Step 9: Put the bag on a shelf in a cool garage, root cellar, or basement. Instead, place it in the refrigerator (a crisper drawer with high to moderate humidity is best, but not necessary).
- Step 10: After six weeks, remove the plant and make sure the materials wrapped around the roots are still wet. If not, moisten them with a mister or spray bottle. Then rewrap the roots and put everything back in storage.
Get the tomato plants out of storage and pot them up approximately six weeks before your last frost date in the spring. You may also keep them dormant until the threat of frost has gone. Then, immediately into the garden, plant them.
This method of overwintering tomato plants provides you a head start. Plus, it’s especially useful for indeterminate tomatoes that are otherwise too large to overwinter.
Can tomato plants survive winter? The final requirements
There are just two more elements to consider if you wish to retain tomato plants all year.
- Tomato blooms are self-fertile, but the pollen inside the blossom must be knocked free in order for the flower to grow into a fruit. Wind or visiting bumble bees accomplish this function in the garden. Yet, if no pollinators are present in your home or greenhouse, you will have to function as a pollinator. Place a cheap electric toothbrush against the flower’s stem, right under the bloom’s base. Keep it in place for three seconds. For each fresh flower that opens, repeat the technique three days in a row. Will tomato plants survive the winter? Sure thing! Will they, however, bear fruit? As you can see, you have some say in the matter.
- Fruits may form on your plants if you provide adequate light (or maybe there were already some green tomatoes on the plant when you brought it inside). I’ve discovered that fruits do not usually mature organically inside. The circumstances are just not great. So instead, I pick the fruits green and hasten the ripening process by putting them into a paper bag with a cut apple. The apple produces ethylene gas, which is a natural plant hormone that promotes ripening.
Give it a try
I hope you’ll try some of these approaches now that you know the answer to the question Do tomato plants survive winter? It’s a great way to save money, preserve treasured varieties, get a jump start on the next growing season, and have fun experimenting.
Can I overwinter my tomato plants?
Absolutely. They do, however, have certain unique needs. The biggest disadvantage of this technique of overwintering is that indoor tomato plants need a lot of sunshine. Well, you may place the pots on a sunny windowsill, but even in the brightest window, they will usually survive the winter with just a few scraggly leaves.
Can I still plant tomatoes in Zone 9?
Tomatoes & Hot Weather Growing Zones
Fall tomatoes may be grown in Zone 8b by planting transplants in late August/early September. Zones 9 & 10 can enjoy fall tomatoes by planting either seeds or transplants throughout September.
What tomatoes grow in Zone 9?
Cherry tomatoes are typically the most reliable plants, producing high yields that ripen early and continue producing through the summer. “Sungold” is a time-tested favorite, known for its sweet-tasting orange tomatoes, disease resistance, and early maturity.
How do you prepare tomato plants for winter?