You worked all summer to keep your plants alive, but the harsh reality of winter is that most of them will die without you putting in more work. This is especially true if you have particularly favorite plants, say a rare heirloom pepper. So how do you keep outdoor plants alive in winter?
We put together this quick guide of how you can keep those plants alive over the winter months when freezing temperatures mean death for most annuals. No two plants are the same, and different parts of the country have different kinds of winter. Treat this not as a strict how-to manual, but tips to help you develop a strategy.
Summer can be a fleeting series of joys, especially if you enjoy gardening. But, you always know that winter is eventually coming, sooner in some parts of the country.
As September rolls around, you might catch yourself asking yourself how you can keep that prized pepper plant alive during the depths of winter. That’s understandable.
Thanks to a wide variety of plants and regional differences in winter, there is no one-way to overwinter plants. You’ll want to develop a basic strategy on how you want to do it. In some cases, you’ll also need to commit to doing more work over the winter. You won’t have to weed or look out for garden pests, but overwintering brings its own set of challenges.
We’re going to take a look at how to overwinter plants that you leave outside and potted plants that you take inside with you. We’ll discuss the difference between annuals and perennials and how that might contribute to what you do, and how to keep your vegetable plants putting on fruit so you can have garden-fresh produce during the cold of January and February.
We’ll also take a quick look at hardiness zones, and why that matters. If your winters are relatively short, you might be more willing to bring plants in for just a couple of months. We’ll go into why you might want to do that.
We’ve got a bunch of topics to cover and not a lot of space, so let’s get right to it.
Knowledge is power
With just about everything, keeping outdoor plants alive in winter starts with knowing about the plants and your winter.
Check the United States Department of Agriculture’s hardiness zone map and find which one you live in. This is important because it’ll give you a more specific idea of just what you’ll need to do and especially how long winter will last from a plant’s perspective.
In the Deep South, some plants considered annuals in the North are actually perennials. Temperatures don’t normally get low enough to kill the plant outright. They might enter a state of dormancy as temperatures dip below where the plants thrive for a period of time, but if temperatures don’t normally dip below freezing they’ll come back pretty quickly in the spring.
In the North, this will give you a more accurate idea of how long your plants will be subject to potentially frigid conditions, including prolonged periods of time when temperatures are below 0-degrees Fahrenheit.
Care for outdoor perennials
If your plants are considered perennials where you live and they are in the ground, you’re in luck. You don’t have to do much of anything. The soil they are planted in will act as a form of insulation. The plants will probably come back the following spring when temperatures start staying above freezing with any consistency. You can add another layer of protection by topping the soil with mulch. If you get the right kind, it will break down over the winter and be a great amendment when it’s time to start working the soil.
Potted perennials require a little bit of care because they lack that insulating layer of soil. Fortunately, they’re also portable, so you can move them to where they’ll be out of the worst winter winds. Garages or garden sheds or enclosed walkways are great places for them if you have space. If not, you can place them along a south-facing wall. They’ll be out of the worst winds, plus they’ll catch a ray or two of sunshine.
You can provide them with some insulation, too. Construct a frame around them from chicken wire. Stuff the frame with newspapers or leaves. You can also wrap them in old blankets. It doesn’t need to be big or elaborate. They’ll probably come back in the spring, especially if your winters are mild, but you can increase the odds.
If the pots aren’t very big, you can just bring them inside the house to provide greenery during the winter months. It might help you to get through the darkest, coldest part of the year.
Start by pruning back some of the summer growth. Don’t worry. It’ll come back the following spring. Each plant is a little different, but a good general rule is to cut it back by about half. You can also spend a little time researching the particular needs of each plant you’re overwintering.
Many of your plants will enter a state of dormancy when the temperatures are cooler outside and sunshine is less available. For these, you just need to lightly water them every couple of weeks to keep them from drying out and give a light feeding of fertilizer once a month.
These won’t require strong, constant sunlight because they aren’t putting on growth, but you’ll want them to at least get some indirect light. If you find that your plants are starting to look ragged, consider moving them closer to direct sunlight along a south-facing window area. Just don’t let the plants touch the window where icy temperatures can burn plant leaves.
Keeping up with culinary herbs
Some herbs like thyme, oregano, and mint can survive outside and come back the following spring. They are also relatively simple to care for over the winter inside. They’ll also keep you in a steady supply of leaves for summer-fresh cooking.
These are easily grown during the warmest months in a pot on your patio or apartment balcony. They also do well inside over the winter as long as you keep up on their maintenance.
You can maintain a pretty normal watering schedule for herbs you’re overwintering because you want them to produce growth. Fortunately, as in the summer, herbs don’t require much or even any fertilizer.
For these, you’ll want to get them some direct sun during the day. You can either them on windowsills facing south, where they’ll probably get enough direct sun to replace leaves you remove for cooking. Again, don’t let them directly touch the window or those parts might be damaged.
You started an heirloom pepper plant from seed the previous March, nurtured it in a pot for most of the summer, and were blown away by its fruit. Now that winter is approaching, you want to preserve it for next summer.
We get it.
It is possible to overwinter annuals. It’s also possible to not just overwinter them, but have them produce food when things are at their coldest and most bleak outside. It will take a little more work replicating summer conditions inside is the key.
First off, you’ll want to put them in a consistently warm place. Most annuals, especially vegetable plants, do best when it is also warm at night. Most homes are kept at pretty close to summer conditions, 68-72 degrees, and there are probably places that are a few degrees warmer for a variety of reasons.
Light is another issue. These kinds of plants like long days where the sun shines a lot. You can either try placing your plants in a south-facing window, but you might find that you don’t get eight hours of consistent sun there.
Fortunately, the consumer market for indoor growing lights is vibrant enough that most people can afford grow lights. If you start your seeds indoors, you might already have one or two. If you don’t, look for ones that offer full-spectrum light and that have a timer. You’ll want your annuals to get a lot of light for several hours per day.
Water and feed these as normal. You aren’t just overwintering them, you’re trying to actively grow them.
As a side note, if you are looking for more tips about indoor plants, you can check out our awesome article about indoor gardening right here.
Winter doesn’t mean you have to start over with your plants. It’s possible to keep outdoor plants alive so you can enjoy them for several summers if you know a few tricks.
The key to successful gardening is knowledge. You want to know what hardiness zone you live in so you can have reasonable expectations for how long your plants will need protection. You’ll also want to know if that plant you purchased as a perennial really will come back next year if your winters are harsh.
You’ll also want to know a little bit about the plants you want to overwinter. Each one will have different care requirements. Knowing what they are will help you do a better job of protecting them over the winter.
Most perennials will come back on their own in the spring, especially if planted directly into the ground. The soil acts as natural insulation to protect the plant if the weather gets terrible. You can add a layer of mulch over the soil in which they are planted for an extra layer of protection.
Potted perennials will probably also come back, but can use a little help because they are more exposed to the elements. So, they have a higher risk of dying in the winter. You can move these to places shielded from the worst of the weather and insulated them with leaves or newspapers stuffed into a frame, or you can wrap them in old blankets.
You can also bring them inside to add a little flair of summer for when it’s so dreary outside.
Some plants will enter into a state of dormancy whereby you just need to maintain them with a little water to keep them from drying out. Overdo it, however, and you can wind up with root rot. Don’t worry so much about feeding them. They’re just waiting for consistent warmth to start growing.
Herbs, on the other hand, require a little attention. Keep the soil a little moist and try to get them as much sun as possible, and they’ll provide you extra flavor for winter cooking.
If you want to bring annuals inside and even keep them producing fruit, that’s possible. You’ll need to keep them warm and well-watered/fed. Sunlight will be an issue, even if you have large windows facing the south. Fortunately, you can purchase grow lights to supplement what you get naturally.
We hope found value in this guide for overwintering outdoor plants. We wish you the best of luck in your growing endeavors.