Do you water plants in winter? For many gardeners, the answer is no. But should you add winter irrigation to your to-do list? It depends. You may think of winter as a season full of precipitation, often filled with wet weather from rain or snow or both. So why on earth would garden plants need extra winter irrigation?
The question of whether you should be watering plants in winter depends on many factors, including the species of plant, how recently your planted it, where you live, and what the winter weather is like.
I'll provide some basics about winter watering that will help you decide whether or not you need to irrigate. I'll also share the three types of plants I found out need regular winter irrigation to thrive. An extra drink or two this chilly season is sure to help them thrive!
Winter Watering Basics
Let’s start with some basic rules about watering plants during the colder months, including when (and when not) to water plants in winter.
Don't water established plants that are dormant, e.g. deciduous plants that have lost all their leaves. Never water outdoor plants when the ground is frozen or when the air temperature is below freezing.
If none of the above rules are applicable, it may be necessary to water certain plants in winter. But how often you water is important.
Plants don’t lose moisture in winter as fast as they do in warmer weather. That means that you don’t have to water them as often. Give them a thorough soaking every month or so, depending on the rainfall.
Since many gardeners in colder USDA hardiness zones have to drain their irrigation systems before the first freeze, use a watering can to water by hand. There are tons of affordable cans on Amazon or you splurge on a beautiful and high-quality watering can from Haws, a British heritage brand that's been beloved by serious gardeners for almost 150 years. Christmas gift idea, anyone?
Now that you understand the basics of winter watering, let's take a look at the plants that benefit from winter irrigation.
Plants You Should Water in Winter
There are the three primary categories of plants that require water in winter. I'll walk you through the reasons why these particular types of plants need a little extra water during the cold months. Plus, I'll share my top tips to keep your plants hydrated this winter.
1. Evergreens
A plant that is not dormant will take in water through its roots then lose the water through openings in its leaves called stomata. The process is called transpiration.
Deciduous plants lose their leaves and go dormant in winter, halting transpiration during the cold season, but evergreen plants hold onto their leaves all year long. That means you may need to irrigate them. But there are a few guidelines to follow.
If the ground is frozen or the air temperature stays below freezing, do not water evergreens. If it rains regularly, do not water evergreens either. If it is sunny with high temperatures and there is no rain or little rain, then you can water your evergreen plants.
There are three primary types of landscape evergreen that may need water:
- Conifers - Conifers are evergreens that grow their seeds in cones. This includes all types of Christmas trees, like pine and spruce. Conifers also include some evergreen trees and shrubs like arborvitae that have scale-like leaves arranged in flat sprays.
- Broadleaf Evergreens - Not every tree with regular leaves is deciduous. Some are evergreens and hold onto their leaves all year long. These are termed broadleaf evergreens and include trees and shrubs like holly, boxwood, rhododendron, camellia, and mountain laurel.
- Ground Covers - Low-growing shrubs that are used like grass to cover bare dirt are termed ground covers. Some ground covers, like English ivy and periwinkle, are also broadleaf evergreens.
2. New Transplants
Anything you plant will need extra water until it gets established. That’s why any newly planted trees, recently transplanted plants, or freshly seeded areas should get occasional water in winter. However, you should never water if the ground is frozen or air temperatures are below freezing.
- Trees & Shrubs Planted in the Last Year - Have you planted any trees or shrubs during the last 12 months? If so, offer these plants water when the ground isn’t frozen and temperatures rise above freezing. These plants must establish a root system in order to survive. That means that they are more at risk than other outdoor plants and require extra irrigation.
- Late-Planted Perennials & Bulbs - The same rules apply to newly planted perennials and bulbs for the same reasons. They have work to do to establish themselves as healthy, vital plants. Put them on the “water occasionally” list in winter.
- Newly Laid Sod & Seeded Areas - Both new sod and newly seeded grass require water. Don’t irrigate if the ground is frozen or if the temperatures drop below freezing. But when temperatures rise, get out the hose and give these areas a drink.
3. Potted Plants
If you grow a container garden, keep in mind that these plants dry out faster than ones growing in the ground. If the plants are deciduous and dormant, there is no need to water them since they will not take up any water during dormancy.
If plants are not dormant, it’s important to keep checking the soil throughout the winter. When the soil feels dry, give the plants a drink.
- Containerized Dormant Shrubs - If your potted shrubs are not dormant, you will need to water them when the weather gets warm. Container plants dry out faster than bedded plants, so you’ll need to keep a closer eye on them in the winter. If the soil is dry, give plants a good soak.
- Window Boxes & Hanging Baskets - Plants in window boxes and hanging baskets are also container plants. They dry out quickly and will need water during winter whenever the weather gets above freezing.
- Raised Beds - Raised beds dry out faster than in-ground beds. That’s because soil in raised beds is more exposed to air and has better drainage compared to in-ground gardens. It’s important to water any perennials in raised beds when temperatures rise above freezing.
