When the weather starts to cool, your plants become more vulnerable to the elements. Regarding your potted plants specifically, you might wonder if you should leave them alone or water them before the temperature turns freezing.
You should water your potted plants before a freeze because it prevents frost from damaging them. Hard frost freezes water inside the plant cells, dehydrating them and damaging cell walls. For sensitive plants, such as tropical plants, even a light frost can be harmful.
In this article, I’ll look at these and other reasons why you need to water your potted plants before a freeze, how much water they require, and other tips that will protect your plants during the winter. Read on to find out how to best water your plants before a freeze!
Why You Need to Water Your Potted Plants Before a Freeze
Despite common misconceptions, the temperature doesn’t have to hit freezing point, which is 32 °F (0 °C), to damage your plants. A frost can occur and damage your plants when temperatures are between 32 and 36 °F (0 to 2.2 °C).
Frost can also be light or hard.
A light frost occurs around the upper end of the above temperature range and can damage the tops of sensitive plants. A hard frost is when the temperature is around 32 °F (0 °C) for a few hours. This causes the ground and air temperature to freeze.
A freeze, on the other hand, occurs when temperatures are lower than 32 °F (0 °C). This is much more damaging to plants than a frost, especially for sensitive plants such as geraniums and tropical plants. Therefore, they need some special care.
Watering your potted plants before the temperature freeze is a good idea.
It prevents frost from harming them, but there are other good reasons why you should always water your plants before winter:
- Watering your plants produces warmth. Since it allows water to lose heat slowly, water helps plants to transition safely into freezing weather conditions.
- Water insulates the plants against ground freeze. During icy temperatures, water under the ground can become iced over so the plants won’t be able to absorb it. Water acts as a preventative measure against this. The moisture forms a barrier of ice that functions as insulation.
- Water plumps up the plant cells. This makes them gain increased strength against the cold.
- Water makes soil warm. Water increases the ability of the soil to maintain heat from the sun, which helps to protect roots from damage.
- Water keeps the air humid. Since humid air holds heat more effectively than dry air, evaporating water gives an additional layer of protection to the plant’s flowers and leaves.
- Potted plants are more vulnerable than in-ground plants. Plants in containers or pots are a greater target for frost damage because they don’t gain the insulation benefits of plants that are planted in the ground.
How to Water Your Potted Plants Before a Freeze
When watering potted plants before a freeze, it’s essential to give them the right amount of water. Watering your plants too lightly won’t give them enough protection against the cold, while watering them too much could cause them to experience damage, such as in the form of root rot which damages their roots.
Here are essential tips to follow when watering your plants before a freeze:
Give Plants a Deep Soak the Day Before a Freeze
This will ensure that the plants have enough water when required. A deep soak is when you let water get absorbed into the ground to a depth of about 6 inches (15.24 cm) or more.
Sprinkle Water Around the Base of Your Plant Before the Freeze
Do this at nightfall so that you keep the soil moist without causing the plant to become waterlogged overnight, which puts it at risk of diseases such as fungus.
Check That the Soil Is Evenly Moist
Checking for even moisture will prevent you from overwatering the plants while ensuring all parts of the plant will be exposed to moisture.
Don’t Water the Plant Leaves
Getting water on a plant’s leaves will freeze and cause frost to form, causing harm to the plant.
Water Your Plants Early in the Morning
Morning watering is a tip you should follow throughout the year to prevent water from accumulating in the soil, but it’s especially important before a freeze. Wet soil absorbs heat throughout the day, which will insulate the plants.
Other Tips To Make Watering Your Plants Beneficial
While you’re watering your potted plants to protect them against freezing cold temperatures, you will have to make sure you also follow other tips to keep them healthy. This gives your plants comprehensive care before and during a freeze.
Add Mulch to Watered Soil
Adding mulch will give more protection to the plant roots. Since heat radiates from the surface of the soil during the night and gets lost in the atmosphere, mulch helps to trap it. Excellent types of mulch for winter include shredded bark, straw, and bark chips. Mulch also helps to maintain soil moisture.
Wrap Burlap or Bubble Wrap Around Plant Containers
Wrapping plant containers will help to insulate heat in the plant. I recommend Anphsin two-pack burlap winter plant cover bags, available on Amazon. They have drawstrings to tighten the bags around the plants to secure and protect them.
Move Your Plants to an Area of the Home That’s Warm
A warm area will keep your plants out of damaging cold winds. It’s also a good tip to group them together for warmth. This will ensure the plants have more thermal mass as they will help each other stay warm.
Place the Plant Containers on Bricks Before Watering
Bricks will enable the water to drain easily from the containers, helping you to prevent them from sitting in cold water overnight.
Choose the Right Pot
Use non-porous containers, such as those made out of metal or plastic, as they absorb water better than porous containers, such as those made of terracotta, which can break in freezing temperatures. Otherwise, your watering efforts will go to waste.
Should You Water Potted Plants After a Freeze?
Once you’ve watered your potted plants before a freeze, should you stop watering your plants or leave them alone? You actually should continue watering your plants during the cold temperatures.
However, you should water your potted plants during the day when temperatures are above freezing. This will protect the plants and their roots, or else they won’t be able to thrive when springtime arrives. If your plant doesn’t seem to be coming out of its dormancy, this could be the reason why.
If your potted plants have been targeted by a freeze, you need to water them so that they don’t lose water and become dehydrated. When the water in the container or pot freezes, the plants lose the water they need. By watering your plants, you’ll help to thaw the frozen soil and ensure they get moisture.
Give your potted plants enough water so that you can see it leak out of the bottom of the pot. However, don’t give your plants a soak in water as they will require less moisture during the cold winter. If you live in a region that hasn’t received rain, it’s particularly essential to water your plants so that they don’t dry out.
What If You Didn’t Water Plants Before a Freeze?
If you didn’t water your plants before a freeze, your plants could have been damaged. This doesn’t mean that they’re dying.
They’ll display symptoms such as the following:
- Brown patches between leaf veins, which are a sign that the young growth of the plant has been damaged.
- Black foliage
- Collapsed stems
- Leaf scorch, which is when the leaves turn brown or die.
To help your plants reclaim their health, here’s what you should do when no more frost is expected in your area:
- Prune any damaged growth on the plant. This frees up room for healthy leaves to grow. Wait for new plant growth to help you see what parts of the plant survived the frost. Check stems to see if they’re pliable or brittle, the latter indicating that they’re dead and can be removed.
- Apply a top dressing of fertilizer as this will boost the plant’s growth.
- If plants have been lifted out of the ground because of frost, re-firm the ground around them.
- Water the plants with approximately an inch (2.54 cm) of water to hydrate them.
If you’re interested in learning more about watering plants in the winter, I recommend reading my other article. You’ll learn all the practices to ensure your plants are well cared for despite the cold temperatures and altered biological processes: The Complete Guide to Watering Your Plants in the Winter
It’s always good to give your plants some water before a freezing night. This serves to protect them and encourages them to maintain more warmth to help them survive cold winters. Some important tips to follow when watering potted plants before a freeze include:
- Watering potted plants thoroughly the day before a freeze.
- Adding mulch to the soil to trap valuable moisture.
- Checking that the plant soil is evenly moist.
- Not watering the plant’s leaves, as this can cause frost burn.