How to protect plants in the high desert from Frost?

Jaime BeamerMarch 12, 2023

0 40 6 minutes read

What to Cover in a Freeze: Frost Protection in the Garden

Living in a mild-winter climate means that you may try to push the boundaries of what can be grown throughout winter. Frost and cold weather may appear suddenly, and knowing what to cover in a freeze can mean the difference between life and death for some of your plants. Gather necessary things such as frost cloth and burlap before a freeze occurs.

This article shares suggestions for keeping your warm-climate garden safe from frost Knowing the most likely frost periods, using smart plant placement in your garden, and understanding what to keep on hand to safeguard plants are just a few examples. These suggestions will help your garden survive frigid conditions.

Disclaimer: This post contains affiliate links. For additional information, please see my disclosure policy.

Contents

6 Tips for Protecting your Warm-Climate Garden from Freezing Temperatures

1. Learn when to expect freezing temperatures

A useful technique for predicting when freezing temperatures are expected is knowing your first and last frost dates. You can look them up here using your zip code.

Frost is most likely to form during clear, calm nights with few clouds and low humidity. Cold winds will also decrease the temperature.

The sun warms the soil throughout the day, and that heat is reflected throughout the night. As a result, the lowest temperatures of the night will come right before sunrise.

To precisely measure your local temperature, use a minimum/maximum thermometer. The reading on the weather app on your phone may not be accurate for your yard.

Light freeze: 29°F to 32°F – tender plants often killed.
Moderate freeze: 25°F to 28°F – causes damage to many plants.
Severe freeze: Several plants are severely harmed by temperatures of 24°F or below.

2. Choose the best location in your yard for frost-tender plants

Cold air descends the hill and settles at the lowest points. Cold places in your yard are ideal for growing fruit trees that need chill hours as well as other cold-loving plants.

Put frost-tender trees and plants in your yard’s hottest spots. . An area with a western or southern exposure with reflected heat from a block wall will be warmer than other areas in your landscape. The heat collected by a block wall during the day will radiate at night.

3. Understand what makes a plant have frost damage

Frost on a plant disrupts the movement of fluids into the plant and dries it up, leaving brown and crispy damage behind.

Some of the characteristics that make plants more or less vulnerable to freezing temperatures are as follows:

Dormancy – A dormant plant will sustain less harm than an actively developing tree or plant. This is why a sudden frost early in the season will often do more damage than a frost later in the season after plants have adjusted to colder temperatures.
Watering — Well-watered plants withstand freezing temperatures better than dehydrated plants. Water in the soil also helps to insulate it.
Pruning – Freshly cut plant regions are more vulnerable to frost damage.
Newly planted — Frost is more likely to injure young plants with less-established root systems.
Plants in containers — Container-grown plants are subject to higher fluctuations in temperature than in-ground plants. They are more vulnerable to harm during a freeze.
Lower temperatures, prolonged exposure to cold conditions, and abrupt temperature reductions cause more damage.

4. What to cover in a freeze and what not to cover during a freeze

For many annual plants, cold weather indicates the end of their life cycle. In warm-climate locations, such as Arizona’s low desert, giving shelter from cold temperatures may extend the growth season.

Plants such as peppers, tomatoes, eggplants, and basil may continue to produce and flourish if shielded from freezing temperatures. In the spring, other vulnerable plants will need to be transplanted.

What to cover in a freeze: Tender — injured by a light frost (cover during a freeze or harvest before cold temperatures).

Basil
Beans
Corn
Cucumber
Eggplant
Ground Cherry
Melons
Nasturtium
Okra
Peppers
Potatoes
Pumpkins (may continue to mature after a frost, although storage life will be shortened) (may continue to ripen after a frost, but storage life will be decreased)
Roselle
Passionfruit Vine
Squash
Sweet potatoes (pick before the soil temperature drops below 50°F)
Tomatillos
Tomatoes (if extended cold conditions are forecast, pick tomatoes and allow them to ripen inside) (if prolonged freezing temperatures are expected, harvest tomatoes and allow them to ripen indoors)

Half-Hardy — withstand light and short term freeze (28°F – 32°F).

Beets
Carrots
Cauliflower
Chard
Chives and Garlic Chives
Garlic
Lettuce
Onions
Parsley
Peas
Radish
Spinach
Strawberries (temperatures below 28°F may cause bloom damage)

Cold-Hardy — withstands moderate freezing temps (24°F – 28°F).

Broccoli
Brussels Sprouts
Cabbage
Chinese Cabbage
Kale
Kohlrabi
Parsnip
Turnip

What to cover in a freeze: Protecting citrus during a freeze

Freezing weather can cause severe damage to citrus trees.

Young trees are more susceptible to frost damage During the first 3-5 years after planting, protect citrus against frost.
Fruit damage may occur after many hours of temps below 27°F. Frost-damaged fruit will have a dry interior.
Pruning frost-damaged limbs and branches should be done when the threat of frost has gone in the spring.

Some citrus trees are more cold-hardy than others.

Kumquat and mandarin trees are most cold-hardy (18°F – 20℉).
Grapefruit and orange trees (tolerate to Mid 20’s℉).
Lemon and lime trees are the most frost-sensitive, with damage occurring as low as 32°F. They are particularly frost-sensitive, so plant them in the warmest parts of your yard. Lemon and lime trees often do not go into dormancy, therefore cold has a greater impact on them than on other trees. citrus.

What to cover in a freeze: Frost-tender landscape plants

Many fragile landscaping plants may recover from mild frosts but will suffer ugly damage if not protected. Tender landscaping plants may be protected by covering them during a freeze. Don’t prune frost-damaged plants until after danger of frost has passed in the spring.

Cover these plants to protect them from harm during a freeze:

Frost-tender landscape plants include Bougainvillea, some cacti, cape honeysuckle, coral vine, fairy dusters, ficus, hibiscus, lantana, natal plum, myoporum, pygmy date palms, succulents, tropical plants (avocado, banana, guava, etc.), yellow bells are only a few examples.

Frost-tender annual flowers include Asters, ageratum, gazania, geranium, lobelia, marigold, nasturtium, verbena, and zinnia are just a few examples.

Cover these plants during a freeze or remove them before the temperature drops.

5. How to protect plants during a freeze

Water plants well before a frost event. Moist soil may absorb more heat and emit it all night.
Cover plants before sundown to keep the heat accumulated from the day. If you wait to cover it until after nightfall, the heat may have dissipated.
Frost cloth, burlap, drop cloths, sheets, blankets, or even newspapers may be used. to cover plants. Do not use plastic.
Let the cover to drop down to the earth and thoroughly cover the plant. all over the place. This keeps the heat inside. Don’t gather the cover around the trunk; it won’t trap radiated heat from around the plant.

Wrap the trunks of frost-sensitive and young trees. Using many layers of material, drape it freely. This can be left in place all winter.
Use styrofoam cups to protect the growing tips of cactus.
Add heat by wrapping heat-generating light bulbs (not LED) behind the leaves of the protected plants. Take care not to have bulbs burn the bark or branches.
Remove sheets or blankets in the morning once the frost has thawed. Dormant plants may be coaxed back to life by leaving plant covers on and retaining heat throughout the day. Plants that are actively growing are more vulnerable to frost damage than dormant ones.
Frost cloth can be left in place for several days without harming the plant.

6. What to do after a frost

Did your perennial plants suffer frost damage? Don’t prune them right away. The plant is protected from additional frost damage by the injured limbs and branches.

Before pruning, Wait until the threat of frost has passed in the spring. and you begin to see new growth. Pruning should be done immediately before the new growth starts. .