With our first freeze in the forecast for the Greater Houston area, we want to make sure you feel prepared to protect and care for your garden and plants. Read below to understand what plants are at risk for damage, steps for protecting them, and how best to care for your plants after a freeze. 

When should I be concerned?

Even in our subtropical climate, most plants will continue to grow and thrive without the need for protection above 40 degrees. It is only when we get into the 30s that we need to start providing additional care for our plants. Our motto is when in doubt, protect.

What plants are at risk?

Plants damaged or killed off by a “light freeze” (between 28°F and 32°F):

• Vegetables: Beans, cucumbers, eggplants, melons, okra, peppers, squash, tomatoes

• Herbs: Basil, cilantro, dill 

• Landscape plants: Tropical or semi-tropical plants (hibiscus, plumeria, banana, etc), young citrus trees (3-5 years old), succulents, annual flowers (nasturtiums, marigold, zinnia, etc)

Plants able to withstand a light freeze, but damaged by a “hard freeze” (below 28°F for an extended time):

• Vegetables: Artichoke, beets, carrots, cauliflower, celery, lettuce, peas, Swiss chard, arugula, bok choy  

• Herbs: Fennel, oregano, lavender

• Landscape plants: Bigleaf hydrangea, hostas, leopard plant, lantana

Plants that can withstand a hard freeze:

• Vegetables: Broccoli, brussels sprout, cabbage, collards, kale, mustards, onions, radish, spinach

• Herbs: Parsley, rosemary, thyme, sage

• Landscape plants: Most Texas native plants, evergreen trees and shrubs

How to prepare your plants for a freeze

1. Harvest: If you have any remaining fruit on frost-tender plants (tomatoes, cucumbers, basil, etc), harvest before the freeze. Temperatures below freezing will damage the produce. 

2. Water: The best way to protect your plants is to make sure they are well-watered before a freeze. If rain is not forecasted, water all raised beds, landscape plants, and pots deeply the night before a freeze is forecasted. 

3. Mulch: Mulch around your perennial shrubs and trees to help insulate the roots from freezing temperatures. 

4. Cover: Prioritize the vegetables and landscape plants that will be significantly damaged by a freeze. Frost cloth is the best option for covering plants. Do not use plastic sheeting. Create a “tent” over the plants by draping the fabric gently over top and anchoring to the ground with rocks or bricks so cold air can’t get inside.

5. Bring Indoors. For smaller potted plants that can be easily moved, bring them inside your garage or home for extra protection.

Caring for your plants after a freeze

1. Uncover: Once temperatures rise above freezing, promptly remove all covers to allow for airflow and sunlight to reach the plants. 

2. Don’t prune landscaping plants: Though you will be tempted to cut off any dead or damaged foliage and branches, do not prune anything immediately. Pruning a plant stimulates new growth, which will make the plant more susceptible to damage if another freeze occurs during the winter season. When the threat of all freeze has passed in the Spring, damaged branches can be cut away or whole plants can be cut down to 2 to 3 inches from the soil. 

3. Water with Microlife Ocean Harvest: Within the days following a deep freeze, water with Microlife Ocean Harvest liquid fertilizer to promote root health and recovery. Follow directions on the bottle for specific instructions. 

Joy of the season

A gift of gardening is understanding the seasons and accepting with grace what Mother Nature provides. Although freezes can be frustrating, let’s enjoy the bounty of what Mother Nature gives us. Personally, my priority is protecting my citrus this season. Everything that slows us down and forces patience, everything that sets us back into the slow circles of nature, is a help. Gardening is an instrument of grace.” May Sarton