Asparagus is not as frost resistant as some vegetables, and can suffer damage if temperatures dip below 30℉ (-1℃). It is essential to understand how to protect your asparagus from frost, as a sudden cold snap can quickly lead to its demise. A quick and easy way to offer asparagus suitable protection is to add a layer of mulch to protect the crown of the plant. You can also cover your asparagus with fleece, or protect it with cloches. These types of covers should be applied early in the evening, whenever a frost is predicted. Positioning cold frames over your asparagus is also a good way to ensure that they survive through colder months.
4 Ways to Protect Asparagus from Frost
If they are given the appropriate care and nutrients, asparagus plants will return, again and again, to add texture to your garden and nutrition to your table. However, cold weather can be the enemy of this tasty vegetable. Follow the tips outlined below to protect your asparagus from frost:
Add a Layer of Mulch
Give your asparagus plants an extra barrier against the cold by adding a layer of mulch. You may also decide to use leaf mold or mulched leaves to add some extra protection to garden beds and provide a barrier against the cold.
- Use mulched leaves, dry mulch, or leaf mold as a barrier against the cold.
- Spread the mulch out evenly to a depth of 4–6 inches (10–15 cm).
- Be aware that spears may be slower to emerge in the spring with this method.
Spread 4 to 6 inches (10–15 cm) of mulch evenly over the entire asparagus patch, making sure to cover the crowns. Your asparagus spears may sprout more slowly in the spring with this method, but that is preferable to losing the bed to frost.
Cover Plants with Fleece
Covering your asparagus plants with horticultural fleece is a great way to protect them from frost. Position several stakes around your asparagus and then create a tent-like structure over their tops with the fleece.
- Use this horticultural fleece to protect your asparagus from frost.
- Set up several stakes around your plants and build a tent-like structure over them.
- Weigh the corners down to prevent the fleece from blowing away.
- Remove the fleece during the day.
Weigh down the corners so that your covers do not blow away during the night. Remove the fleece during the day so that your plants can enjoy some sun. With this method, asparagus can continue to thrive even when the nights turn frosty.
Protect Plants with a Cloche or Cold Frame
Use a cold frame or cloche to protect your asparagus from frost. A cloche is the best choice for smaller plants or seedlings, while a cold frame is more appropriate for more mature plants.
- Invest in a cold frame or cloche to protect your asparagus.
- Use a cloche for seedlings and small plants.
- Choose a cold frame for mature plants.
- Allow your asparagus plants to “breathe” uncovered during the day.
Make sure you remove any coverings you use during the day to allow the plants to “breathe.” If you leave asparagus plants covered, they will get limited sunlight and struggle.
Keep an Eye on the Forecast
One of the best ways to prevent frost damage to your asparagus is to keep an eye on the forecast. It’s important to watch the weather report on a daily basis.
- Watch the weather on a daily basis.
- Be aware that soil is warmer during periods of higher humidity.
- First frosts typically happen on calm, clear evenings.
By keeping track of weather conditions you can make the appropriate decision quickly. Also, be aware that evaporation cools and condensation warms. Therefore, when humidity is higher, the soil will be warmer, and during drier periods it will be colder.
Does Frost Hurt Asparagus?
Frost can hurt asparagus, particularly if temperatures go below 30℉ (-1℃). Frost-damaged asparagus spears look water-soaked and their color will change to dark green.
- Frost is damaging to asparagus, especially if temperatures dip under 30℉ (-1℃).
- Asparagus damaged by frost appears waterlogged and features a dark green color.
- Young spears that are frost-damaged turn black and shrivel up.
- Spears will normally die back in winter but produce again in the spring.
Young spears damaged by frost will become shriveled and discolored. It is normal, however, for spears to die back with winter frost. However, even if frost kills visible portions of your plant, the crown of the plant underground will survive and produce new sprouts in the spring.
When Should You Protect Asparagus from Frost?
Any time asparagus is in danger of encountering frost, it should be protected. This largely depends on the seasons where you live, and the average temperature. In many areas, early spring and late fall are common times when sudden frosts may be encountered.
- Protect your asparagus from frost whenever it occurs.
- Spring and fall are the most common times for sudden frosts.
- Have your method in place ahead of time to ensure the best results.
Regardless of what you are using to protect your asparagus from frost, you should have your method in place several hours in advance. Get your fleece or cloches ready before the sun goes down so that by the time any frost appears, your plants are already protected.
How to Cover Asparagus from Frost
You can cover asparagus from frost in several different ways. Whichever method you choose, make sure you keep an eye on the weather and have your method of protection in place in advance.
- Add 4–6 inches (10–15 cm) of mulch over your entire asparagus bed.
- Use horticultural fleece to create a tent-like structure over your asparagus plants.
- Weigh the corners of the tent down so it doesn’t blow away overnight, and remove it during the day.
- Cover your asparagus with a cloche or cold frame.
- Cold frames are better for mature plants and cloches are the best choice for seedlings or young asparagus.
By using these methods to protect your asparagus, you can keep spears from being destroyed by cold. Just remember to carefully track the weather so you’ll know when to cover your asparagus before a frosty night.