The transition from late winter to spring is full of fake-outs and freak frosts. Just when you think the threat of freezing weather has passed, Jack Frost pulls a fast one, and your newly planted spring garden bears the brunt of the impact! But with proper preparation, you can protect your delicate plants and seedlings from potential damage during a late frost.
The average date for the final frost of spring in Des Moines is April 18th, but it’s still entirely possible for freezing temperatures to arrive later in spring. Stay prepared and keep your eye on the forecast through April and May!
Necessary Tools for Late Frost Preparation
It’s always better to be prepared! Keep these materials on hand this spring as they’ll be helpful when the inevitable late frost creeps in.
There are a lot of different materials you can use to cover flower gardens and raised beds. You can purchase fabrics or plastic tarps meant explicitly for protecting plants from frost, some with built-in frames to keep the weight of the material off of your plants. You can also use old bed sheets you’ve got lying around. Just make sure they aren’t too heavy—you don’t want to crush your plants. If it’s a windy night, use stakes or rocks to keep the corners of your plant covers in place.
Freezing temperatures can damage roots, which are the most sensitive part of any plant. To insulate roots from the cold, spread a fresh layer of bark mulch across the surface of the soil. Mulch also keeps out weeds, so you’ll spend much less time weeding for the rest of the year.
Cut 2L Pop Bottles in Half
Delicate seedlings aren’t strong enough to stay up underneath a fabric tarp. Create DIY cloches for individual seedlings and new, small transplants by cutting 2L pop bottles in half. You can place each half can overtop of a plant and press them one inch into the soil to stay in place.
What Temperature Should I Cover My Plants for Frost?
Frost occurs at 32°F. However, some plants are more sensitive to the cold than others. For example, tomato plants can suffer damage at 35°F, while cool-season plants like cabbage can handle 28°F. To err on the side of caution, use frost protection for your plants if the forecast calls for 35° or lower. Keep an eye on the overnight temperatures—that’s when spring frosts usually hit.
Make a point of watering your plants before the frost. Moist soil retains heat much better than dry soil, which will help protect roots from temperature shock.
Bringing Potted Plants Inside for Frost Protection
You can bring container plants indoors to protect them from the cold. If you have a garage, put them in there to prevent introducing pests from outdoors to your indoor houseplants. If you have to bring them indoors overnight, spray some insecticidal soap on the leaves first, and keep them in a room away from your houseplants.
The Surprising Upside to Spring Frost
While frost in the garden can be annoying, the good news is that it brings some unexpected perks! If you have a vegetable garden, some of your cool-weather veggies may taste better after a cold snap. Root vegetables like carrots and parsnips will become sweeter and more flavorful. Your broccoli will taste better, too!
All the supplies you need for late frost preparation in Des Moines are available here at Ted Lare Garden Center. Visit us soon to stock up ahead of time—it’s better to be prepared than scramble at the last minute!