“April showers” may be more famous than “April cold snaps” because of a cute garden rhyme that gets passed down from generation to generation, but if we don’t fend off the frost and freezes that come with those showers, there won’t be any May flowers! The good news is there are some simple things you can do to protect your garden.
1. Plant smart.
Even though we live in a certain climate, our own landscapes have distinct micro-climates Amazingly, even one degree in temperature can make a huge difference, and where you place your plants can truly affect how well they survive temperature drops. Buildings retain warmth so planting near walls, buildings, trees or other heat-retaining structures can emit just enough warmth to make a difference. Though tricky, wind is also something to consider. In the right circumstances it can be a positive force to fight frost because it can keep it from settling on leaves. Cold air sinks, so avoid planting in low areas. It’s also smart to plant foliage that is hardy for your zone. Some options known for their cold-hardiness include crocus, narcissus, pansies and tulip flowers or vegetables like broccoli, carrots, lettuce and peas.
2. Be prepared.
There is a difference between a frost and a freeze, and for the most part it doesn’t matter which one happens, what does matter is how low the temperature gets and for what length of time. Watch the weather report and listen for temperatures below freezing (32F). A “light” frost/freeze means temperatures of about 28F for just a few hours. A “moderate” freeze or “killing” frost means 25-28F for several hours. Below 25F for several hours is “severe.” Have cold-fighting tools on hand and be ready to use them: old blankets, burlap, newspapers, mulch (straw or old leaves), large tubs and old pots, old milk jugs, cloches (jars to set over plants), etc.
3. Prioritize tender plants.
Rather than try to protect your entire garden, prioritize the tender plants that are most vulnerable to cold snaps. If a severe freeze is projected, then more action can be taken to protect other plants, such as wrapping fruit tree trunks with burlap or placing mulch at the base of evergreen trees to keep soil free from frost.
4. Water before freeze.
It may sound crazy to water before a freeze, but actually water insulates plants, it strengthens them to withstand cold damage, and moist soil stays warmer than dry soil. Water the roots (not leaves) a day before the forecasted freeze, and do it well before sunset so the plants have time to absorb it before the cold comes.
5. Cover with cloth.
Soil loses its warmth over time, so the idea behind covering plants is to create a space to contain the warmth for the duration of a cold snap, like a mini-greenhouse. Avoid using plastic, and make sure the cloth doesn’t touch the foliage if possible by using wire or stakes. (If you can’t prevent touching, it’s still better to cover than not.) The cloth can be an old blanket, flannel or fleece material, sheets, towels or burlap. It should touch the ground securely so it won’t flap up. Cover the plants before the sun sets so the warmth has time to establish. If rain is projected, then you can use plastic to cover and protect the cloth.
6. Warm with water jugs.
You can also prolong or increase warmth under the cover by putting warm water in old milk jugs and placing them in with the plants before you secure cover to the ground.
7. Creatively protect.
Other options for protecting plants include using cardboard boxes, old or unused pots turned upside down, bubble wrap to insulate hanging plants, whatever you have on hand. I’ve heard of fruit tree growers using Christmas tree lights to help keep blooms from getting too cold. Some place electric fans to blow on plants. Don’t “throw in the towel” because you think a freeze it going to kill your crop, instead, use it to cover something and know that even that can make a difference.
8. Uncover on time.
Once the frost has cleared, remove the covers and protection. If it sticks around for a while, be sure to give your plants some time in the sun if they are covered completely. And don’t remove covers too soon either because direct morning sun can cause plants to de-frost too quickly.
9. Bring potted plants indoors.
These are particularly vulnerable to cold because their roots are more exposed being in a pot than being in the ground. Root damage will stunt growth. If your pots are too big to move, wrap the pots with blankets to insulate them, and cover the plantings as best you can. If you have hanging plants, you can either bring them inside or lay them on the ground and cover them there.
10. Feed and fertilize (but not too much).
Another thing you can do before a frost to help your garden and landscape survive is to fertilize to make sure the plants have nutrients available and are thriving, but be careful not to over fertilize which can damage and weaken plants.
April snaps don’t have to mean May mishaps. These 10 tips can empower you to fight the frost and freeze so that April showers bring your May flowers, and much harvest throughout the growing season.