After spending hours and hours planting and fertilizing this spring, you don’t want to fall victim to a late frost. That white glaze may look beautiful, but it can be devastating to your flowers, vegetables, and even young fruit trees. If you know the warning signs and a few simple tricks, though, you’ll be able to keep your plants happy and healthy despite any temperature fluctuations.
What is Frost?
Frost is a layer of ice crystals that forms as water vapor condenses and freezes. When most people talk about frost, they are typically referring to a light frost, which occurs when the temperature dips below 32° Fahrenheit. If the temperature drops below 25° for four straight hours, it is called a hard freeze. Your young, tender plants may be able to survive a light frost without help, but a hard freeze would mostly likely kill them.
Warning Signs of Frost
We’ve compiled a list of frost indicators to help you know the weather patterns and planting features that support – and don’t support – frost. Keep in mind, though, that your garden and flower beds have their own unique microclimate. Your neighbor may experience a frost when you don’t, and vice versa.
Note: According to The Old Farmer’s Almanac, there’s a 50% chance every year that there will be no frost after April 6th in our area. If you don’t like those odds, check your local weather forecast every evening for frost warnings.
Signs that Frost may be Coming:
- The dew point is below 45°
- The sky is clear
- There’s no breeze
You’ll Probably be Safe if:
- The daytime temperature reached over 75°, making it unlikely to dip below 32° at night.
- The sky is cloudy, preventing the warm air from the day from escaping back into the atmosphere.
- There’s a gentle breeze mixing warm air with cold air, heating your plants.
- Your garden is on a slope or small hill. Frost likes to settle in low places, so a gentle slope or raised bed could be enough to keep your plants out of harm’s way.
- Your plants are very low to the ground, insulated by the warm soil.
- You have trees on three sides of your garden or flower bed, trapping heat in just like cloud cover.
Ways to Protect Your Plants from Frost
If all the signs point to a frost, here are some ways to ensure that your plants and trees stay safe:
- Bring potted plants inside.
- Insulate plants and trees with two inches of mulch. Straw and grass clippings are good options for vegetable gardens, while shredded hardwood and wood chips are ideal for flower beds and trees.
- Cover each plant with a plastic pot or bucket.
- Use a sheet, light blanket, or burlap to cover your beds. If your plants are tender, you will want to avoid crushing them by propping the cover slightly above them. You can then put a bucket of hot water under the sheet. The water will gradually release heat and help to keep your plants warm.
- Water your plants and trees to a depth of a least six inches the day before the frost. Wet soil can hold heat better than dry soil.
Note: If you plan to cover your plants, the general rule of thumb is to cover them by 8:00 PM and uncover them by 8:00 AM. Never leave them covered during the day.
If you aren’t sure if you’ve fallen victim to a frost, you’ll know within a few days. Check the inside of your buds; if they are brown or black, they’ve been damaged. Don’t prune away that damage just yet, though; make sure you are beyond frost warnings first.
The easiest way to avoid frost issues is by being patient. Even though warm winter days may be luring you to the seed aisle, wait to plant your warm season vegetables and delicate annuals until after the threat of frost is gone. If you have any questions, feel free to give us a call. We can help you plan, plant, and mulch your landscape so that it stays hearty and healthy from spring to fall.
Sunrise Landscape and Design is Northern Virginia’s premier landscaping company offering a full range of landscaping services. Our landscape and design services include hardscapes, water features, irrigation and landscape lighting. Our property maintenance services will keep your landscape vibrant and healthy year round with mulching, edging, garden cleanups, lawn mowing, tree pruning and mosquito/deer control. Contact us today for all your landscape and lawn care needs!