The frigid morning yesterday brought Calgary’s first frost into the city, which may have taken some by surprise. The frost warning may not have reached everyone, and some may have not taken the precautions to cover their plants and bring what they could inside.
Whether you had a light or a hard frost will make a big difference in how well your plants will fare for the rest of the fall. Attempting to mitigate frost damage is a good idea. Plants need to be healthy in order to enter dormancy properly and thrive the next year.
A light frost occurs when the air has reached the freezing point, but the ground has not. The more hardy trees, shrubs, perennials and annuals can weather an occasional light frost relatively well, but those with a lot of water in them (such as begonias and impatiens) will often take a deathblow.
A hard frost will freeze the water inside plants’ cells, causing it to crystallize. When the ice begins to melt, it expands, weakening the plant from the inside and allowing water to escape. It seems backwards, but frost damage actually causes plants to dehydrate.
Annuals and perennials are affected first by frost damage, as they do not have bark to protect their fleshy parts. Once they have been exposed to frost they will appear wilted and shriveled, and the wilted parts will eventually turn brown or black and die. On trees and shrubs, you will notice frost damage in the leaves first, which will curl up and then turn crispy and brown.
It’s tempting to trim away the damaged parts of your plants right away, but this can actually put them in even more peril. The dead parts actually act as a shield from further damage until new shoots can appear.
Get Out There Fast On Frosty Mornings
Water can be your saviour on a cool morning when there hasn’t been an overly hard frost. If you can get out there fast before the sun comes up, lightly spraying your plants with water will help prevent them from defrosting too quickly. The moisture will also help replenish what was lost during the frost.
How to Protect Your Plants From Frost Damage
An early winter that sets in fast does not allow plants, shrubs, and trees enough time to enter dormancy properly can mean a very slow start to the spring. Protect your valuable perennials, shrubs, and trees by:
- Bringing in your pots at night
- Covering everything else with burlap, a sheet, or plastic
- Stake down coverings to help trap heat inside
- Grouping pots together so that they can provide each other warmth and protection
Give Your Shrubs and Trees a Good Drink
Your shrubs and trees need lots of water to get them through to spring. Let a garden hose run slowly at the base of your shrubs and trees until water penetrates to two feet. To reach two feet you will need to apply eight inches of water. Check them weekly to see if they need any more moisture for as long as consistent frosts hold off.
In a few weeks when the temperatures start to get closer and closer to freezing at night, it will be time to cut back your perennials. It can be hard to do, as they’re so beautiful and provide so much joy year after year, but cutting them back is the best thing you can do for them and for your garden.
It’s important to cut your perennials back before the ground starts freezing. In frigid climates such as ours in Calgary, you want to give your plants the very best possible chance for spring. Cutting your perennials back keeps the energy from the roots in the roots themselves.
Shut Off Your Irrigation and Schedule Your Fall Clean Up
Every fall, before the ground freezes up, those with underground irrigation should turn off the water and run their sprinklers until the lines are dry. For those without underground irrigation, now is the perfect time to consider installation. That way you will be up and running quickly come spring.
It’s also time to schedule your fall clean-up. A fall clean-up includes a full raking and debris removal plus a fall fertilization application.
With three generations of landscaping residential and commercial properties in Calgary, we have experience to take on just about any project imaginable. Have a look at our portfolio and contact us for a free quote on any outdoor project.