Frost Warning Issued For GTA. How Can You Protect Your Plants?
Posted May 11, 2009 12:00 pm.
This article is more than 5 years old.
We’re only a week away from the Victoria Day holiday weekend, normally considered the unofficial start of summer. So why are we talking frost?
A high pressure system is bringing in cooler than normal Arctic air over southern Ontario, deflating temperatures and creating a risk of frost overnight Tuesday. Environment Canada has issued a special weather statement on the front, which will give us lower than normal readings most of the week.
The yearly May holiday is also traditionally the start of gardening season, leaving those who jumped the gun vulnerable to losing what’s already in the ground.
How bad you get hit depends a lot on where you are. Those in higher evelations will get the worst of it.
Temperatures dipped to around 2C in Toronto overnight, but it was -1C in Caledon and -3C in Barrie. Highs for the day will reach a still pleasant 15C, but chilly winds from the north will make it feel colder. We should be at 19C at this time of year.
This week promises to be below normal overall, with the exception of Wednesday, when we could hit 21C. Thursday could see about 10 millimetres of rain and highs will only get to 16C right through Sunday.
It all follows a wicked blast on Saturday that saw many GTA residents shoveling out their driveways from a huge hail storm. See a gallery of your pictures here.
What can you do to protect the plants and flowers that are already in the ground? Here are some frost fighting suggestions from Breakfast Television’s Frankie Flowers and The Garden Helper.com
Plants at greatest risk include any soft stemmed, large leaf, tender shoot and water stemmed plants. Examples are:
Impatiens Tomato Plants Pepper Plants Squash Plants
Coleus Potato Vine Sunshine Impatiens Hibiscus
And many more…
Things to do:
-Don’t cover your plants with plastic and if you do make sure there’s a good separation of air between the plant leaves and the plastic. If the covering is touching the leaves the frost will still harm the plant.
-Water the garden thoroughly before nightfall. The soil will release moisture into the air around your plants during the night, keeping the air somewhat warmer.
-Cover up before dusk. By the time it gets dark much of the stored heat in the garden has already been lost.
If you have time, build a simple frame around the plant or row of plants. (Even a single stake can be used in many cases.) Then drape a cover of newspaper, cardboard, plastic tarps, bed sheeting or any other lightweight material over the frame to create a tent.
If you don’t have time to create a frame, lay the protective cover directly onto the plant. This will help to slow the loss of heat rising from the foliage and the ground. Remove the covers in the morning, once the frost has thawed, to let the light and fresh air back in, and to prevent overheating by the sun.
-For smaller individual plants you can use glass jars, milk jugs with the bottom removed, paper cups or upside down flower pots as heat traps. Don’t forget to remove them in the morning.
-You can collect heat during the day by painting plastic milk jugs black and filling them with water. Place them around your plants where they will collect heat during the day. Water loses heat more slowly than either soil or air. The collected heat will radiate out throughout the night.
-Potted plants are particularly susceptible to frosts because the roots are also unprotected. If you aren’t able to move your container plants indoors or under cover remember to also wrap the pot in burlap or bubble wrap, or simply bury the pot in soil in addition to protecting the foliage
It’s not really that unusual to have frost at this time of year. In 2007, a warning was issued for June 7 th, well into what most would consider past the danger zone.
And below freezing temperatures happen frequently overnight in mid-May. The coldest reading for this date was back in 1966, when we dipped to a chilly -4.4C.
For more on frost protection, read Frank’s blog for May 11th
Haven’t seen enough of Frankie Flowers? Follow him on a recent tour of the Netherlands and Belgium, where he – and you – will get to see the world’s largest outdoor spring garden and an intimate castle garden, along with advice on how to get your backyard flower bed looking its best this season.
You can see the special, called “Frankie Flowers: Diggin’ It In The Netherlands & Belgium” a number of times this month. Here’s when to “plant” yourself in front of the tube or set your PVR.
Monday, May 11th
1-2pm
Saturday, May 16
12-1pm and 8-9pm
Saturday, May 23rd
12-1pm
Sunday May 17th
8-9am
Sunday May 24th
8-9am
