WARMING UP YOUR SOIL
Tips for plants that love heat
The teacher called me at work. She wanted to talk to me about my son, who was in Grade 1. “Your son is special,” she said.
Of course I was delighted and happy to speak to the teacher about my special son and I immediately told everyone at work about the good news. I was expecting the best but I was in the dark. The word special has two meanings and the message the teacher delivered wasn’t good.
Gardening in Calgary is also “special,” especially for heatloving beans, melons, pumpkins, zucchini, butternut squash, tomatoes, eggplants, cucumbers, basil, peppers and corn. If planted too early, these plants slowly rot in our cold Calgary soil. If planted this week — and given a little extra help, everything will thrive.
The long-range forecast this month is all sunshine and roses, but if you live on a hill in Bearspaw or Bragg Creek, you know the climate is changeable. Why take a chance? Here are some tips to keep plants cosy this summer, especially in the beginning.
WARM THE SOIL
Clear plastic stretched tight over smooth soil warms the ground by eight degrees. The trouble with this solution is that clear plastic also helps weeds. Newer plastics, like Infra-red transfer (IRT) mulch has some colour added to the plastic so it discourages weeds from growing while still warming the soil. Biodegradable plastics, available online, are not as good as clear plastic for warmth but are better than black plastic, so the choice is yours this spring.
HOT- CAPS
If your space is small and you don’t want to cover the whole bed with plastic you can buy special hot-caps or use four-litre milk jugs with the bottoms cut out to warm the air and shelter young plants. Make sure to take the caps off the jugs to allow heat to escape. Simply sink the jugs into the ground to keep soil warm until seeds have germinated or seedlings have fully rooted in place.
This plan went sideways for me this spring when my plasticloving puppy saw an opportunity. Within minutes of leaving the house, Core had trampled the garden and ripped all the newly added plastic jugs off the soil. I was forced to defer my plant cover plan until next spring when puppy enters her preteens. Meanwhile, I am combining fabric row covers with IRT mulch to encourage my melons in the puppy-excluded front yard.
PLANT ON A SLANT
If your tomatoes are already too big to plant under milk jugs or too tall for fabric covers, try planting tomatoes on their side this year. The logic? Only the top 10 cm of soil actually warms up below covers. To make use of the warmest soil zone, remove your tomato’s lower leaves and lay plants in a shallow trench. Tomatoes can root all along their stems so planting on a slant with the top exposed helps it to root and grow faster.
WIND PROTECTION
I love my greenhouse because it is cosy and free from puppy meddling. Sadly the greenhouse is too small to fit everything, so my next-best place is a sunny spot out of the wind. I placed a row of potatoes in old nursery pots along the narrow path beside my house because it was sheltered from wind and was south facing. Shelter from wind is especially important in new neighbourhoods, but all plants benefit from shelter so make use of sheltered spots first.
GROWING IN POTS
Even with only a few hours of sun per day, the heat radiating off my house and into my potato pots made sure they grew fast beside my house. And if you haven’t planted your potatoes yet, you have until mid-June. Just pull off and throw away any long sprouts on the spuds and pop the roots directly into a pot. Plant in a 20-30 cm depth of soil and add extra garden clippings or straw as the spuds sprout this summer. Potatoes exposed to sun as they grow don’t get sunburned, they get green and then taste bad. The straw or clippings are the sunscreen. Plants that love heat thrive in pots so I use sunny spots for pots all over my yard. A big pot in the sun with a sheltered position next to a fence or building is ideal. If you are short on space, use stakes for cucumbers, peas and pole beans so they will grow up instead of out.
HAPPY ENDINGS
My son was “special” because he couldn’t figure out the immersion program he was in and the teacher didn’t have time to figure him out. Calgary gardens are special because our elevations vary, and life on our almost mountaintop means we can get snow, frost, wind and hail more than other Alberta city. Our climate means sudden changes in weather.
My son is now a teacher so luckily his problem was one of improper diagnosis and not something more serious. If your tomatoes, zucchinis or basil aren’t thriving you can improve their lot by warming the soil and supporting them through the month of June. It won’t be long before we are complaining about too much heat!