After months of waiting, cooped up at home contemplating a snow-covered garden, then tasting the persistent cold once the snow has melted, the urge to sow and plant our vegetables makes itself felt. The first sunny days, when the thermometer climbs to 25°C (77?), give us the impression that gardening time has finally arrived!
For those of you who grow garlic, you know that as soon as the snow disappears, the garlic starts to appear… as do the dandelions and other weeds. That’s when you think, “Wow, nature’s awakening, time to start the garden!”
Yes for some vegetables, but no for others!
Take Ground Temperature Into Account!
While some vegetables prefer cool temperatures and cool soil, such as the Liliaceae (garlic, onion, shallot, leek) and many leafy greens (kale, spinach and lettuce), this is not the case for many other popular vegetables, especially the fruiting vegetables of the Cucurbitaceae and Solanaceae families. Peas, beans and corn are also very skittish. Putting seeds in the ground when it’s still cold can cause them to rot instead of germinating. You’ll then have to resow, which won’t save you any time.
In practice, we tend to rely on the outside temperature, the temperature in the air, whereas the most important thing is the soil temperature, which will determine whether your fragile plants will develop normally. Your fragile vegetables need warm feet! If the soil is warm, they’ll be comfortable, even if the air is cool! It’s a bit like when the floor in your house is cold: you’re not comfortable even if the air in the house is warm. Outside, however, warm floors require sunny days and warm temperatures, especially at night. So you have to give the sun time to warm up the soil, and not just after a few days of sunshine.
Soil Type Influences Warming
It also depends on the type of soil. A light soil, such as sandy soil, will warm up more quickly than a heavier soil, such as clay or loam. This is because the finer the soil particles, the greater its capacity to draw water up from the subsoil by capillary action. As sandy soils are made up of coarser particles, less cold water rises up from the subsoil, so the sun is able to warm this water more quickly, enabling earlier sowing or planting.
If your garden is planted on clay or loam soils that take a long time to warm up, it’s best to grow on mounds or raised beds. The mounding method was actually invented for these soil types. By creating a mound, you increase the distance between the groundwater source and the surface. This reduces the effect of capillary action. What’s more, the surface area exposed to sun and wind is increased by the mound’s curvature, compared with flat ground.
Simple Tips for Warmer Soil
Here are my three simple and effective tricks to get the soil warmed up so you can start gardening sooner:
- Clear the garden of snow as soon as possible! To do this, I apply the wood ash I’ve accumulated over the winter to the snow in the garden in March and April. The sun’s heat is captured by the ash, and the snow melts away. The snow-free garden drains more quickly and the soil warms up more quickly;
- In clay or loam soils, use mounds or raised beds;
- Once planted, if you place a Logissol-O-type watering device near the root ball, you can use water from a recovery barrel heated by the sun during the day to fill the devices at the end of the day. This water will warm the soil near the roots overnight, reducing the shock of transplanting in soil that is still too cool.
Wood ash is best used in the garden in small quantities, at a rate of around 100 grams per square metre per year, spread evenly over the soil. It enriches the soil with minerals and raises the pH, which can be beneficial, except for acid-loving plants such as blueberries and rhododendrons. It’s important to use only untreated wood ash, and to avoid excess so as not to unbalance the soil. The best time to apply it is in late winter or early spring, when the soil is still moist.
There is no need to rush; harden off
When sunny days are few and far between and cold, heavy rains continue to chill the soil, there’s no need to hurry. Instead, acclimatize your small tomato, bell pepper, cucumber or squash seedlings to outdoor conditions by taking them out on days when the temperature is above 15°C (59?) and bringing them in if the night-time temperature drops below 10°C (50?). But beware of the wind and direct sun on the first few days, because your plants aren’t used to it and could get sunburned, just like us when we expose ourselves too quickly to the spring sun!
Remember, it’s not the date or daytime temperature that determines when to plant cold-weather varieties, but the soil temperature. Soil temperature improves if there’s sunshine, if night-time temperatures stay above 12 to 15°C (54 to 59?)for more than a week, and if there isn’t a heavy downpour of cold rain.
Happy gardening!
One additional tip I’d suggest is to lay down a layer of black landscape fabric or plastic over your garden beds a few weeks before you plan to plant. This helps absorb the sun’s heat and warms the soil faster, so you can get your plants in the ground earlier and avoid transplant shock. Plus, it also helps suppress weeds, which can save you time and effort later on!
I believe patience and careful preparation make all the difference when transitioning from winter to growing season. Thanks for sharing these detailed and easy-to-implement strategies!