Spring has arrived, which means it’s soon time to start planting seeds in the ground, depending where you're growing. We’ll walk through the basics of direct sowing, helping you make the most of the early growing season and set your garden up for success.
Direct sowing refers to planting seeds straight into the soil outdoors, rather than starting them earlier in containers like pots or seed trays. It’s a simple, hands-on approach that allows seeds to grow right where they’ll eventually mature. Many plants thrive better when direct sown because some things are sensitive to stress or root disturbance from transplanting.
When Can You Direct Seed Outside?
There are a few things to consider before you start direct sowing outside, including soil temperature, local last-frost dates, and the upcoming forecast.
Soil Temperature
One of the most common mistakes with spring direct sowing is planting too early, while the soil is still cold and overly wet. Although seeds need moisture to sprout, they also require warmth. If planted too soon, seeds may sit in heavy, damp soil that is too cold for germination, which can cause them to rot instead of grow. As the soil naturally drains after the spring thaw, it also begins to warm, creating better conditions for seeds to sprout.
Warmer soil temperatures lead to faster and more reliable germination. All of our seed packets list an ideal germination temperature on the back of the seed packet, seeds can still germinate below this ideal temperature range but it will be a bit slower. To speed up soil warming, you can cover your garden beds with a dark sheet, or a floating row cover.
In early spring, once the ground has thawed, the soil is usually very wet. It’s important to wait a few weeks before working it. Digging, tilling, or ploughing saturated soil can compact it and damage its structure. This can harm the soil ecosystem, restrict root development, and reduce how well plants take up nutrients. If you're growing in a raised bed or containers, this is less of a concern.
Frost Dates
Not all crops respond to frost in the same way so this section is less relevant to frost-hardy plants. Some cool-season vegetables can tolerate light frost and even benefit from early planting, referred to as frost-hardy. Others, known as frost-tender plants, are easily damaged or killed by cold temperatures and should only be planted after the risk of frost has passed.
We’ve outlined examples of both frost-tolerant and frost-tender crops below in the section "What Plants Should Be Direct Sown" to help guide you.
Now that that's out of the way, last frost is an important factor in when to direct sow frost-tender plants. This is the average date in spring when temperatures stop dropping below freezing. You can find your local last frost date by searching online using your town or region (for example, “last frost date + your city”) or by using gardening calendars like the Old Farmer’s Almanac.
It’s important to remember that this date is only an estimate, not a guarantee. Frost can still occur before or after this window, so it’s best to use it as a guideline rather than a strict rule. Every spring is a little different.
Before planting, take time to check the 10–14 day weather forecast. Keep in mind that forecasts become less reliable the further out they go, so the closer you get to planting time, the more accurate your decision-making will be. Look for:
- Nighttime temperatures consistently staying above 4°C
- No sudden dips or frost warnings
- A general warming trend rather than fluctuating cold snaps
There are a few other weather conditions to keep in mind when planning your planting days. Aim to sow seeds when light rain or drizzle is expected, or when the soil is already evenly moist.
A gentle rain can help settle and water your seeds naturally, while a heavy downpour can displace them or wash them away.
On the other hand, hot, dry, and windy conditions are less ideal. Strong winds can scatter lighter seeds, and dry soil requires more water before it can properly support germination. In these conditions, much of the water you add will first go toward rehydrating the soil rather than reaching the seeds.
If you do need to plant on a hot, sunny day, it is best to water your seeds deeply in the evening or early morning. This helps reduce evaporation and allows more moisture to reach and stay around the seeds long enough to initiate germination.
What You Can Do In The Case Of An Unexpected Late Frost:
If a sudden hard frost threatens your garden, there are a few steps you can take to protect your plants or seeds.
- Use sheets, floating row covers, or cloches to shield tender seedlings. An overturned plastic tote weighed down with a rock is a good choice if you don't have cloches or row covers on-hand.
- Water your plants thoroughly just before the frost hits. Moist soil and hydrated plants insulate the cells of the plant, which can help prevent frost damage.
Frost can damage frost-tender plants at a cellular level. When water inside plant cells freezes, it expands, which can rupture cell walls. This causes leaves and stems to turn black or brown and become wilted or mushy. While there are no guarantees against frost damage, these simple measures can improve your plants’ chances and help minimize losses.
What Plants Should Be Direct Sown?
Frost-Hardy Plants to Direct Sow (Can Be Sown Before Last Frost)
- Carrots
- Peas
- Beets
- Kale
- Potatoes
- Rutabaga
- Lettuce
- Radishes
- Spinach
- Swiss Chard
- Mustard Greens
- Arugula
Frost-Tender Plants To Direct Sow (Sow Only After Risk Of Frost)
- Summer Squash
- Winter Squash (Including Pumpkins)
- Beans
- Cucumbers
- Melons
- Corn
Although you may see some of these things available as started plants at the garden centre, there are some benefits of starting them by direct sowing.
- Root Integrity: Many plants, particularly taprooted vegetables, do not handle transplanting well, which can lead to stunted growth or poor yields.
- Faster Growth: Certain fruits and vegetables can germinate and grow so rapidly when directly sown that they outpace or catch up to those started indoors. This is often the case with vining fruits and cucurbits like melons, squash, and cucumbers.
- Reduced Expense and Space: Direct sowing eliminates the need for seed-starting supplies like pots and light kits. Don't overcrowd your indoor starting space with things that will do better sown outside anyways.
Of course depending on the length of your growing season, there may be tradeoffs here and you may need to give some long season crops a head start at the expense of some transplant shock if you are gardening in the extreme north with less than 100 frost-free growing days. Luckily, we specialize in offering a selection of vegetable seeds that are specifically chosen for their short days to maturity, and are bred to thrive in more northern climates. So if you're having a hard time getting your winter squash or your melons to ripen before your fall frost arrives, try some of our short-season varieties.
We would love to hear in the comments your suggestions if you're growing in these conditions, and the adaptations you've made.
Maintaining Moisture and Soil Nutrition
Providing your plants with consistent water and nutrients is one of the most important factors for a successful garden. Healthy plants with access to what they need can better withstand weeds, pests, and disease.
Preparing your soil before planting, by providing lots of organic matter and loosening compacted soils, gives your seeds a strong start. To keep your garden thriving throughout the season, consider side-dressing your beds a couple of times during the summer with natural amendments such as compost, worm castings, bone and blood meal, or other amendments. These additions help maintain soil fertility and support steady plant growth.
Mulching your beds will keep more moisture in the soil and help to block out weeds. Deep, even watering, especially when done in the evening, will give your garden the moisture it needs to thrive. It's always better to deeply water a few times a week rather than watering a little bit every single day. And remember, you're watering the soil not the leaves. It's best to avoid getting water on your plants leaves when possible (rain is fine, use a sprinkler if you need to, but constantly wet foliage can increase risk of fungal disease).
There is a whole world of organic soil amendments out there to learn about if you are interested in diving into compost teas and liquid fertilizers. But you can keep it simple with aged compost and worm castings and have great success.
Recommended Reading
If you made it through to the end, these articles may be of interest for you next:
How to Make the Most of Canada's Short Growing Seasons: a Beginner Gardener's Guide
"Fast Food" Garden - Quick Yielding Vegetables & Garden Plans
Save Water, Grow Food: The Best Strategies and Plants for a Drought-Resistant Garden
What About Wildflowers?
In this article I've focused on the veggie garden, because it's a bit of a different set of priorities. I'll cover more in-depth the various things to consider when direct sowing wildflower seeds in another article, but there is lots of info available in our Seed Starting Resources page so check it out.
