After winter made a rather rude appearance in February, delivering one of the coldest months on record, many of us are ready for spring. If you long for outdoor colour or flavours of homegrown vegetables, you can start spring now by sowing seeds.
There’s something magical about growing from seed, and it is an ancient art that can be challenging and sometimes even discouraging.
After growing all kinds of seeds for over 60 years, I’ve learned a few things. Here are my Top 10 tips for success with seeds:
1. Timing is everything. Don’t sow seeds too early. In household conditions and even in a greenhouse, seeds started too soon can become tall and leggy. Most seed catalogues give an approximate date for seeding each variety, and their recommendations are accurate. Balance this with early or late weather patterns, which can vary up to three weeks. The golden rule is: Better a little late than too early.
2. Find a suitable site for seed germination. The best location is close to an east or north facing window where you can open the window to cool things down a bit. Having an electrical outlet nearby is handy if you want to use a grow light or a heating mat or cable.
3. Seed secrets. When selecting seeds, choose the varieties you know and love but each year, many new, improved varieties become available — some with more disease resistance and others that produce in less time.
The AAS Winner symbol on the seed packet indicates the variety has been awarded distinction by impartial judges from across the US and Canada. I recommend planting a few new varieties.
Less is more, too. If you’re not intending to feed the whole neighbourhood, usually one seed packet is plenty.
4. Cold storage. Unless it’s a tropical seed, for years I have had a lot of success by putting all our seeds in the freezer before planting, and after I put any leftover seeds back into the freezer. This cold storage helps stratify the seeds for improved germination. If the World Seed Bank in Norway does it, it works for me.
5. Make smart choices. Seeds are not inexpensive, especially some of the new hybrids. Sow early seeds like peas, beans and some root crops directly in the garden, but when it comes to brassicas, onions, leeks and lettuce that take a long time to grow and harden off in the cold, it’s often cheaper and easier to plant a pack of pre-started plants.
6. Technique matters. Use plastic trays that you can wash and bleach to use again. Fill them with a quality starter mix like Dutch Treat for tiny seeds, and quality soil blends like Sunshine Mix #4 or Pro-Mix H.P. for larger seeds.
Make sure everything is very clean. For tiny seeds like lettuce, make small furrows with a pencil and seed lightly into the row. Don’t cover the tiny seeds with soil. Poke large seeds into the soil just below the surface. Water them thoroughly with a quality watering can that has lots of tiny holes.
The trick for this first watering is to use very hot water; so hot you can barely put in your hand. The extra heat will help both the speed and the success rate of germination. Cover the seeded furrows with a layer of newspaper topped with plastic that is tucked around the bottom of the tray.
7. Be watchful. Most seeds will germinate in average household temperatures. Your seed catalogue or packet will give approximate times of germination. It can vary from three or four days to two or more weeks, depending on the type of seed. All seeds need to be checked daily to make sure the soil or growing media is moist, not wet, at all times.
8. Use a fan. When sprouting occurs, the newspaper and plastic covers must come off because the seedlings need exposure to as much light as possible to stop them stretching.
The biggest challenge is to prevent diseases like botrytis and root rot. Run a household fan on low speed to keep the air circulating, and keep the soil a bit dryer, especially at night.
9. Cool them off. Once the first true set of leaves appear, move the seedlings to a very well lit area where they can be kept cool. Keeping them just moist, in good light and as cool as possible (10 to 12 C) will toughen them up as they continue to send out more leaves.
10. Prepare outside. Create a spot outdoors in the sun where the seedlings can acclimatize before being planted in the garden. Even a makeshift cold frame covered in clear polyethylene works.
On warm days, the cover should be rolled up so the plants don’t overheat and then rolled down at night.
It is only necessary to pre-start seedlings for crops that need a head start because they require a longer growing period, like tomatoes, cucumbers and squash.
Most short season crops like peas, beans and corn, can be seeded directly into the garden once there are consistent day and especially night temperatures of about 10 C or higher.
Heat-loving crops (tomatoes, cucumbers and squash) can be set out when you are confident of warm weather, traditionally on the May long weekend.