Growing plants from seeds is both cost-effective and rewarding. Seeds are not only cheaper to purchase than mature plants, but they also offer access to a broader range of plant varieties not commonly found in local nurseries. There's an inherent satisfaction in nurturing plants from their earliest stages of life, and by saving seeds from your garden, you can select for desirable traits, ultimately leading to stronger, more resilient plants over time.
Where to acquire seeds
You can find seeds at seed exchanges, in catalogs, at nurseries, and from existing plants.
Storing seeds
Keep your seeds dry until you're ready to sprout them.
Germination times vary
Some seeds, like beans and sunflowers, can sprout within a week. Others, may take months or longer. And while some seeds remain viable for years, others are good for just a couple of years. You can test viability by covering the seeds with water in a glass. Viable seeds will sink. Throw out those that float.
Stratification and scarification
Some seeds, like black-eyed Susan and delphinium require stratification. This simply means the seeds must be exposed to periods of cold to simulate outdoor conditions. To do this, you can scatter seeds on a moistened paper towel, fold the paper towel over, and seal it in a labeled plastic bag. Pop the bag into your refrigerator for a few weeks to a few months depending on the plant.
Some seeds, like nasturtiums and sweet peas, have a hard coat which needs a nick – scarification – to absorb water. You can easily do this with a sharp knife, sandpaper, or nail clippers. Make small cuts or scratches on the seed coat, being careful not to damage the embryo inside.
How to plant seeds
What you'll need:
Seed-starting trays or small pots with drainage holes
Seed-starting or potting mix (not garden soil)
Spray bottle
Labels or markers for identifying plants
Planting steps:
Plant seeds at the depth and spacing outlined on package.
Cover lightly with potting mix.
Gently spray to moisten without disturbing seeds.
Keep the soil moist during germination and seedling stages. Avoid overwatering to prevent damping-off disease.
Place in bright, indirect light like a sunny window. Or use artificial grow lights positioned two to three inches above the seedlings.
Most seeds germinate when the temperature is between 18-24°C. Until germinated, cover seeds with plastic wrap to maintain a relative humidity level of 50-60%.
Ensure seedlings receive adequate moisture, light, and ventilation. Thin as they grow.
Fertilize with a diluted, balanced fertilizer once the second set of leaves develop.
Before transplanting outdoors harden off for one to two weeks by gradually increasing their exposure to sun and wind each day.
Transplant the seedlings into larger containers or directly into the garden once they have several sets of leaves and the outdoor temperatures have warmed sufficiently.
Seed germination is a great way to include a wider variety of plants. It may require experimentation; as you understand the needs of different seeds, you can successfully grow your own plants from scratch and watch your garden come to life.
Our thanks to the Mississauga Master Gardeners for sharing their knowledge with us. To learn more about the Mississauga Master Gardeners, visit their website and follow them on Instagram and X.
