Raising Plants from Seed

Raising plants from seed is one of the most satisfying parts of gardening. It costs a fraction of buying punnets, and it opens up hundreds of varieties you will never find on a garden centre shelf.

Suppliers like Kings Seeds carry a huge range bred for New Zealand conditions. With a few trays, some seed mix and a warm windowsill, you can grow far more than you ever could from bought seedlings alone.

Sowing your seeds

Use a proper seed-raising mix rather than garden soil or potting mix. It is fine, free-draining and low in nutrients, which is exactly what young seedlings need. Fill clean trays or pots, firm gently and water before you sow.

Sow seeds at the depth on the packet, usually about twice their own width, and barely cover fine seed. Label everything, because seedlings look alike early on, and keep the mix moist but never soaking.

• Use seed-raising mix, not garden soil
• Sow at the depth recommended on the packet
• Keep the mix moist, warm and out of harsh sun
• Label every tray with variety and date

Warmth and light

Most seeds need warmth to germinate, so a sunny windowsill, glasshouse or warm spot indoors gets things moving. In the cooler South Island and through early spring, a heat pad or warm cupboard makes a real difference for tomatoes and other tender crops.

Once seedlings appear, they need plenty of light or they stretch tall and weak reaching for it. Move them into the brightest spot you have, and turn trays on a windowsill so they grow straight.

Pricking out and hardening off

When seedlings have their first true leaves, prick them out into individual cells or pots so each has room to grow on. Handle them by a leaf, never the fragile stem, and water them in.

Before planting out, harden seedlings off over a week or so by putting them outside during the day and bringing them in at night. This toughens them up to wind, sun and cold. Hold tender crops back until the frost risk has passed, around Labour Weekend for much of the country, later in the south.