Learning how to grow vegetables from seeds is a rewarding task! However, there is a learning curve that many new gardeners might find hard to navigate. To help you out, we’ve created this guide to help you understand everything you need to know about sowing vegetable seeds.

When to Sow Vegetable Seeds

Whatever the season, there is a vegetable seed to sow. There are a few exceptions to this rule, so make sure you double-check the sowing instructions on every seed you buy – especially if you’re new to growing that plant.

To start off seeds early, you can sow some varieties like lettuce and salad crops in February under cover or indoors.

Some varieties are sown constantly throughout their growing season to keep the crop consistent. This includes plants like lettuce, carrots, chard, and radishes.

The Methods of Sowing Vegetable Seeds

The method you choose to sow your vegetable seeds greatly depends on which vegetables you’re growing. Some vegetables can be sown directly outdoors, like carrots and parsnips. Others can be grown outdoors but moved to their final positions once they’ve grown slightly. Some are grown indoors or under cover, ready to plant in spring. This method is the preferable option if you’re growing tender vegetables that won’t survive the cold.

Sowing Vegetable Seeds Indoors

Sowing seeds indoors is the best way of growing tender vegetables that will eventually be moved outdoors or herbs that will sit on a windowsill.

• Pick a container that is suitable for vegetable seeds. A 7.5cm pot or any container with holes in the bottom will do. Cell trays or seed trays are effective, as they allow you to transplant small plants without causing damage to the roots.
• For large seeds, use bigger containers.
• If you’re growing herbs or crops that can be cut and will grow again (cut and come again plants), use containers of polystyrene or small plastic containers with drainage holes.
• Use appropriate compost for each seed. If the seed is average size, potting compost is fine. For small seeds, use fine-seed compost.

Sowing Vegetable Seeds Outdoors

To grow seeds outdoors, follow this method:

- Prepare your sowing site, removing any rocks, stones, and clumps of soil.
- Create shallow drills (grooves) with your trowel. The smaller the seed, the shallower the grooves will need to be (check growing instructions for measurements).
- Sow each seed along the groove, spacing them apart to the specs on their instructions.
- Push the soil from either side of the drill together to cover the seeds.


Sowing Outdoors Under Cover (Greenhouses, Cold frame)

Tender crops can be grown in greenhouses or polytunnels until they are ready to be grown outdoors. For example, the following plants are ideal for this method: Pumpkins, tomatoes, sweetcorn, cucumbers, squash, and courgettes. These will be sown in spring in a greenhouse for transplanting later in the growing season.

Harden off any vegetables before growing them in their final positions. This means moving plants outside each day for a week or two for the day until dusk, where you will bring them back indoors. This will help them adjust to the outdoor climate.

How to Thin Plants Successfully

This method is known as ‘pricking out’ seedlings. To thin them out without damaging the plant or stem, do the following carefully.

- Use a pencil to extract the seedling and its roots, holding the plant by its leaves. Doing so by the stem could ruin the plant’s chance of growing.
- Move each seedling into a small pot or cell tray to give them their own space.
- Make a hole in the compost and pop in the seedling until the surface of the soil reaches the lowest set of leaves.
- Firm down the compost to ensure it’s in place.
- Small seedlings can be transplanted into a seed tray
- Aim for 12 seedlings per tray and mark them out with your pencil for even spacing.
- Large seedlings are best transplanted into individual pots.

Common Problems & How to Solve Them

Damping Off – This term refers to seedlings that are grown too close together or in humid conditions. This disease grows a fungus on seedlings, and they will collapse and become unusable. To avoid this disease, you can use commercial growing compost as it is free of these organisms. Sow seeds thinly, if possible, to avoid overcrowding. Allow each seed proper space to grow.

Failing seeds – Sometimes, a seed might fail, growing an inadequate seedling. This seedling can be removed, and you can re-do the process with a new seed. This process will only set you back by 2 weeks if you’re worried about growth timings.

Birds – Birds love seeds. This can be a problem, especially when growing seeds directly outside. To avoid them from stealing your seeds, cover the area with cloth or netting.

Slugs & Snails – Slugs and snails love baby seedlings and plants, and if given the chance, will chomp on any greenery you’ve grown. You can avoid this by growing your plant in a larger pot before transplanting outside. You can also set traps or use barriers. You can find out more about how to stop pests in their tracks here.