An overview of the sowing and growing process

An Overview of the Sowing & Growing Process

There are a few simple but key conditions seeds need to germinate. Now we'll cover the different methods of sowing, how to ensure seeds are getting what they need, and what the next steps are to get your seedlings off to the best start.

When you sow seeds, you're facilitating a natural process that is programmed to happen. However, making sure you provide the right conditions is important.

Different seeds have different requirements, so before sowing, read the seed packet for sowing instructions:

• Do these seeds require darkness or light?
• Should these seeds be sown deep, shallowly or not covered at all?

Sowing under cover vs direct sowing

Under cover (in pots/seed trays) – this is my preferred method as you have more control:

• sowing inside is the best way to improve your success rate
• hardy annuals can be sown outside, but sowing inside still gives them a kickstart.

Direct sowing (in rows or scattered in borders, where they are to flower):

• seeds are at the mercy of heavy rain, dogs, children in wellies, and slugs and snails
• more haphazard but necessary for seeds that resent root disturbance, e.g. poppies, Nigella (love-in-a-mist).

The right conditions for germination

Seeds should be stored in a dry, cool place. After sowing, they will need a bit of warmth, moisture and air to germinate. You just need to make sure you're providing these three conditions.

Conditions to think about when sowing

1. Appropriate container: what's best to raise your seeds in will depend on the size of seed. I use:

• for tiny seeds: a flat seed tray that is half-size (around A5 size) to prevent too many seedlings. E.g. foxgloves, tobacco flowers
• for seeds large enough to easily handle: a modular tray, which produces plugs that you can then plant straight out or pot on. E.g. sweet peas, cosmos
• for big seeds: individual small pots. E.g. sunflowers

1. Warmth: 18°C (64°F) is a good general rule. I don't use a propagator or anything fancy, just my boiler room. Some half-hardy annuals like it slightly warmer, perhaps 21-22°C (70-72°F), but most seeds will germinate at 18°C (64°F).

1. Moisture: ensure the compost is lightly moist, and then put a lid or clear bag over the seed tray to retain moisture.

1. Light or dark: most seeds don't need light to germinate, but some do, so check the seed packet. Seeds that need light should be sown on the surface of the compost.

• You can use a top-dressing of vermiculite or milled cork (more environmentally friendly than vermiculite), which helps keep the seeds moist while still allowing light in.

1. Depth: seeds vary in size and this affects how deep they need to be sown. Larger seeds may need to be planted deeper, but a general rule of thumb is a thin layer of compost on top.

• I used sieved compost so that it's fine and easy for seeds to break through.

What to do once the seeds have germinated

After sowing my seeds, I keep them inside in my boiler room, which is the right temperature for germination – 18-19°C (64-66°F). However, once your seeds have germinated, they need slightly different conditions.

As soon as your seeds start to germinate, it's important to do these three things.

1. Move them to a cooler place, such as a greenhouse or cold frame.

• This prevents them from becoming weak and leggy from growing too fast.

1. Give them as much light as possible, even if they didn't need light to germinate, by putting them on a bright windowsill or in a greenhouse or cold frame.

• This will allow your seedlings to start photosynthesising to fuel their growth.

1. Remove the lid that you used to retain humidity during germination, to prevent damping off.

• This is when fungal diseases attack seedlings, and shows as mould on the surface of the compost or seedlings dying off despite having light and moisture.

Pinching out and potting on

If you've sown in seed trays, your next step, usually once the seedlings have their second pair of leaves, is to prick out.

• This is the process of removing seedlings from the tray and planting them into individual small pots or modular trays, where they can carry on growing without crowding or competition.

The seedlings will grow quickly in their pots, so you may need to repot into larger pots when roots are poking through the base to avoid the nutrients in the compost being used up.

Why don't we sow seeds into bigger pots in the first place?

The reason we don't sow or pot up into larger pots straight away is that when roots are forming, hitting the edge of the pot causes them to branch out. This means you get a better root system if you prick out into modules or small pots and pot on into slightly larger pots when needed. It takes a bit of time and effort, but it's worth it and the process can actually be quite therapeutic.