Seeds to start indoors in April UK

April 15, 2026

April is when the growing season really gets into its stride. The days are longer, there’s more warmth in the sun, and things start to move quickly - especially if you’ve got seedlings on the go.

There’s plenty happening outdoors, but for many gardeners, April is just as much about what’s happening indoors or under cover.

Seeds to Start Indoors in April

This is one of the key windows for sowing tender crops that will be planted out later on. With the extra light, seedlings establish quickly; often much better than earlier in the year.

Good options to start now include:

• Courgettes
• Squash and pumpkins
• Sweetcorn
• Cucumbers
• French and runner beans (towards the end of the month)
• Basil and other tender herbs

These are all crops that don’t enjoy the cold, so getting them started indoors gives them a much better start before they move outside in May.

Give Seedlings the Best Start

At this stage of the season, it’s less about getting seeds to germinate, and more about growing strong, healthy plants. Good light, steady watering, and enough space for roots to develop all make a noticeable difference.

This is where many gardeners find soil blocking particularly useful. Instead of sowing into lots of individual pots, you can raise multiple seedlings together in a single tray, each in its own small block of compost. It keeps everything contained, simplifies watering, and helps avoid that gradual spread of pots across every available surface.

If you’re starting a batch of seeds this month, you can explore our Soil Blocker range here.

Sowing Outdoors (When Conditions Allow)

While indoor sowing is in full swing, there’s plenty you can direct sow outside if you have limited space indoors:

• Carrots
• Beetroot
• Radish
• Lettuce
• Spinach
• Peas and broad beans

As always, it’s best to work with the soil - if it’s still wet or cold, waiting a few days will usually give better results. Or you can opt to start indoors and move outdoors once the weather has settled and the plant has established.

Sow Little and Often

It’s easy to get carried away in April and sow everything in one go, but a steady approach tends to work better - especially when it comes to harvesting. A few seeds now, a few more in a week or two, and you’ll have a more manageable flow of plants and harvests.

Keep an Eye on Space

One of the biggest challenges this month isn’t sowing, it’s finding room for everything once it starts growing. Seedlings can quickly take over windowsills, greenhouses, and any spare surface. Keeping things grouped together, rather than spread across lots of pots, makes a big difference. It’s easier to water, easier to move, and easier to keep track of what’s what.

Start Hardening Off (Towards the End of the Month)

If you’ve got sturdy seedlings, you can begin hardening them off towards the end of April. A few hours outside on mild days, bringing them back in at night to begin with, helps to prepare them for planting out once the weather settles.

Be Patient with Tender Crops

Even if the days feel warm, nights can still catch you out. Tender plants are best kept under cover until the risk of frost has properly passed - usually into May, depending on where you are. A bit of patience now is well worth it.

A Month of Momentum

April isn’t about rushing, it’s about building momentum. Seeds started now will carry you through into summer, and a steady, organised approach makes the whole process much more enjoyable.

A tray of healthy seedlings, growing on well, is often the best sign that the season is heading in the right direction.

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