Growing Flowers Now for Summer Colour

April 22, 2026

By mid-spring, it’s not just about vegetables. There’s often a point around April where you start to think about how you want the garden to feel, not just what you want to harvest from it. A few flowers can completely change a space; softening edges, bringing in pollinators, and adding colour that carries right through the summer.

If you’d like a summer garden filled with the scent of flowers, now is the time to get things started. With the extra light and a bit more warmth in the air, seeds germinate readily and seedlings tend to grow on without too much fuss. It’s one of the most straightforward times of year to grow flowers from seed.

Flowers to Sow Now

There’s no shortage of choice, but some flowers are particularly well suited to sowing at this point in the season.

Good, reliable options include:

• Cosmos
• Zinnias
• Calendula
• Cornflowers
• Nigella
• Sunflowers
• Sweet peas (if you haven’t already)

They’re all straightforward, fairly quick to get going, and generous once they settle in. A few well-grown plants will give you plenty of colour, whether that’s in borders, planters, or a handful of stems for the kitchen table.

Starting Strong Seedlings

At this stage of the season, it’s less about getting seeds to germinate and more about how those seedlings develop in the weeks that follow. Good light makes a big difference, as does steady watering, but what’s happening below the surface matters just as much.

Seedlings that have space to develop a healthy root system early on tend to grow into stronger, more balanced plants. They establish more quickly once planted out, and generally cope better with whatever the weather throws at them.

This is why we - and many other gardeners - favour Soil Blockers for flower seeds. Each seedling grows in its own small block of compost, without becoming restricted by a pot. As the roots reach the edge, they naturally branch and air prune, rather than circling, which helps build a sturdier plant overall. 

It also keeps things feeling a bit more manageable at this time of year. A tray of seedlings in blocks is easier to keep an eye on than lots of individual pots scattered about.

Don’t Sow Everything at Once

It’s very easy to get carried away with flowers, especially when the weather turns and everything feels possible again. But sowing everything in one go often means everything flowers in one go too.

Staggering your sowing by a couple of weeks gives you a much longer display through the summer, and it spreads the workload a little as well. A few sown now, a few more later, and the garden keeps giving.

Looking Ahead

Most of these seedlings will be ready to plant out in May, once the risk of frost has passed. Until then, it’s just a matter of keeping things ticking along - enough light, enough water, and a bit of space to grow.

If you’re planning to grow flowers from seed this year and want to keep things simple from the start, you can explore our Soil Blockers here.

It doesn’t take much to get going - and a few small trays now can turn into something quite special in a few months’ time.

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