What to plant now for a colourful summer garden

If your borders still look a bit bare and the pots on the patio are more compost than colour, you’re right on time to change that. With the right mix of quick performers and steady flowerers, you can turn things around in a few weeks and keep colour going into autumn.

The quickest wins: plants to buy and plant today

For fast impact, think ready-grown plants rather than seeds. Trays of bedding and small perennials from a garden centre will fill gaps almost immediately.

Good choices to plant now for reliable summer colour:

• Geraniums (pelargoniums): Ideal for pots, window boxes and a sunny balcony. They cope well with a dry spell and keep flowering if you deadhead.
• Petunias, calibrachoa and trailing verbena: Excellent for hanging baskets and the edges of containers. They’ll spill over the sides and soften hard lines.
• Dahlias (tubers or young plants): Bigger pots or borders, full sun, rich compost. Great for bold, repeated cutting.
• Cosmos and zinnias (young plants): Light, airy colour in borders; cosmos especially is good for that slightly wild, cottage feel.
• Lavender and hardy geraniums: Perennials that flower well this year and come back, so you’re not starting from scratch next summer.

When you get them home, check the roots. If they’re tightly circling the pot, tease them out gently so they can grow into the new compost. A pot that feels unexpectedly heavy is usually already wet – in that case, water lightly around the edges after planting rather than soaking again.

Sowing now for colour a bit later

If you have a border or a spare raised bed, a few packets of seed will give you generous colour for very little cost.

Look for “sow direct outside” on the packet and choose:

• Nigella (love-in-a-mist) and cornflowers for soft blues and pastels.
• Calendula (pot marigold) and nasturtiums for warm oranges and reds.
• Sunflowers for height at the back of a border or against a fence.

Rake the soil so it’s crumbly, water the area first, then sow thinly. This is the point where many people water again too soon: if the top dries but it’s still damp 2–3 cm down, leave it. A quick finger check tells you more than the surface.

Pots, colour and keeping it going

For a small garden, balcony or rented flat, containers are your shortcut to a colourful summer.

• Use fresh multi-purpose compost and a pot with good drainage holes.
• Combine a “thriller, filler, spiller”: one taller plant (dahlia, upright geranium), some mid-height fillers (petunias, nemesia), and one trailing plant (lobelia, ivy-leaved geranium).
• Water thoroughly, then empty any saucer that’s still holding water the next morning. Constantly soggy compost leads to weak, floppy growth rather than more flowers.

To keep colour going, deadhead often. Snip off faded roses, dahlias, cosmos and bedding flowers right down to the next leaf. If the plant looks green but stingy with blooms, a general liquid feed in the watering can every couple of weeks usually helps – just follow the label.

Even a single well-planted pot by the front door or a bright trough on a windowsill can change how your whole space feels. Start with one area, plant it generously, and you’ll see colour building within days and improving all summer.