What Flowers to Plant in July UK

July is a vibrant month in UK gardens, with warm soil and long daylight hours offering the perfect environment for new plantings. Whether you're adding to an established garden or starting fresh with containers or borders, planting in July can extend flowering right through to autumn. The key is choosing flowers that enjoy a good dose of sun and can cope with warmer temperatures.

Benefits of July Planting

Planting in July means your garden doesn’t have to lose momentum during late summer. Many annuals and perennials respond well to being planted now, especially if they are grown from pots or plugs. The warmth encourages quick establishment and steady blooming. By choosing the right varieties, gardeners can fill gaps in borders, brighten up tired flowerbeds or prepare for a late summer display.

Flowers That Thrive When Planted in July

Several flower types adapt well to July planting across the UK. These plants are generally fast-growing, sun-loving and eager to please with long-lasting colour. Some will bloom before the season ends, while others establish roots and provide interest the following year.

Best Flowers to Plant in July UK

Sweet William (Dianthus barbatus) is a cottage garden classic that can be sown or planted in July to flower the following year. Its clusters of fragrant blooms are ideal for cutting and look striking in mixed borders.

Wallflowers (Erysimum) are another July favourite, particularly when preparing for a bold spring display. These can be planted now to get a head start on autumn growth.

Calendula is a hardy annual that germinates quickly and can produce flowers well into autumn if planted in July. Its bright orange or yellow daisy-like blooms are cheerful and low maintenance.

Foxgloves (Digitalis) are biennials that benefit from a summer start. Sow or plant them in July for tall, elegant spires the following spring or early summer.

Delphiniums can also be planted in July as young plants. They’ll focus on establishing strong root systems through late summer and provide towering colour next year.

Cornflowers (Centaurea cyanus) are perfect for sowing directly into the soil in July. These hardy annuals bloom quickly and add rich blue tones to beds and borders.

Nigella (Love-in-a-Mist) can still be planted in early July. This annual produces delicate, airy flowers in pastel shades, often accompanied by lacy foliage and ornamental seed pods.

Keeping Summer Colour Going

When planting flowers in July, it’s essential to keep newly planted specimens well watered. The heat can cause soil to dry out more quickly, so regular moisture is key during the establishment period. Mulching around the base can also help retain soil moisture and suppress weeds.

By selecting hardy annuals and robust perennials that suit July conditions, it’s possible to inject fresh colour into the garden and even plan ahead for the seasons to come. From quick blooms to next year’s stars, July offers plenty of floral possibilities.

Think Ahead with Biennials and Spring Flowers

July is the perfect moment to get a head start on flowers that will bloom next spring. Biennials like Sweet William, Foxgloves and Wallflowers need time to develop through autumn and winter so they can burst into life in spring. By planting these in July, you're giving them the full seasonal cycle they need.

Late-Sown Annuals Can Still Shine

Many hardy annuals can still be sown or planted in July, especially in southern parts of the UK where the first frosts come later. Calendula, Nigella, Cornflowers and Cosmos can all still be sown directly into the soil or added as young plants. They may not reach their full size but they’ll still put on a good show and support pollinators.

Take Advantage of Warm Soil

The soil is at its warmest in July, which helps seeds germinate faster and young plants settle in more quickly. This is ideal for establishing perennials like Echinacea, Rudbeckia and Delphiniums. While they may not flower much this year, they’ll come back stronger the next.

July Planting Helps Fill Gaps

If early bloomers are starting to fade and borders are looking tired, now’s the time to refresh them. Adding late-blooming flowers like Zinnias or Gaillardia will inject instant colour and extend your garden’s season well into September or October.

Don't Forget to Water

Newly planted flowers need regular watering, especially in July’s heat. Water early in the morning or late in the evening to reduce evaporation. A layer of mulch around the base will help keep moisture in the soil and discourage weeds.

Plant for Pollinators

July is a high point for bees and butterflies, so adding nectar-rich flowers can really support your local wildlife. Lavender, Verbena bonariensis and Scabiosa are great options that can still be planted this month.

Consider Containers Too

If your borders are full, you can always plant in pots or containers. Many of July’s best flowers, like Cosmos and Calendula, do very well in pots, adding splashes of colour to patios or doorways.

List of Flowers to plant in July UK

• Sweet William (Dianthus barbatus) – biennial, great for planting now to bloom next year

• Wallflowers (Erysimum) – perfect for autumn growth and spring flowering

• Calendula – hardy annual, flowers into late summer and autumn

• Foxgloves (Digitalis) – biennial, plant now for tall blooms next spring

• Delphiniums – perennials that benefit from a summer start

• Cornflowers (Centaurea cyanus) – fast-growing annuals, great for direct sowing

• Nigella (Love-in-a-Mist) – delicate annual with unique seed pods

• Poppies (Papaver) – can still be sown in July for late blooms or early spring colour

• Echinacea (Coneflower) – long-lasting perennials that thrive in warm conditions

• Cosmos – fast-growing annuals that provide blooms well into autumn

• Gaillardia (Blanket Flower) – heat-tolerant perennials for bright borders

• Zinnias – bold annuals that love sun and flower quickly

Final thoughts

July is a great time to plant flowers in UK gardens, thanks to warm soil and long days. It’s ideal for adding quick colour or preparing for next season’s blooms. Hardy annuals like calendula, cornflowers, cosmos, nigella, and zinnias can still be sown or planted, often flowering into autumn. Biennials such as foxgloves, Sweet William, and wallflowers planted now will bloom next spring. Perennials like delphiniums, echinacea, and rudbeckia establish well in July's warm soil, even if they flower next year. Regular watering and mulching are key, especially in the heat. For pollinators, add nectar-rich plants like lavender and scabiosa. Containers also work well if space is limited.