What Flowers to Plant in April UK

April brings a welcome shift in the garden as longer days and rising temperatures create ideal conditions for flower planting. In the UK, this month marks the sweet spot between winter’s lingering chill and the warmth of late spring. The soil begins to warm, frosts become less frequent, and many flower seeds and young plants can finally take root outdoors. Whether you’re refreshing borders, starting a wildflower patch or simply filling containers with colour, April is full of floral potential.

Tips for Successful April Planting

Before getting stuck in, it’s important to make sure the ground is ready. Choose a dry day to prepare your soil, removing weeds and raking the surface to a fine tilth for seeds. If you’re planting young plants or perennials, dig in compost to enrich the bed and improve drainage. In colder areas, it’s wise to keep an eye on the forecast and be prepared to use fleece if a late frost sneaks in. Water newly planted flowers regularly, especially during dry spells, and mulch where needed to help retain moisture and suppress weeds.

Hardy Annuals to Sow in April

April is an ideal time to sow hardy annuals directly into the soil. These are flowers that can withstand a bit of chill and will bloom within the same year. Cosmos is a favourite for its daisy-like flowers and long flowering season, while calendula brings bright orange and yellow cheer to beds and borders. Other great choices include cornflowers, love-in-a-mist and poppies. These annuals not only provide quick results but are also great for pollinators and cutting gardens.

Perennials and Bulbs to Plant Now

If you're looking to invest in long-lasting beauty, perennials are a wonderful option. April is a good month to plant varieties like delphiniums, lupins and echinacea. These plants may take a bit longer to bloom but will return year after year, growing stronger each season. Dahlia tubers can also go in the ground in April, as long as you wait until the soil is warm and frost danger has passed. Lilies, gladioli and begonia tubers can also be started off in pots and later moved into the garden when conditions are more stable.

Ongoing Care for April Plantings

After planting, consistent care will make the biggest difference. Keep an eye out for early pests, particularly slugs and snails which thrive in damp spring conditions. Try natural deterrents like crushed eggshells, copper tape, or wildlife-friendly pellets. Deadheading—removing spent blooms—will keep your plants looking tidy and encourage more flowers. For taller varieties such as delphiniums or sunflowers, it’s a good idea to stake them early to prevent wind damage.

Flower Gardening in Small Spaces

Even if you don’t have a large garden, you can still enjoy a colourful display. Container gardening is ideal for patios, balconies, and smaller spaces. Choose flowers that thrive in pots, such as nasturtiums, calendula, or dwarf sunflowers. Use a quality potting mix and ensure containers have proper drainage. Water regularly, as pots dry out quickly, and feed plants every couple of weeks with a liquid fertiliser to support healthy growth and extended blooming.

Planning for Colour Beyond Spring

April is also the time to think ahead. To keep your garden vibrant into summer and beyond, plan for continuous flowering. You can start biennials like foxgloves and wallflowers now, which will bloom the following year. For ongoing colour this season, consider succession planting. Combining fast-growing annuals with dependable perennials and summer-flowering tubers ensures your garden stays full of life from now through to autumn.

Region Matters

While April is broadly suitable for flower planting across the UK, local climates can make a difference. In southern regions like Cornwall or Kent, warmer conditions may allow you to start planting earlier and take more risks with tender varieties. In contrast, cooler northern areas or those with higher altitudes may still experience late frosts, so it’s best to stick to hardy plants or start more delicate ones indoors.

Starting Seeds Indoors vs. Direct Sowing

Not all flowers need to be sown directly outdoors. Some benefit from a head start indoors. Sweet peas, for example, can be started under cover in pots and then planted out once established. Sunflowers and nasturtiums also do well this way, giving you a stronger plant to transplant once frost risk has passed. This approach is especially helpful if you’re gardening in a colder part of the UK.

Soil Types and Flower Choice

Understanding your soil can also guide what to plant. Sandy soils warm up faster in spring but dry out quickly, making them better suited for drought-tolerant flowers like poppies or cornflowers. Heavy clay soils take longer to warm but retain moisture well—ideal for moisture-loving plants like lupins and delphiniums. Digging in compost or soil improver can help create better conditions for most varieties.

Companion Planting for a Healthier Garden

Some flowers not only look good but also support your garden in other ways. Calendula and nasturtiums can attract beneficial insects and deter pests from nearby vegetables. Lavender, though typically planted a bit later, helps draw in pollinators while its scent can confuse pests. Mixing flowers with practical benefits into your beds or borders can boost the health and productivity of your entire garden.

A List of Flowers to Plant in April UK

• Cosmos

• Calendula

• Cornflowers

• Love-in-a-mist (Nigella)

• Poppies

• Sweet peas

• Sunflowers

• Lupins

• Delphiniums

• Echinacea

• Dahlias

• Gladioli

• Lilies

• Begonias

• Nasturtiums

Final Thought

April is the ideal month for planting flowers in the UK due to warming soil, fewer frosts, and longer daylight hours. To prepare, clear weeds, enrich soil with compost, and monitor for late frosts. Hardy annuals like cosmos, calendula, cornflowers, love-in-a-mist, and poppies can be sown directly into the ground for quick, vibrant blooms. For longer-lasting impact, plant perennials such as delphiniums, lupins, and echinacea, along with tubers like dahlias, lilies, gladioli, and begonias. Regular watering, mulching, and frost protection are key to success.