What to plant in August – Hydrangea and Hibiscus

August is a time when gardens should be bursting with colour, texture and life. By now, your spring and early summer bedding plants have likely passed their peak, making way for hardy perennials and summer-flowering bulbs to take centre stage. But if your borders or pots are looking a little tired, there’s still time to inject some late-summer vibrancy.

Two standout choices for planting in August are Hydrangeas and Hibiscus.  Both offer bold, long-lasting flowersand can bring a fresh splash of colour to your garden as we move towards autumn. Here’s why we rate them so highly:

Hydrangea – Classic Summer Showstoppers

Hydrangeas are beloved for their large, dramatic flower heads that can keep their colour well into autumn and even beyond as dried arrangements. They’re incredibly versatile and can thrive in borders, as feature plants, or in pots on patios.

Key Highlights:
• Late summer colour – Hydrangea blooms are long-lasting and ideal for cutting and drying. They transition beautifully into autumn shades as they age.
• Light shade lovers – While they prefer dappled or morning sun, Hydrangeas will tolerate a sunny spot if the soil stays moist. They’re happy in beds, borders or containers.
• Soil pH affects flower colour – Acidic soils encourage blue flowers, while alkaline soils produce pinks and purples. You can alter their colour using ericaceous compost or colour-enhancing treatments.
• Flexible planting time – Container-grown Hydrangeas can be planted at any time of year, though August is a great opportunity while the soil is still warm. Water thoroughly after planting to help them establish.
• Spring frost protection – Keep an eye on new shoots in early spring as late frosts may scorch tender growth. This isn’t usually harmful but may affect appearance.
• Safety tip – Hydrangea leaves can cause skin irritation, so gloves are recommended when handling. They are also mildly toxic if ingested.

Hibiscus – Exotic Blooms with a Hardy Streak

For a touch of the tropics that’s perfectly suited to the British climate, Hibiscus syriacus (Hardy Hibiscus) is a fantastic choice. These showy shrubs are surprisingly low-maintenance and reward you with bold, trumpet-shaped flowers from late summer into autumn.

Key Highlights:
• Long flowering season – Hardy Hibiscus typically starts blooming in August and continues to flower until the first frosts.
• Exotic appearance, easy-care nature – Despite their tropical looks, they’re robust and thrive in a sunny, sheltered spot with well-drained soil.
• Ideal for pots and borders – Hibiscus are happy in large containers or planted directly in the garden. For pot-grown plants, re-pot every 2-3 years in spring to keep them vigorous.
• Deciduous habit – Don’t worry when they drop all their leaves in autumn; they’ll come back strong the following year.
• Minimal pruning required – Older shrubs can be pruned after flowering to maintain shape and airflow, but Hibiscus are best left to grow naturally if space allows.
• Indoor option – For smaller spaces, consider a tropical (tender) Hibiscus as a houseplant. With proper care, they’ll flower indoors from May through October.

Ready to Plant?

We have a wide selection of Hydrangeas and Hibiscus in stock, perfect for adding instant colour and interest to your garden this August. Whether you're looking to refresh a border or brighten up a patio pot, now’s the ideal time to plant.

If you're planning to tackle a few more jobs around the garden this month, find our August garden jobs advice here for more tips and ideas to keep your outdoor space looking its best.