A reliable selection of perennial flowers that bloom all summer can help your garden look its best for as long as possible. A variety of summer plants provide flowers from June to September and even beyond, in the UK, offering long-lasting colour as well as food for pollinators such as bees.
Long-flowering summer plants may need deadheading to keep blooming, while a weekly application of tomato fertiliser can promote new flowers to grow.
Browse our pick of the best summer flowers to grow
Pelargoniums

With regular deadheading, these easy-to-grow perennials will provide beautiful blooms throughout summer. There are many pelargonium types to grow – find out more in our feature on pelargonium types explained.
- Buy perlargoniums from Crocus and Thompson and Morgan
Erigeron

Erigeron karvinskianus is a spreading, perennial daisy with an informal growth habit, ideal for planting in the crevices of walls, steps and paving stones. It’ll often flower well into autumn, too. Good for a well-drained spot in full sun or partial shade.
- Buy erigeron karvinskianus from Crocus, Thompson and Morgan, and Dobies
Abutilons

If you can provide them with some form of winter protection from frosts, abutilons will prove their worth with year-round flowers. Give them a sunny position, with plenty of water and feeding to get the best from them. Pictured is the trailing abutilon, Abutilon megapotamicum.
- Buy abutilons from Crocus and Thompson and Morgan
Campanulas

For flowers all summer, try the creeping campanulas like Campanula portenschlagiana and Campanula poscharskyana. Like Erigeron karvinskianus, they’re ideal for growing in cracks and crevices. The flowers are popular with pollinators.
- Buy campanulas from Gardening Express and Thompson and Morgan
Iberis sempervirens

Commonly known as candytuft, this perennial, low-growing plant is a brilliant ground cover choice for the front of borders or in containers. It’ll provide clouds of frothy blooms from spring to autumn.
- Buy Iberis sempervirens from Crocus and Gardening Express
Potentilla

Potentillas are compact shrubs and herbaceous perennials, well-suited to growing as floral hedges or growing in well-drained herbaceous borders. Potentillas respond well to deadheading, which will provide you with the best display. Pictured is the beautiful hybrid Potentilla x hopwoodiana.
- Buy potentillas from Primrose, Crocus, and Gardening Express
Sweet peas

These popular annuals can begin flowering as early as May. When deadheaded, or if the flowers are snipped just before opening for cut sweet peas, you’ll easily have flowers throughout summer and into autumn. Follow the growing advice in our sweet pea grow guide.
- Buy sweet peas from Thompson and Morgan, Dobies, and Crocus
Perennial wallflowers

Perennial wallflowers like ‘Bowles’s Mauve’ and ‘Apricot Delight’ not only flower throughout summer, but have even been known to flower all year. Just make sure you deadhead spent flower spikes to encourage plants to produce more.

More plants for flowers all summer
- Fremontodendron
- Verbena bonariensis
- Geranium ‘Rozanne’
- Salvia microphylla
- Coreopsis
- Penstemons
- Nepeta x faassenii
This article was last updated in April 2022. We apologise if anything has changed in price or availability.