Annuals are plants that grow, flower and die within a year. They are popular in gardens for adding colour and seasonal interest. Annuals are planted each year as seeds or seedlings. Seeds are sown one to two seasons before flowering time. Growing from seedling shortens the length of time between planting and flowering, so seedlings for summer flowering can be planted in spring or even in early summer. You'll find a wide variety of flowers to plant in spring or summer at your local Flower Power Garden Centre.


Favourite annuals for summer flowers

These annuals can be planted in spring for flowers from late spring to summer. Many will continue to bloom well into autumn. All do best in full sun and can be grown in garden beds or in containers. Look for annuals in punnets or as advanced plants already in bloom (Flower Power call these 'potted colour' or 'bloomers'). The annuals in this ‘top five’ are guaranteed to give long flowering and need little special care.



Petunias are the brightest and boldest of summer annuals. They love summer heat and bounce back after heatwaves or periods of stormy weather. They come in a huge range of flower colours, shapes and sizes including red, white, purple, blue, yellow and pink. Very popular are new colour combinations including ‘Night Sky’, which is deep purple splashed with white markings like a starry night sky. Flowers can be single, double or frilled. Petunias are low, spreading plants for garden beds, pots or hanging baskets. For small flowers in bright colours also look for calibrachoas, which are petunia-like in their growth and flowering. To keep plants growing and flowering, water regularly (daily or twice daily in very hot weather) and liquid feed every 7-10 days. Lanky growth can be cut back to encourage a flush of new growth and to keep plants compact. Plant seedlings 20-30cm apart.


Dianthus or Sweet William

Dianthus are pretty, long-flowering annuals that bring both height and fragrance to gardens. Sweet William (Dianthus barbatus) produces large heads of small flowers in pink, red, white or mixes of all three. Plants grow 30-60cm high. They are easy to grow and can be picked to enjoy as a posy in a vase. To keep in bloom, regularly cut back spent stems, water and liquid feed every 4-6 weeks. Plant seedlings 15-30cm apart.



Lobelia adds bold blue or bright white to the garden. There are also selections with pale blue or pink flowers. Select compact forms to grow as an edging around a pot or garden bed, or use a cascading form to spill over the side of a hanging basket or tall pot. Lobelia works well in a mixed planting of annuals or bulbs. Plants tolerate a little shade. Keep well-watered, especially as the plants establish and during hot periods. Liquid feed every 4-6 weeks. Plant seedlings 10-15cm apart.



Cosmos (Cosmos bipinnatis) is a tall annual that can reach 1-1.5m high with pretty, ferny leaves and long stems of delicate, daisy-like flowers. Cosmos comes in tones of pink or white but there are also yellow and orange cosmos. While the commonly grown varieties are single, there are varieties with curved and decorative petals and combinations of colours. Grow cosmos as a cut flower or plant it for swathes for colour right through summer. For containers or small spaces, look for compact varieties such as ‘Purity’. Tip-pruning plants helps create branching growth with more flowers. Keep plants flowering by regularly picking flowers or deadheading spent blooms. Water regularly, especially during hot spells, and liquid feed fortnightly. Plant seedlings 50cm apart.



Marigolds are fantastic flowers to plant in spring, and are loved for their bright orange, yellow or bronze flowers. Marigolds have aromatic foliage. There are two main types of marigold to grow. African marigolds (Tagetes erecta) are large plants (up to 1m high) with big, frilly flowers in orange, yellow, bronze or white held high on narrow, tubular green stems. They can be grown in garden beds or containers for a splash of colour. French marigolds (Tagetes patula) are small, compact plants often grown as an edging or planted among other flowers or vegetables to attract pollinators. French marigolds can be grown to control pest nematodes (also known as root knot nematode) in soils. Water regularly and liquid feed once a month. African marigolds are highly attractive to snails, so check plants regularly and remove these pests from among the leaves and flowers. Plant seedlings 30cm apart (African) and 15-20cm (French).