Annual Plants

Annual honesty is a flowering plant that belongs to the same family as cruciferous vegetables called Brassicaceae.

Honesty produces lightly scented purple or white flowers in spring, developing into intriguing translucent seed pods in the summer. These pods are where the plant's common names derive from. The pods have a papery skin where the seeds inside are visible, hence the name honesty.

The leaves of honesty look somewhat similar to that of stinging nettles. They are green heart-shaped with toothed edges.

Honesty is a very low-maintenance plant. In fact, it can thrive in the garden with no attention at all. Their excellent self-seeding ability ensures that new generations will continue to add beauty to your garden year after year.

Honesty can also be grown as either an annual or biennial. Sowing seeds in late winter to early spring for the former or late summer for the latter.

Papaver somniferum is widely known as the Breadseed Poppy and the Opium Poppy.

Both edible poppy seeds and opium derive from Papaver somniferum. However, in gardens, they're cultivated for their stunning blooms.

Numerous cultivars of Papaver somniferum vary in colour and flower appearance. Two noteworthy ornamental cultivars include Lilac Pompom, featuring glamorous frilly petals forming a pompom shape, and Hungarian Blue, which produces lovely open single-flowered blooms with marked purple petals.

Papaver somniferum cultivation may be illegal in certain countries/jurisdictions, so ensure legality before planting. Despite edible seeds, improper processing can contaminate them with plant latex containing opium, making consumption extremely harmful, even deadly. Consider growing it solely as an ornamental plant where permitted.

Read more on Poppies in our guide.

Cockscomb, named for its resemblance to a rooster's comb, is a type of celosia primarily available in red or pink hues, with orange and yellow cultivars also available.

It serves as an excellent choice for cut flowers, suitable for various arrangements.

Alongside cockscomb, other species of celosia exist, ranging from the spear-shaped blooms of Celosia spicata to the plume-like flowers of Celosia plumosa.

With a height range of 30cm to 1m, celosia is a versatile addition to flowerbeds, providing vibrant colour and serving as an effective filler plant.

Cleome is an annual plant commonly known as the spider flower.

Blooming in summer, they produce delicate-looking flowers with long thread-like stamens earning their nickname "spider flower."

Varieties range in colours, including purple, pink, and white.

Typically they range from around 85cm to 110cm tall.

They're less popular than some of the other plants on this list. However, they can make an impressive addition to the garden, especially summer flower beds.

Once established, cleome are relatively low-maintenance plants. However, the seeds are renowned for being tricky to germinate.

Cold stratifying the seeds for around 10 days in a refrigerator before surface sowing them in a warm, sunny location has been known to give good results. So, if you're looking for a challenge, try growing cleome from seed.

Once treated as a weed, the common poppy is now a welcome addition to the garden, suited for borders, flower beds and wildflower gardens.

They have unmistakable scarlet red bowl-shaped flowers which bloom in summer.

They grow to around 60 - 85cm in height.

They self-seed. However, germination is usually triggered by disturbing the ground, such as digging over the soil.

Read all about Poppies in our guide.

Cornflowers are a must-have for any wildflower garden.

They are true, hardy annual plants known for their vibrant blue flowers.

Blooming in the summer, they typically grow to a height of 65-80cm, with some larger varieties reaching up to 1m

They are relatively easy plants to grow, requiring little maintenance. Cornflower seeds can be sown directly where the plant is to flower.

In addition to wildflower gardens, they're well suited in cottage-style gardens and pots. They make great additions to cut flower arrangements.

Deadhead spent flowers to encourage the plant to produce more blooms. Just remember to let a few set to seed for future plants.

Cosmos is a familiar annual favourite and another essential for anyone growing a cut flower garden.

They are fast-growing and produce a profusion of flowers throughout their long blooming season.

They range in colour, including red, white, pink, yellow and orange.

They are well suited for borders and are a great way to sustain colour in the garden from late spring until the first frost.

Read all about Cosmos in our guide.

Marigolds are easy to grow and produce delightful, colourful flowers.

They're a favourite among many and are well-suited for summer borders and containers.

They are typically a shade of orange or yellow, with some dark oranges being almost brown. They can be single-coloured or bicoloured.

They have recognisable feather-like foliage which produces a strong aroma.

There are claims that the aroma of marigolds can deter pests, such as aphids.

Nemesia is a small annual shrub-like plant commonly known as Cape Jewels.

They are fast-growing and have a long blooming season. Flowering from late spring until mid-autumn.

Some are highly fragrant, having a sweet vanilla-like scent.

They range in many colours, including shades of red, white, purple, pink, yellow and more. They can be single-coloured or bicoloured.

They grow to around 15 - 35cm tall.

Due to their large range of colours, they can be a great addition dotted throughout the garden, including in beds, borders and containers.

Petunias are a familiar flowering plant.

These beauties are typically grown cascading down baskets and containers. However, they also make fantastic bedding plants.

Petunia varieties range vastly in colour. They can be solid, bi-coloured, or multicoloured, with some being striped or having patterns.

Some varieties will grow upright, with others varties being trailing.

Petunias are not true annuals. Despite being widely grown as annuals in the UK and colder climates. Hence, I've decided to list them here. They are technically short-lived tender perennials, and in warmer zones where there is no chance of frost, they can live up to around three years.

Nigella damascena is a cottage garden annual favoruite.

It is commonly known as ove-in-a-mist.

There are a few varieties ranging in colour, including blue, white, pink, and dark purple.

They have feathery green foliage.

Nigella damascena typically grows to around 40 - 50cm in height and flowers in mid to late summer.

They suit well mixed within flower beds, as gap fillers and in wildflower gardens.

Sunflowers don't need much of an introduction.

Tall, fast-growing, with large flower heads and yellow petals.

Variations range in height, with some reaching well over 2m tall.

The flowers typically have yellow petals and brown centres. However, some variations have burgundy, orange-brown petals. Some varieties have white tips on their petals.

They look great grown against walls in full sun and can make an impressive statement.

It's worth noting that whilst some sunflowers are annuals, some are perennials.

Antirrhinum majus, known as snapdragon, is a breathtaking annual flowering plant.

They're called snapdragons due to the way the flower resembles a dragon's mouth that opens and closes like a snap when squeezed from the sides.

Snapdragons, boasting a variety of colours and heights, make a perfect choice for planting throughout the garden in various locations.

Colours range from white, pink, yellow, red, orange, and purple. They can be single-coloured as well as bicoloured.

They typically flower from early summer until mid-autumn, making them a long-lasting addition to garden beds. Snapdragons also serve as excellent cut flowers, emitting a delicate fragrance.

Let's face it. This list wouldn't be complete without including the sweet pea.

Delicate looking, with an alluring fragrance, sweet peas are loved by many.

There are many varieties, ranging from vibrant to pastel colours.

They serve as excellent cut flowers, making a great visual addition to bouquets and vases whilst providing a lush scent.

To prolong their blooming period, it is essential to deadhead the spent blooms.

Their delightfully sweet scent can vary between varieties, with some more intense than others.

The variety, Matucana (pictured), is often referred to as having the most intense scent of all sweetpeas, which is very pleasant.

Zinnias are easy to grow and produce a wealth of flowers.

Their flowers are typically daisy-like. However, some double-flowered varieties can look somewhat like dahlias.

They vary in colour, including shades of red, pink, purple, yellow, orange, and green.

They have a long blooming season from late spring until the first frost.

Depending on the variety, they range in height, typically between 30cm - 1m.