7 of the easiest seeds to sow for a riot of colour in summer

Undated Handout Photo of a child sniffing a sunflower. See PA Feature GARDENING Advice Seeds. Pictur

There are plenty of seeds which can be easily sowed for a riot of colour in the summer. - Credit: iStock/PA

Some of the most beautiful flowers are easy to sow from seed, says Hannah Stephenson.

If you’ve had a go at gardening during lockdown and want to progress by sowing your own seeds, now’s a good time to start.

Sowing your own, budding gardeners on a budget can produce plants for a fraction of the cost of buying mature ones from garden centres later on. Seeds you’ve sown indoors are also likely to flower earlier if you’ve given them a head start.

Which are the easiest seeds to sow?

Annuals are a good starting point; these plants only last a year, but will give you lashings of summer colour and are great for plugging gaps in borders. They can be started off indoors from February to April, before being transplanted and then put in their final position when all risk of frost has passed.

Many perennials, including hardy geranium, echinacea and sea holly, can also easily be grown from seed, although you’ll need more patience, as some won’t flower in their first year.

Annuals benefit from nurturing indoors and then hardening off before placing into the garden when all danger of frost has passed.

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Here are some of the easiest flowers to grow from seed.

1. Sunflower (Helianthus annuus)

Growing sunflowers is child’s play, and is favoured by parents keen to get their youngsters involved in gardening. They have large seeds – perfect for small hands – and can be started off indoors in February and March in individual pots in potting compost, and then transferred to their final position in late May or early June.

2. Cosmos

These pretty half hardy annuals come in an abundance of colours, from white to deep pink. They are great for plugging gaps in the summer border with their feathery leaves and daisy-like flowers. However, they won’t withstand frost, so you’ll need to start them off indoors in a seed tray or pots, with one seed per cell.

Cosmos in a pot

Cosmos in a pot. - Credit: iStock/PA

3. Nicotiana (tobacco plant)

These annual favourites have a delicious perfume, so plant them close to the house or on the patio once they are coming into flower. Sow seeds in seed compost indoors in early spring, on a sunny windowsill. Sprinkle a small pinch of seeds in each cell, then cover them with vermiculite and water lightly.

4. Nasturtium (Tropaeolum majus)

These pretty trailers have multiple uses – they can add colour to summer pots, the flowers can be eaten and they can even lure aphids away from French and runner beans – and they’re really easy to grow from seed. Start them off indoors in seed trays of compost in February, placing the large seeds a few centimetres apart on the surface, then cover with another layer of compost, firming it gently. Place a sheet of cling film over the seed tray and put in a warm spot on a windowsill or in a light area. Once they’ve germinated, you can remove the cover and in a week or two you’ll be able to transplant them into seven centimetre pots, before putting them in their final spot in the garden in early summer.


Nasturtiums. - Credit: iStock/PA

5. Californian poppy (Eschscholzia californica)

Californian poppies can be sown in spring or under cover now. They have delicate ferny foliage and bright yellow, orange, red or white flowers that are a magnet for butterflies, bees and hoverflies. The poppies make good cut flowers and thrive in poor but well drained soil.

Californian poppies.

Californian poppies. - Credit: iStock/PA

6. Calendula

Beautiful orange and yellow flowers are produced from these seeds for an extended flowering period, lasting until the first hard frost and sometimes beyond. It’s a great companion plant to include in your vegetable garden to attract beneficial insects and keep the pests distracted. The flowers are edible and can be used in soups and salads. It’s also easy to collect seed to re-sow the following year.

Calendula growing next to tomatoes.

Calendula growing next to tomatoes. - Credit: iStock/PA

7. Cleome (spider flower)

These unusual hairy annuals produce impressive upright stems to 1.5m, with scented flowers in shades of violet-pink, rose-red or white from early summer to early autumn. They are another excellent gap-filler in borders, where they extend colour later in the season, or are great grown in large containers.


Cleome. - Credit: iStock/PA

Quick guide to sowing seed

Emma O’Neill, head gardener at national horticultural charity Garden Organic (gardenorganic.org.uk), offers the following tips for seed-sowing success.

Read the packet. Seed packets carry a wealth of information detailing when to sow, how deep, the spacing required and what sort of temperature they need to germinate effectively.

Use organic seed compost. Fill your tray or pot with good quality organic seed compost, first ensuring you don’t have any large lumps, tamping down to make sure there are no air gaps, and firm using another seed tray or pot to level it. If the seeds require covering, sieve a small amount over the top and firm again so they are in good contact with the compost.

Undated generic photo of someone sowing seeds. See PA Feature GARDENING Advice Seeds. Picture credit

Sowing seeds for the summer... - Credit: iStock/PA

Water before sowing. Use a fine rose on a watering can, or sit the tray in water.

Label. Otherwise you may not remember what you planted.

Thin out. You may have to thin out seedlings as you don’t want them competing for nutrients and water. Remove the weakest seedlings and compost the waste. They will grow towards the light, so turn the tray regularly to ensure even growth.