If you want your garden to be bursting with colour, fragrance, and life this summer, now is the time to start planting.
While some plants need to be started indoors to get a head start, others can go straight into the ground and will flourish when the warmer months arrive. Whether you’re after vibrant flowers, lush greenery, or delicious homegrown produce, planting at the right time is key. Here are 10 plants to sow or plant now for a truly stunning summer garden.
1. Sweet peas for a fragrant and colourful display
Sweet peas are a classic summer favourite, known for their delicate petals and beautifully scented blooms. They climb quickly, making them perfect for adding height to fences, trellises, or garden arches. March is the perfect time to plant sweet peas outdoors, or if you started them in autumn, you can move young plants into their final growing positions. They prefer a sunny spot with well-drained soil and will thrive if you pinch out the tips early to encourage bushier growth. Keep picking the flowers, and they’ll keep blooming right through summer.
2. Dahlias for bold, long-lasting blooms
If you want a show-stopping garden full of bold colours, dahlias are a must. Their stunning flowers come in endless varieties, from giant dinner-plate-sized blooms to delicate pompons. In March, you should start dahlia tubers indoors in pots or a greenhouse to give them a head start. They can be moved outside once the risk of frost has passed in May. Dahlias love full sun and benefit from regular feeding, so with a little care, they’ll reward you with spectacular flowers all summer and well into autumn.
3. Sunflowers for a striking focal point
Nothing says summer like a towering sunflower. These cheerful blooms add drama to borders and are surprisingly easy to grow, making them great for kids and beginners alike. In March, start sunflower seeds indoors in small pots, then move them outdoors from April onwards. If you have mild weather, you can even risk direct sowing in the garden later in the month. Sunflowers need a sunny spot and will benefit from staking if you’re growing tall varieties. The best part? Their seeds attract birds, adding even more life to your garden.
4. Lavender for scent and pollinator appeal
Lavender isn’t just beautiful—it’s one of the best plants for attracting bees and butterflies. Its soft purple flowers and relaxing scent make it a perfect addition to borders, pathways, or even pots. March is a great time to plant lavender as young plants, ensuring they have time to establish before summer. If growing from seed, start them indoors, as they can take a while to germinate. Lavender thrives in full sun and well-drained soil, and once established, it requires very little care while providing year-round structure to your garden.
5. Cosmos for effortless beauty
Cosmos are one of the easiest summer flowers to grow, producing delicate, daisy-like blooms in shades of pink, white, and purple. They create a soft, romantic look in flower beds and attract pollinators. Sow cosmos seeds indoors in March and transplant them outside in May once the frosts are over. These flowers thrive in poor soil, so they don’t need much feeding. With regular deadheading, they’ll bloom continuously from early summer until the first frosts.
6. Tomatoes for homegrown summer flavour
There’s nothing better than a juicy, sun-ripened tomato straight from the garden. Whether you prefer cherry tomatoes for snacking, plum tomatoes for sauces, or beefsteak varieties for sandwiches, March is the perfect time to start them. Sow tomato seeds indoors in pots or trays, keeping them somewhere warm and well-lit. Once they’re strong enough and the weather is consistently warm (usually in May or June), move them outside into grow bags, pots, or a greenhouse. Keep them well-watered, feed them regularly, and you’ll be harvesting delicious tomatoes all summer long.
7. Herbs for fresh summer cooking
Herbs are a fantastic addition to any garden, providing fresh ingredients for summer cooking, while also attracting beneficial insects. Basil, parsley, thyme, and rosemary all do well when planted in early spring. March is an ideal time to start basil and parsley indoors, as they prefer warm conditions. Hardy herbs like thyme and rosemary can be planted directly outside in well-drained soil. If you grow them in pots, you can keep them near the kitchen for easy access when cooking.
8. Courgettes for an easy summer crop
If you want a vegetable that gives a huge harvest with minimal effort, courgettes (zucchinis) are the way to go. They grow rapidly and produce an abundance of fruit, perfect for grilling, roasting, or adding to salads. In late March, start courgette seeds indoors in pots, then move them outside in May when there’s no risk of frost. They need plenty of space and regular watering but will reward you with more courgettes than you know what to do with!
9. Petunias for vibrant hanging baskets
Petunias are a go-to choice for adding long-lasting colour to hanging baskets, window boxes, and containers. Their bright, trumpet-shaped flowers come in an array of colours, from soft pastels to deep purples and reds. Start petunia seeds indoors in March, as they need warmth to germinate. Once the weather warms up, move them outside to their final position. Regular watering and deadheading will keep them blooming all summer long.
10. Peppers for a colourful, edible crop
Peppers, whether sweet or spicy, are a great way to add colour and variety to your summer garden. They thrive in warm conditions and are perfect for growing in pots or directly in garden beds. March is the perfect time to start pepper seeds indoors in small pots, keeping them in a warm, sunny spot. Once the temperatures stay above 10 °C at night, you can transplant them outside. They need plenty of sun and regular watering, but with a bit of care, you’ll have a steady supply of peppers throughout summer.
By planting these now, you’ll set your garden up for months of beauty, fragrance, and fresh produce. Whether you’re filling your space with bright flowers, delicious homegrown vegetables, or fragrant herbs, a little planning now will ensure your garden thrives all summer long.
