Best Flowers to Plant in May in the UK: A Guide for Potted Gardens

As the weather warms up in the UK, it's the perfect time to start planting flowers in pots for a vibrant and colourful display throughout the summer. May is an ideal month for planting as the soil has warmed up and the risk of frost has significantly reduced. Here, we'll guide you through the best flowers to plant in pots in May, ensuring your containers burst with life and beauty.

Before we dive into the specific flowers, let's briefly discuss some essential aspects of planting in pots. Firstly, choose pots with drainage holes to prevent waterlogging, which can harm your plants. Secondly, use well-draining, nutrient-rich potting soil to support your flowers' growth. Lastly, consider the pot size, as larger pots can dry out slower, reducing the need for frequent watering.

Annual Flowers for Instant Colour

Annual flowers complete their life cycle in one growing season, providing instant colour and impact. They are perfect for adding a quick burst of vibrancy to your pots and can be easily replaced once they've finished blooming.

Here are two annual flowers that thrive when planted in pots in May:

Nasturtiums (Tropaeolum majus)

Nasturtiums are easy to grow and come in a variety of colours, including red, orange, yellow, and white. They have a trailing habit, making them ideal for hanging baskets or cascading over the sides of pots. Plant nasturtium seeds directly into the pot in May, ensuring the soil temperature is consistently above 10°C (50°F). Keep the soil moist but not waterlogged, and nasturtiums will reward you with beautiful flowers from June to October.

Tip: Nasturtiums are edible and have a peppery flavour. You can enjoy their leaves, flowers, and even their young seed pods in salads or as a garnish.

Marigolds (Tagetes spp.)

Marigolds are another popular annual flower that thrives in pots. They come in various sizes, from dwarf varieties suitable for small pots to taller types that add height and structure to larger containers. Marigolds prefer full sun and well-draining soil. Plant their seeds directly into pots in May, ensuring the soil temperature is consistently above 15°C (59°F). Keep the soil evenly moist, and marigolds will bloom from June to October, attracting beneficial insects like ladybugs and lacewings to your garden.

Tip: Marigolds are known for their ability to repel pests, making them an excellent choice for companion planting with vegetables in pots.

Perennial Flowers for Long-term Beauty

Perennial flowers live for more than two years, providing long-term beauty and value. While some perennials may not bloom in their first year, they will reward you with stunning displays in subsequent years. Here are two perennial flowers that can be planted in pots in May:

Lavender (Lavandula spp.)

Lavender is a fragrant and drought-tolerant perennial that adds a touch of Mediterranean charm to your pots. Plant lavender in well-draining soil and full sun, ensuring the pot has good drainage. Lavender is not frost-hardy, so it's best to plant it in a pot that can be moved to a sheltered location during winter. Plant lavender plugs or small plants in May, and they will reward you with beautiful, fragrant flowers from June to August.

Tip: Lavender attracts pollinators like bees and butterflies, making it an excellent choice for a wildlife-friendly garden. Additionally, lavender flowers can be dried and used for crafts or in potpourri.

Heuchera (Heuchera spp.)

Heuchera, also known as coral bells, is a shade-loving perennial with attractive, lobed leaves in various colours, including green, purple, silver, and bronze. Heuchera plants have small, bell-shaped flowers on tall stems, but it's their foliage that truly shines. Plant heuchera in pots with well-draining, consistently moist soil in partial shade. Heuchera can be planted in pots in May, and they will provide year-round interest with their colourful leaves and summer blooms.

Tip: Heuchera is an excellent choice for adding texture and colour to shady pots. Combine it with other shade-loving plants like ferns and hostas for a lush, verdant display.

In conclusion, May is an ideal time to plant a variety of flowers in pots, from annuals that provide instant colour to perennials that offer long-term beauty. By choosing the right plants and providing them with suitable growing conditions, your pots will burst with life and charm throughout the summer and beyond. So, get out there and start planting – your garden is waiting!