What to plant in May

artvs3
May 1
4 min read

Now that the soil is getting warmer and the risk of frost has probably passed, many things can be sown or planted directly into the soil. Some of the easiest annuals to grow from seed are Nasturtiums (Tropaeolum) making them ideal for beginner gardeners and children. They are not only decorative, making good cut flowers, but also edible, and bees love the flowers, so a great all-round plant for your garden.

Nasturtiums produce masses of vividly coloured blooms from mid summer to the first frosts. They come in a wide range of colours; orange, yellow, red, cream, salmon pink, burgundy and crimson (and often a mix of several colours). Some also have attractively marbled or mottled leaves.

Two different forms of Nasturtiums are available, and both types grow very well in containers, so they can be grown even in a small garden or on a balcony. Bushy or dwarf (Tropaeolum minus) varieties also look great in hanging baskets or at the front of a border, while climbers (Tropaeolum majus) can be trained up wigwams or obelisks and will twine through other plants. The climbers can also be used as ground cover, spreading across gravel or cascading down a slope or bank.

Also known as Indian cress because the flowers, leaves and seeds are edible, Nasturtiums make good companion plants for vegetables. The caterpillars of large and small white butterflies are lured away from brassicas to feed on the nasturtium leaves, and blackfly may choose nasturtium leaves rather than your beans. The flowers and young leaves have a peppery taste (nasturtiums are closely related to watercress) and are a great addition to salads. The seed pods can be used as a substitute for capers (they are known as 'poor man's capers'). You can pick them when mature but still green, and pickle them in vinegar.

Nasturtiums flower best on poor soils and need sunshine for at least half the day in order to grow well. A free-draining soil is essential. Fertile soil leads to lots of leafy growth and the flowers are buried beneath the foliage.

You can sow nasturtium seeds directly where you want them to flower, so you can simply pop seeds around the garden, for example around the edge of raised beds or borders.

Rake the soil to a fine tilth and make sure it is free of weeds. Water the area before you sow – this will ensure that you don't wash away the seeds once sown
Sow the seeds 1.5cm deep, around 10cm apart – either push them in with your finger, or use a bamboo cane to make a shallow drill
Cover the seeds with soil
Once the seedlings emerge (after about two weeks) thin them to around 30cm apart

You can also sow nasturtium seeds in pots – this is a good way to get earlier flowers and is a good option if you want to plant up a beautiful container display later in the season. Simply sow one seed per 9cm pot in a greenhouse or on a sunny windowsill, harden off and plant outside in late spring.

If you don’t want to grow your own plants from seed, you might find small pots of nasturtiums at the garden centre in late spring or early summer that are ready for planting out. They should be planted in a hole the same size as the pot, with the crown of leaves at soil level and watered in well.

If you’re planting your potted nasturtiums into a container rather than into the ground, mix two-thirds peat-free multipurpose compost with one third fine gravel or grit. This will reduce the soil fertility and ensure good drainage. Again, plant them so that the crown of leaves is at soil level and water them in well.

Nasturtiums are easy to care for and need little maintenance. Plants growing in the ground rarely need watering. Plants growing in containers should be watered to keep the compost evenly moist, but don't feed them. Deadheading will encourage more blooms over a longer period.

You can collect nasturtium seeds when they're ripe and save them somewhere cool and dry to sow next year. In mild areas, nasturtiums are also likely to self-sow, so you may get seedlings springing up in future years, but these can be easily pulled up if you don’t want them.

Here are some nasturtium varieties you may want to grow:

Nasturtium 'Black Velvet'

Tropaeolum minus 'Black Velvet' is a compact nasturtium with velvety dark red flowers. Height x Spread: 30cm x 45cm

Nasturtium 'Phoenix'

Tropaeolum minus 'Phoenix' has flowers with unusual split petals, in shades red, orange and yellow. A bushy variety. Height x Spread: 30cm x 30cm

Nasturtium 'Empress of India'

Nasturtium minus ‘Empress of India’ is a bushy nasturtium with crimson-red flowers and dark leaves. Height x Spread: 25cm x 45cm. 'Princess of India' is a dwarf version.

Nasturtium 'Orange Troika'

Tropaeolum majus 'Orange Troika' is a climbing or trailing variety with vivid orange flowers and marbled foliage. Height x Spread: 30cm x 1.5m

Nasturtium 'Alaska Series'

Nasturtium minus ‘Alaska Series’ produces flowers in yellow, cream, orange and red, shown off against cream and green marbled leaves. Bushy. Height x Spread: 25cm x 45cm.