Bulbs are great for providing colour when our gardens most need it – and they don’t all need to be dug up in autumn . . .

Crocosmia is a useful bulb making a comeback

Late summer-flowering bulbs such as dahlias, crocosmia and lilies bring a burst of colour in the borders when a lot of other plants are past their best. However, their maintenance can become a chore in the autumn, when many will need to be dug up and stored until next year.

Busy gardeners might not have the time or the inclination to dig up bulbs, clean and dry them off and store them in a frost-free place until next year.

However, there are summer-flowering bulbs which are happy to stay in the ground and will perform in subsequent years, says Miek Stap, consultant at the Netherlands Flower Bulb Information Centre.

Truly perennial bulbs include lilies, Anemone coronaria, crocosmia, liatris and Commelina coelistis.

“Most of these bulbs are sun lovers,” Stap says. “Plant them in spots where there is a lot of sun during at least three-quarters of the day.”

Lilies like “cold feet” in summer, so they perform better when they are mixed in a border planting where other plants cover the ground. Plant them with companions with heavy foliage such as Alchemilla mollis and heuchera.

Anemone coronaria and Commelina coelistis are also both sun lovers. They prefer the soil to be warmed up easily and therefore need to be planted in a more solitary setting, but will soon fill up the border and give good flower displays. If the ground is too cold in early spring, they will have trouble emerging.

Crocosmia is a very easy plant, but is also quite invasive, so be careful where you plant and which variety you choose. In more organic and moisture-retentive soil, the plant will grow large leaves but bear fewer flowers, so they don’t need much watering – the drier the ground, the more the plant flowers. Liatris also prefers drier, less-rich soil.

Other bulbs which might come back, depending on the winter rain and snow, include Gladiolus calianthus, canna, crinum, eucharis, Nerine bowdenii, tigridia and Zantedeschia aethiopica.

“All these bulbs return better when the soil remains dry in winter time. As soon as they are surrounded by wet soil and the frost gets into the ground they will start rotting,” says Stap.

Lilies are an excellent choice. These beautiful, fragrant summer-flowering bulbs produce large, flared trumpet flowers in an array of colours just when the garden may be running out of steam in mid-summer. Some can grow really tall, giving them extra prominence in a busy border.

Lilies are quite hardy, won’t be worried by cold weather and should come up year after year.

There are ways to improve the chances of bulbs left in the ground to repeat-flower in subsequent years.

“Plant the bulbs a little deeper than the packaging says, although they will take a little longer to come up in the first year’s season as the soil stays cold longer on a deeper level,” she says.

“If you are not harvesting the bulbs in autumn and you would like them to return next summer, it is important that they have nutrients – nothing special, regular fertilising of your summer borders will do.”

Allow leaves and stems to die down naturally, because if you cut them down it often disturbs the growing process for next year’s bulbs.

Those that don’t die down until heavy frosts appear, such as canna and crinum, should be covered with leaves or straw to protect them over the winter.

Of course, if you want your dahlias, begonias and gladioli to survive the winter without having to dig them up, grow them in containers and just put the pots containing the bulbs in a frost-free shed or cool greenhouse for the winter. There, they will become completely dry without any work involved.

If the plants have had plenty of feed in late summer, it will give them a strong base for next year.

Most will need to be repotted in fresh compost in spring, apart from nerines, crinums and amaryllis belladonna, which don’t like to be tossed around and should be left unless they have grown too big for the container. Summer bulbs in containers will need warmth to get started again, so don’t put them out too early next year.