When to plant daylilies – for colorful, elegant flowers

Knowing when to plant daylilies is vital for success. With large, sumptuous flowers in a range of rich, fiery colors and attractive arching leaves, daylilies (Hemerocallis) are essential perennials for the summer backyard. Their sophisticated blooms, which are reminiscent of amaryllis or lilies, suggest they might be tricky to grow, but far from it – in fact they are easy, hardy plants that anyone can manage. 

One thing you might know if you are growing daylilies is that, as the name suggests, each flower lasts for just one day. But daylilies produce such a generous succession of blooms over many weeks that the plants are always a plentiful mass of flowers. 

‘Daylilies are the workhorses of the perennial border,’ says Pennsylvania-based landscape designer Nathan Tuno, who works at Roots Landscape Inc. ‘With a variety of hues and habits, they give a great color blast during the warm months.’ 

Follow our easy guide to discover the best time to plant daylilies to enjoy their gorgeous summer blooms. 

When to plant daylilies?

Like most summer-flowering perennials, daylilies are best planted in spring, late summer, or fall. However, it is possible to plant them in mid-summer or in winter, if need be. 

When to plant daylilies in spring

Planting daylilies in March or April gives daylilies time to settle and establish a root system before the flowering season starts in summer. May is also fine, if you miss the early spring window. 

‘Daylilies benefit from being planted after the soil has started to warm up,’ says Pollie Maasz, who holds a National Collection of Hemerocallis and sells a huge range of them at her daylilies nursery. ‘This usually means planting from early March onwards.’ In the warmer US states, daylilies can be planted earlier, in February. 

When to plant daylilies in summer

If need be, daylilies can go in the ground during summer – even whilst they’re flowering, if you see one in bloom that you can’t resist buying. 

If you must plant in summer, it’s vital to keep the soil moist. ‘As long as they are watered well, new plants will even cope with very hot conditions,’ says Pollie. 

Ideally, wait until flowering has finished – usually in late August, depending on the variety – to plant daylilies in summer. 

‘Daylilies can be planted at any time of year, but planting in late summer will allow plants to establish and flower well the following year,’ says Paul Harris, who owns Brookfield Plants, a specialist daylily nursery.

When to plant daylilies in fall

Planting perennials, such as daylilies, in the fall allows them time over winter and spring to establish a good root system, in turn making them healthy, robust plants. The optimum fall planting month is September, but October is also ideal. 

‘Daylilies benefit from being planted before late October, whilst the soil is still relatively warm, says Pollie. ‘However, I have been known to plant them well into the winter – they are extremely forgiving plants.’ 

If you want to plant in winter, avoid doing it during very cold weather or when the ground is frozen or waterlogged.