How to grow hemerocallis

What are hemerocallis?

Hemerocallis are popular border plants with lily-like summer flowers in a wide range of colours and forms. Individual blooms are short-lived, hence the common name daylily, but they’re produced in rapid succession, with multiple flowering stems per plant, so creating an abundant show.
 
They are hardy, so can survive British winters outdoors with no additional protection, and most are herbaceous perennials, meaning they die down every autumn, then re-sprout reliably every spring. Some are evergreen, keeping their leaves all year round.

They need little attention once settled in, and are happy in borders and containers.

Choosing the right hemerocallis

Hemerocallis have been widely bred to produce a vast array of cultivars, with flowers of different colours, shapes and sizes.

Flowers range from yellow, orange and red to purple, pink and white, often flashed or patterned with contrasting or complementary hues. Petals may be wide or narrow, rounded or pointed, smooth or ruffled, forming trumpets or starry shapes, up to 20cm (8in) across.

There are early-season, mid- and late-season cultivars, some are fragrant, and plants range in height from 20cm (8in) up to 1.5m (5ft), for the front, middle or back of borders. 
 
Daylilies are easy to grow and thrive in almost any soil, in sun or partial shade, and will survive even the coldest winters. They combine well with many other border plants, including ornamental grasses, in both formal and informal, traditional and contemporary settings. The dwarf forms are ideal when space is limited.

How and what to buy

Daylilies can be bought in containers or as

These have been lifted from the ground while dormant, with little or no soil around their roots. Various plants may be available bare root, including fruit trees, hedging plants and some perennials. They are generally cheaper than plants in containers, but are only available in winter/early spring, while dormant

• Established plants (in 1 litre pots or larger) are sold in full growth (even in flower) and can be planted directly into borders

• Smaller, younger plants (in 9cm/3½in pots) are cheaper, but need to be grown on in containers for a few months, before they’re ready to be planted into borders

 
Bare-root plants (without soil) are also available in some garden centres or from some online suppliers, usually between spring and autumn. Several specialist

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

Where to plant

Daylilies like well-drained, fertile soil, but are very adaptable and will tolerate poorer soils and heavy clay. They prefer some moisture in spring and summer, although they dislike sitting in waterlogged soil. Established plants will cope with drought, although flowering may be reduced.

Hemerocallis perform best in full sun, but are fine in partial shade. Some of the richer colours can become bleached in scorching sun. Avoid planting in heavy shade, as plants will become straggly and flowering will be poor.

They are fully hardy and don’t need any winter protection. Most hemerocallis are deciduous and will die down in autumn, stay dormant over winter, then re-sprout every spring. Evergreen types keep their leaves all year round.

Hemerocallis work well in borders combined with other summer-flowering perennials and ornamental grasses, in almost any style of garden. The more vibrant, exotic flower colours also work well in tropical displays.

The smaller and dwarf cultivars can be planted in large containers, where their arching leaves will cascade over the sides.

Choosing plants for borders

Choosing plants for borders

When to plant

Daylilies are best planted in autumn or spring, although you can plant in summer if you keep the soil around the new plants moist. Autumn planting allows them time to establish over winter, so they'll flower well the following summer.

How to plant

Hemerocallis can be bought in containers or as bare-root plants. Both are easy to plant, although bare-root and young plants need a little more attention initially.

Containerised plants

• Established plants (in 1 litre pots or larger) are sold in full growth and can be planted directly into borders. Make sure the crown is level with the surface of the soil

• Smaller, younger plants (in 9cm/3½in pots) should be repotted into slightly larger containers, then allowed to grow on for a few months before being planted into borders.

Bare-root plants

Hemerocallis are often old as bare-root plants (without soil), either in packets in garden centres or from online suppliers. These can produce good plants, but need more care initially:

• If possible, check the plants in the packet are firm and have buds or small shoots. Avoid any with long, pale shoots
• Pot them up using peat-free multi-purpose compost, and water in well
• Place pots in a coldframe or unheated greenhouse and keep the compost moist
• After a month or two, once they've grown plenty of strong leaves, they can be planted into borders

Daylilies are general robust, reliable and self-sufficient plants that need little attention once established. Still, to keep them looking good, you may wish to deadhead faded blooms. Established clumps will benefit from being divided every few years to keep them flowering abundantly.

Watering

Once established, hemerocallis tend to be drought tolerant as they have an extensive root system. However, they perform best when they have plenty of water during the growing season. Younger plants should be watered in dry spells.

Those growing in containers should be watered regularly through the growing season, as they have less access to water. 

Tips on recycling and collecting water

Tips on recycling and collecting water

Feeding 

Daylilies don't generally need additional feeding, but to boost growth you can apply a general-purpose fertiliser, such as Growmore, in spring at the rate recommended on the packet.

Plants growing permanently in containers need regular feeding during the growing season, as the compost will soon run out of nutrients. See our guide to container maintenance.

How and what to feed plants

How and what to feed plants

Mulching

Applying a thick layer of mulch around plants in spring helps to hold moisture in the soil and deter weeds. Use well-rotted organic matter, such as garden compost or manure, and top up annually.

Deadheading

To keep the display looking good, deadhead withered blooms regularly. This will also help to control hemerocallis gall midge (see Problems below).

Caring for older plants

Established clumps should be lifted and divided every three or four years, to keep them vigorous and healthy. This has the added benefit of giving you new plants to fill any gaps in borders or share with friends.

Simply follow our guide to dividing perennials. 

Hemerocallis do not require training or staking, as their flower stems are usually sturdy and upright. 

Once a whole stem has finished flowering, cut it down to the base, to encourage the plant to produce more.

You can also cut back the old faded foliage, either in late autumn or early spring, to neaten up borders. However, the old leaves do provide useful overwintering sites for insects and other small creatures.

The easiest way to propagate hemerocallis is by division – see our guide to dividing perennials. 

You can divide established clumps every few years, in spring or autumn. The resulting new plants will be vigorous and settle back in quickly. ​You can plant them straight into any gaps in your borders or share them with friends. The new plants will have exactly the same characteristics as the parent plant.

Daylilies are generally robust and vigorous, with few pests or diseases seriously affecting their health.

However, hemerocallis gall midge can significantly reduce flowering displays. The main symptoms to look for are:

• distorted flowers
• buds that fail to open

Other less serious pests include:

• aphids
• slugs
• snails

However, these generally only cause minimal damage.

There are no significant diseases affecting hemerocallis. However, a new rust disease was found on an imported plant in 2001. Thankfully, it has not been reported in the UK since, but remains notifiable. The typical symptoms are numerous yellow or orange pustules, mainly on the lower leaf surface but occasionally on the upper surface or stem.