Growing Daylilies

Daylilies are among the easiest of garden plants to grow well, producing dozens of flowers if they are given enriched, well-drained soil, ample water and are sited in a sunny position.

Most gardeners love daylilies for their toughness. They tolerate poor soil and a wide range of soil conditions as well as periods of drought. Plants are rarely bothered by pests or diseases and are some of the best low maintenance plants you can grow.

Daylilies are a very showy perennial that will brighten up your garden and return year after year with little effort on your part. There’s also a huge variety to choose from and almost endless colour options.

True to its name, daylily flowers only last a single day. They bloom in the morning and fade by the end of the day. However, each plant has many stems filled with blossoms, so they remain in bloom for about a month. You can find daylilies in shades of orange, red, yellow, purple, cream, and pink. The only shades lacking are blue and true white.

Daylily is the common name for Hemerocallis from the Greek words hemera ‘day’ and kalos – ‘beautiful’. “Beautiful for a day”. Originally from China, Korea, and Japan, their large showy flowers have made them popular worldwide.

The first written record of Daylilies was about 2700 B.C. when Emperor Huan Ti arranged for a Materia Medica to be written. Daylilies were used as food at that time. They were thought to benefit the mind and strengthen the willpower. The plants grew wild in the woods and were moved to gardens for use at the table. There were also references in the writings of Confucius which date from around 550 B.C.

In Europe the history of the Daylily is difficult to trace but references to the Daylily appeared in the writings of European herbalists of the 16th Century. The pioneer plant hunters Ernest Wilson, George Forrest, Frank Kingdom Ward, and Joseph Rock brought plants back from the Orient and by 1890, most of the known species of Hemerocallis had been introduced into European and American gardens.

In the 1920s an American, Dr Albert Steward was teaching botany at the University of Nanking where he met and taught many of China’s botanists. Dr Steward was highly regarded by the Chinese and was readily admitted to many gardens and farmyards where he found interesting “forms” of daylilies. These were sent to his close friend Dr Arlow Stout, the leading botanist at The New York Botanical Garden

Dr Stout used them in his breeding work and continued systematic selective breeding for more than three decades. In over 50,000 cross-pollination experiments, he produced over one hundred viable Hemerocallis hybrids. His work has revolutionized nursery breeding and popular interest in daylilies.

A difficult question, as there are differences of opinion and systems of classification. About twenty different daylily species is thought to be a reasonable approximation.

There are almost 100,000 officially registered varieties. They are all to be found in the online database at These cultivars are the result of either deliberate pollination carried out by hybridizers or of natural pollination by insects.

Daylilies should be planted anytime during their growing season (spring through to early autumn). When planting daylilies, dig a hole larger than the root system you are planting. The best way to do this is to make a mound of soil, (preferably mixed with well rotted compost or manure) in the prepared planting hole and spread the roots out over the mound much as you would if you were planting asparagus. Check that the crown of the plant is about one inch below soil level – if it is buried too deeply flowering may be inhibited.

Make sure there are no air pockets left under the plant, firming the soil gently but avoid treading as it is easy to damage the roots. Then all you need to do is water your new plant. Daylilies appreciate the added moisture retentiveness of a good mulch of compost in spring.

Daylilies can be used around a pond or water feature, but they prefer not to have their ‘feet wet’ during the winter.   It is especially important to keep the crown of the plant from becoming too wet as that can lead to crown rot.

Daylilies do respond to feeding. A fertiliser applied in spring with a low nitrogen content will help the plants flower production. If you wish to cut the foliage back in autumn or spring to ‘tidy them up’ this does no apparent harm and many growers favour this approach.

Specimen daylilies can thrive well in pots, but as a rule they generally perform much better when planted directly in the soil. 

Daylilies stay in tight clumps and faster growing cultivars may need dividing every four to five years. The flowering will diminish if you have waited too long to divide your clumps. However, this does not mean you have to discardd your neglected clumps. The best time to divide is in the spring or early autumn. Bear in mind that dividing a huge clump can be hard work and dividing sooner rather than later is wise and you can swap plants with other daylily lovers! The foliage can be cut back on new divisions and long or damaged roots can be trimmed back which helps to reduce the stress of division.

While some daylilies are less hardy than others, established plants should overwinter in the British climate without difficulty. However, in areas prone to frosts or freeze/thaw cycles a mulch is recommended particularly for young plants.

Some daylilies lose all or most of their foliage in winter, but new growth will emerge in the spring. These are known as dormant or deciduous.Evergreen daylilies retain their foliage throughout and may need tidying up in the spring. A third category, known as semi-evergreen, exhibits partial foliage dieback in winter.

Growing daylilies from seed is easy and enjoyable but remember not to try and cross diploids with tetraploids as they are incompatible due to their different chromosome counts. When making a cross, take some pollen from the flower of one prospective parent and transfer it to the end of the pistil (stigma) of the other. A small artist’s paintbrush is useful here.

It is true that some daylilies make better parents than others but if pollination has been successful a seed pod will develop and ripen in about six weeks. Pick off the pod when it begins to open and remove the seeds which should then be refrigerated in an airtight container until the Spring. Prior to sowing, it is advisable to soak the seeds in water for a day or two. They should then be sown in pots or deep trays initially, rather than in the ground.

If you have poor germination in a seed compost, there are several methods of germinating seeds that give good results. You can also use hydrogen peroxide to encourage sprouting:
1.    Fill a zip-lock plastic bag or a small glass jar with a handful of perlite. It’s a volcanic mineral, available at garden centres or online. Place the seeds in the perlite.
2.    Take a 500ml bottle of water and fill the cap with a 3% hydrogen peroxide solution. Pour the contents of the cap into the water bottle and shake.
3.    Carefully moisten the bag or jar containing the perlite so that it is evenly moist. Make sure the water does not collect at the bottom of the container.
4.    Close the container and label it with a waterproof marker.

Using this method most seeds should germinate in about two weeks. Although there are many different approaches to germination, using hydrogen peroxide has produced good results for many hybridizers.

When shoots appear they will need some protection from frost. Plant out or pot on in the summer but be aware that it will take two or three years before the first flowers are seen. Keeping the young daylilies in a greenhouse will speed up the process.

Daylilies will grow in most conditions but will grow best in fertile soil in sun. Too much shade will result in fewer and inferior flowers with the flower stems (scapes) leaning towards the light.

Hemerocallis Gall Midge
Very few pests and diseases trouble Hemerocallis. The major pest is the Hemerocallis Gall Midge, which seems to affect only the early-flowering buds of some Daylilies. If the gall midge has been active in your area, you will notice that some buds are swollen and distended, which indicates the presence of gall midge larvae. Picking off infected buds and destroying them is probably the best method of control. It may also be worth growing later flowering daylilies as they are unlikely to be affected.

Spring Sickness
‘Spring sickness’ has been a puzzling disease of cultivated daylilies in gardens in North America and Europe. Its symptoms tend to manifest as active growth begins. The new leaves become distorted, often with ‘ragged’ edges and holes, as well as yellowing. This affects plant vigour and in severe cases the entire fan can die back. However, identifying the cause has remained difficult – with explanations ranging from fluctuating environmental conditions to damage by bulb mites.

Other problems
Slugs and snails are usually a minor problem even though they can damage new divisions and seedlings in longer periods of rainy weather. Daylilies are not troubled by Lily Beetle or any other problems of bulbous lilies.

The bloom colour of daylily varies on a very wide scale. From a single clear hue to intricate colour transitions and patterns. Compared to naturally occurring species with flowers ranging from yellow to rusty red, the colour range of modern varieties is huge. Only clearest white, black and blue flowers have so far proved to be beyond the reach of the hybridizers. Here are some common categories used to describe the colour of daylilies. Read more…