The Ultimate Guide to Growing Daylilies [Hemerocallis]
Here I aim to provide the knowledge and inspiration to get the best from these wonderful perennial plants that can beautify and enhance any area.
The Daylily – an introduction
Hemerocallis are native to Asia and the many modern fancy hybrids we see today are derived from a mere handful of modest yellow to orange-yellow species. They are not bulbous plants, unlike ‘true’ lilies but grow from a permanent partly rhizamotous clump. This enables them to store water during periods of drought meaning they will survive where other plants may give up and fail. The Daylily is frost hardy and also surprisingly tolerant of wetter soils. They form a solid clump from which to grow each year and do not ‘disappear’ or fade away like true bulbous lilies often do. Infact a Daylily clump has been known to last for decades and are frequent survivors in very old gardens!
Uses in the garden
Because they are very undemanding they can be incorporated into almost any area regardless of size.
At their very best they shine and surely deserve an area devoted entirely to them and the massed display is truly breathtaking. If this is out of the question then rest assured they associate well with other plants – perennials, shrubs, grasses etc. See my separate article on great plant association with Daylilies. They look beautiful by water features where the fascinating colours and patterning is reflected in the water, their graceful arching foliage cascading downward. Smaller growing varieties can be used as edging, grown in raised beds or on a rockery. And just about all of them can be grown in containers – although this is where the smaller and miniature flowered varieties really come into their own even the larger flowered varieties will do well in 10 litre capacity containers. Hemerocallis have latterly been frequently used in the newly popular ‘Priairie Style’ planting where plants are drifted en masse creating an impressive yet naturalistic style and beauty. Here the spider type Daylilies are particularly appropriate.
Flower forms and colours
Daylilies are almost infinitely diverse. The classic large flowered single is the most well known – and to my mind the most impressive, with flowers that can achieve up to 8” across in some varieties. At the other end of the scale is the small and miniature flowered class which will have flowers of 3.5” or less. These are phenomenal bloom producers giving huge value. They are usually [although not absolutely always] smaller and more compact in growth too making them perfect not only for smaller spaces but pots and planters too.
Easily the most unusual of all is the Spider and Exotic varieties. These have huge airy linear flowers which seem to capture the breeze, the petals often curl and twist in some varieties as well. Full of airy grace and animation, these work very well in plant combinations.
One group that seems to be fast increasing in popularity is the doubles. With many petals recalling the beauty of a rose or carnation, they are lavish and fulsome in appeal.
The colour spectrum provided by over 40,000 known varieties [yes really] is nearly fully covered; only true blue has remained elusive to breeders and will probably remain so without laboratory intervention. But true blue shades are represented in eye patternings. There are plenty of lavender and lilac coloured Daylilies, as well as dark and brooding purples, pinks in every shade from apple blossom to coral. Sumptuous velvety reds galore, terracotta and near brown ….cool creamy whites, apricot and of course many first class yellow and orange varieties. Some have a band around the throat of the flower that is a different colour and this is known as an eye-zone. Still more have extravagantly ruffled gold or silver edges to the petals.
Plant Characteristics
Height – Here too there is variation in the height of the flower stems. The majority fall within the 20-26” range but a few are taller – a select few much taller and suitable even for the back of the border. And there are plenty of true dwarfs with flower stems which reach no more than 12-16”, normally within the small and miniature class with growth in perfect proportion to the size of the flower.
Foliage type is divided into dormant, semi-evergreen, and evergreen. Dormant varieties lose all foliage as Autumn progresses. Evergreens maintain a good amount. Semi-evergreens – somewhere between the two!
Flowering Period
July is the peak season for Daylily blooms. But those marked as early will begin in June. Mid season is mid-late June and through July. Late varieties normally begin to open their flowers the second half of July and will last well into August. So with careful variety selection you can have Daylilies flowering in your garden for much of the Summer!
Re-blooming characteristics are mentioned in the variety descriptions. What this means is that secondary flower stems appear after the main flush has finished. I have discovered over the years that almost any variety is capable of producing re-bloom if conditions fall right but some varieties are much more likely to do so and where this is the case it is mentioned accordingly. Although it can never be guaranteed in this country as some seasons the weather is more encouraging for re-bloom than others, it is always a joy to have those extra blooms appear in September – and sometimes even in October!
It is also worth noting that some of the small and mini varieties will almost habitually flower in successive flushes throughout the summer and are very hard working, particularly varieties like the esteemed ‘Stella d’oro’ and ‘Happy Returns’ amongst others.
Soil Requirements
Hemerocallis grow well on most soil types and are not specific as to ph or type. Ordinary soil works just fine, clay – normally that most troublesome of soil type – produces very hearty clumps, they can also tolerate standing water but only for short periods otherwise the crown will rot. Drier soil types also give good results – remember those fleshy roots will store water for use during times of stress – but the foliage will not look it’s best and although they will readily produce new growth when conditions improve it’s better to provide additional water or to improve the soil with the addition of compost at planting, or to provide a mulch around the base of the plant where conditions err on the side of dry.
Planting Daylilies
Daylilies are provided in two forms; our own plants come pot-grown and this is the easiest option to transplant and they do establish more quickly. But some specialist Daylily nurseries still provide their plants as bare rooted and this is the traditional way. They don’t look so promising on receipt and are usually supplied quite dry but they do grow although it will take longer for them to establish and make new growth.
Planting pot grown plants is easy; prepare a hole a few inches bigger than the container by making sure it is well worked and add some compost and a little growmore which will act as a fertilizer to provide lush new growth. The plant should be set so the compost in the pot is level with the soil. If the plant is set deeper flowering may be inhibited. If it is too shallow the roots may dry out. Infill with compost/soil mix and firm well. This is important so that there are no air pockets around the roots. Puddle the plant in heavily and continue to water daily for the first 10 days or so and thereafter until properly established. Watering is best done early in the morning or in the evening. Pot grown plants can be planted out at any time of year – even winter if the weather is reasonably open, but Spring, Summer and early Autumn is usually considered best. Plants set in early Autumn usually establish well to provide flowers the following summer.
With bare root plants the basics as to depth and soil preparation are the same. However the method is a little different. Those long spidery roots should be spread over a ‘cone’ of soil, then fill in as described above. Watering with bare root plants is especially important since they do not have an actively established root system to draw from. They may require watering following planting for longer than 10 days especially when planted during the growing period.
Planting Distance
Although single plants of a variety make a wonderful flower-laden clump the best effect is always achieved by planting in groups of 3 – or even 5 if space allows. When planting in clumps a planting distance of around 18” between plants with the larger flowered varieties is ideal and they will then appear ‘as one’ once they have grown. With mini and small flowered varieties 15” is fine. If planting individual varieties you can allow a little more so there is room between them for cultivation.
Siting
Hemerocallis are best in a relatively open full sun position but they can tolerate some shade – I have clumps which flower well in dappled sun and part shade part sun. Generally I would say that as long as they get 3 hours of sun a day then they will perform well. Growing isn’t really an issue – even Daylilies planted in quite deep shade will actually grow but they flower poorly.
Feeding and aftercare
If you give no aftercare whatsoever Daylilies will thrive and give enormous satisfaction but as with so many things the more you put in then the greater the reward will be.
On the Nursery I provide additional feed with a liquid Seaweed extract provided as a foliar feed every 3 weeks or so. Because we have a lot of plants this is applied using a knapsack but with a smaller number of plants it can be given directly to the plants at soil level. I find seaweed maxicrop encourages good foliar colour and health as well as boosting flowering capacity. A less labour and time consuming way to give your Daylilies that extra boost is to use bonemeal raked gently into the soil around the roots and then watered. This can be applied in Spring and again in early Autumn. For plants grown in pots Osmocote granules are by far the best way to feed Daylilies and this slow release option will last the entire growing season so you only need to apply once per year.
Deadheading
The single most important summer task. It isn’t essential but it will improve greatly the appearance, bloom production, size and quality of blooms. Because each flower lasts but one day removal of spent flowers early in the morning gives room for newly opening buds to unfurl and whilst many varieties aren’t prolific seed producers what pods do appear is wasted energy that can go into bud production. As you can imagine I have a lot of plants but I actually find this a pleasure rather than a chore, you can already see the buds that are opening fresh for the day so you get that anticipation of beauty to come….
Once the flower stems have bloomed out and all buds have opened and faded the stems will start to turn brown. At this point it is a good idea to cut them out with sharp scissors or secateurs, never attempt to pull them out [they are surprisingly strong!]
Dividing Hemerocallis
After 3-5 years most varieties will have made hearty clumps. Generally if the clump is 8+ shoots then the clumps can be divided. Again this isn’t a necessity – even larger clumps that appear congested generally continue to bloom well unlike other perennials where when this happens flower production can peter out. Division is best carried out in Autumn or early Spring. Lift the plant from the ground with a sharp spade, shaking as much soil as possible from the roots. Division can be done with a sharp spade – even brutally cut divisions will grow – or a sharp knife inserted between the growths and cut straight down to the root. Longer roots can be reduced in length at the same time. Re-plant or pot where required.
Cutting Back
On the Nursery I employ the practice of cutting all foliage back to within a couple of inches of the ground, in mid-late September. This cleans them up, gets rid of most pests and diseases and you will find the evergreen types produce new growth quite quickly, before Winter. The dormant varieties of course will wait until the Spring until new growth appears.
Diseases
The only troublesome disease is Gall midge. This is easily identified as it produces malformed, twisted and variably coloured flowers. Happily this only affects the earliest blooms, as the mite only has one generation it will disappear within a couple of weeks leaving the main part of the bloom season with many perfect blooms. But I do get a lot of enquiries about this. Removing malformed buds as soon as they appear will reduce the effect for next season. Systemic insecticides are very effective but the timing of protection is key – apply just as the first juvenile flower stems are emerging low down within the centre of the plant. This is when the adults lay their eggs on immature buds. Remember plants with gall midge grow strongly and healthily just the same so whilst it is annoying to lose some of the early flowers it isn’t really a serious pest and it doesn’t affect any other plants in the garden.
Leaf streak disease causes yellow and brown streaking to the leaves. Cut back the foliage to near the crown and when new growth appears – which it will, within a couple of weeks – apply a systemic fungicide.