Daylilies have long been known as one of the easiest perennials to grow. While this is true to some extent, just like any plant, the better care you provide, the better your daylilies will perform. The following is designed to help you better understand daylilies and their needs.

Where to plant

Q - Should I plant my daylilies in full sun?
Daylilies grow best when planted in full sun to partial shade. In areas that receive less than 6 hours of sun during the day, your daylilies will probably produce fewer and smaller blooms, and the foliage may not be as robust. Here in the deep south, daylilies appreciate having some afternoon shade because of the hot sun. I have obtained excellent results by planting in the filtered sunlight under very tall pine trees.
Q - Are there any soil requirements that I should be aware of?
Daylilies will grow in a fairly wide PH range but best results will be obtained if your soil is either neutral or slightly acid. Daylilies will grow in most soil types, but like any other plant, they prefer a soil that is neither too hard or too sandy. Your best bet, especially if you have either a very sandy or hard clay soil, is to add humus when you prepare the soil for planting. One of my favorite forms of humus is composted manure but any good compost will do.
Q - I have a low spot in the yard that collects water after a hard rain. can I grow daylilies there?
Be sure the place you want to plant has good drainage. If you think you may have a drainage problem, dig a hole about a foot deep and fill it with water. If the water has not drained from the hole after 12 hours, you should probably find another place for your daylilies or build a raised bed filled with good garden soil.
Q - Is there anything else I should watch out for when deciding where to plant my daylilies?
Areas where the daylily roots will have to compete with the roots of larger plants such as shrubs and trees should also be avoided. The primary problem is that some trees and shrubs have root systems that will quickly take up all the moisture and nutrients. Daylilies are not very agressive and can't complete with these trees and shrubs.


Q - When is the best time to plant daylilies in southern climates?
In the deep south where we have very hot summers and mild winters, the best time to plant is in the fall after the heat of the summer subsides. Because the ground does not freeze, the daylilies will continue growing all winter and be well established before the heat of the summer arrives. If planted here too late in the spring, the daylily may not have had enough time to get completely established and may suffer from the summer heat.
Q - What is the best time to plant in northern climates?
In the north, the summers are neither as hot nor as long as in the south so planting in the spring is recommended. If planted too late in the fall, the ground will freeze before the daylily has a chance to become fully established, reducing its chances of survival.
Q - What if I live somewhere in between?
I would not plant daylilies less than 60 days before the first hard freeze or 60 days before daytime temperatures consistently reach the 90's. The exception to this would be transplanting container grown daylilies which can be planted at any time of the year that the ground can be worked as long as you do not disturb the root ball when planting.


Q - How should I prepare the soil prior to planting?
You should prepare the soil by digging to a depth of at least 12 inches (18" would be better). The soil should be loose and any amendments should be well mixed in. One of my favorite tricks is to place a shovel of composted manure in the bottom of the planting hole and cover with a few inches of soil. The daylily planted on top will eventually send its roots down to reach the nutrients. I believe this also encourages the roots to grow deep rather than shallow, an advantage here in the hot south.
Q - Should I prune the daylily before planting?
Yes. Trim the foliage to a length of 6-8 inches. This will help the plant compensate for water loss while it's re-establishing itself. The roots can also be trimmed to 6-8 inches in length to make it easier to plant however there are varying opinions as to whether or not this is beneficial. One side of the arguement says that 'root pruning' as it's called, will encourage the plant to send out new roots while the other side believes that because the plant's reserves are held in its roots, trimming some off only reduces the amount of reserve energy the plant has available while re-establishing itself. Personally, I only root prune when the roots are extremely long.
Q - How deep should I set the plants?
Plant the daylily with its roots spread out so that the crown is about one inch deep in the soil (the crown is the area of the plant where the roots all come together). In the north, planting a little deeper is recommended but daylilies planted too deep will not grow properly.
Q - How far apart should I space my daylilies?
Daylilies can be planted as single plants when you are doing a mass planting, or in groups of 2 or 3 together which form clumps. When I plant single plants, I space them about 12 inches apart while I space the groups 18-24 inches apart. Because daylilies multiply, planting any closer together will result in them needing to be divided sooner and I don't like to create any unnecessary work for myself. Some plants tend to be more robust than others. These should be given extra room.


Q - How much water do daylilies require?
Probably the most important ingredient in beautiful daylilies is water. While daylilies can withstand drought because of their fleshy roots, I find it amazing the difference I get when they get all the water they need. This was brought to my attention some years ago when our daylily club was touring gardens in Louisiana. In several of the gardens, we were enjoying some of the best blooms we had ever seen on some varieties we were familiar with and commented that we just had to find out what kind of fertilizer the grower was using to produce these spectacular blooms. When asked, we were told that he just used a regular fertilizer and applied it only once and sparingly at that. Asked how he produced such blooms with only a little fertilizer, he said it was a very wet spring and every time the spring was wet, he had the same results - spectacular blooms.

So give them plenty of water, at least 1 inch a week. Do not over water however, as daylilies do not like to have their roots immersed in water for extended periods of time. Give the soil a chance to drain well before you water again. Here in the south, I begin to cut back on the watering once I have harvested my seeds. Beginning in mid July I only water once every 5 days or so. While daylilies like lots of water, keeping the soil wet when the temperatures are high for a lengthy period of time will encourage fungal and bacterial rots which can sometimes kill a daylily.

Q - Should I fertilize my daylilies?
Fertilizer is important for healthy daylilies. Proper feeding will result in more and larger blooms and the plants will be more vigorous. In 1995 (a year where I had a good fertilization program) I compared the number of blooms per scape on some plants with the number of blooms from the same plants the previous year (without fertilizer). A few varieties showed very little increase, but the majority increased significantly. The biggest increase was almost 2.5 times the number of blooms as the previous year.
Q - How often should I fertilize?
If you're using chemical fertilizer, I recommend that daylilies be fertilized at least twice a year. The first application should be in the early spring when the daylilies begin their spring growth. In the south, the second application should be in the fall once the temperatures start to cool off. Further north the second application should be after the peak bloom season. It is not recommended to fertilize too close to your average first frost date.
Q - What kind of fertilizer should I use?
I highly recommend that you have your soil analyzed and let the experts tell you what your soil needs. Most states have a program where you can submit samples for analysis.

Once you have determined what your soil needs, then you can develop an effective fertilization program. Personally, I prefer the organic approach using soil ammendments like animal poop and the like. I have tried both and found that while non-organic methods seem to produce better results on the short term, over the long term, the organic method wins hands down. See my Soil Health page for more info.

If you decide to go with the chemical approach, you should still rely on the soil analysis to tell you what your soil needs to avoid problems. For example, too much phosphorus over time can build up in your soil and actually harm your plants. If you can't find a place to analyze your soil, I would use a balanced fertilizer such as 13-13-13 applied in moderation or the Hooker Formula (see separate page).

Q - Should I mulch my daylilies?
Daylilies will benefit from mulching. Mulch helps maintain a more consistent soil temperature and also help retain moisture.
Q - Are daylilies bothered by insect pests?
Unfortunately, daylilies are not quite as pest and disease free as many nurseries would lead you to believe (almost, but not quite). Pests which will sometime infect daylilies include aphids, spider mites, thrips, slugs, and snails. If you find that you need to spray your daylilies you should use something that has been rated for use on daylilies or you know for sure will not harm the plants. I know of a new daylily grower who sprayed all his plants with kelthane for spider mites. Kelthane (no longer available) is harmful to daylilies. He didn't kill his daylilies, but that year he didn't have very many blooms. If I want to try something new that is not rated for use on daylilies, I will try it first on a single plant (I keep a few plants growing in pots just for this purpose). I use a stronger solution than is recommended and use repeated applications over several months. If the insecticide passes this test, then I feel comfortable using it on the rest of my plants.
Q - What about diseases?
Daylilies are affected by a few disease problems.
  • Crown rot is a daylily disease that affects daylilies in climates with long hot summers like here in the Houston area. Excess watering during the summer months can increase the number of plants that die from crown rot.
  • Daylily Rust is a fungal disease that affects daylilies. It was first detected in this country in 2000. It does not normally kill a daylily but makes the foliage look unattractive. It doesn't seem to overwinter in northern climates but can appear on newly planted daylilies received from the south.
  • Leaf Streak is yet another foliage disease that makes the foliage unattractive but does not kill the daylily plant. The disease is thought to reside in the soil and overhead watering (including rain) will spread the disease.


Q - How do I know when my daylilies need to be divided?
Daylilies multiply by individual plants dividing and by sending up new fans right next to the old fans. If your daylilies have formed a large clump (lots of fans clumped tightly together) and the blooms are smaller or fewer in number than the previous year, you probably need to divide your daylilies.
Q - What's the best time to divide them?
That depends on your climate. In general, the fall is considered the best time to divide but spring is also a good time except in the deep south. Dividing can be done in the spring when the ground can be worked and the daylilies are actively growing but you run the risk of reducing the number of blooms you will get. In the fall after they finish blooming is considered better as long as they have enough time get established before winter sets in. A rule of thumb is to give them at least 6 weeks before the first frost to get established. The following table will give you an idea based on your climate zone:

Zone Spring Fall
7AprilSeptember-Mid October
8 (Pacific Northwest)April-MayAugust-September
Q - How do I divide them?
Dig up the entire clump and shake off the dirt. A garden fork works well for this. Separate the plants by either pulling them apart or cutting into individual plants with scissors or knife. When cutting apart a large root with more than one fan growing out of it, try and include an equal amount of root with each fan.
Q - Can I plant the divisions right away?
Yes, I usually do. However, it is recommended that you wait at least long enough for the any cut areas to dry before planting.
Q - So, what do I do with the extra daylily plants?
Give them to your friends, give them to your neighbors, or give them away at work. Daylilies are becoming so popular that I'm sure they'll be appreciated.