You can propagate daylilies in both ways - by their seeds or vegetatively. You should only propagate daylilies by seed when you want to grow true species, developed separately, or for breeding purposes. On the other hand, you should use vegetative methods for propagating hybrid daylilies. Generally, four vegetative means are used to propagate daylilies - division, proliferations, tissue culture as well as the Lanolin-BAP-IAA technique.
This is not only the simplest method of propagating daylilies, but also time-tested technique, provided you do not divide the daylily clump to just a single fan. However, you can undertake this method successfully with practice. The division method involves digging out the daylily clump and resting it on any hard surface like concrete or the ground itself and then put in two garden forks positioned back-to-back right inside the middle of the clump. Pull the handles of the two folks slowly together, in a manner that the spikes serve as levers, thereby dividing the clump into two smaller clumps. Subsequently, you may require forcing the forks outwards as well as downwards to separate the two smaller clumps completely. You can repeat the process to divide the smaller daylily clumps into further lesser clumps and so on.
Ensure that the final daylily divisions each possess a minimum of two fans. You can separate the final few fans with your hand in the same manner as you separated the larger clumps. Alternatively, you may even use a propagator's knife or a sharp freezer to cut the clumps apart. Generally, the entire operation is made easier provided you first cut down the foliage to anything between 2 cm and 5 cm (1 inch to 2 inches) on top of the crown.
Following the division, you need to use a sharp knife to trim back the roots to roughly half their original length. When you do this, it will promote the sprouting of new shoots from the divisions just higher than the places where you have made the cuts. In this case you will not be required to try and reactive the older roots.
You can either pot up the divisions or plant them directly into the soil in your garden. In case you are returning the divisions to the soil, you should never replant them in the place where they were growing earlier, unless you have renewed the soil in the planting hole or re-revitalize the soil using fertilizers and manures. On the other hand, if you are potting up the divisions, it is suggested that you do so in a proprietary growing mix. Generally, the pot ought to be big enough to accommodate no less than two times the quantity of roots present at the time of potting. Bear in mind that these plants or divisions need to be watered adequately and sheltered from the direct sunlight as well as strong winds till they are established. Usually, it takes a few weeks for the divisions to become established. In addition, it is important to label the plants clearly.
It is best to divide the daylily clumps either in spring or during autumn. However, you should be familiar with the weather conditions in your region and never divide the clumps when it is raining heavily or the weather conditions are extremely hot or cold. Therefore, the ideal time to divide the daylilies is at a time when there will be bare minimum disturbance to the plants' growth. It is advisable that you divide the clumps soon after the second growth boom, which occurs right after the blooming season. While this is the best time to divide daylilies, it is worth mentioning here that these plants are so tough and easy to grow that they can endure division in nearly all conditions, expect when there is extreme heat or heavy frost. However, it is important that you cut down the foliage as well as the flower scapes close to the ground to ensure that the plant's energy is directed to developing a healthy and robust new root system.
When we talk of proliferations in terms of propagating daylilies, we actually refer to the small fans of the plant's leaves that are found on the scapes. These fans usually occur where there are bracts or nodes just under the place where the scape branches out. It has been found that these proliferations can often grow into baby plants on some daylilies. The baby plants come with leaves measuring about 5 cm to 7 cm (2 inches to 3 inches) and roots measuring roughly 1cm (about half an inch). Hypothetically speaking, if it is possible to bring the root of these baby plants in contact with soil or a suitable growing medium, it is likely that the proliferation will grow into a full-fledged daylily that is same as the parent plant genetically.
Hence, the proliferation method involves separating the proliferation from the scape on which it appears by making 2.5 cm (1 inch) long cuts above as well as below the point of their occurrence. Subsequently, the stem section along with the attached proliferation is pushed into a potting mix or soil with the roots under the soil. The section of the stem is allowed to remain undisturbed with the roots of the proliferation firmly embedded. Instead of using soil or a potting mix, some people favour using perlite, vermiculite or sharp sand.
Once you have planted the proliferations, you need to ensure that they remain warm and receive sufficient light till the period they are established. Usually, they take some weeks to become established when the growing conditions are favourable. However, you do not require pampering the proliferations, provided they already have healthy roots while they are still on the scapes. On the other hand, if you find that they do not have roots, it will certainly be possible to develop new plants more quickly if you grow them in a propagator or under glass. However it is important to provide them with adequate bottom heat.
Many daylily growers suggest that you keep the proliferations humid as well as warm. This can be achieved by placing the proliferations under a clean polythene sheet. However, this type of closed conditions may possibly also encourage rotting of the proliferations. Thus, it may be necessary to use fungicides to prevent this problem. When the proliferations have established themselves into young plants, you can treat them as you treat any normal daylily plant.
The tissue culture method involves producing whole plants from a solitary cell in a laboratory or under conditions similar to those in a laboratory. This process is especially apt for nurserymen who wish to reproduce specific daylilies in large numbers.
Currently, this method is being used to produce several thousand daylilies in several different countries. However, the success rate of propagating daylilies through the tissue culture process has been mixed so far. While some daylilies like "Gentle Shepherd" and "Joan Senior", which are usually dependable, but the success rate with several other types of daylilies has not been so positive. In fact, majority of specialist nurseries growing daylilies are aware of the varieties that are dependable and, hence, will never market varieties that are unreliable. In case of any doubt, ensure that you notice the tissue-cultured daylilies in the blooms prior to purchasing them.
Often, it has been noticed that when the growing point or meristem of any daylily fan is removed or damaged, several fans will grow from the place rather than just one. However, usually it has been seen that the entire fan dies in such instances. However, several new fans can be developed from the meristem by using a substance called the Lanolin-BPA-IAA paste.
People who support the Lanolin-BPA-IAA technique for propagating daylilies assert that this method makes it possible to grow as many as six new shoots in just three to four weeks time. Moreover, they claim that applying this method repeatedly can help the growers obtain up to 20 new shoots compared to the original solitary fan. On the other hand, there are people who say that this method does not offer any advantage compared to the normal division process. Moreover, they state that instead of providing any advantage, the Lanolin-BPA-IAA method may actually damage a plant, which would otherwise have excellently healthy fans. Nevertheless, it has been found that this method is likely to be most successful in places having hot climatic conditions.
Sometimes you may find daylily seeds germinating unexpectedly in your garden. However, you need to provide additional care when you are raising seedlings deliberately. Generally, it is best to sow daylily seed under a glass dome or covering where you can control the environment. If you are not able to sow daylily seeds under glass, you may also sow them inside a propagating case. Alternatively, you may also raise them on a properly lit windowsill or in a conservatory.
In general terms, ideally you need to sow daylily seeds during the period between early and mid-winter so that you are able to maintain the minimum germination temperature, which is about 5°C (41°F). Following germination, you need to ensure that the seedlings continue growing. This can be achieved by potting the seedlings when needed. The seedlings can be hardened off in mid-spring and moved outdoors for transplanting during the latter part of spring. If you follow this schedule, you can be assured that the plant will grow robustly and nearly all of them will produce flowers in the second year of their existence.
Usually, daylily seeds are sown in seed trays or pots in any patented seed mix. Moreover, you need to cover the seeds with the proprietary seed mix in a manner that they are just under the mix and/ or sharp or silver sand. If you are raising the seeds in a closed condition, it is important for you to use a fungicide with a view to prevent damping-off.