For those who enjoy growing daylilies on an amateur basis, there can be few things more pleasurable than producing their very own hybrids, an activity which is not only exciting but extremely simple.
Initially, all that is required is a basic knowledge of the reproductive parts of a flower. Also necessary is a knowledge of the ploidy of the daylily chosen for parenthood, essential because diploids and tetraploids are incompatible due to their differing chromosome counts.
Since the flowers of daylilies contain both male and female organs, there is some danger of self-pollination, so in hybridization programmes it is usual to emasculate the flowers ( that is, on the flower chosen as the pod parent, the stamens are removed).
A certain amount of patience is also required because although it is often only nine months from seed to flower in the hottest climates, in cooler regions it takes 2-3 years, depending upon individual growing conditions; at least a further year is then needed for the daylily to mature and show its paces. After 2-3 seasons, bud count, branching and flowering may improve or change significantly.
Choosing your parents
To start with, it is tempting just to put the pollen from one pretty face on to another to see what will happen and, if you are lucky, this can work very well, but it is better to have specific aims, such as an improvement of color or form, the development of unusual patterns or the refinement of edges. When choosing your first parent, try to select a daylily that is as near to your aim or ideal as possible and then look for another parent to complement it, preferably with other qualities your first parent lacks, such as the ability to lift the bloom above healthy foliage on graceful scapes or well and evenly branched scapes producing many buds to give a long season of flower. Many amateur breeders, as well as the professionals, develop an eye for a good breeding plant (a bridge plant), one that will never be good enough to be introduced in its own right, but is able to pass on certain exceptional qualities.
There are also pitfalls to avoid. Two daylilies with the same weaknesses should not be crossed, however beautiful. For instance, if ruffling is wanted, 'Dance Ballerina Dance' would contribute this trait but due to its difficulty in opening fully in cooler climates, it would be unwise to use it with another daylily having the same defect. Crossing 'Dance Ballerina Dance' with a daylily that opens easily and, preferably, early in the morning, could bring about an exciting new break.
As knowledge about the pedigrees of cultivars grows, and there are now stud books to assist, one can use breeding techniques such as line-breeding, which is the crossing in succession of two parents and the resulting seedlings with each other generation by generation. Outcrossing is the crossing of seedlings with unrelated cultivars to strengthen the lines and further one's aims.
To make specific crosses it is sometimes necessary to store pollen for later use if the pod parent is not in bloom at the same time. This is not difficult. Scrape fluffy, dry pollen from the anthers of the pollen donor into a china egg cup or similar container, taking care not to add any fleshy bits as these will decay. Collecting in this manner should be done as early in the day as possible so that insects have had little chance to mix the pollen. If the pollen is only to be kept until the following day, it will be sufficient to cover the container and keep it in the fridge. If it is to be kept for a longer period say, two weeks, put it into small, well-sealed gelatin capsules, and then store in a larger uncovered container (the type of plastic tube used for pain killers or throat lozenges is ideal) and place this into a tightly covered box with some silica gel (the material used for drying flowers). This allows the pollen to be stored in the fridge without deterioration taking place. Pollen can also be frozen for a longer period, even for a year or so, as long as the same initial drying procedures are carried out. Once dried it can then be put in a sealed polythene bag, or any other suitable container, such as a contact lens case or pill box, and labeled with the cultivar name. A small square of paper towel placed under the pollen will absorb any remaining moisture. The pollen collected on the paper towel can then be applied direct to the pistil.
Making a cross
In its simplest form, cross-pollination consists of placing pollen from the anthers of one flower onto the stigma of another. The pollen should be golden-yellow, dry and fluffy (creamy-white, hard pollen is infertile). Ideally pollination should be carried out as early as possible on a cool, dry morning. This is particularly important when working with tetraploids which are more difficult; diploids can be pollinated successfully until midday or a little later.
To make the pollen transfer use an artist's small paint brush, which must be washed with soap and water to make it completely clean for each cross. Use flat-ended tweezers or fingers to hold the stamen and anther, and gently stroke the pollen on to the stigma of the pod parent. Many hobby hybridists then carefully cover the ends of the pistil with a small cap of foil to prevent further unplanned pollination, for the time necessary for fertilization to take place.
Having made the cross, mark the pod parent to help prevent the accidental removal of the flower when deadheading. Initially, a piece of colored wool is sufficient, but once you are bitten by the hybridizing bug, it is necessary to keep records so the first step is to mark the pod parent with a small tie-on label on which are written the details of the cross number, the two parents used and the date, the pod parent usually being written first. Needless to say, the details must be written with an indelible garden pen or pencil. The label is then carefully attached to the stem under the flower and each cross noted on a pad for transferal to a record book or a computer.
Do not be dismayed if some crosses do not take: pollination is not always successful and there are many hazards. Sometimes a parent is infertile, or the weather is too hot and humid causing the pollinated flower to drop off, or a seed pod may start to grow but then wither, particularly if the weather is very cool and changeable. However, if pollination is successful, the base of the pistil swells and the flower sheds, revealing the little green seed pod. Do not be tempted to try removing the withered flowers from around the emerging pods, as this can very easily snap the whole thing off. If all is well, the pod will grow and about six weeks later it will ripen, dry and crack open at the top. This is when it should be removed and the seed and label placed in small paper bags or self-seal plastic bags for storage in a container in the fridge until needed.
Sowing & growing on
If heat and light are available, sowing can be done at any time during the winter but most gardeners prefer to wait until early spring, thus avoiding having vulnerable seedlings ready for planting out too early in the year. When removed from cold storage, the seeds, which will have lost moisture, may appear rather dry and wrinkled and it is a good idea to soak them for a day or two before sowing, changing the water daily. They should then be sown in open-textured compost, 5-10mm (1/4-1/2in) deep, lightly covered and gently tamped down. Use deep trays, individual pots or special self-watering polystyrene seed trays and put them into a gently heated propagator, an airing cupboard or on a warm windowsill until germination takes place. If they are not in a covered propagating case, they will need to be covered with a polythene bag to keep the moisture in. Successful germination is apparent when strong grass-like spears begin to sprout, in about 7-10 days. The containers should then be kept in a light, frost-free place until ready to be hardened off for planting outside when all danger of frost has passed.
When planting out the seedlings, put them into a well prepared and sunny patch in the garden and plant approximately 22cm (9in) apart in rows that are 30cm (12in) apart, giving each plant room to develop over the following year or two. The seedlings should be well watered and mulched for the summer to help them develop a good root system before their first winter, after this there is not much to do other than to wait with eager anticipation for a scape to appear and to see the first flowers.
However much excitement and pleasure is obtained from the first crop of seedlings, a critical eye will be necessary as many of the seedlings may well be of indifferent quality and not worth keeping. Give them time to mature and then be as selective as possible and try to see the plant as a whole. When starting to hybridize try not to make too many crosses. Professional hybridizers produce several thousand seedlings a year but this would be far too many to handle for someone just breeding as a pleasurable hobby and a hundred or two from carefully chosen parents will probably be more than enough.