The aspect of breeding plants involves facilitating the pollen from a selected male parent to come in contact with the selected female parent’s receptive organ. Simultaneously, it is essential to ensure that no other agent is allowed to introduce other pollens to the chosen female parent. The procedure of plant breeding is somewhat easy. However, it requires some basic understanding of the constitution of the flower that is to be fertilized with the chosen pollen.
Considering the above-mentioned aspects, the flowers of hostas have a very simple structure. Characteristically, these flowers have only one stigma (female organ of a flower) and many, about six, anthers or stamens (male organ of a flower). All these anthers surround the stigma, which is longer as well as thicker compared to the stamens. The stamens of hosta flowers have a significant similarity, particularly in illustrations, to the elongated eyelashes having curled up tips.
Preparing the Pod Parent
To ensure that the selected hostas flowers are not pollinated by any natural agent, including bees, it is important to emasculate the plants. However, before trying to emasculate the plants, it is necessary to examine or undertake some research pertaining to the hosta flowers with a view to understanding precisely when they would be opening, as it is essential to ensure that you catch the flowers before they open in the late afternoon. In other words, it is important to catch the flowers while they are still in the bud stage but nearly set to open.
The procedure involves first split opening the flowers carefully and exposing their reproductive organs without causing any harm to them. Subsequently, you remove the sepals and petals by cutting them using sharp scissors. Next, you need to find the anthers and also remove them by cutting without causing any harm to the stigma. When you remove the sepals and petals, you actually deprive the insects of a landing platform on the flowers. Therefore, it is unlikely that they will try to pollinate the flowers. On the other hand, removing the anthers does away with the chances of self-pollination by the hosta flowers. Wind pollination is ruled out altogether because the pollen’s of hosta are considerably heavy for this purpose.
Gathering and Storing Pollen
The pollen’s of a flower is the medium through which a plant transfers its male gametes to the female organ of a flower. By its nature, pollen is not only extremely susceptible to changes in the temperature but also has an extremely short lifespan. As the hostas pollen’s ripened and is ready to use, their texture becomes somewhat powdery. The viability of pollen’s is governed by enzyme activity that is primarily temperature-controlled. In fact, a reasonable amount of heat is required for the pollen’s to ripen. On the other hand, the viability of pollen’s deteriorates quickly when they receive excessive heat. The feasible range of temperature varies from 18° (65°F) to 29°C (85°F). It is believed that the optimum temperature for pollen’s is 24°C (75°F).
As the pollen’s are extremely susceptible to temperature variations, it is vital to gather the pollens at the appropriate time. If you collect the pollen’s very early in the day, the atmospheric temperature may not be adequately high. On the other hand, the temperature may again below if you collect the pollens during the afternoon or in the evening. Therefore, it seems that collecting the pollen’s during the mid-morning may be appropriate for optimum enzyme activity. However, there is one problem during this time of the day – the bees may have gathered around the flowers by this time and they may steal the pollens. This is the main reason why it is advisable to collect the anthers, which bear the pollen’s, some logical time early in the day. Once you have collected the anthers, you need to take them indoors and place them in a dark place and allow them to attain the optimum temperature prior to harvesting or using the pollens.
You may use the pollens for making crosses immediately when they have attained an appropriate temperature or they may also be stored in low-grade paper’s fold. You may also note down the source of the pollen on this paper for records. While storing the pollen’s in a folded paper, you should first fold the paper and subsequently open it, dab the pollen’s to get them in the middle section of the fold and refold the paper again. You may store these folded papers containing pollen’s in a refrigerator and they will remain usable for the remaining season and, sometimes, even till the early part of the next year. This is significant as it allows you to make hostas crosses from pollens of different plants that do not necessarily flower during the same part of the year. However, remember never to keep the papers inside a freezer, as it is extremely cold there and the low temperature may make the pollen’s nonviable for use.
Transferring the Pollen
The actual mating of hostas, or for that matter any other plant, is complete when the pollen collected from the anthers (male organs) is transferred to the stigma (female organ). After the mating is complete, the stigma becomes damp and somewhat distended indicating that the stigma is most receptive at that moment. However, the formation of dewdrops means that it is very late for the stigma to receiving the anthers. The most uncomplicated as well as the most normal means to achieve this is to brush the anthers loaded with pollen’s on a somewhat viscous stigma. In this way, the pollen’s are deposited on the stigma. However, this can only be achieved when the stigma, as well as the anthers, are in season simultaneously.
You will be requiring a sable or fine camel-hair brush if you are using stored pollens for crossbreeding hostas. Take the pollen delicately on the brush’s tip and then wipe the tip across the stigma to facilitate the positioning of pollen’s on the sticky stigma. It is important to use one brush for only one type of cross. Using one brush for making several crosses will defeat your purpose. It is also essential to clean the brushes in mentholated spirits after using them. Since you also need to dry the brush prior to using it again, it is sensible to work with the whole lot of brushes and then clean them together. This will save you much time and effort. Alternatively, you may use another method to transfer the pollen to the stigma. You may use a strand of cotton wool; hold them with tweezers to transport the pollen to the stigma. Remember to use a fresh cotton wool piece for every different mating.
It is often difficult to cross a number of hostas varieties compared to others. For instance, H. plantaginea, as well as a number of its progenies, are known to be notorious for refusing to accept the pollens from different other hosta varieties. However, you may employ one technique to successfully mate H. plantaginea with other chosen hostas. You need to place the stigma of the other parent hosta chosen by you in the center of the H. plantaginea stigma.
Many breeders are of the view that it is not necessary to do anything more to shield the stigma once the cross has been done because it just takes an hour and a half for the pollen to reach the ovary. Nevertheless, it is also a known fact that often bees invade the flowers and whip the pollen from the stigma after a breeder has placed it there. Therefore, the simplest way to defend the flowers used for making a cross is slipping a small portion of a drinking straw on top of the anther.
It is important to note that several factors may actually hold back pollen from taking. The timing for making a cross is extremely vital. In fact, H. plantaginea, as well as nearly all of its aromatic progenies, are known to be infamously difficult hosta varieties to promote seed setting. One problem with H. plantaginea is that this is a nocturnal hosta species that opens its flowers during the evening, just when the dew comes down. As the stigma is quite damp at this time, it may put off the pollen taking process. To some extent, this may help to explain why crosses made at around 4.00 p.m. on a day prior to the opening of the flower is often successful, while crosses made on a subsequent morning maybe not successful.
In addition to the timing, watering as well as the fertility of the soil may also prove to be contributing factors. It has been found that hostas growing in infertile soils rarely yield high-quality seed set. This is also true in the case of plants which are not watered properly. In addition, you may also need to take into consideration the length of time a hosta plant has been thriving at the same place. It has been found that hostas that have been planted newly rarely produce a superior quality of seeds. On the other hand, hostas thriving in a particular place for many years are more likely to produce a good set of seeds.
Last, but not the least important is the fact that it may be easier to undertake early-season as well as late-season crosses provided the pod parent is shifted to a greenhouse or placed on the windowsill because the fancies of the weather may possibly thwart the mating from being successful.
Labeling and Recording
Labeling and recording of hosta plants, especially the hybrids, is important. You should essentially label the hybrids and maintain their records so that you can breed the same cross in future. Alternatively, once you have seen the young plants from the crosses, you may not want to breed them again. You may also want to breed a reverse cross or to grow backcross. You may also want to use some different pollen plants and things like this.
First of all, you should label the pod parent. You need to tie the label to the pedicel (the short stalk that bears the blooms) where it is joined to the scape. If the label is fastened only to the pedicel, it may be pushed off by the distending pod. Avoid using plastic labels, as they are very heavy and sometimes have a tendency to bend the scape almost to break it. It is advisable that if possible, you should use jewelry tags, which are definitely a better option. At the same time, ensure that you use indelible ink to write the label.
Remember to always write the name of the pod parent first. Follow this with an “x” and, subsequently, write the name of the pollen parent. A number of people have a preference to use a number instead of names. This may prove to be very useful as far as maintaining secrecy is concerned or if you care too much about secrecy, but while writing numbers instead of names, it is also important to maintain another set of records to denote what the numbers indicate. It is very important to maintain a record of all the crosses as soon as possible, particularly if you are breeding a number of hybrids. This will help you to steer clear of confusion.
Harvesting and Storing
Hostas relatively take a very small time to produce seeds. It has been found that it takes about six to eight weeks time from the time a cross is bred to the seed to ripen. In fact, most hosta varieties that produce seeds early can allow their seeds to become full grown on their own and open to the elements. Nevertheless, it is essential to remove the withered flowers after the seed pods ripen. Leaving the spent flowers in place may make them become disease sources. It has been found that seeds of several hosta varieties, especially the late and mid-season ones, do not mature completely outdoors. As a result, seeds of these plants need to be taken indoors and soaked in sugar water to facilitate their ripening. You can do this by adding one-fourth teaspoon of sugar to about 600 ml of water and keep stirring the solution until all the sugar dissolves. Leave the sugary solution in a cool place before using it to ripen the semi-mature hosta seeds.
On the other hand, you can harvest the seed pods when their color turns brown and they start splitting. Care should be taken while harvesting the seed pods. It is advisable that you collect all the pods belonging to the same cross and keep them loosely in a paper bag. It is preferable to use a brown paper bag to store the seed pods, as it will allow them to ripen faster and better. Be careful never to use plastic bags, as keeping them in plastic bags will help the pods to retain moisture that may be remaining in them and eventually result in their decomposition.
After you place the seed pods in paper bags, you should seal those using paper clips or staples and label them properly. Plenty of hosta pods usually do not split properly on their own and need to be assisted. Therefore, gently stroke the pods using a pencil tip to coax the seeds to come out of the pods. Subsequently, you should blow on the seeds with a view to winnow the seeds from the husks. It is very important to remove the entire husk as well as the husk fragments, because leaving any useless remains with the seeds may lead to diseases. It is advisable that you pick away the husk and husk fragments using tweezers. Provided you do not have any particular facility, you should keep the seeds that have ripened completely while disposing of the others.
If you sow the hosta seeds immediately after they ripen, usually they will germinate very successfully. Otherwise, they need to be stored. However, you should only store the seeds when they are completely dry and they have been cleaned thoroughly. Always take care to store the dried out seeds in a cool and dry location. The seeds usually keep well for about a month or little more if you store them in a refrigerator.
Sowing the Seed
Normally, hosta seeds germinate without any problem, irrespective of whether they are sown fresh or you are using stored seeds. Several gardeners prefer to grow hosta seeds under glass, as they are of the view that in this case, they have better control over the germination process. However, this is not needed. Hosta plants, as well as their seeds, possess the aptitude to tolerate frosts well and, therefore, you can directly sow the seeds into prepared beds outdoors in the garden, if possible in shaded locations. You may control the pests to a greater extent if you sow the seeds in cold frames – either right away in seed trays (flats), pots or into the ground outdoors. In case the ground heaves due to the heavy frosting, you may require firming down the soil now and then.
After the germination of the seeds, it is essential to grow the seedlings in a shaded place and water them regularly. Once the seedlings have grown sufficiently big for handling, you should pick them out individually and plant them in small containers or pots. Ideally, you should undertake this process when the seedlings have about four or five proper leaves. You may transplant them in rows outdoors in a nursery when the young plants have about 15 leaves. It is advisable that you space the rows about 45 cm (18 inches) apart and plant the young plants at a distance of 20 cm (8 inches) from one another; it will ensure that they will reach adequate size so that you can truly assess their worth.