Propagation of the Hosta

Propagation of the Hosta

Kurt Easterday

Information about hostas.

Hostas are hardy herbaceous perennials grown primarily for their beautiful foliage, thus making them a very popular plant to grow. Hostas are very easy to grow, thus adding to their popularity. The leaves grow in different shapes, colors, sizes, and textures, as well as either solid in color or variegated in different combinations of blue, green, white, and gold. Some people like the flowers that grow on the hosta, but most people cut them off when they grow because of their odd appearance against the rest of the foliage. There are over 2,500 different cultivars throughout the world right now. The home of the hosta is Japan, China, and Korea. In the 1700’s, the hosta was introduced to Europe, and then made its way to the United States in the 1800’s.

Propagation and Division.

Most hostas are propagated by division. Division is the easiest, cheapest, and most widely used method for propagating hostas. This is because when hostas are propagated by seeds, only Hosta ventricosa becomes true.

When division is to be done, there should be no shoots growing from the center of the mature clump. The factor to look for to see if the hosta needs to be divided is if there is a bare area in the center. If there is, then the hosta plant is mature enough to divide. Division will improve the overall appearance of the plant.

To divide, dig up the hosta and wash off the roots to remove excess soil. This will make it easier to see where to cut to divide the clump. You can use any type of cutting tool, from a knife to a spade/shovel to an axe. Just make sure that you wash the cutting surface of the tool to remove diseases.

The best time to divide hostas is the spring. This is because new shoots are only a few inches high and the leaves have not expanded. It is important not to over divide the hosta in the spring. You should divide only the fast growing hostas then. If you divide the Sieboldianas or the Tokudamas in spring new roots will not grow until the foliage has fully expanded and hardened off. This can be critical because the leaves may desiccate quickly on warm days, since the roots have been reduced in size or were injured during division. A very hot day may cause leaf burn, but this will most likely not be permanent damage.

Division that is performed in the spring is the easiest, but summer division is preferred. This can be done in August, and must be done at least 30 days before the first fall frost date. The warm soil and high humidity promotes better root growth, and this may cause a small growth spurt.

You need to keep newly divided hostas well watered for at least two weeks after division because of the sudden decrease of root size. This is even more critical during dry periods. You can cut back some of the larger leaves to help reduce water loss and to cause the plant to put more energy into root growth.

If you divide a hosta too frequently, you will restrict plant and leaf size, and keep it from developing to its desirable mature features. Thus division should not be done until the plant needs it.

Seed Propagation.

Hosta species can be propagated by seed. Sexual propagation is mostly limited to producing plants from seed resulting from selected crosses by hosta hybridizers. However, rarely does a good variegated hosta cultivar result from uncontrolled pollination.

When seed has been produced, it can be directly planted or stored in a cool dry environment for a short term. This includes storage in a refrigerator, which allows storage for a longer amount of time. However, hosta seed viability varies greatly.

Seed are broadcast on a fine textured medium and kept moist and at 60-75oF in order to achieve good germination. When true leaves appear, light is needed. Both hybridizers and amateur gardeners alike must be diligent in culling out the unacceptable seedlings for planting.

Tissue Culture.

Tissue culture can play a critical role in the propagation of hosta because of slow production of plants by division. Tissue culture has made it possible for hostas to be in every landscape because many new cultivars have been / are propagated by tissue culture. There is some belief however that the production of plants produced are not true to type and the older the culture gets the more likely there will be "sports" on those plants. Because there is so many variations in tissue cultured hostas, tissue-culture techniques will continue to be refined by both large and small commercial laboratories to eliminate deviant plants from the production cycle and, ultimately, from getting to the consumer. This will continue until all problems with variegated hostas from tissue cultures are resolved.

Conclusion.

Because of the problems with tissue cultured and seed propagated hostas, division will continue to be the best way to propagate hostas. The economic, labor, aesthetic, reproductive, and timesaving benefits will continue to keep the division method as the main propagation method for the hosta.

Works Cited/References.

http://ohioline.osu.edu/hyg-fact/1000/1239.html

http://www.ca.uky.edu/HLA/Dunwell/HSTPRP.html