Propagation and Division.

 

Propagation of hostas is easily achieved by dividing existing plants. Hostas do not come true when planted from seeds, with Hosta ventricosa being the one exception. Most home gardeners will propagate hostas by division.

Division should be done when:-

 

a) No shoots are growing from the centre of the mature clump and this bare area detracts from the appearance of the plant. Division of the clump will improve the plant’s appearance.

b) When the hosta has outgrown the position it has in the border.

c) The hosta  has outgrown its’ pot and becomes difficult to water or shows signs of distress.

d) You wish to ‘swap’ cultivars with a friend!

 

Lift the entire hosta clump and wash the soil from the roots, if possible, to make it easier to see where to cut to divide the clump. Cut with a sharp knife or spade to make the divisions.

Early spring is the easiest time to divide plants because new shoots are only a few inches high and the leaves have not expanded. Be careful not to overdivide hostas in spring; divide only the fast growing hostas then. Do not divide the sieboldianas or the Tokudamas in spring. New roots will not grow until the foliage has fully expanded and hardened off. During this period, the leaves may desiccate quickly on warm days, since the roots have been reduced in size or were injured during division. A hot day may cause injury such as leaf burn, but this is probably not permanent damage. Division of miniatures should be done with great care and only when the plant is well established.

 

Though spring division is easiest, summer division is preferred and can be done in July as warm soil and higher humidity at this time promotes better root growth, and plants may put on a little growth spurt at this time.

 

Keep newly divided plants well watered for the first two weeks, especially if there is a period of drought. Some of the larger leaves on a division may be cut back to reduce water loss. Frequent division of a clump will restrict plant and leaf size, and keep it from developing to its desirable mature features.