Perennial Plant Propagation

Perennial Plant Propagation

Marilyn HS Light

April 2005

One of the great things about gardening is sharing - plants, seedlings and seeds. To make such an exchange possible, we must either part with an entire plant or learn how to propagate it so that we have some for our own garden and some to share with others.

Seeds - Plants produce seeds which can be germinated to make more of the same kind but these may or may not exactly resemble the seed-bearing plant. Plant height, foliage, flower size, colour and floriferousness are variable characters. To produce very similar offspring, hand pollination of selected parents should give some satisfaction but several generations of selection may be required to fix a desired trait.

Vegetative propagation

The easiest way to obtain an exact duplicate of a plant is to propagate it vegetatively, by division, by cuttings or offsets. Commercial enterprises employ tissue culture to produce the large number of duplicates needed for the commercial market but mass production has a price: there may be mutations which alter the characteristics of the cultivar. Most plants can be propagated in early spring before growth resumes but some like Oriental Poppy should be divided only in summer when they are dormant. All cutting tools should be very clean and wiped with disinfectant between plants to avoid spreading diseases.

Plant Type: bulbs, corms, tubers SKILL LEVEL EE or EEE

Method: This type of plant often forms offsets which can be removed and grown separately to maturity. In the case of lilies, bulb scales which can be carefully loosened and rooted separately. Plant the scales in a sandy potting medium with half the scale protruding from the surface. Scales will produce little bulbils which can be planted on. Older corms will produce multiple shoots. Such corms can be cut into two or more portions each having a bud. Let air dry and plant in a well drained medium.

Examples: lily, Jack-in-the-Pulpit, dahlia

Plant Type: rhizome SKILL LEVEL EE

Method: Rhizomes are prostrate horizontal stems which lie at or just below soil level. They can produce new vertical stems at every node. Sever the rhizome into portions each having one or more growing points. The rhizome can be cut with a sharp knife or secateurs.

Examples: Violets, some grasses, daylily, iris

Plant Type: stolons, runners SKILL LEVEL E

Method: Stolons are horizontal stems that run over the soil surface. The can produce roots and shoots at every node. Sever a stolon into pieces having a minimum of two nodes.

Examples: strawberry, periwinkle, creeping buttercup

Plant Type: taproot SKILL LEVEL EEEE

Method: Tap-rooted plants are challenging to propagate because there is only one principal root and side shoots develop only after many years. An entire plant must be lifted and washed when individual shoots can be removed and rooted in a propagator.

Examples: hollyhock, poppy

Plant Type: clump SKILL LEVEL E

Method: Some plants produce short rhizomes which give rise to many closely packed shoots. It can be difficult to separate the mass so the simplest approach is to lift the entire clump and cut it into two or more equal parts using a sharp sturdy knife or a spade.

Examples: geranium, hosta, columbine, some grasses

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