Propagation of Alpine Plants

The propagation of alpine plants is a very rewarding pastime

It allows for favourite plants to be multiplied and little known and rare species to be increased. Spare plants can be exchanged with fellow enthusiasts, taken along to plant sales or given as presents. It really is a win-win situation.

Before 1950 many large plant nurseries and estates with fine gardens employed propagators skilled in the various process of maintaining, reinvigorating and increasing stock of interesting and decorative plants, particularly trees and shrubs but all manner of plants besides. Today, the situation is very different. Large commercial firms, especially in places like Holland, still rely on propagators. However, the tendency is to produce a large number of relatively few types of plants. Most of these are intended for the garden centre and supermarket trade.

Fortunately, there are some specialist alpine nurseries that propagate large numbers of alpines for a specialist and often enthusiastic market. This includes alpines, small herbaceous perennials, small hardy shrubs, bulbs and small hardy ferns. However, wonderful though this is, there is even greater satisfaction in learning to and propagating you own plants.

One can propagate alpines through various methods.

The propagation of alpine plants by seeds

Seed is by far the easiest way to add plants to your garden. Seed may be collected from your own plants or bought from a supplier.  Seeds of alpines can also be obtained through the extensive and much-lauded Alpine Garden Society annual seed distribution.

Most seed is best sown as soon as possible after it is ripe, even if, in some instances, germination may be very slow. Peonies, for instance may take more than a year to germinate. Patience is a virtue. However, most seed germinates quite rapidly, often in the early spring from an autumn or winter sowing.  Seed of species generally comes true to type but certain genera hybridise in the garden (e.g. Aquilegia) so mixed results are to be expected. There is always the chance of a novelty arising which is one of the great thrills of growing your own plants from seed.

Be aware that many countries restrict or prohibit the collection of seed in the wild, especially from national parks and reserves or of particularly endangered and critical species.

Propagation by cuttings

Cuttings provide a very useful means of increasing favoured plants. As far as “alpines” go this primarily applies to small shrubs (e.g. daphnes, dwarf rhododendrons) and to a host of charming and diverse little alpines such as saxifrages, androsaces and gentians.

In its simplest from, suitable cuttings can be placed in a pot of fine horticultural sand or perlite, watered well and sealed in a plastic bag, then placed in a light but shaded place to await rooting. Garden centres sell various propagators from the simple cloche type to ones with an integral base warming cable. On a larger scale a box propagator with a thermostatically controlled warming cable can be set up in the greenhouse (or by the window in the garage!). Using these devices takes time to practise and experiment with. The prime rule is hygiene, keeping pests and diseases, especially mildew, away from the delicate cuttings. Regular inspection is advisable.

Propagation by division

Division is a practise used widely by gardeners, especially for herbaceous perennials which from increasingly large clumps from year to year. It also applies to similar but smaller herbaceous alpines. Tired clumps can be invigorated by division.

The favoured times to divide chosen plants is either immediately after they finish flowering or in the autumn. While many alpines can be divided, the majority of tight cushion-forming species cannot and will only be ruined if any attempt is made. For these tricky individuals, small cuttings are the answer. These can also be increased by seed if that is available (e.g. many saxifrages, dionysias).

Some alpines such as pulsatillas greatly resent any disturbance once establish and should not be divided. Fortunately pulsatillas set seed quite freely in most seasons. Propagating by division ensures that you replicate known and favoured specimens in the garden and of course it saves money.

Other types of plant propagation

Other rather more specialist forms of propagation are employed by enthusiasts.

This includes grafting (often used for Daphne cultivars) and layering where a small branch is pinned down and encouraged to root. The rooted later can eventually be severed from the parent plant and grown on as a new individual.

One skill which has become increasingly popular in recent years has been chipping. This applies particularly to bulbs in which a bulb is divided into segments each of which has a piece of the base plate attached (the part of the bulb from where the roots arise!). This technique is used particularly by both amateur and professional growers to increase rare and often expensive bulbs. Many of the rarer and more exciting snowdrop cultivars respond really well to chipping.

A good sized bulb can be divided into perhaps 16, sometimes more segments. If treated well it will result in as many new little bulbs which can be grown on to flowering size in relatively few years.

Propagation is both fun and a rewarding pastime. It ensures that interesting, rare and little known plants are preserved in cultivation and spread more widely amongst the keen gardening fraternity. Today nowhere is more important than the world of alpines. Small they might be, colourful, diverse and intriguing they certainly are.

Happy propagating!