Propagating Trees and Shrubs from Seeds

Propagating Trees and Shrubs from Seeds

I find it great fun gathering the berries, fruits and various seed pods from my trees and shrubs, mainly because many of these plants grow readily from seed. Although some seeds may take a long time to germinate, others will take a comparatively short time and will make flowering specimens within two or three years.

The hybrid shrubs and trees will not come true from seed, but nevertheless there is always the chance that an exciting plant may be produced. If you want hybrids to come true (that is to say, have exactly the same characteristics as the parent) then you should propagate them by one of the vegetative methods.

propagating trees and shrubs The shrubs which I grow from seed include berberis. Very few berberis come perfectly true but some of the variations in flower, fruit and foliage colour are most attractive.

Cotoneasters are also easily raised by this method and while there may be slight variations from the parent plant in some cases I have noticed that C. horizontalis and C. simonsii come true.  Brooms, Euonymus europaeus and other deciduous species of this genus, genistas, hollies and pyracanthas can all be grown from seed.

Now we come to trees, and of these I like to try my hand at acers, especially the Japanese maples (varieties of Acer palmatum). Most acers produce seed freely and while some will come fairly true to type the varieties of A. palmatum will not.

However, many of the resulting seedlings are very beautiful. Amelanchier, beech, crataegus, crab apple, mountain ash, sycamore, oak, ash, many conifers and silver birch can all be raised easily from seed.

Gathering the Seeds

Most seeds will be ripe and ready for harvesting during late summer and autumn. They can be stored in a dry, frost-proof place during the winter and then sown in the spring. There are exceptions to this rule, however, as all fleshy fruits and berries which contain hard-coated seeds have to be ‘stratified’ before sowing. This does not apply to the ‘dry’ seeds.

 Stratifying Seeds

seed stratification Fleshy berries and fruits such as those of berberis, cotoneaster, hollies, crab apples, pyracantha, hawthorn, mountain ash and Euonymus europaeus must be stratified during the winter preceding sowing, in order to soften the hard coats of the seeds. This speeds up germination in the spring. I must also include here the fruits of ornamental plums, peaches, almonds and cherries, the true species of which I like to raise from seed.

My method of stratification makes use of an old cocoa or coffee tin. First I make small holes in the lid of the tin so that air can get to the seeds. Then I place alternate layers of equal parts moist peat and sand and berries in the tin. Finally, the tin is buried in the ground for the winter, and of course, I only put one species or variety of berry in any one tin and I am careful to label each tin with the appropriate name.

Many gardeners like to use ordinary clay flower pots for stratifying seeds. Again, the berries are placed between layers of moist peat and sand and the pots are placed under a north-facing wall for the winter. It is essential, though, to cover them securely with wire netting to prevent vermin from disturbing the seeds. 

Sowing Seeds

The best time for sowing seeds is in early spring, about March. Those stratified should be sifted from the peat and sand mixture and separated from the remains of their fleshy covering. Then, together with the seeds which were stored ‘dry’, they can be sown either in seed boxes or 6 inch pots filled with John Innes seed compost. The containers must be well drained by placing a good layer of crocks in the bottom.

After sowing the seeds cover them with fine compost to a depth not exceeding the diameter of an individual seed. The containers can then be placed in a cold frame or unheated greenhouse. Keep the pots well watered as drying out will inhibit germination. To prevent rapid drying out the pots can be plunged to their rims in ashes.

If preferred, some seeds may be sown in drills in a prepared bed in the open garden. Hollies, hawthorn, cotoneasters, mountain ash and so on can be treated in this way.

Care of Seedlings

When the seedlings are large enough to handle easily they can be pricked out into seed boxes, using John Innes No. 1 potting compost. If they have been raised in a greenhouse they must be hardened off thoroughly before planting them out in a nursery bed the following autumn.

 

28. July 2010 by Dave Pinkney
Categories: Plants & Trees, Propagating | Tags: , , , , , | 1 comment

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