One of the most rewarding gardening tasks is growing trees and shrubs from seed. Late winter/early spring is a great time to sow many varieties, especially those that require a cold snap to germinate (known as stratification). Another good reason for sowing now is that some plants often germinate at the time they naturally start into growth. So while daffodils will soon be pushing through the soil so, too, will their seedlings.
WHAT TO GROW
Home-produced or seeds from a friend (as opposed to bought) can be your best bet. You know when it was gathered and you know its parents. Go for plants that are expensive in garden centres, difficult to propagate from cuttings and total charmers. The chart toppers are probably daphnes.
Many Daphnes suffer from viruses, but if you propagate from seed you usually get virus free plants. D.mezereum seedlings will often germinate in early spring and are ideal to sow now. If you don’t have a supply of berries, find a friend with a parent plant with a good colour that flowers freely, then beg. You may have missed the boat this year as even unripe berries are like caviar to green finches. In this case, netting from finches should occur next July. Alternatively, order the dried seeds from Forestart ( 01939 210563; 25 seeds for £1.20).
HOW TO SOW
Sow the ripe berries in boxes or deep seed trays. Trials show there is no need to clean the flesh from the seed. Leave the seed trays in a shady place, maybe tucked up by a north-facing hedge. The greenhouse warmth would inhibit germination. If sown now, about 15 per cent should germinate immediately this spring, the bulk of the rest the following spring. Once germinated, bring them into a cold frame just for the added protection against slugs, cats and the like. This is the most vulnerable part of their life. Then in autumn, prick out the seedlings into a mini hoarding border and leave the seeds that have not germinated in the tray outside. As daphnes do not like being moved don’t let them get tray bound, but pot them on and when they have had one growing season plant them into their permanent place. If you are a daphne fan, try others such as D. tangutica, which is an evergreen species.
OTHER TOP SEEDS
Another candidate that the nursery trade favours sowing now is Cytisus battandieri. This prefers a little protection and if you sow in February on a warm window sill you should get about 50-60 per cent germination in seven days or so. This plant has wide-ranging attributes: I love the cone-shaped, yellow, pineapple-scented flowers in July and the grey, silky leaves. It is ideal as a small tree, or against a wall.
Cercis siliquastrum, the Judas tree, appreciates a warm spot, and is a star in May when the leafless branches are adorned with lilac/pink flowers. Sow seeds in February or March, in a cold frame, and you should have some great seedlings about 20cm high for Christmas presents at the end of the year.
One of my favourite trees, and the only non-native tree that Capability Brown used frequently, was the cedar of Lebanon. This and Cedrus deodara and C. atlantica are usually propagated by seed, sown in February under cold glass. The oily seed does not keep. You know when the seeds are ripe as the cones start to disintegrate on the tree. Some of the seeds from the blue forms will come up blue. It should germinate in two to three weeks and the problem you then have is finding 30 friends with stately homes with grounds to accommodate them!
Other trees, such as birches, grow so rapidly when propagated this way that it is the best method to use whenever possible. Species usually are reasonably true from seed, although botanical authorities think hybrids between our native birches may rarely occur. If you have a beautiful white-barked Betula ermanii, for instance, you can quickly propagate a grove or alley of them, with none of the establishment problems often associated with container-grown birches. Sown under glass in February, you can have 1.2m-high plants four months later in June, providing you keep potting them on frequently so growth is not checked.
The list of seeds you can sow now is long. My favourites include arbutus, acers (most, but don’t let seed dry out, sow fresh), acacias, yew, holly, bay, roses (for species), Quercus ilex (don’t let acorns dry out), pinus including P. mugo, species tree peonies, Luma apiculata, hydrangea species (under glass) and Ginkgo biloba. Remember that many herbaceous plants are best sown in late winter/early spring too, and that you can produce hundreds of plants for a few pounds. Seed propagation is a sexual method, so you do get the possibility of genetic variation – seeds may more or less breed true from species but you often get variability within a species. If you examine different evergreen oaks, Quercus ilex, for example, you will frequently see mini differences in leaves, colour and form. You never know, you might just breed a new winner!
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