Ursula Cholmeley advises us how to germinate the big trees of the future.
Black walnut, wellingtonia and Atlas cedars make magnificent specimen trees. At Easton, they’re grouped together at the end of the south lawn. The walnut has limbs that sweep down from a grooved trunk over the snowdrops and spring bulbs.
Further on, the path widens out into the aptly named Cedar Meadow, where four big conifers stand. The tallest is a wellingtonia (Sequoiadendron giganteum) whose lower branches reach down to the ground. Its spongy bark is pitted with holes and colonised by spiders, bats and small birds. This impressive tree is probably 130 years old and yet it would be dwarfed by relations in its native Californian forests. Even here in Lincolnshire, in fewer than 10 years, the main stem has grown an astonishing 18ft.
A classic reaction to the magnificence of old trees is to admire the foresight and generosity of our ancestors who planted the sapling, but would never see it reach maturity. Occasionally, a visitor will say to me that they’re too old to plant trees. Both of these observations may be true, but to focus on the mature tree alone denies the gardener one of the wonders of nature.
It’s not just the big tree that is impressive the germination of a small seed that will one day become one of the largest organisms on Earth is just as moving. The wonder of creation is dazzlingly evident in the emergence of a delicate, green point from a seed and it’s easy to have a go. It was a proud moment here, 10 years ago, when two of our Sequoia sempervirens seeds germinated. They’re now planted in our car park and reach well above my head.
The next stage, from seedling to sapling, is a much harder process and, initially, I had many losses, largely due to my own forgetfulness. Fortunately, I was able to go to a remarkable man, Michael Walford, for advice. He’s lived on an island near Skye for most of his life and, with just one other person and occasional help, has deer-fenced the hill and planted thousands of home-grown trees.
His technique is deceptively simple. Old fish boxes are filled with soil (mixed with sand and leaf mould) and the seeds placed in the earth. Then, a frame with a wire mesh is secured on top to keep out vermin and the whole container left outside for the wind and rain to scarify the seed. (Many tree seeds need a period of cold, wet or dry to trigger germination.)
That’s it until all the seedlings reach above 6in, when they can be potted on. Both Michael and I use Air-Pots to encourage the sapling to develop a great ball of young roots before planting out. Made by horticulturist Jamie Single in the UK, these clever containers are now available to the amateur grower (01875 835360; www.airpotgarden.com).
The resulting young trees are full of promise and great fun to surround with naturalised plants. We use cyclamen (also easy to grow from fresh seed), unusual snowdrops, blue Anemone blanda and autumn-flowering colchicums.
Here’s one I made earlier
For instant effect, I like to sow birches (Betula spp.). They germinate easily, are fast growing and make good in-fill trees while we wait for the larger trees to mature. Several of my nurselings are now 15ft tall.
However, if time is short, a good source of young Betula trees is the National Collection created by the late Kenneth Ashburner in Devon (http://stonelanegardens.com). We chose B. albosinensis Pink Champagne and B. pendula ssp. mandshurica.
Many members of the cherry family (Prunus) make a similar contribution in a garden setting. We’ve planted Prunus x subhirtella Autumnalis Rosea, more relaxingly known as the winter-flowering cherry. Its canopy is light, so it doesn’t overpower lowgrowing plants around its feet.
About now, when the leaves have fallen, I roam around the garden checking on the annual growth of coniferous and deciduous branches; it’s an activity that has a particular resonance if I’ve watched over the tree all its life.
Four plants for £30 – Get four mixed hardy plants, selected for you from the Country Life nursery and delivered to your door, for £30. Visit www.countrylife.co.uk/nursery for your special offer.