Gardens: Howick Hall in Northumberland

Howick Hall in Northumberland is an imposing hunk of a stately home. In the garden, there are good mature trees and an extensive network of paths through 65 acres of grounds. So what makes this place so extraordinary? These are trees grown from seed that has been gathered from far flung corners of the world, from Nepal to China to Korea. Since the 1980s, Howick has become the largest private collection of wild trees in Britain.

The owner, Lord Howick, inherited the place in 1982 and wanted to do something different. At that stage no one outside botanic gardens was planting wild trees on any kind of scale, but since then he and his team have put in more than 11,000 trees and shrubs with around 1,800 different species, all of them grown from wild seed, many collected by Lord Howick on numerous expeditions. This makes the place a kind of living ark, a gene bank of material from all over the world, all meticulously documented. So you can find out not only where the parent plant was growing, but also when the seed was collected, who collected it and when the tree was planted.

Different parts of the world are represented by various sections of the arboretum, with China the most extensive. To the casual visitor, the new planting is so subtly woven into the existing landscape that if you didn't know the back story you may miss it altogether. This is unlike many other tree collections where brightly coloured lollipops seem to light up every corner. At Howick, you can wander through groves of mature beech interspersed with young plantings of impossibly obscure trees and shrubs, under an 18th-century viaduct, over a series of little stone bridges, past a grand and silent lake. Eventually you are lured down the Long Walk, which takes you for a mile down a valley, where the sound of rustling leaves is overtaken by the distant roar of the sea. Then in a great moment of drama the valley opens out on to a low headland and there, 50 yards in front of you, is the sea, all grey and cold and spumous.

I came back from Howick thinking that so many of our gardening endeavours are instant fixes: shallow things by comparison with this great statement of faith. It is an antidote to the quick gratification of the makeover garden. First find your seed in some far-flung corner of the world, then germinate it, document it, plant it out, tend it and record it and then care for it for decades and watch it, remembering, in the case of Charles Howick, its parent tree perched on a windy ridge in Sichuan or a roadside in Massachusetts.

I visited Howick on the same day as going to see the nearby garden at Alnwick for the first time. With its gargantuan tree house, garden of slick water tricks and acres of car park, Alnwick is an impressive achievement and has revitalised a whole community. But as big gardens go it is about as different from Howick as it is possible to imagine: grand, flashy, brimming with expensive distraction and finally a bit exhausting. Howick is quiet, subtle, slow and beautiful. In a world where our horizon is, at best, centred on our own lifespan, and gratification comes in prepackaged chunks, this was the perfect, refreshing antidote – along with a great gulp of fresh air off the North Sea.