Bunch of blossoms on planters of grit

There are all sorts of practical reasons to try your hand at rock gardening, which is not the cultivation of stones but the placement of dry-loving plants in beds deep in grit and gravel. Such a garden can flourish without mulch, mowing or pesticides and needs little feeding and weeding.

It's an ideal horticultural art form for people who travel a lot or don't want to spend the whole weekend playing in the dirt. And because the rock garden is free-draining and mulched with gravel, it is inherently equipped to handle the gully washers.

Hardy beauties

But those attributes are not the reason I am growing fonder of a form of gardening I used to think of as staid and ill-suited to the Washington climate.

No, it's the plants. Consider the beauties that thrive in an arid setting. Pinks — so much lovelier than their ungainly kin, carnations — are now a thicket of stems capped with star-like blossoms in pink, white and red.

After flowering they revert to cushions of blue-grey, huddled against the drying winds.

The more you probe this rocky world, the more obscure and captivating is the flora. In late spring, plants are transformed into bloom. Take Delosperma nubigenum, a creature with low, tiny leaves and now topped with bright yellow daisies.

Most of these plants are small. Indeed, a big plant would look unnatural in a rock garden setting; that's why rock garden fans stick in slow-growing dwarf conifers as a foil to the perennial flowers and diminutive ground covers such as Elfin thyme and various stonecrops.

The beauty of these otherworldly gardens is that you can do it on a tiny scale, in home-made troughs or around your entire property.

Small-scale scopes

Holly Downen, a seasonal gardener at Green Spring Gardens near Annandale, Virginia, recently made two troughs to replace old ones that were crumbling.

Essentially, you take a form of some kind; she uses foam sheeting nailed together, but a cheap plastic basin would work.

She then takes Portland cement, peat moss and perlite and mixes them dry.

Then she adds water, mixes them again and adds nylon fibres to reinforce the mix.

The concoction is poured into the mould, where the sides are formed by hand and allowed to set.

The trough is wrapped in plastic to cure slowly over three weeks and then left for at least two more weeks for most of the lime to leach out, for the sake of the plants.

A garden at workplace

Downen puts a base of gravel in the troughs, which must have drainage holes, and then builds a growing mix that consists mostly of grit, sand, potting mix and more perlite.

Young plants are watered to get established, but then thrive on neglect. She plants the troughs with dwarf conifers, stonecrops, sempervivums, thyme species and scutellarias, among others.

Michael Bordelon is living proof that you can turn your yard into a trough garden, even if his gravel garden is not where he lives, but where he works.

A plant collections manager at the Smithsonian Institution's botany greenhouse in Suitland, Maryland, he was fed-up with the landscape crews kicking up stones and breaking the windows when they mowed the grass around the greenhouse.

He fixed the problem by removing the turf, creating berms of compost and smothering two sides of the greenhouse with more than 40 tonnes of river bank gravel.

No recurring costs

Here, an orange-tan aggregate is his mulch, and while the initial installation was a big job, he no longer has to worry about the recurring cost and labour of spreading organic mulch or of watering.

Part of the 3,000 square feet garden incorporates a gully, dry when sunny but a fast-moving stream when it rains.

I love the way the pinks have multiplied and produced new seedlings.

There are stands of a violet-purple variety of the prairie phlox that is as fragrant as it is vibrant. Who knew that such an unyielding environment could present so many beautiful and interesting plants?