How to plant an alpine garden and miniature succulents

If you can make room for a miniature rock garden—one of the tiny plants that grow within the confines of a faux stone tub—the promise of a huge reward awaits.

Within the walls of the trough, you can simulate the conditions required to grow select species that will sink into most in-ground beds: some colorful and sculptural succulents, as well as alpine trees from the harsh environment exposed above the tree line.

Then there is Lori Sheeps Oliver Nurseriesin Fairfield, Connecticut, a worker calls his “Little Theatre”.

You see trough gardens attract the public.

Mrs. Chips He tells the story of a designer and client she has known for years who, despite his extensive experience in the gardening industry, would never plant a small tub. He bought a cylindrical one made of hypertufa—a mixture of cement and peat that mimics the look of stone—and a miniature creeping thyme to put in it. A humble beginning for sure.

On a return visit to the nursery, where Mrs. Chips had worked for 27 years, he recounted his first appearance. He had placed the boat in his yard, where there were larger containers of spinning plants, but it was the trough that got the most attention from visitors.

He said, “Everyone who entered would say, ‘What is that?'” “Because she appeared in a small tub.”

At Oliver’s Nurseries, alpine plants that prefer tub-like conditions are a small part of the broad offering, as they have been since the nursery opened nearly 60 years ago. These diminutive stars can be seen scurrying out of pockets in a 35-foot rock wall, in the gravel bed above it, and of course in other ponds and ponds.

Selling young plants may not be the mainstay of the business, Ms. Chips joked, “but it’s one cow”. The nursery, in a rustic setting that looks like an old garden, attracts a clientele that includes gardeners and junior experts who come for the carefully curated selection and depth of expertise of the staff.

Not surprisingly, rock garden plants are an indelible component of Oliver’s DNA: Early on, the nursery’s founder, John Oliver, assigned Eleanor Spingarn, who is credited with starting the Connecticut chapter of North American Rock Garden Association. The rock wall was built and planted by Mrs Spingarn in the 1970s.

Covered with perennials and succulents with distinctive geometries, the showy wall was restored and replanted this year, and is one of the various projects tackled by the nursery’s new owners, Jed Duguid and Will Hebbs, who bought the retail and landscaping business last year. Both were long-time employees of the previous owner, Mr. Duguid said, and aim to carry on the nursery’s traditions.

“We’re trying to be a plant nursery,” he said. “And to get some unique things throughout that are going to be hard to find elsewhere.”

Including Mrs. Chips, and her infectious love of the Alps.

Ms. Chips has helped keep alpine and rockeries traditions strong in the nursery, and in 2018, her passion resulted in the book, “Hypertufa Containers: Creating and Growing an Alpine Basin Garden.” He explains in detail every aspect of the process, from how to mix Portland cement, peat moss and fiber mesh (a multi-fiber reinforcing material) to molding the ponds.

Inspired by ancient stone tubs and farmhouse water basins of another era, these containers have much thicker walls than those of a basic flower pot. It is also weather resistant.

“It’s not weatherproof,” Ms. Chips stressed.

This is especially true if the ponds are left to overwinter in a highly exposed spot, she added, “like on top of a deck, where cold winds blow beneath them all winter,” adding to the freezing and thawing stresses.

Even for those who buy a pre-made container, some of the advice in the book—the same advice you give to clients asking for help with container design or care—stand out as essential to success.

First: It may be tempting to convert a shallow concrete birdbath into a sink, but think again. While plants with an alpine heritage may appear pressed above the ground, like pillows or tight mats, their roots need room to run.

In the mountains, Ms. Chips said, they cling to “pockets in shifting rocks, where pebbles and boulders scarcely form the idea of ​​soil.” “The roots of the plants have evolved into a wide, deep yard, where they find coolness and drainage.”

A sink at least six inches deep is recommended; The one with 10 best. Place a piece of window screen at the bottom to prevent blockage of the drain holes.

The planting medium Miss Chips uses starts with a commercial peat-based potting soil, such as Pro-Mix’s HP or BX formulations. If the brand of potting soil available does not contain perlite, she dilutes it with some, so that the perlite makes up to a quarter of the mixture. Next, you add the 1/4-inch diameter pea gravel (also about a quarter of the total volume of the potting medium you’re mixing in). Gravel has multiple benefits, resulting in less plant losses, especially during the winter, because the plants stay put better.

“The freeze and thaw are relieved, because there are some stones in there,” Mrs. Chips said. “I think the roots are entwined around the little pebbles, like an anchor.”

A layer of gravel is placed on top after planting – and not just for cosmetic purposes. “It also helps keep the roots cool,” she said, “and weighs down the plants.”

When you plant a wall garden, she said, more gravel goes into the mix—up to three-quarters of the gravel for a quarter of a purchase of weeds and pathogen-free soil.

Customers with existing walls often ask nursery staff about planting them. Staff tip: Freestanding stone walls make better homes for chipmunks than plants. However, a non-destructive retaining wall is fair game.

Planting while building the wall gives the best results. But here’s a trick you can try with an existing wall: Lift a few stones (preferably ones that have settled a little lower than the rest) to make planting pockets for cascading plants. Line the exposed spot with some of this soil mix. Then place the plants inside, gently separating their roots and crowns flush with the face of the wall. Cover with more mixture, then replace the capstone and water the area gently.

Spring blooms in this wall at Oliver Nurseries include the purple-flowered Dalmatian bellflower (Campanula portenschlagiana) and the golden, chain-like flowers of Chiastophyllum versitifolium. Like other perennials that often find their way into ponds—rosy (Dianthus), for example, and thrift (Armeria)—they attract attention.

But remember: these blooms don’t last long.

“The Alps won’t bloom all season,” said Mrs. Chips. “So you have to fall in love with each plant for its texture and habit.”

Hardness is another consideration. Any plant grown outdoors year-round in a container—in a trough or otherwise—should have at least an area hardier than the local one, because its roots will not have the insulation of the earth. And even if some species are technically hardy, they may be more susceptible to winter moisture. This includes most plants with silver leaves or fuzzy tops.

When clients ask for design help, Ms. Chips offers this essential piece of advice: “I would say, ‘Include a hardy shrub, a couple of other flowering plants, a drool or a mound. “


Yes, you heard that right: It’s about the smallest of thyme, such as the Elfin variety, or madwort (Alyssum wulfenianum), and some ground cover sedum plants. It softens the rim of the tub and spills, as if it were liquid on solid. With low-growing sedums, look for ones that don’t bloom early — or as often.

As for the ‘hill’, one possibility is a rosette-shaped succulent plant, such as Sempervivum, Rosularia or Jovibarba. But when you’re shopping for those, steer clear of a vase full of a single rose. “Don’t buy one pot with one giant artichoke in it,” she said, “I tell customers—you’ll lose everything.”

These succulent plants are monoecious, which means they die after flowering. Instead, purchase a pot with different sizes of a particular succulent plant in it, and encourage them to colonize your tank by periodically removing some babies from the mother plant and placing them nearby.

Conifers are another frequently used component of ponds and other rock gardens, including gravel gardens and slit gardens. These diminutive trees add structure year-round.

And Ms. Chips recommends varieties that are not just dwarf (slow growing), but true miniatures (meaning they never get old), such as the Jan Dilly white spruce (Picea glauca). Other favorites: Distinctive mugo pine (Pinus mugo slowmound) and Chinese juniper (Juniperus chinensis Shimpaku).

Miniature irises are another possibility. Mrs. Chips said it does better in tubs than on land. But to its eye, it does not do well in a tank containing a conifer, unless it is a large container. Otherwise, the two will fight for the honor of being the straight architectural element of the show.

“Having both would throw off the aesthetic,” she said.

That visual intent reminded us: “It’s about being in Lilliputian land—about making your pool believable, a landscape in miniature.”

Margaret Roach is the creator of the website and podcast way to gardenAnd a book of the same name.

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