Growing a Hillside City Garden
By creating ground cover and flat terraces, Barbara Hobens Feldt shows that growing a beautiful hillside garden in the middle of a city is easy. Learn some tips and tricks to keep these plants happy.
E-mail This Page to Your Friendsx
A link to %this page% was e-mailed
There are plenty of ups and downs to gardening — especially if you live on a hillside. If that garden is located in the middle of Manhattan, there's even more to cherish. Author Barbara Hobens Feldt explains how she made this uphill battle seem like it's all downhill.
Challenges common to all gardening include getting good soil, adequate sunshine and water. The critical factor with hillside gardening is stabilizing the soil, so it's good to start with a plan.
"Like in other forms of gardening, no matter where you are, grouping your plants and choosing the ones that work together is vital," she says. "Not just in the beauty of it but for the practical purpose of it. You don't want to waste water or have the soil erode, but you do want to keep the nutrients where they are."
Plant selection and diversity are key. Much like the netting you see along freeways that hold rocks in place, deep-rooted plants do a great job of holding themselves upright and keeping the hillside stable. But even shallow roots can work wonders at inhibiting topsoil from eroding. Hobens Feldt suggests using a little of both. Groundcovers, like shrubs and flowering perennials, are especially wonderful because they'll grow to capture the moisture and stop erosion.
Besides being smart about what they plant, hillside gardeners are also smart about how they plant. "The best way to make your hillside work for you is to terrace, and the way you do that is to literally trench and add," says Hobens Feldt.
To form her terrace, Hobens Feldt uses heavy granite blocks. She digs into the soil at an almost 90-degree angle and positions the block in nice and tight, creating two level planes as she spreads the dirt. With plants now on a flat surface, watering becomes more efficient. Instead of flowing downward and forming a gully, rain water and irrigation has a chance to percolate through the soil and hydrate the plants.
"The most important issue with hillside gardening is to be able to keep the moisture where you want it—at the plants." With a cherry tree she planted, the wood chip mulch was washed away due to runoff, prompting her to create a "moat" around the plant.
Moats around trees should be as big around as the tree's canopy and reinforced with the displaced soil. They'll be shallower at the top than on their downhill lips because this is where most of the erosion happens. Test out your moat by filling the ditch with water. Reinforce weak spots and catch potential leaks with this test run.
Next, a thick layer of mulch — only on the lower (downhill) side of the plant — strengthens the moat. The area closest to the tree doesn't need to be mulched if it already has a natural surrounding leaf cover.
To finish your hillside garden, don't be afraid to use design elements. The lopsided landscape may prove a challenge, but as long as benches are stable and paths are level, there's no danger of things toppling over.
Another way to stabilize your garden is to incorporate rocks. Boulders can inhibit erosion because of their size and also add interest to the space. Little rocks shouldn't be underestimated; they can wall off dirt just as well.
If you have an extreme slope, you may have to take extreme measures to garden on the edge. It may involve major earth-moving or adding a retaining wall.
Whether you plant annuals or perennials on the hillside, make sure you use plants that are well suited for the environment. Having durable plants to begin with considerably increases your chances of success.
Simple improvements can make a crowded patio look larger, cleaner and more modern.