University of Georgia horticulture greenhouse supervisor Lamont
Sudduth says each
crevice between the boulders provides a unique amount of heat,
drainage and shade, or microclimate.

Sudduth designed the rock garden at the University of Georgia’s
Research and Education Garden. The garden is on the Griffin,
Ga., campus of the UGA College of Agricultural and Environmental
Sciences.

“With rock gardens, you’re replicating the plants’ origin to the
best of your ability,” Sudduth said. “You can localize the kinds
of soil you use. You can put plants that need organically rich,
well-drained soil next to not-as-sensitive plants that are just
fine with a local clay soil.”

You can put a sun-loving plant next to one that will wither
under too much heat, too, if you build it a shade-heavy
crevice.

Sudduth said rock gardens give experienced gardeners the chance
to work out their green thumbs.

“They’re are horticulturally challenging,” he said. “But they’re
visually appealing. And they give gardeners the chance to try
new combinations of plants. It gives them a place to indulge in
their plant passions.”

If a rock garden sounds like your next project, here are some
basic steps to get you started.

Ideally, you want your garden to look like a rock formation
being exposed by an eroding hillside. So look for a nice slope.
Gardening on a slope ensures proper drainage, too. The site
should also be clear of overhanging trees.

If all you have is flat land, you can create your own mounds
with rocks or with soil covered over with rocks.

Sadduth says there’s a good rule of thumb when selecting rocks
for your garden. “If it only takes one person to carry it, you
don’t want it,” he said.

Try to get local rock of the same color and type, too. This
makes your outcrop look like it came out of the ground instead
of out of the local home center.

Before you start arranging your boulders, take a look at some
local rock formations to get some ideas. “You don’t just want to
make a pile of rocks,” Sudduth said. “That’s what we call a
dog-grave garden.”

Bury your rocks a few inches below ground level to aid in the
illusion that they’ve been exposed by eroding soil.

You could pick your plants and then create microclimates
specifically for them. Or you could place your rocks and then
pick plants that match the microclimates you’ve created.

For a listing of plants commonly used in rock gardens, check out
the Georgia R&E Garden’s Web site
(www.griffin.peachnet.edu/garden/
rockgrdnlist.html).

The last step to creating your rock garden is to cover all the
exposed soil with pebbles. This topdressing helps conserve
water.
And it helps the planted area blend in with its rocky
surroundings.