From:
http://www.herald-dispatch.com/2003/July/03/LFlist1.htm

Thursday, July 3, 2003
Plant shorter plants around house to help keep it cool

DEAR JIM: I am trying to decide between using decorative gravel or ground
cover plants near my house. I know the gravel gets hot in the sun, but the
plants will make the air more humid. Which is the best to use? -- JOE R.

DEAR JOE: Gravel or stone that is exposed to the hot afternoon sun can
become a heat island. This hot area can reradiate the heat up through your
walls and into your windows. Also, since gravel has a high thermal mass
capacity and is heavy, it stays hot long after the sun goes down at night.

Decorative gravel can be an attractive accent, but limit its use to areas
that receive shade from deciduous trees.

Low-growing ground cover in sunny locations adjacent to the house is a good
choice for most climates. This is particularly true if you air-condition
your home. If your windows and doors are properly weatherstripped, the
higher humidity air above the plants will not get inside your home.

Plants, even small ones close to the ground, act as mini-air conditioners.
The air temperature near them is often at least 10 degrees cooler than the
ambient air temperature. This lower air temperature near your house means
that less heat energy will transfer indoors through walls and windows.

If you don't air-condition and rely on natural ventilation through windows,
plant very low ground cover that is drought resistant. This is especially
true for humid climates. Drought-resistance plants will give off less
humidity and they will not absorb and hold the sun's heat as gravel does.

When selecting your plants, consider the plants' height, spread, texture,
foliage and whether they are deciduous or evergreen. Try to select ones that
have similar watering requirements.

Write for (instantly download -- www.dulley.com) Update Bulletin No. 793 --
list of 55 ground cover plants showing foliage descriptions, acceptable
hardiness zones and U.S. map, heights, spacing, preferred soil, and a mulch
selector guide.

Please include $3 and a business-size self-addressed, stamped envelope.

James Dulley's Sensible Home column appears in newspapers across the
country. Write to him in care of The Herald-Dispatch, 6906 Royalgreen Drive,
Cincinnati, OH 45244.