Q: I have a large galvanized cattle water trough that I want to use as a planter. What kind of drainage holes I should drill in the bottom? Steve Conway, Decatur

A: Tony Johnson is manager of the UGA Research and Education Garden in Griffin. He turned a cattle trough into a planter that was very attractive. Start by punching 1" holes in the bottom and putting a layer of capped soft drink bottles a foot thick into the trough. Cover the bottles with landscape fabric, to keep soil from settling among them, and fill the trough with good quality potting soil. To ensure good soil drainage, mix a quart of perlite with each cubic foot of soil. Elevate the trough a couple of inches on pressure-treated wood. If you want to paint it, Tony recommends a high quality primer and enamel paint but you'll likely need to repaint it every few years.

Q: Can I grow porterweed in metro Atlanta? I saw some in the butterfly house at Callaway Gardens and I just fell in love with it! Bobbie Kilgore, Douglasville

A: Porterweed, Stachytarpheta jamaicensis, is an excellent butterfly attractor. The blue flowers bring hungry butterflies by the dozens. Despite this, I rarely see it in local garden centers. Unfortunately for you and the butterflies, it is a tropical plant, not winter hardy in Atlanta. Substitutes include lantana, salvia and cosmos. I have several lists of butterfly magnets at bit.ly/GAbutterfly.

Q: I am going to till my yard and sprig it with St. Augustine grass. Is it OK to overseed with fescue until the St Augustine fills in? Bob Vineyard, email

A: The two grasses will compete for a couple of years, but your process is similar to what my neighbor and I did several years ago. We bought pieces of sod and tore them into sprigs, which we planted 12 inches apart. Over the course of time, the St. Augustinegrass has choked out the fescue in our lawns. Once your St. Augustinegrass has covered most of your lawn but still has a few clumps of fescue in it, use atrazine herbicide to kill the fescue.

Q: I'm looking for someone to draw up landscape plans. We'll probably do the work ourselves, but we really need some professional help. Donna Sutton, Forsyth County

A: Strictly speaking, if you want a "plan only " service, it's illegal for someone other than a Registered Landscape Architect to draw up landscape plans for you to install. Georgia law governing landscape architects defines the practice as "consultation, investigation, planning, design, preparation of drawings and specifications….". Further, the law states "No person shall perform or offer, attempt, or agree to perform any act which would constitute the practice of landscape architecture."

An exception is given to landscape contractors, who “may not perform design services without also performing the installation of said design” and to people “whose services are offered solely as a gardener or nurseryman.” Basically, if it is “incidental” to their main business, they can prepare plans.

In effect, if a person is a garden designer, he must work with a contractor to install his designs. You can’t legally get plans from a small designer and install the plants yourself. You can, however, hire a landscape architect to do the plans and guide you on how to proceed. You can find a list of professionals at www.urbanagcouncil.com

Listen to Walter Reeves Saturday mornings on AM 750 and 95.5 FM News-Talk WSB. Visit his website, or join his Facebook Fan Page for more garden tips.