“Shrubby tree” is natural form for serviceberry

Listen to Walter Reeves Saturday mornings on News 95.5 FM and AM750 WSB. Visit his website, www.walterreeves.com, follow him on Twitter @walterreeves or join his Facebook Fan Page at bit.ly/georgiagardener for more garden tips.

Q: My serviceberry tree has a single trunk and is 12 feet tall but it wants to be shrubby. Every couple of weeks I cut off shoots that come from the base of the trunk. What is the best way to keep it a tree? Claudia Day, email

A: There are several species of serviceberry. Amelanchier laevis, A. alnifolia, and A. canadensis are the most common. They differ a bit in form but most species and cultivars could be described as shrubby trees. It's simply their nature. If that's the form yours wants to assume, you'll just have to get used to occasional pruning. Enjoy the fruit each spring!

Q: I heard you say on radio that it is not necessary to apply a winterizer to bermuda lawns. Why not? Marlee Fischer, email

A: Mostly because you will be wasting your money except in limited cases. Bermudagrass starts slowing its growth rate in mid-September. It begins storing nutrients in its root system, to use at next spring's green-up. If you apply fertilizer now, you'll force the grass to take nutrients out of its roots to grow new green shoots. This sends the grass into winter with less reserves than it needs to withstand cold damage.

What’s needed is a fertilizer containing low amounts of nitrogen (the first number on the bag) but higher amounts of phosphorus and potassium (the other two numbers). A 5-10-15 would be great but it’s almost impossible to find at garden centers. I commonly see winterizer fertilizers with ratios of 30-0-10, way too much nitrogen in my opinion. My recommendation is to stop fertilizing bermuda and zoysia lawns in early September. I have references to back up my point at bit.ly/winterizer.

Q: I supervise building dozens of houses each fall and winter. We are required to have almost total coverage by lawn grass prior to receiving our Certificate of Occupancy. We typically sod the front yards and put down a mixture of annual rye and fescue for the rear yards. Is it advisable to mix fescue and rye? Jim Blackstone, Habitat for Humanity

A: Turf expert Clint Waltz says when soil temperatures are above 55 degrees and conducive for germination, there is no need to mix fescue with ryegrass. In December, January, and early February, when soil temperatures are much cooler, it might be reasonable to mix the seeds. The ryegrass would germinate and establish quicker than fescue, serving as a nurse grass. If they are mixed, don't exceed 40 percent ryegrass. Two pounds of ryegrass plus three pounds of fescue equals the recommended five pounds of seed per 1,000 square feet.

Q: What are your thoughts on placing 3-inch-diameter river rocks around my trees instead of mulch. Rose in Suwanee

A: I'm an agnostic when it comes to landscape decoration. My wonderful neighbors have forgiven my six-foot high lighted angel hovering high in my pine trees, so I have little ground to stand on when asked if something is appropriate. Despite the nice appearance of the rocks, I foresee eventual problems with weeds growing between them. Also, the rocks do not decompose and feed the soil beneath like organic mulch would.