Once it starts, hawthorn leaf spot is hard to control. WALTER REEVES

Hawthorn leaf spot is hard to control

Q: I have Indian hawthorn shrubs that have gotten scraggly and the leaves that are left have black spots on them. Any suggestions on what I should replace them with? Joan Bonnett, Centerville

A: Why not different hawthorns? Indian hawthorn has beautiful white flowers in spring. Some varieties also have attractive blue fruit but older varieties have little resistance to leaf spot. The disease is tough to control once a plant is infected. These varieties don’t seem to get leaf spot as badly as others: ‘Calisto’, ‘Majestic Beauty, ‘Yedda’, ‘Spring Sonata’, ‘Eleanor Tabor’, ‘Indian Princess’, ‘Betsy’, ‘Olivia’, and ‘Snow White’. Be sure to purchase plants showing no leaf spot symptoms.

Q: This past fall I noticed little snails crawling on my outdoor furniture. I think they are coming from the decaying mulch we put down last year. How do I get rid of the snails? Name withheld by request, Cobb County

A: Your snail population should decrease pretty quickly this winter. They only eat living plant material and there’s not much in your courtyard for them to consume. A saucer of beer can be placed next to your groundcover plants to trap any that remain.

Q: How do I sample for root-knot nematodes before planting a fig? Dick Kretzmer, Marietta

A: Nematodes are microscopic worms in the soil. Some species, like root knot nematode, harm plants by parasitizing roots. It is difficult to sample for nematodes before you plant. They will not be present in great numbers until a susceptible plant has grown in the spot for a few years. Even then, the number of nematodes around the plant varies greatly from place to place, depending on soil moisture and temperature. Unless you have definitely seen nematode damage on plants where you plan to put your fig, I doubt they are present. Call your local University of Georgia extension office (800-ASKUGA1) for instructions on how to submit a soil sample if you decide to proceed with testing.

Q: I bought Scotch broom bushes two years ago. They had beautiful yellow blooms then but only one is green now; the other is brown. Is it dead? Shelley Medders, email

A: Call the plant undertaker. Scotch broom is vigorously invasive in other parts of the country but I have never seen it prosper here. Like you, I’ve planted it but haven’t had much success with Scotch broom. Mine died after just a couple of years.

Q: What do you do with the stump once you remove a pine tree that has been killed by pine beetles? Lance Franklin, email

A: Pine beetle attacks are not typically so low on a tree trunk as to infest the stump. I wouldn’t worry too much about it. If the tree has been cut close to the ground, you could cover the stump with soil to allay your worries.

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, on Pinterest, or join his Facebook Fan Page at bit.ly/georgiagardener for more garden tips.