Grumpy Answers Your Top May Gardening Questions
1. What is the correct way to spread mulch around a tree? —Jorita
Grumpy Says: Don't build a "mulch volcano." This consists of a conical mound of bark mulch 6 to 8 inches tall that wraps around the trunk. It's a common mistake. Mulch should never touch the trunk and never get that deep, or a multitude of problems could result. Instead, spread a 2- to 3-inch-thick layer of whatever kind of mulch you prefer around the base of your tree, starting 1 inch from the trunk and extending out 18 to 24 inches. Don't apply new mulch over last year's mulch if the resulting layer will be more than 3 inches deep. Let the old mulch decompose first.
2. How can I get rid of fire ant mounds in a vegetable garden? —Judith
Grumpy Says: I wish I could come up with a natural solution that's long-lasting and effective, but I don't know any that will do the trick. My advice is to sprinkle fire ant bait on the mounds according to label directions. This will kill the ants but won't be absorbed by your vegetable plants.
3. When daffodils are done blooming, can you cut off their tops? —Jerry
Grumpy Says: If by "tops" you mean the bloom stalks, absolutely. But don't cut off the leaves of daffodils or any other spring bulbs until they turn yellow. They need these leaves to make food for the bulbs below. A premature haircut means no flowers next year.
4. We have a euonymus hedge that gets heavily infested with scale every year. How can we get rid of the scale without getting rid of the hedge? —Carole
Grumpy Says: Grumpy hates euonymus for this very reason, so he wouldn't shed any tears if you tore it all out and replaced it with less troublesome evergreens, such as loropetalum, holly, glossy abelia, or yew. But if you want to give the euonymus one last chance, you can either spray it with horticultural oil (making sure to wet all stem and leaf surfaces) or treat it with a systemic insecticide like Bayer Advanced 12 Month Tree & Shrub Insect Control.
5. The stems of my blueberry bushes look like leafless sticks loaded with berries. What happened? —Susan
Grumpy Says: Young blueberry bushes tend to overbear, setting so many berries that the fruit is inferior. Use pruners to shorten the flowering stems in spring. This means fewer flowers and bigger, tastier berries in the future.
6. My "Forest Pansy" redbud doesn't produce maroon leaves anymore and has only a few flowers. The leaves are plentiful but green. The tree gets mostly indirect sun. Any ideas? —Melissa
Grumpy Says: The reason for the green leaf color and lack of flowers is the same—not enough sun. For deep purple leaves and lots of blooms, you'll need to move your tree to a sunny spot this fall.
7. Three years ago, I planted "German Queen" tomatoes, and they produced a ton. The last two years, they've started off strong but then wilted and died. Why? —Debra
Grumpy Says: Unfortunately, many heirlooms, like "German Queen," lack the disease resistance of newer hybrids. Don't plant heirlooms in the same spot twice, because wilt disease persists in the soil. You can also plant wilt-resistant tomatoes.
8. Squirrels keep gobbling up all my birdseed. Will adding chili powder to the seed deter them without harming the birds? —Sharon
Grumpy Says: Being (incredibly annoying) mammals, squirrels react to eating hot peppers like people do: Their tongues ignite! Once this happens, they'll beg for milk and never touch your seed again. Pepper is harmless to birds, though—they don't even sense it. You can add cayenne pepper to birdseed yourself (1 tablespoon per 10 pounds of seed) or buy something like Cole's Hot Meats, which are sunflower meats infused with habañero oil. Let the flames begin!
9. My roses have lots of flowerbuds, but they're dry and not opening up. What do I need to do? —Ginger
Grumpy Says: This is a snap, Ginger. It sounds like your roses are infested with tiny insects called thrips that suck the juice from the buds. Stick a white sheet of paper under a bud, and gently tap the bud. If you see brownish yellow specks on the paper, these are thrips. To control them, apply some Monterey Garden Insect Spray according to label directions. It contains spinosad, which is a natural insecticide.
10. I've been told a leak in my basement is caused by the landscaping in front of the house. Do you have any idea what that means? —Tom
Grumpy Says: My guess is that your yard slopes toward the house, so rainwater runs toward the foundation. Your downspouts also may be emptying against the house. What you need to do is pile some additional soil against the foundation and regrade so water runs away. If your downspouts don't direct water away from your home, add lengths of flexible corrugated plastic pipe to the ends so they will. Or put your basement on the Bassmasters tour.
11. We have a mess of wild blackberries growing in our yard. I've decided against cutting them down, so I can use the fruit to make some yummy jam. When should I cut them back and tame them? —Laura
Grumpy Says: Blackberry canes live two years. They just grow the first year. The second year, they flower, set fruit, and die. So after a cane fruits, cut it to the ground. New canes will sprout around it. Control them by tying them to a wire that runs 3 to 4 feet above the ground between two posts.
12. What causes the leaves of my peace lily to turn brown? —Martha
Grumpy Says: The most common reason is letting the plant dry out and wilt badly. Number two is placing the plant in hot sun or near a cold window. Number three is giving it water straight from the tap. (Allow the water to sit out overnight before using it so it reaches room temperature and the chlorine evaporates out.) Number four is a buildup of fertilizer salts in the soil from not watering thoroughly. You can wash out these salts by watering so the excess runs out the drainage hole.
13. Do you know of any way to stop our sweet gum trees from producing gum balls? —Kelly
Grumpy Says: A Kelly, this is a question that plagues everyone who has ever had a sweet gum in the yard. Sorry, but once a sweet gum starts dropping those nasty things, your only options are to learn to love 'em or cut that sucker down. One selection, called "Rotundiloba," doesn't drop gum balls and has leaves with rounded lobes rather than pointed ones.
14. Our small garden has become like Disney World for chipmunks! The critters chow down at our neighbor's bird feeders and then come to our yard for playing and mating. Their tunnels are more adventurous than any ride in Orlando! Any suggestions for getting rid of these funsters? —Fred and Elke
Grumpy Says: As with other rodents, the birth rate for chipmunks is directly tied to the food supply. (More food means more babies.) Unless you can curtail the never-ending banquet next door, you're stuck. Try convincing your neighbor to use Cole's Blazing Hot Blend birdseed, which is coated with habañero chile oil. The birds won't mind at all, but those chipmunks will be smoking!
15. My gardenia hedge isn't doing well. The leaves turned yellow and I can see through the foliage to the trunks. —Mary
Grumpy Says: Like azaleas and camellias, gardenias need acid soil with a pH lower than 6.0. When they don't get it, their roots can't absorb enough iron and their leaves turn yellow between the veins. To fix this, feed your shrubs according to label directions with an acid-forming fertilizer, such as Espoma Holly-tone 4-3-4 or Miracle-Gro Water Soluble azalea, Camellia, Rhododendron Plant Food 30-10-10.
16. Last year, I was successful in getting cucumbers to climb large cages in my raised beds. This year, the ones I planted won't climb. Do only certain types do that? —Loraine
Grumpy Says: Cucumbers, squash, and beans come in two forms: bush and climbing. Only the latter will climb, so look at the seed packet before you buy. If it says "bush" anywhere on the label, it's not the type for you. There are many more climbers than bush types. Bush types are usually better for small gardens, but climbers produce more over a longer growing season.
17. My impatiens have burnt orange spots on the leaves. What is it, and what can I do about it? —Rena
Grumpy Says: Your plants have either necrotic spot virus or botrytis blight. If you find stunted leaves near the top of the plant, it's the virus, which is spread by tiny thrips. There is no cure. Just pull up the infected plants, and throw them out with the trash. If botrytis is the culprit, spray your plants according to label directions with a fungicide called Immunox.
18. The roots of our river birch are breaking the patio, so I'm going to remove it. What should I plant in the bed left behind to go with my birdhouses and feeder? —Dot
Grumpy Says: Plant a butterfly garden. Good flowers for this include lantana, zinnia, dwarf butterfly bush, pentas, catmint, salvia, marigold, cosmos, phlox, and sedum. Don't worry about birds picking off all the butterflies. Most birds that come to a feeder eat seeds, not insects.
19. We had lovely lilacs when we lived in Illinois. We live in Virginia now, and the lilac flowers are wispy and not as showy as the ones before. Can you give me the names of some better lilacs with nice fragrances? —Kathy
Grumpy Says: Most lilacs don't like the South as much as the North or Midwest, because our winters are too short and mild for them to bloom well. However, some new kinds that need less cold to produce showy, fragrant blooms are 'Betsy Ross' (white), 'Old Glory' (bluish purple), 'Cheyenne' (lavender-pink), and 'Declaration' (reddish purple). Older ones such as 'James Macfarlane' (pink) and 'Lavender Lady' (lavender-purple) also bloom well here.
20. My spiraea was full of blooms, and then my husband sheared it into an ugly box. It was the focal point of my yard, and he took off nearly 2 feet! Can anything be done? —Liz
Grumpy Says: I suggest the two of you make an appearance on Dr. Phil to address serious gardening issues that threaten your relationship. As for the spiraea, it's a tough plant that will soon return to its former lovely shape. But just to make sure, enroll your hubby in Pruners Anonymous.