MAY
2011

 

 

 

By
B. Rosie Lerner
 
Purdue
Extension
Consumer Horticulturist

 

 

 

 

 

05-05-11

Question and Answer


Q. We've planted phlox along our sidewalk a few years ago, but have a problem with grass growing among it at various places. Where did we go wrong planting it and what might be a solution?

A. You didn't go wrong; it is just the nature of the beast. The definition of a weed is any plant growing where it is not wanted. Turf grass can be very aggressive when it invades flower beds. If the grass is only in a few spots, you can try digging it out or smothering with cardboard, carpet remnants, or plastic mulch. However you don't want to leave those items in place too long or it might injure the phlox roots as well. Another option would be to use a selective grass control herbicide such as fluazifop, sethoxydim or clethodim, sold under a variety of brand names at garden retailers. These products selectively kill emerged grass plants without harming the phlox. These herbicides will be most effective on young, actively growing grass plants that are not under drought stress. As with all pesticides, please read and follow all label directions before applying.

Q. This is the time of the year I start anticipating delicious tomatoes. I cannot remember the last time I got a good store-bought tomato. For this reason, I have been attempting to raise my own for the last few years. Regardless of the type of plant I use, I keep getting deep groves at the top of the tomato, radiating from the stem. My garden soil mixture is a combination black topsoil and sand. Any ideas on my problem would be greatly appreciated.


photo credit/ David Rhodes, Purdue Horticulture

A. Cracking of the tomato skin is a common problem in home garden tomatoes and is thought to be due to rapid uptake of water. Cracking occurs more frequently during hot (above 90 degrees F), rainy periods, especially when preceded by a long dry period. Fruits exposed to the sun are most susceptible. Radial cracking as you've described is most common, but concentric cracks also occur on some cultivars. There's not much that can be done once the cracks have formed, and, of course, we can't control the weather. But watering regularly as needed and mulching the plants with an organic material can help even out the moisture supply by reducing evaporative loss of water from the soil during hot dry weather. Look for crack-resistant cultivars when shopping for your seeds.

Q. I have a severe problem with moles in my yard. They are destroying it. They have tunnels everywhere and then push up huge mounds of soil that look like an eruption. Of course, it's hard on the lawn mower trying to go through these obstacles. I have tried the poisoned peanuts and other products to put in their holes with no luck. I try to catch them when they are digging but this hasn't been too fruitful, either. My husband suggested I kill the grubs with pesticide, but we have a pond in the back yard. I would hate the run-off from this in my water since we swim in the water. Is there anything out there eco-friendly? What else could I do?

A. You are in good company; many of our rural and suburban readers share your pain! Purdue Extension has several articles of interest regarding mole "control" and I do use that term loosely. Perhaps abatement might be a more feasible philosophy, as it is unlikely that you will permanently control moles. They'll be back!

While moles will eat grubs, their primary food source is earthworms, so killing grubs with insecticide is NOT going to effectively reduce the mole population. The two most effective means for the short-term abatement are trapping and selective poison baits appropriately targeted to moles. You'll find information on both of these strategies at
www.ppdl.purdue.edu/PPDL/hot08/4-21.html and extension.entm.purdue.edu/publications/ADM-10.pdf.

Q. I have been raising blackberries for years. This year, I have a problem that I have never had before. About one half of my new growth died. It is evident that some kind of insect has laid an egg in the stalk because it is swollen twice its size and about 1-inch long. I would like to know what kind of insect it is and what and when to spray for them. -- Paul Kaufer, New Albany, Ind.

A. There are several insect borers that damage blackberry canes; the rednecked cane borer and the raspberry cane borer could both be at work here, but the swelling you describe is more likely to occur from the rednecked cane borer. Both pests overwinter as larvae deep in the canes and hatch as adults in early to mid summer. Those adults lay eggs and thus another cycle of plant damage begins. Once the larvae tunnel in the canes, the damage is pretty much already done. So the best strategy is to prevent future generations of borers. Small plantings can be managed with well-timed pruning of affected canes before the adults emerge. Since you should thin out the canes that are allowed to remain anyways, inspect the plants and remove any affected canes first. There are insecticides labeled for borers in brambles, but pruning is more effective. The "Midwest Home Fruit Production Guide," http://ohioline.osu.edu/b940/ available through Ohio State Extension has excellent information on this and many other pests of home fruit plantings.

 

Writer: B. Rosie Lerner
Editor: Olivia Maddox,