Brown ground wasp, 'no mow' grass seed and spoiling tomatoes

Ask a Master Gardener

<p>Submitted</p><p>The Great Golden Digger Wasp is a large solitary wasp, often seen feeding busily from flowers. The abdomen is orange or rusty-red in front and black at the end. The head and thorax have golden hairs. Like all solitary wasps, they are not aggressive.</p>

Submitted

The Great Golden Digger Wasp is a large solitary wasp, often seen feeding busily from flowers. The abdomen is orange or rusty-red in front and black at the end. The head and thorax have golden hairs. Like all solitary wasps, they are not aggressive.

Q: We have these large brown ground wasps that are still around. We have tried to eliminate them but to no avail. My husband said they're called the "Gardener's Friend," as they dig holes and keep the garden vibrant. The wasps aren't terribly aggressive. They will buzz me if they are in their nest. What are they and should we be concerned?

A: It is a Great Golden Digger Wasp (Sphex ichneumoneus), a solitary wasp that is not aggressive. Like many solitary wasps, it has its place in our ecosystem, usually as a predator. Your husband gets the gold star on saying to tolerate it. Thanks to Kris Simpson, collections manager at the Enns Entomology Museum at University of Missouri, for helping.

Q: I am interested in a "No Mow" grass seed for my hilly yard in mostly full sun. It is promoted by High Country Gardens and is a mix of dwarf Fine Fescue grass varieties. What are your thoughts about it?

A: I had never heard about it, which may mean it doesn't work too well in Missouri. If you look at the map the company provides for where it performs well, you will notice that Missouri is in the "transition area," which means it is of only marginal success throughout most of Missouri. If you have good quality soil, success with it would be better. Soil such as loess or silty loam would be preferable. A heavy clay soil would not be a good match. If you currently have tall turf type fescue growing, it will have to be killed before you establish it. This would need careful consideration to prevent erosion on a hilly site.

A low care, full sun turf grass recommended for Missouri is Buffalograss. It takes a bit of work to establish and control weeds in the first two to three years, so it is often preferred with smaller areas. See extension2.missouri.edu/g6730.

Q: My tomatoes seem to spoil quickly. They get these brown soft spots on them that sometimes get a black center. What is it and is there anything I do?

A: This is a fungal disease that worsens with fall conditions - cooler weather with longer nights that usually leads to more dew. Its name is Anthracnose and may be referred to as "ripe rot," which describes its tendency to develop on ripe fruit. It is slowed or partly controlled with a broad-spectrum fungicide, but most home gardeners have lost their zeal for spending energy on the tomato patch by now. The best thing to do is pick the tomatoes earlier, like (for red types) when turning pink/light orange, then bring indoors to finish their ripening. If the spots develop indoors, trim out the spot and cook or consume quickly. Putting in the refrigerator will slow the spot development.

Q: I have heard about BT for an insecticide. Is there a common name for this? What do I look for in the pesticide aisle as a name? My kale has been destroyed several times this summer with worms. They strip the plants of all leaves. I notice white butterflies flying around. Is there something I should be doing about them? Are they laying the eggs that turn into grubs?

A: Insecticides referred to as "BT" use the bacterium of "Bacillus thuringiensis" to kill certain insect pests. It is most widely known for controlling caterpillars, being one of the most environmentally safe products. It is often sold under the trade names of Dipel or Thuricide. Weekly applications will give outstanding control of the three typical caterpillars affecting cabbage and similar leafy greens. Applying every 14 days is often enough for typical home gardens, but shorten the span to weekly for a severe problem. The white butterfly you mentioned is almost assuredly the "European cabbage butterfly," which lays eggs that hatch into caterpillars. If those caterpillars get large enough, they will overwinter as pupae in the soil. Controlling with a "BT" product on the vegetables they are attacking is the best option. Turning over the garden soil in mid- to late-November will bury some of the pupae and kill them. The flowers of any vegetable of that plant family (Brassicaceae) attract the butterflies, so cut back the flowers when they occur or remove the plants.