ISU Extension News

Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915

6/16/03

Contacts:
James Romer, Horticulture, (515) 294-2336, jromer@iastate.edu
Jean McGuire, Continuing Education and Communication Services, (515) 294-7033, jmcguire@iastate.edu

Yard and Garden Column for the Week Beginning June 20, 2003

Ask Dr. Grow-It-All's Hortiplantlooza Tour 2003

By James Romer
Extension Horticulture Specialist
Iowa State University

Dear Dr. Grow-It-All:

Last year, I had big hopes of growing some record-breaking pumpkins for the Pumpkin Festival in Anamosa. One day as I strode out to the patch I found, to my horror that the vines had wilted. I first suspected that little Johnny, the neighborhood hooligan, was up to no good. I found small holes in the stems near the base of the plants. I also noticed what looked to be sawdust close to the holes. Dr. Grow-It-All, did I purchase a package of bad seed or should I have a chat with Johnny?

Yearnin' in Mount Vernon

Dear Yearnin:

At least this time it looks like little Johnny is off the hook. It sounds to me that the squash vine borer has affected your plants. As you noticed, the runners or entire plant suddenly wilted due to the presence of squash vine borer larvae in stems and leaf stalks. Masses of coarse, yellow-green excrement are pushed from the holes in the base of stalks. The moths (adult stage) may be seen flying around the base of the plants during the day and are wasp-like with metallic, copper-green forewings and an orange and black abdomen.

Begin to treat the base of the plants with either malathion or rotenone in mid-June and continue at weekly intervals to control borers before they enter the stems. It's possible to remove borers by splitting the infested stems with a knife and then covering the slits with moist soil. In fall, destroy the vines immediately after harvest and cultivate the soil to destroy overwintering pupae.


Dear Dr. Grow-It-All:

A friend of mine gave me a trumpet vine five years ago as a housewarming present. She said the orange flowers attract hummingbirds. I planted the vine next to my house so that I would be sure not to miss any visiting hummingbirds. I was thrilled to see the plant take hold and start to grow. It hasn't had any problems growing, but this thing has taken over my front yard and it still has not bloomed. I have new shoots sprouting several feet from the original. It's becoming a struggle to get in and out of my home.

Hidden in Glidden

Dear Hidden:

If the front of your home looks more like a scene from the "Crocodile Hunter," I have good news for you. Trumpet vine can be pruned at any time of the year, however; you may want to think about moving your vine away from its current location. Trumpet vines have been known to damage a home's siding and break windows.

Controlling the vine may be a difficult task at this point. Trumpet vines have a suckering growth habit. Suckering plants produce new shoots from their roots. These new shoots may spring up several feet away from the original vine. Use a spade to dig out the unwanted plants. Persistence is the key as new plants will continue to emerge. If you want to kill your plant, cut the vines off at ground level and carefully paint the cut ends of the vine with Round-Up, then repeat as needed.

It usually takes about five or six years for the vine to reach mature blooming stage. Trumpet vine can be a beautiful addition to your yard if used properly. The bright orange or yellow flowers do attract hummingbirds and provide a nice seasonal screen or backdrop.


Dear Dr. Grow-It-All:
My Aunt Hilda always used to have the best displays of chrysanthemums in the fall. As a child, I can still recall seeing the masses of color with each plant more beautiful than the last. I remember her saying that she pinched her plants. Dr. Grow-It-All, does this make any sense to you? I can't see how physically pinching those, or any plants, would help them to flower. It sounds like an idea only "America's Master Gardener" would come up with. What do you think?
Puzzled in Palm Grove

Dear Puzzled:

No, unlike mixing stale beer, cat hair, and aspirin, the technique of pinching is effective. Chrysanthemums will have a more full, compact form if pinched. Simply pinch out the tip of the stems to produce a more stocky plant with more flowers. Discontinue pinching July 4th to ensure that your plants will bloom before frost. Some newer cultivars don't need to be pinched. With a little extra work, you can have plants that would make Aunt Hilda proud.

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Editors: There is no photo is available for this week's column.


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