Fielding Questions: Identifying a weed, wintering geraniums and cracking tomatoes
Q: Can you tell me what type of weed this is and how I can kill it? Roundup seems to take multiple doses without much effect. — Tyler Kummeth, Fargo.
A: The photo shows a fascinating plant called horsetail, whose botanical genus is Equisetum. The plant grows as all stems with no leaves. Horsetails are prehistoric plants considered to be living fossils. This perennial plant reproduces by spores, instead of seeds, which is somewhat unusual for modern green plants. It also spreads by underground rhizomes and roots.
With the stem’s waxy coating, and without leaves to absorb chemicals, herbicides like Roundup’s glyphosate have limited, if any, effect. Digging or cultivation is sometimes the preferred control, if the patch is manageable. Continued rototilling or other cultivation to keep the area free of any regrowth for several years can deplete the horsetail's survival reserves.
You might also try an herbicide with the active ingredient triclopyr, applied to any actively growing horsetail plants, applied now in September and again in spring as plants regrow. Persistent weeds often require several years of diligence to wear down their ability to resurface.
Q: I read with interest your winter plans for geraniums, and I’d like to share my geranium story. I was told of this process by an old timer, Betty Trana, of Granville, N.D., now long deceased, and who always had a lovely garden. Fifteen years later, I decided to give it a whirl. — Mary Liz Davis, Velva, N.D.
A: I always enjoy hearing of success stories.
Mary continues, “Last fall, before a hard freeze, I pulled up my geranium plants, shook the dirt off, clipped the green growth to about 3-5 inches, and tossed them unceremoniously into a big empty planter that I stored in our now-retired basement coal bin where it was dark and cool. I almost forgot about them.
"In mid-April I potted the plants into 4-inch peat pots, and began watering. I made the mistake of not starting them in late February or early March, as I should have. I put the pots in front of our sliding glass door, which receives brilliant sunlight. Of the six roots, five became beautiful Calliope geraniums, with only one rotting. At $5.99 a plant, it whittled a bit off the spring nursery bill.
“I had some fretful moments in mid-June (remember I was late starting them) wondering if they would bloom, as I was concerned about the hybrid factor! When I saw the first bud, I was elated. They not only bloomed, they were prolific. The window boxes are overflowing with deep red geraniums. In a few weeks, you know what I’ll be doing once again.”
Thanks for the great story, and describing one time-honored method of wintering geraniums. A note about hybrid geraniums: wintering the original plant or starting cuttings preserves the original variety. Growing offspring from seed collected is the only time that variance would normally occur.
Q: What’s causing all the cracking on my tomatoes this year? — John W., Fargo.
A: You’re not alone. Tomatoes all across the region have been troubled by cracking this growing season.
Cracking and splitting happen most often when rapid changes in soil moisture cause fruits to expand quicker than the tomato skin can grow. Heavy rainfall, especially after slightly drier conditions, is the common culprit. Mulching can help reduce moisture fluctuation.
Sometimes the cracks are vertical, extending downward from the stem, and are called radial cracks. Other splits occur in a circular pattern around the tomato top, and are called concentric cracks. Some tomato cultivars are more resistant to cracking, which is a characteristic usually emphasized on the tag or plant description. Resistant, although not immune, cultivars include Big Beef, Big Boy, Big Girl, Celebrity, Mountain Fresh, Mountain Pride, Super Fantastic and Park’s Whopper.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at email@example.com or call 701-241-5707. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.