NEWS for North Dakotans
Agriculture Communication, North Dakota
State University
7 Morrill Hall, Fargo, ND 58105-5665
March 4, 1999
Hortiscope
Ron Smith, Extension Horticulturist
North Dakota State University
Q: Enclosed is a sample of a marigold that I planted in a flower bed on the west side of our home. Every year for the past five or six years something comes and attacks the marigolds and sucks all the life out of them. Eventually the plants look like this sample. Do you have any ideas what I can spray the plants with the stop this from happening? (Garrison, N.D.)
A: There could be one of, or a combination of, diseases that are afflicting your marigolds. Two wilts, Fusarium and Verticillium, are common where the entire plant is wiped out, and gray mold, a species of Botrytis, is also know to infect marigolds.
Here is what I would suggest: First rotate your plantings. Don't plant marigolds in the same spot each year. Generally a three-year rotation is needed. Second, practice fanatical sanitation. Clean up all plant debris in the fall; roam the garden with a plastic or paper bag and discard any faded blooms, or rogue out any sickly plants on the spot. And third, protective spraying with Fore, Zineb, or Captan will help control the spread.
Q: My 20-year-old Ficus tree is losing its leaves and I am wondering what I can do to save it? (Valley City, N.D.)
A: I would suggest getting it repotted with fresh potting soil, one that has some nutrients in it. You can obtain it at any garden supply store or discount chain.
Ficus do not like to be moved. If you've had it for 20 years, try and recall the location where it did best. They prefer strong, indirect light for best growth and being kept away from drafts.
Q: I would like to plant some begonias, but I want the kind that you dig up in the fall and it has bulbs under it. Can you tell me what kind of begonias these are and when is a good time to plant them? Also, what kind of flowers do you recommend for hanging baskets? (Brooks, Minn.)
A: The begonias you're referring to are known are tuberous begonias. You are better off purchasing plants from a nursery or greenhouse this spring and planting them out in the shade when all danger of frost has passed. In the fall, you can dig them up and store them dry in a cool location. Generally, you repot in early February to initiate new growth and produce flowers by the time late spring has settled in.
For hanging baskets, you might want to try one of the "wave" petunias. I have seen a purple wave hanging basket that was cascading with flowers!
Q: I have some low-growing evergreens and I am wondering if there is some type of spray or granular herbicide that I can put on them to kill the grass that is growing around them? (Mayville, N.D.)
A: The grass you are seeing is very likely quackgrass. The herbicide Casoron 4G is labeled for quackgrass, and many other grassy and broadleaf weeds. Your evergreen is likely blue rug or some other prostrate cultivar of juniper. It is on the label, so it should be safe.
Q: Enclosed is a leaf from one of my plants. Can you tell me what kind of plant it is and why the edges are turning brown? (Doland, S.D.)
A: Your plant is a fiddle-leaf fig. The frying along the edge of the leaves is not uncommon at this time of year. It is an indication of salt accumulation and dry air. I suggest watering with either distilled or reverse osmosis water for about 6 weeks. The new growth should then be free of the fried edges.
Q: I have a Honeycrisp apple tree which is 4 years old and has never blossomed or borne fruit. The tree seems healthy, but doesn't produce fruit. We are wondering if we are having trouble with pollination or if the ash tree in the next yard is causing the problems? (Cooperstown, N.D.)
A: My best suggestion, right now, is patience. You have done everything rightplanting, location, other trees, etc. In another year or two it should begin bearing fruit.
In the meantime, don't be too good to the tree; cut back on watering and fertilizing, allowing it to be a little stressed. That will push it into reproducing a little faster.
Q: I am interested in the blunt-leaved type peperomia and how to grow it? I also would like to get some information on the dieffenbachia, whether or not they can handle a little bit of neglect? (e-mail)
A: I must confess that I don't know what you mean by the term "blunt-leaved" types of peperomia. However, the few that I have grown in my lifetime tolerate benign neglectthat is, forgetfulness in regular wateringand still look good. In going through some of my references, I find that my neglect was basically the correct thing to do, as one reference claims that "the quickest ways to kill peperomia is to overwater them...even for short periods of time." Most like bright, indirect light. So, since you sound like me in terms of plant care, this is one for you!
As far as dieffenbachia goes, I have a living testimonial in my office to robust growth with benign neglect; in fact talking about it now reminds me that it has gone more than a week without water!
Another good choice for you: the Dracaena godseffianaone that I have not had any direct experience withbut my reference tells me that to "keep the soil just moist from spring to autumn. In winter, water even less." For some reason it seems to be easier to keep things watered in summer than it does in the dead of winter!
Hope this info helps!
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Do you have a gardening or houseplant question? Write to Hortiscope, Box 5051, NDSU Extension Service, Fargo, ND 58105 or e-mail to Ron Smith at ronsmith@ndsuext.nodak.edu.
Source: Ron Smith (701) 231-8161 ronsmith@ndsuext.nodak.edu
Editor: Dean Hulse (701) 231-6136