February 6, 2003

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I’m looking for information on bag worms. We have two beautiful blue spruce but this fall we noticed they had bag worms. We pulled off as many as possible but could not get them all. We would like to spray to eradicate these pests. (E-mail reference)

A: I wish email addresses came with some kind of zip code so I could tell where you are writing from! Your hand picking during winter is one of the best, least toxic, and least expensive ways to control this interesting pest. For those you cannot reach, or to be sure you have taken care of all of them, spray from mid-spring (May) to early summer (July) with Bt (Bacillus thuringiensis), an organically accepted method, or with Orthene or Sevin. Spray again in 10 days if activity is still noted.

Q: I have a large peace lily that has developed dried yellowing, eventually blacking tips and edges on the mature leaves. It is in a small pot. Am I over watering and should I repot? (E-mail reference)

A: Divide and repot. It sounds like you have it in a container that is not freely draining. When repotting, be sure that the container drains, and yes, you are possibly overwatering it.

Q: We are planning on getting two bengal cats in the near future and had decided to make our own cat tree. We cut down a tree but now we’re not sure if it's an elm tree or not. We didn't notice until we got it inside that it has gray patches that look like warts spotted on the trunk and branches. The bark is brownish and rough. From all the cutting we had to do, it appears to be a very healthy tree. Will this be safe for our cats? (E-mail reference)

A: Speaking as someone who is "owned" by three cats, the wood should be safe based on what you have told me, unless Bengal cats have a particular sensitivity that I don't know about. You might check with your local vet to see if they have any unusual allergies that you should be aware of before making the acquisition.

Q: What is your opinion of boxwoods? I have seen Korean boxwoods available in my area. Do they need to be trimmed and shaped often? What about their hardiness for our area? Also, what do they require for sun exposure? If they are not successful in my area what would be similar to them for a northeast corner of a house? (Onida, S.D.)

A: If you have seen them successfully growing in your area, I would think they are fairly hardy enough to make it. They are the kind of plant that responds well to trimming which should be done on a seasonal basis to maintain optimal looks. They are usually considered a "formal" plant, and no, they do not require full sun exposure. In fact, winter sun causes a winter burn or sun burn on the foliage in many locations, so a northeast exposure would be acceptable. My experience with boxwoods has been limited to Ohio, New York, Pennsylvania, New Jersey and through the south. We cannot successfully grow them in North Dakota.

Q: I enjoy reading your column every week and always learn something new. I have a silver vase bromelaid that I need advice on. I only water the soil when it is very dry but I keep the vase constantly filled with water. I have one in a sunny south window and one in an east window. The ends of the leaves are turning brown and I'm worried about losing them. Can you tell me what I am doing wrong and how to care for them properly? They have gorgeous blooms when they reach maturity. (Woonsocket, S.D.)

A: Thank you for your very kind words! I try my best. Your term silver vase translates into a specific bromeliad for me. I think you mean the urn plant - Aechmea fasciata. You are correct in keeping the vase (the cup-like center of the plant) filled with water and I hope that you change it frequently to keep it from becoming stale and smelly. The leaf ends turning brown is an indication of the air being too dry (small wonder with our outside temperatures being what they are!). The plants should be misted often with distilled water that is at room temperature. It doesn't sound like you are overwatering and it appears you are giving them sufficient light, so dry air is my best guess.

Q: I recently purchased a small pussy willow tree. It didn't come with instructions so could you tell me how much sun and water it needs? I live in Minnesota so I’ll have to keep it inside until this spring. (E-mail reference)

A: I will assume it is a pussy willow tree so keep it in direct sunlight as much as possible while inside. Keep it well watered. When spring arrives, plant it in the wettest part of your yard or where you can keep water readily available to the plant. Depending on where you live in Minnesota, it may or may not survive. It is hardy to zone 4.

Q: I recently moved from a western exposure apartment to an eastern exposure apartment. My old apartment was very well lit and I kept my jade plant close to the window. It thrived in that environment. My current apartment is much darker with not as much sun exposure. I now have steam heat. Recently, all of the bottom leaves on my plant started falling off. The ones near the top seem healthy and I see no signs of mold. Is this normal or should I be concerned? Is there anything I can do to help my plant? (E-mail reference)

A: When a plant is moved from an area of high light intensity to a lower one, it is natural and normal for the older, lower leaves to drop off. It then stabilizes for the new environment that it has been placed in - assuming there is sufficient light to maintain the plant. So, nothing to be concerned about at this point.

Q: What varieties of green bell peppers do you recommend this year? What short season Jupiter would good? Also, what about enterprise and whopper imp? Also, what color bell pepper would be most accepted in the market? Can I expect about a dozen peppers per plant? (Cando, N.D.)

A: Pepper plants are so fickle in their production. I thought we were going to lose every one of our plantings last year due to a flooding rain and standing water, but we got some pretty good production anyway. Production depends so much on the timing of planting and the maturity of the plants at that time. In other words, don't bet the farm on dependable pepper production. If they suffer watering lapses or cool temperatures (below 60 degrees F. ) while in the seedling stage, it can affect fruit production. It makes me sound like I'm not a fan of growing peppers, which is not true - I welcome the challenge by planting a wide variety of cultivars and usually get results that satisfy. In the past, I have had my best productive results with lady bell, but can no longer find it on the market. Last year Jupiter did well, as did our bell boy hybrid and the big early hybrid (huge fruits!). I’m sorry I don’t have any data or information on enterprise or whopper imp. We had some of the big early hybrid fruits turn red for us, and the color contrast was outstanding. Red would get my vote any day! You are about on the mark with expected production if you have good conditions. Again, so much depends on the care of the seedlings and the timing of the transplanting. We generally do it at the same time we plant tomatoes, which isn't the best, as tomato plants are much tougher environmentally speaking than pepper plants ever can be.

Q: What is the average shelf life for garden products like Miracle-Gro? I would like to know about powder and liquid forms of garden products. Does it affect shelf life if the products are kept in an unheated garden shed? (E-mail reference)

A: The powdered product should last virtually forever. I’m uncertain about liquids if the shed is subject to freezing. I wouldn't take a chance as separation could take place or a chemical reaction could occur that would change the composition of the material. Most of those liquids have a definite shelf life, usually at room temperatures in the 60 to mid-70s range. I would suggest that if you have doubts or concerns that you contact the manufacturer of the particular product.

Q: My 3-year-old cactus has tiny webs at the ends of the stems. I don't see any insects and the plant, in general, is healthy looking and making new sprouts. I hope my problem isn't spider mites. I don't want to infest my other plants near it. (E-mail reference)

A: Well, you might want to take back your thanks in advance because it sounds like you do have spider mites. Place a clean white piece of paper under some of the leaves and tap them lightly. You have spider mites if the specs that fall move around. Misting and a dose of insecticidal soap will take care of them so don't worry.

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. Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations.

###

Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu