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Ron Smith answers reader's questions about the world of plants and gardening.

By Ronald C. Smith, Horticulturist

NDSU Extension Service

Q: I read your column every week. I must tell you about the azalea I received as a gift a few years ago. After the blossoms fade and fall off, I put it outside for the summer and then the plant starts blooming again. I bring the plant back in the house when fall arrives. Once in the house, the plant continues to bloom. I usually catch rainwater or melt snow to water the plant. The plant continues to grow larger, so it needs repotting on a regular basis. (Pelican Rapids, Minn.)

A: Thanks for being a faithful reader! Thanks also for sharing your success story. You obviously have a knack for getting the azalea to rebloom!

Q: I attended your seminar at the Marketplace for Entrepreneurs in Fargo to listen to your discussion about growing grapes and making wine. It was crowded in the room, so I wasn't able to take very good notes. Can you please give me the basics for growing grapes in North Dakota? (e-mail reference)

A: As a hobby, grape growing is fun, but growing grapes as a business requires a lot more investment in learning than what I can give you in this column. Grapes thrive in warm locations and in soil of moderate fertility. Given too rich a soil or one that is heavily fertilized, a vigorous vine will result, but will bear little fruit. Soil that has decent drainage also is important, so don't locate any vines at the bottom of a swale or where water tends to collect following a heavy rain. Look for varieties that are hardy so you won’t have to bury the vine each year. Some examples are native beta, valiant, Swenson's red, king of the north and frontenac. Plant in early spring while the vines are dormant (if possible). Be sure to give the vines a good initial watering. The vines take off with initial vigor, which, if not tied to a stake the first year, will wander all over the place. In subsequent years, you want to establish a permanent trunk so you can train the plant to bear fruit efficiently. With proper training, it will take about three years before fruit of any quantity is produced. After that, you need to be a good manager of the vine or vines, which includes timely pruning, monitoring for disease and insect problems, keeping bunnies and deer at bay, and when the fruit starts to mature, keeping the birds from wiping out the crop. There are almost limitless variations that can influence the success or failure of growing a new crop. I encourage people interested in such ventures to educate themselves as much as possible through reading reputable books, attending seminars, taking notes on your successes and failures and learning from other growers. Most growers are willing to share their knowledge.

Q: I am interested in growing organic vegetables for my family and the local farmers market. Can I do that by not using pesticides? (e-mail reference)

A: You can, but the term organically grown is a legal one that can’t be used without certification. There is a certification agency known as the Organic Crop Improvement Association that will certify your crops as organically grown. The certification will allow you to legally use its label. Rather than give spotty information in this answer, I suggest that you contact the agency chapter in North Dakota. The chapter is in Garrison and can be reached at (701) 337-5789. The contact person is Darlene Philbrick. She will give you the details. In the meantime, you can tell customers that you are working toward being organically certified.

Q: I have been growing beautiful houseplants for many years. I add buttermilk to the soil to provide nutrients for healthy plant growth. In the past, you have written that practices such as this are just so much hokum, but I have had success using buttermilk. Your comments please. (e-mail reference)

A: It is hard to argue against success, that's for sure! Nothing I tell you will change your mind or practices. However, you have stimulated me to do a little investigating as to what buttermilk contains (I used to drink it as a kid, influenced by my grandmother Smith). Dairy products are rich in protein, which makes them a source of nitrogen. Being in the protein, the nitrogen slowly will become available to the plants as the proteins decompose and then provide a mild stimulant for plant growth. In essence, your use of buttermilk for this purpose is better than nothing. However, is it better than using the right commercial fertilizer? I doubt it because using buttermilk is a waste of good food intended for human consumption. I believe that the right commercial fertilizer, applied at the right time and in the correct concentrations, would do more for the plants and less expensively than the buttermilk treatment. These are my comments!

Q: I want to start a greenhouse business growing hothouse tomatoes for local supermarkets. I am a smoker and have heard that greenhouse tomato plants will be subject to more disease problems because I smoke. I have grown tomatoes in my outdoor garden with no apparent problems. Why would the situation change if I were growing them in a greenhouse environment? (e-mail reference)

A: The big answer is that it is in a greenhouse environment. In attempting to control the factors of growth, such as heat, light and nutrients, we also are creating an artificial environment that removes some of the checks and balances that Mother Nature throws into the mix. The big problem with smoking (as far as tomato plants are concerned) is that many tobacco leaves are carriers of tobacco mosaic and spotted wilt virus. Both diseases can be very destructive to a greenhouse tomato crop. The chance of you giving up smoking is probably remote, so if you persist in this habit and in your desire to grow greenhouse tomatoes, be sure to follow the best sanitation procedures possible. Wear a lab coat to cover your clothing and thoroughly wash your hands before going into the greenhouse to handle the plants.

Q: I have a concern about my 25-year-old ficus. It looks like it may have some sort of insect infestation. There are tiny, black dots on the back of the leaves. Many of the leaves are spotted. The spotting is light yellow in most places. On the leaves where the spotting is more advanced, it is grey on the back of the leaves. Some of the leaves are dying, starting at the leaf tip. Does this sound like an infestation? I normally would treat this with a light solution of detergent. Would that work? Is there a better treatment? (e-mail reference)

A: This sounds like it could be a leaf spot fungus known as cercospora spp. Please go to to see if the symptoms match what is in this publication. If so, follow the recommended control procedures.

Q: I have a question about tulips bulbs. I have a bunch of excess bulbs that we dug up last summer, but did not get them all planted last fall. They are stored in a cool, dry place. I was hoping to use them for our 4-H club. We made a bunch of planter boxes for our community last year and I thought of taking the boxes indoors, planting the bulbs and have them bloom this spring. Do you have any advice as to when the bulbs should be planted? Should the boxes be put outside so the plants bloom normally? If so, how long should the boxes be inside after the bulbs are planted? (e-mail reference)

A: You have a sound plan for the tulips to bloom this spring. Get everything set up with pasteurized potting soil and then get the bulbs planted and watered as soon as possible. Set the plants outdoors as soon after as possible. Everything will freeze solid, which is OK. If you want to control the emergence of the flowers in the spring, move them to the north side of your house to slow them down. Put the plants on the south side of the house to speed up flowering. Your biggest problem will be with rabbits and voles nibbling on the new growth. Have some Liquid Fence or similar product available as a preventative. Rabbits and voles can wipe out your efforts literally overnight!

Q: I planted some hollyhock seeds indoors to get them started. I would like to let them grow for a while and then put them outdoors to go dormant. How long should I let the seeds grow before putting them outside? My hope is that I can plant them later this spring and get blossoms this summer! How long is the required vernalization period for hollyhocks? (e-mail reference)

A: I have no idea and none of my references tell me, either! I can't locate any research that has been done on this, so I'll try to make an educated guess/suggestion. I'm assuming you are in North Dakota. If not, modify what I tell you accordingly. When the danger of a killing frost is past, set the plants outside. There is no need for freezing to take place for a herbaceous plant to become vernalized. If spring arrives and there doesn't appear to be any flowering taking place, visit a local garden center to see if it has gibberellic acid. Gibberellic acid is a flower inducer that takes the place of a cold period. Sorry I can't be of more help.

Q: I’ve been reading your column trying to find out what I should be doing and expecting from my calla lily that I received. It is in my office. I water it about three times every two weeks. The plant receives little light. It seems to be doing well, except that the five white flowers on it seem to be turning green. Is this normal for a calla lily? Should I be doing something different? What will happen to it next? I also see that two of the leaves have broken and are now bent over. I do not move the plant except to water it and neither do any of my co-workers. (e-mail reference)

A: The calla lily is beginning to go into dormancy even though it isn't spring. Allow it to go dormant and let it completely dry down for about two months. Then shake off the old soil around the roots, repot in a pasteurized media and set it in a bright light source. The lower leaves are probably breaking off because of the low light situation. Most houseplants do not get enough light, which causes weakness in the lower leaf tissue because that area is the greatest distance from the light source. This weakness is manifested in different ways. In some cases, it causes leaf drop. In other cases, the leaves will break as you described. In essence, you have nothing to worry about because everything your calla is doing is normal.

Q: We have a shelterbelt with two rows of spruce and a row with a mixture of acute leaf willow and tower poplars. The towers are suckering a lot, so it is a major undertaking to cut these down every year. The suckers are now spreading to the spruce trees. If we cut these towers down, will the suckering stop or will the roots keep sending up more? (e-mail reference)

A: Poplar tree suckering can become a nightmare. The way I found to conquer this invasion of unwanted sprouts is to wait until the trees completely leaf out this spring and then cut them down. This uses up the food reserves from the roots that were stored last year going into fall. At the point of full leaf-out, the reserves will be at their lowest, resulting in reduced or weakened sprouting. The sprouts that do emerge can be controlled with careful applications of glyphosate (Roundup). If you persist, the battle will be over this summer. Cutting the trees down before they leaf-out allows all the carbohydrate reserves to remain in the roots, which then are available for a strong surge of suckering that will drive you crazy!

Q: I've written to you before and gotten some very good advice. I need some more! I've had a philodendron for eight to 10 years. The plant has been repotted into larger pots three times. It has done remarkably well during the years. I have it in a south window, keep track of watering, keep it trimmed and only use rainwater or melted snow. For the past two weeks, I get a moldy odor from the plant. It sits right next to my recliner, so I get a whiff of that smell occasionally. My husband says I'm watering it too much, but I usually wait 18 to 20 days between watering. The last repotting took place about five years ago. I used Miracle-Gro potting soil and fertilize the plant about twice a year using Miracid, which I've heard is no longer available. Is it time to repot again? Does dirt get old? Any help will be greatly appreciated. (Bordulac, N.D.)

A: You could have two potential causes for the unwanted odor. It could come from the soil being too old or, more likely, the soil being in a container that doesn't have good drainage. If that is the case, what you are smelling is an anaerobic condition in the lower part of the soil. This condition definitely would produce a moldy smell. Either way, I suggest that you repot with fresh soil and use a container that is free draining. As you water the plant after the repotting, dump off the excess water that drains into the saucer about 10 to 20 minutes later. I also would suggest repotting on an annual basis rather than every five years because the soil compacts from watering. This compresses the macropores in the soil to (if you are interested!) micropores. Micropores are less able to hold a balance of air/water that is odor-free. Thank you for the kind words. I'm glad my past advice was good for you!

NDSU Agriculture Communication

Source:Ron Smith, (701) 231-8161,
Editor:Rich Mattern, (701) 231-6136,
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