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By Ron Smith, Horticulturist

NDSU Extension Service

Q: I planted some heritage raspberries two years ago. The main stems grew some leaves and a few shoots developed the first year. I let everything stand until spring. At that time, I whacked them to the ground. The second year, the patch exploded, so I had canes galore. I thought I was going to get fruit in the fall, but no flowers or berries developed. The plants were very healthy, but no flowers or berries. Does it take three years for heritage berries to mature? I have read so many conflicting reports on years to maturity. The nursery says heritage berries should bear fruit right away. Should I cut the plants down again this spring? Another thought was that I was sold a summer-bearing variety that I shouldn’t be cutting down. Is there a way to distinguish between the two varieties? Do you think I should try to mow the plants down once more to see if I get berries this fall or should I let them alone to see if they produce berries in July? (Wisconsin)

A: The heritage plantings I've known have all delivered berries the first year. I think you probably have a summer-bearing variety. I'd suggest not mowing the plants down this spring to see if the canes produce flowers and fruit this year. As for distinguishing between summer-bearing and heritage, I'm sure someone can do it, but it isn't me at this point. Everbearing red raspberries, such as heritage, can be pruned to produce fruit once or twice a year. If you follow the pruning methods used for summer red raspberries (cutting them down to size and removing spindly canes before leafing out and again removing the bearing canes immediately after harvest is finished), heritage raspberries will produce fruit once in the spring and once in the fall. However, many home gardeners and commercial growers mow or cut all heritage canes to the ground in early spring (March or April) for the sake of simplicity. With the vigor you describe, once you get the right pruning system established, they should be good bearers for you. Enjoy!

Q: You helped me with my croton a couple of months ago and now it's back to not dropping leaves and new leaf growth has developed. I need to prune it, but want to know if I should wait until spring (even though it's a houseplant) or can I do it now? Now to the gardenia I have. I saw this beautiful little plant at a store. It was so cute because the plant was pruned to look like a tree. It has lots of blooms, but I've read that gardenia is very hard to grow as a houseplant. Any suggestions on growing this plant would be great. I am getting so much conflicting information on the Web. (e-mail reference)

A: You are welcome! You can prune the croton while it is actively growing. As for the gardenia, enjoy its innocence while you can. Typically, these beautiful, fragrant plants seduce people into buying the plant with the hopes of having a lifetime of satisfying blooms through most of the year. The plant’s needs are simple on paper. It needs consistent moisture; acid pH; strong, but not direct midday sunlight; and fertilization on a regular basis, especially when new growth is evident. If you move the plant outdoors during the summer months, place it in the shade of a tree or the north side of the house. The only frustration most people have is getting it to reflower after bringing it home from the store.

Q: I have a fertilizer question for you. I've read that I should not apply fertilizer to damp grass. Instead, I’m supposed to apply fertilizer on dry grass and then water thoroughly. Why would it matter if the grass is wet before I apply the fertilizer if I am going to water immediately after applying it? (e-mail reference)

A: If it is your intention to water immediately after applying the fertilizer, then it doesn't matter. If it is applied and not immediately watered in, foliar burn could result. It wouldn't be lethal to the grass, just look unsightly for a time. High temperatures and bright sunshine later in the day mixed in with a dry fertilizer application that was composed of highly water-soluble material would have that damaging effect if not immediately watered in.

Q: I have two hibiscus plants that I bring in every fall, but every time I bring them in, the plants get bugs. The bugs are little, white flies or aphids. I can't seem to get rid of them without almost killing the plant. Is there a specific spray or homemade concoction I can make to get rid of the bugs? The plants continue to flower, but the leaves start falling off. (e-mail reference)

A: Have you tried an insecticidal soap? That would be my first line of defense because it is the least toxic to you or the environment. One tactic I tried and got away with a few years ago was to set the plant outdoors for a few hours on a subfreezing day. This will kill the bugs and wipe out the remaining leaves, but not kill the plant. Bring the plants inside, repot in fresh potting soil and dip the leafless top into the insecticidal soap solution. After that, place the plants in a warm, sunny location and keep them evenly moist. In a few weeks, you should see new growth emerging, followed by flowers. In the future, allow a couple of first fall frosts to hit the plants. That will reduce the number of insects on the plants to a manageable level or kill them all.

Q: My ficus plant was given to me in good faith by a friend who could not take it with her when she moved, so, I consider it something of a sacred trust. My problem is that my mother’s cat likes to urinate on the plant. It has been difficult to keep the cat away from the plant, but I feel I have found a good solution. However, I still have contaminated soil. I found a reference on your Web site about flushing the soil with water to dilute the salts from the urine and save the plant. However, I live in Edmonton, Canada. It is sometimes really cold here in winter, so I am concerned that if I flush the plant, it may die. But, if I don't, it may die anyway. Help! (e-mail reference)

A: If there is any civilized place in North America that is colder than Fargo, it has to be your community! Flushing is still the best way to solve the problem, but don't use water directly from the tap. Allow the water to sit at room temperature for 24 hours. By then, the water temperature will be somewhere around 60 to 70 degrees. To my knowledge, that temperature range has not killed any ficus houseplants. I am assuming that you have the plant in a container that drains well.

Q: I have not been successful at growing cone flowers even though there is a hill with clay soil near our house that has plenty of the flowers on it. I've tried several ideas to get the flowers to grow, but have not had any luck. Your thoughts? Thank you in advance. (e-mail reference)

A: Try transplanting a seedling from the site you mentioned. Do the transplanting early this spring to see what happens. Most people have problems with this species when they try taking very good care of them. However, cone flowers don't need it. If you can get a couple of mother plants established, they will self-seed naturally. I have had more luck with allowing Mother Nature to do the seeding for me than I have with my best efforts at planting seeds.

Q: My kids knocked over a pot the other day. As I was cleaning up the mess, I noticed these big, white bulb-looking things where the roots should be. What are they and where do I go from here? (e-mail reference)

A: Those bulb-looking things are storage vessels for water and nothing to worry about. Think of them as humps on a camel that store water. The water is there for the plants to use should there be too long an interval between watering cycles. As to where you should go from here, I don't know what else to tell you other than to repot the plant. Water it as you would any other houseplant under similar conditions.

Q: I raise habanero for my salsa. I grow it inside during the winter. This year, my habanero plants keep dropping blossoms. I’ve grown habanero for many years, but have never had this problem before. Do you have any tips for me? (e-mail reference)

A: There could be one of several reasons for your problem or a combination of problems. It could be that you allowed the habanero to dry down too much before watering again. There may be too hot or cold shifts in temperature. The roots could have been overdeveloped at transplanting time, but this usually corrects itself as the season wears on. If you are using florescent lighting, but haven't changed the bulb in more than a year, the light may be too weak.

Q: I have a Christmas cactus that seems to be growing fine, but is developing hairlike roots coming from the joints of the leaves. I tried watering more, but that didn’t help, so I started watering less, but still no luck. Can you please help me find out what may be causing this problem? (e-mail reference)

A: The plant is doing what comes naturally, so don't try changing anything in your care regimen. Christmas cactus is a rainforest native where the development of aerial roots is common. You must be providing a very good, high-humidity environment for this plant to be doing this in your home. Enjoy!

Q: We have a ficus tree that we have had for a year. We have noticed lots of leaves falling off. I have seen gnats at the bottom of the tree. I'm also not sure if I'm overwatering or underwatering it. Any suggestions? We also are going to replace the pot using new soil. Please help with any suggestions. (e-mail reference)

A: The standard recommendation is to give it more light and less water. Many houseplants are killed from overwatering and not getting enough light.

Q: I’ve had my garden for about 11 years. I started from scratch and added lots of good amendments when it was fresh. I’ve added mostly composted manure and some mulch. However, during the past few years, most of my plants won’t stand erect like they should. The Russian sage, phlox, Veronica, Lucifer crocosmia, Becky daisy and iris plants tend to flop over after growing up. Is this a soil or drainage problem? (e-mail reference)

A: Without a complete soil test, it is hard to say what might be wrong. From what you tell me, my best guess is that there is too high a nitrogen level in the soil, so get it tested.

Q: What a great service you are providing by helping people with their tree questions! I did read through all the questions about weeping birches, but our question was not answered. My husband and I have a beautiful, tall weeping birch tree in our yard. We live on the Mendocino coast in California. I understand these trees have a fairly shallow root system. We are planning to build a garage, which means digging a trench for a propane line about 20 feet from the trunk. The line would be just outside the canopy area. We also will need to dig a trench to run a line to the septic drain field. The trench will be located below the tree and its canopy. Will either of these projects endanger the tree? Is there anything we can do to lessen the impact of the digging? (e-mail reference)

A: Nice to meet another lover of this beautiful tree. I have one that is in front of our house and we love it! Unfortunately, established trees don't respond well to having their roots disturbed. I suggest digging into the local phonebook to find an International Society of Arboriculture certified arborist. You need an onsite visit by someone who can tell you what the options are for maximizing the survival chances of the tree. It would take 25 years to get a tree this size again. I would hate to see you lose the tree to some not- well-thought-out plan to save it.

Q: I saw a garden on the edge of Jamestown College where a lady was growing sun-tolerant coleus. She said the plants were hybrids. Have you seen these plants or had experience with them? The garden centers in Fargo and Grand Forks did not carry them this summer. (e-mail reference)

A: I am not aware of this type of coleus, but that seldom means anything of significance! I am forwarding your inquiry to my very competent colleague, Barb Laschkewitsch, to see if she can provide an answer for you. Good hearing from you!

Q: I’ve just learned that we need to temporarily move our beautiful, healthy dogwood tree for landscaping reasons. It has small, ivory and purple flowers in spring. We live in Seattle, so we have mild temperatures. We need to move the tree next month. We plan on replanting in the same spot. (e-mail reference)

A: I would encourage you to locate a company that has a tree spade with a bucket at least 44 inches in size. I wouldn't go any smaller. Also, find a landscaping company that can ball and burlap the tree while it is moved to a temporary location. Mulch the temporary location. This option probably is more expensive, but your objective is to save this beautiful tree. Taking this route is the least traumatic to the tree. Be sure to check credentials and references!

Q: As a 4-H project, my kids planted terrariums just before Christmas to give as gifts. We kept two of the terrariums. I’ve noticed the terrariums have fruit flies. All of the containers have been closed and the recipients have been told to keep them closed until I hear from you. Do you have suggestions on how to control fruit flies in closed terrariums? (e-mail reference)

A: My best guess would be to get a pump applicator of insecticidal soap. I suggest the pump and not the aerosol type because the aerosol would have a carrier that might burn the foliage. You might try some yellow sticky cards and insert them if anyone is at all leery about spraying the plants. The bugs will be attracted to the yellow color and become entrapped on the sticky surface and then expire. It might take a couple of cards to get rid of these pests, but it should work in an enclosed setting.

Q: I have a beautiful, young spider plant. The inside is green and there are white stripes on the outside. It produced only one spiderette. After the flowers disappeared, I noticed a three-sided pod growing off the stem. I thought it might be a seedpod of some kind, but neither my husband nor anyone else we know is aware of what it might be. Please help. We are curious to know. If it is by chance a seedpod, can we start more spiderettes from the seeds? (e-mail reference)

A: If the seeds are viable, yes. Otherwise, it is just too easy to propagate them from the spiderettes. You have nothing to lose by giving it a try.

Q: I purchased a Gerber daisy a few months ago. It was doing well, but in the last month, I've noticed gray fuzz growing on some leaves. I'm worried it may hurt the plant or kill it. Do you know what’s on my plant? If so, is there a cure? Thanks for your help. (e-mail reference)

A: It sounds like it might be powdery mildew showing up. Purchase some fungicidal soap at a garden center and follow the directions for its use. This should get rid of it. Once you do that, you might try to place the plant somewhere where there is better air circulation, but without it being near a heater blowing directly on the plant.

Q: We have a very old ficus tree that suddenly lost 80 percent of its leaves and the rest are dried out. We have a much younger ficus that is thriving. I think the dying ficus was starved for light when it was moved to a northwestern corner of the house. The tree gets virtually no sunlight. My roommate says ficus like low light, so this negative turn is because I occasionally run the woodburning stove, which is nowhere near the tree. What do you think? (e-mail reference)

A: I think the demise of your ficus is due to both factors. You probably also can throw in overwatering. While ficus can tolerate low to moderate light, it can do so for only a short period of time. In a well-lit office situation, ficus usually thrive. In a home or apartment where the lights are not on all day and away from a south- or west-facing window, it will start to decline. A woodstove dries the air as it heats up. Ficus are tolerant to some dry air, but not when it is desert dry and hot, as it would be from a woodstove. Combine that with a normal watering regimen and you have conditions set up for a ficus wipeout.

NDSU Agriculture Communication

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