Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have two potted roses the discount store was going to throw away. They are not hardy to my area. My area is zone 3. They are suitable for zones 5 - 9. My free babies produced large fragrant beautiful blooms all through late fall. I brought them in this winter to see if I could save them. Now I noticed very small green bugs on the leaves and the leaves are wilting. Aphids? I cut them back before I brought them in. They grew back nicely, but the leaves are very tender. Am I crazy for trying? Also, how do I plant a mango seed my parents brought back from California? (E-mail reference, Doran, Minn.)

A: Not crazy, just tender-hearted. The roses would have been better off being left in the soil in their outdoor environment, and allowed to harden off going into winter. You could have then covered them with soil and leaves to protect the crown and scion wood. I am afraid that from this point on, it will be nothing but a down-hill trip for the plants. If you have an unheated garage, I would suggest moving them in and allow them to go dormant. Water enough to keep the soil from drying out. If the temperature should drop to below zero, I suggest running a small space heater to keep it a little above that point around the plants. Then plant them in the spring and see what happens. Concerning your mango, since these are warm season tropicals, they should be germinated at about 80 degrees F. Since this is warmer than most homes are kept, I suggest bottom heat (from propagation pads or cables) and keeping the medium evenly moist. I have no idea how long it will take, but don't be surprised if it stretches into six weeks or more.

Q: I have a beautiful, healthy, Christmas Catus that is loaded with buds. Can you please tell me how to take care of it to keep it healthy? Can I put it outside in the summer, and when is the time to repot it? (E-mail reference, Wentworth, S.D.)

A: Your Christmas cactus will probably fare better indoors than outside, if your winds are anything like ours in North Dakota! If you feel you really must plant it outside, try placing it in a protected location, like an eastern exposure. Taking care of Christmas cactus is basically the same as taking care of poinsettia. Keep it out of sudden drafts, and keep it evenly moist.

Q: I have a coffee plant and I repotted it because it looked like the roots were showing. However, the tips are turning brown and the brown is starting to spread up most of the leaves. Could this be salt or fluoride damage? Should I water with distilled water? Should I cut away or remove the brown leaves? (E-mail reference, Elizabeth, N.J.)

A: There could be a number of sources for the problem you describe.

• Watering with cold tap water - allow it to become room temperature (70+ degrees)
• A non-free draining pot, water collecting in bottom causing anaerobic conditions
• Salt or fluoride damage, as you said
• A new location the plant is unhappy with; too much light; or not enough; or too drafty.
• Air too dry due to winter heating system - mist frequently with distilled water.

It shouldn't hurt it to be watered with distilled water for awhile, and try cutting it back somewhat. Grow lamps can be obtained for just under $20. I suggest you might try growing it under one for a few weeks to see if that doesn't improve things somewhat.

Q: Can a North Dakotan "plant" a peach pit indoors and expect to get an indoor plant of some kind? If the answer is yes, how do you "plant" it? Do you put the pit in soil, or do you break open the pit to retrieve the "seed"? (E-mail reference, Grand Forks, N.D.)

A: It would take forever for a plant to emerge from a peach pit, so I recommend removing the seed from the pit first. Now, it isn't as easy as that -- nothing is! Prunus persica, or the common peach, has a complicated dormancy that is tricky to overcome. Even if successful, I doubt it would make a decent indoor tree, as it is a temperate zone plant needing so many hours of chilling to be grown in a satisfactory manner. If you are looking for something to start easily from seed, try grapefruit, orange, or avocado. All will give much better results in a shorter period of time, with longer lasting enjoyment.

Q: This fall, a friend gave me her geraniums before they froze. I cut off the tops and planted them in 4-inch pots. I have them under fluorescent bulbs and am amazed how fast they have grown. Some are about ready to bloom. So they won't get leggy before next spring, should I cut them back again, or keep pinching off the new growth? I realize this is a long time to wait, but I have the room for now, and would love to have them in great bloom in the spring. (E-mail reference)

A: I suggest cutting them back as they get too tall. Also, keep the flowers deadheaded. As they complete blooming, remove them so they don't set seed. You might even try taking cuttings on the longer growth to see how many you can propagate before planting time next spring!

Q: We are interested in planting some chokecherry bushes in our garden and note that several nurseries list the Brilliant Red Chokeberry (Aronia arbutifolia ‘Brilliantissima’) and Glossy Black Chokeberry (Aronia melanocarpa elata), but not a chokecherry. The chokecherry bush that we are familiar with grows in the wild producing white flowers in spring and reddish black berries in late summer that are excellent for jelly, syrup, etc. What’s the difference between a chokeberry and a chokecherry? Is it just a matter of correct name? (Baudette, Minn.)

A: Thanks for the very good question. While both are in the rose family, they are distinctly different species. Aronia spp. or chokeberry is an ornamental with little if any wildlife (or human) food value because of extremely astringent fruit (even the birds don’t like them). The chokecherry -- Prunus virginiana -- has edible fruit (with some significant doctoring). Unfortunately this species is being plagued by black knot, a fungal disease that is wiping out domestic and commercial plantings in our prairie region. If you do decide to plant them, don’t invest any more than you can afford to lose in a few years.

Q: Regarding this question about gladiolus changing colors, I don't know if this is true, but Mom used to say that if you stored different colors gladiolus corms together, they would eventually all become the same color. And of course, I never doubted mom. (E-mail reference, Fargo, N.D.)

A: Smart man -- and if you are really smart, don't ever doubt your wife either! However, that still doesn't explain why or how the change takes place, so I am still stumped! But thanks for responding, and who knows if there isn't some science behind what your mom says?

Q: Our neighborhood has pine trees (Ponderosa pine, I think) in front of each home. They were planted by the city. Our tree produces more sap than any other tree in the neighborhood (I estimate 10 to 20 times more). It has ruined the paint on our car and it is tracked into the house and it soils our flooring. Is there anything I can do to reduce the amount of sap produced by our tree? It may get more water than most of the other trees, but there are no other differences that I am aware of. Any help that you can provide will be appreciated very much. (E-mail reference, Cerritos, Cal.)

A: You folks have a nice long growing season, which can spell trouble insect-wise. Your tree could be infested with scale or aphids which secrete a "honeydew" from their feeding habits that create the mess you are describing. If that is the case, these insects are easily ID'd and controlled with a low toxicity spray. If the insects are not present in sufficient number to be the cause of the sap flow problem, then I'd suggest spraying the tree every 12-16 weeks with an anti-desiccant like Wilt-Pruf or something similar. This product, it goes on milky and dries clear, sealing the stomates and hydathodes, which are openings on the foliage, reducing the flow of sap somewhat. As new growth emerges, it of course, must be covered with this material. Since this interferes with the normal gas exchange in plants, it will slow down growth, but that shouldn't be a concern from your description of the situation.

Q: This past summer we purchased lake shore property on West Battle Lake, Ottertail County Minn. There was a heavy growth of brush, etc., including poison ivy and poison sumac as well as regular sumac. We cleared the brush, and have sprayed the property four times with a product containing Tryclopyr which was recommended for use on lake shore property. This has all been in an effort to kill the poison ivy and sumac. Currently we have a cabin under construction and are concerned about how to stop the future growth of the poisonous plants. I dug a trench for electric conduit in early November and evidently came in contact with poison ivy roots, as I am now going through my third medical treatment this year for poison ivy. The soil is sandy and top soil will need to be added to establish a yard. What should we do to prevent recurrence of these plants? We have small grandchildren that will be visiting frequently and are very concerned about their exposure. (Sartell, Minn.)

A: Poison ivy is nothing to take lightly. While we are all born with an initial immunity, once past that stage in our lives, it can create an almost eternally itchy rash. I’m sure you don’t need to be told! There are cultural and chemical controls for Rhus radicans ( poison ivy). My advice- - stay away from any cultural control. Here is a listing of chemicals I’ve been able to run down for poison ivy control.

• Glyphosate -- sold as Roundup - Apply as a 2% solution with hand-held equipment.
• Crossbow -- this is a 2,4-D/triclopyr combo. This mixture will deliver a synergistic effect that neither herbicide applied separately will have.
• Weedmaster -- this is a dicamba plus 2,4-D mixture that is very effective in eliminating this irritating plant.

Keep in mind that all parts of the plant are poisonous at all times, even in winter. I had a professional associate in Ohio who was clearing a wooded area in winter to build a condo complex. Much of the shrub and tree growth was cut and burned -- without realizing some of it contained poison ivy. Just from smoke drift, two of his men were hospitalized! Perhaps your best approach is to have a professional apply glyphosate. It is not soil active and is very much translocated. Keep in mind also that the fruit is very desirable to birds and other wildlife, and as the seed passes through their digestive systems, it can grow where it is dropped. You might look for a product known as Multi Shield that can be applied prior to possible exposure to this plant. And of course, there is nothing like educating your grandchildren about poison ivy -- "leaflets three, let it be!"

Q: I came across your website while trying to find information on banana apple trees. The two trees my grandmother planted in 1938 have died and I've been unable to locate a nursery that sells them. Is there another name, or am I just looking in the wrong places? (E-mail reference, Connecticut)

A: I think the term "banana apple" is a reference to the golden color of the apple skin in Golden Delicious, Honeygold, or Granny Smith types. I have lived in apple country a good part of my life and have never heard of the term banana apple. Perhaps one of our readers will know just what if any, variety that term refers to. If they do, I'll certainly let you know.

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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: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu