January 30, 2003

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have a jade plant that I got as a cutting from a friend. It has been growing really well and looks healthy but recently some black, raised spots have grown on the leaves. What is it and what can I do to get rid of it? (E-mail reference)

A: Those black spots could be the start of scale insects invading. Take your thumbnail and see if they scrape off with a smear or if they come off dry with a little bit of tissue. If it comes off as a smear, then you have scale insects. If they are confined to just a few leaves, remove them and then monitor your plant carefully after that. If it isn't scale, then it is likely a type of gall that should not be a problem, health-wise, to the plant. Just keep your eye on it to be sure the plant isn't being debilitated.

Q: I'm interested in doing some landscaping with native grasses and plants so I need a local supplier of seeds, plants and general information. (Grand Forks, N.D.)

A: No problem - here are three companies that I would suggest you contact:

Prairie Nursery
P.O. Box 306
Westfield, WI 53964 
www.prairienursery.com 
Phone: 1-800-476-9453

Prairie Moon Nursery
Route 3, Box 1633
Winona, MN 55987-9515 
www.prairiemoonnursery.com 
Phone: 507-452-1362

Prairie Restorations, Inc.
Bluestem Farm
P.O. Box 1027
Hawley, MN 56549 
www.prairieresto.com 
Phone: 218-498-0260

Any one of them should be able to help and advise you. Good luck!

Q: I have two crabapple trees in my front yard that are around 20 years old or older. I am having a problem with limbs dying. They have been falling off all year long and one seems to be rotting from the inside. Any ideas? (E-mail reference)

A: It sounds like your trees are not long for this world. You can get someone locally, such as an arborist or county extension agent, to come out and give you a better diagnosis than I can at this distance. You might start looking through some of the spring catalogs that are beginning to arrive to make a replacement selection.

Q: I just bought a new ficus and was wondering where to place it. Right now it is across the room from a window and does not get direct sunlight. Should it be in front of the window or just leave it where it is and see what happens? (E-mail reference)

A: If you leave it where it is, most likely some leaf drop will occur and then it will stabilize. Depending on the light level, the plant may be able to survive, but it will do better if it can get more direct light.

Q: I have a Christmas cactus that is at least 30 years old. Last year it bloomed beautifully but this year it is limp and loaded with buds that are dying without opening. I have it in a west window but not in direct sunlight . Up to now it seemed to love that location. It gets watered once a week but only if needed. It’s located close to a heat vent. Could that be causing the problem? I had it split and repotted about four years ago and last year is the first year it bloomed so well. (E-mail reference)

A: You identified the problem with your inquiry. Get it away from the heat vent ASAP and begin misting the foliage to keep the blooms from falling before they open.

Q: I have searched the Web for a prayer plant like mine and have been unsuccessful. My daughter forgot to water it so it died. It had grown to an incredible size. It was dark purple with little white flowers that popped up periodically. I don't know the scientific name of the plant. Almost every Web site with a photo shows a green prayer plant. (E-mail reference)

A: I don't know if I can really help, but I will try. The Maranta Massangeana has deep purple on the undersides of the leaves, with almost black markings about the midribs on the upper side of the leaf. The Merythroneura has purplish red undersides with many bright red lateral veins leading away from a light green midrib on the upper side. Finally, what you may be talking about is the M. tricolor - I have seen some with very dark upper leaf surfaces.

Q: I found a very unusual tree in my back yard when I moved into my house. A clipping I found in the basement along with some research showed it to be a catalpa tree (cigar tree, also known as a catawba tree). I have since noticed a handful of catalpa trees in the area. However, every one has seed pods. Mine blooms but never produces pods. (For which I am thankful after reading that they can make a mess). Why doesn't mine have pods? Is it a female? Is there anyway to reproduce the tree by seed or another manner? I have never seen the tree offered by any local nursery. I did notice that a nursery in the twin cities offered it, but advertised it as having pods. Is mine a freak? I would like to grow more but without the pods. (Moorhead, Minn.)

A: The catalpa is usually considered too coarse a tree for planting in a refined landscape setting. The wood is extremely resistant to rot while in contact with the soil, hence it's early use as a source for railroad ties. The trees were usually available through mail-order catalogs as "super bean" trees or from soil conservation sources. The wood is brittle, second only to Lombardy poplar in providing kindling. Seed will germinate readily without any pretreatment. As a kid I used to collect the giant pods, pop out the seed and grow them in small pots, most of which died (thank goodness!) but it gave me a confident green thumb. Root cuttings taken in early winter will develop and if yours is truly a non-fruit bearing tree, that is the way it should be propagated. I suspect that you don't have the Catalpa speciosa, instead you probably have the Catalpa bignoniodes. It’s a southern species that is somehow surviving but the sexual parts of the flower are killed off by our capricious weather. All the catalpa species have perfect (male and female parts) flowers. Hope this information helps!

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.

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