|
January
26, 2006
Hortiscope
Ronald C.
Smith, Horticulturist
NDSU Extension Service
Q: I’m thinking
of taking a cutting from a birch tree instead of buying a seedling and
waiting five years for the tree to turn white. Is it possible to take
a cutting from a tree that is white to grow roots? I know I can try air
layering, but prefer using a cutting. (e-mail reference)
A: Cuttings will
root if you pay attention to detail. In other words, rooting may be
a challenge for some. Take the cuttings in late summer (Sept. 1) and
dip the cuttings in a rooting hormone. After that, place the cuttings
under a mist. Allow the cuttings to go through a normal dormancy and
then move the cuttings after their spring flush of growth. Some swear
this works, but others swear it doesn't. I never have rooted any because
I’ve always depended on seedling development, with the bark turning
white in two to three years.
Q: I have about 20
acres of what is considered "farmable wet ground." I would like
to grow some type of crop on it. Do you think it is a good area for raising
wild rice? How do I go about raising and harvesting it? Do you know if
there is a market for it? (Sebeka, Minn.)
A: Growing wild
rice is light years from my expertise. I do know there is a market for
it. Perhaps the Minnesota Department of Natural Resources can help you.
According to the DNR Web site, wild rice grows best where clear, shallow
water flows over a soft, mucky bottom, such as in the upper Mississippi
River and its tributaries, or in spring-fed lakes and marshes. Though
some wild rice grows in Wisconsin and Michigan, Minnesota is the only
state where wild rice is found in great abundance.
Q: I have a Christmas
cactus that just got through blooming. I might need to replant it in a
bigger pot. What kind of potting soil should I use? (e-mail reference)
A: Use a potting
soil high in organic matter. It is called African violet potting soil
in some outlets.
Q: I just found your
e-mail question-and-answer pages and noticed that someone asked about
hardy, yellow roses. Last summer, I had a terrible time with rust. I sprayed,
cleaned up the dead leaves and sprayed the ground beneath the plants.
Any help you can give about preventing and treating rust would be welcome.
(Moorhead, Minn.)
A: Rust on roses
has to be taken care of by one of two methods. You can use preventative
sprays or get rid of the alternate host, which are junipers. The latter
is the better method to follow, but you don't have to dig out all of
your junipers. Survey your property to see if you can find the fruiting
bodies of the rust on the junipers. Do the survey this winter or in
early spring. The rust is an obvious brownish orange. Pick off the fruiting
bodies and destroy them. This breaks up the cycle of what is known as
cedar-apple rust disease.
Q: I have several
aloe vera plants that I’ve been growing for more than five years.
They have done quite well, but the plants have developed strange black
spots. The spots seem to be more concentrated in one bunch. I thought
my kids may have overwatered, but the soil feels fine. What do the black
spots mean, and are my precious plants dying? What can I do? (e-mail reference)
A: It is not a good
sign if an aloe plant develops black spots. They probably have been
overwatered, which is something that can be changed very easily. I would
suggest that you take some offsets or divisions from the healthy parts
of the plants and propagate them. For techniques on this, go to www.ext.nodak.edu/extpubs/plantsci/landscap/h1257.pdf
to download the publication I have on home propagation techniques. Take
the cuttings or divisions and allow them to dry for a few days before
attempting to root them. This will cut down on the possibility of the
cuttings rotting. As for the spotted parts of the plant, allow the potting
media to dry before watering again to see if they can recover. Don't
be surprised if they don't. Once a fungus sets in, it is difficult to
control.
Q: I have several
arborvitae I use as a hedge. Deer ate them and now there is nothing left
but a tuft on top. Do they have a chance to survive? If so, what should
I do to nurse them back to health? Should I fertilize now or wait for
spring? Also, should I put up protection for the remainder of the winter,
even though there is nothing left to eat? I hate to replace them because
they were very expensive. (e-mail reference)
A: You want to purchase
a material known as Plantskydd, which is the best deer repellant on
the market. It is a powder that needs to be mixed with warm water and
then applied. It will keep the deer from continuing to feed on what
is left. Other than this, there is nothing you can do right now. In
the spring, see if any new growth breaks out. If it does, will the form
be what you want in your landscape? Probably not, so you likely will
need to replace these trees. Knowing what you do now, take proper protective
action next fall.
Q: I have a ficus
tree that I've had for several years. It was my grandma's for 15 years
before that. It has been very healthy until recently. I moved in October
and put the tree in my sunroom. It was fine until last week. The leaves
are drying and falling off. The leaves are not changing color. What could
be the problem? I had forced-air heat in the old apartment, but now have
radiator heat. The tree is not near a radiator. Could it be a moisture
problem in the house? Do I need a humidifier? Could it be bugs? What can
I do to save my tree? I don't want to lose the tree because it has a lot
of sentimental value. (e-mail reference)
A: It sounds like
it could be dry air causing the problem. I would suggest a room humidifier.
Wait six to eight weeks to see if any new growth emerges. Ficus plants
are extremely fussy about being moved, pouting from a little difference
in humidity, air movement, temperature or light. Have patience; chances
are it will recover after going through this fit of defoliation.
Q: I’ve had
a jade plant for five or six years. In December, it bloomed for the first
time. However, some of the leaves have started to turn yellow, shrivel
and fall off. Can you please help me? (e-mail reference)
A: It is probably
due to insufficient light. Whenever a houseplant flowers that normally
does not, the plant consumes a lot of energy. I'm willing to bet that
the majority of foliage you see in the condition you describe is coming
from the oldest leaves. If that is not the case, and it seems to be
a general malaise of the plant, then I suspect overwatering.
Q: I have several
blue spruce trees with 18 to 24 inches of new growth on top. Can I prune
the new growth back to 12 to14 inches so the tree doesn't look out of
shape or is it better to leave the new growth alone? (e-mail reference)
A: Go ahead and
trim the trees this spring. Glad they are growing so well for you. The
blue spruce obviously love the site where you have them.
Q: We purchased a
potted Norfolk pine from a department store for our Christmas tree because
we have a small child and cats that surely would have knocked over a larger
tree. Within a week, the pine started drying and browning. I paid careful
attention to its watering by waiting for the top inch or two to dry before
watering again. It was away from heat vents and next to a south window.
I took off all the decorations and gave it a heavy pruning, ridding it
of the dried branches. If nothing else, it will look green for a couple
more weeks. There's not a whole lot left, just the main shoots and leaders.
Is there anything I can do or is it going through an acclimation period?
Is the southern exposure too much? Did it get too shocked when brought
outside from the store to our house? The temperature was in the teens.
(e-mail reference)
A: You could have
problems if the tree was not double-wrapped before leaving the store
or it wasn't placed in a prewarmed car. All it takes is about 40 seconds
of exposure to temperatures in the teens to cause the problems you describe.
The tree never will recover the lateral branches that have been lost.
You might as well throw the plant away. Pick up a new tree this summer
when transporting it from store to vehicle and vehicle to house is not
a threat to the well-being of the plant.
Q: My Black Hills
spruce trees are covered halfway up with snow. Is this a problem? Should
arborvitae be watered midwinter if temperatures are at 32 degrees? (e-mail
reference)
A: No to both questions.
Q: I have the Extension
publications about growing herbs in the garden, but are there any special
considerations when growing herbs inside? (Lakota, N.D.)
A: Herbs that are
adaptable for growing as indoor plants are thyme, chives, parsley, marjoram,
oregano, rosemary and the shorter forms of basil. What you need for
success is light and plenty of it from window sills and fluorescent
units. I would suggest utilizing both sources. Place the light unit
on 14-hour days using an automatic timer. Normal room temperature is
OK, but if possible, lower the temperature by 10 degrees at night. Place
the herbs together and try to have a gentle fan blowing across the foliage
most of the time. The herbs will do better if grouped and set on a tray
of pebbles that are kept wet. Use only pasteurized potting soil and
allow it to dry slightly between waterings. Be sure the containers are
free draining.
Q: Last fall, before
freeze, I took in some geraniums in large pots with good soil and put
them in a window that faces south. They bloomed well for a time, but not
lately. I think they have enough water and fertilizer. Do they like to
rest? Should I quit watering for a time? They still have green leaves,
though some are dry now and then. (Moorhead, Minn.)
A: The sunlight
in our region has been very low until just recently. I suspect the plants
are low on carbohydrates because of the flowering. Don't overwater and
be patient. As our sunlight intensity and duration increases, the plants
will be able to photosynthesize more, store more energy and then bloom
again. I am sure they will bloom again before the snow melts!
Q: I am moving to
another house, so I want to dig up some iris bulbs and take them with
me. Do I need to replant them right away or wait until spring? (e-mail
reference)
A: Wait until spring
to replant. Go to www.ext.nodak.edu/extpubs/plantsci/landscap/h113w.htm
for complete information on growing and planting iris.
Q: I'm concerned about
my baby Lisbon lemon tree. It was doing beautifully, but all of a sudden
it developed what I think is a fungus. It looks like there is dirt on
the tree and it looks like there are spider webs on the branches near
the base of the leaves. I'm going to try to wash the leaves and branches,
but beyond that, I have no idea what to do! (e-mail reference)
A: This sounds like
a spider mite problem. Washing the foliage is the correct thing to do.
You also might want to try misting the plant on a regular basis. Mist
the tree two to three times a week to keep the mites under control.
Mites often show up in large numbers on some houseplants during the
winter months because of the dry, indoor air from central-heating systems.
###
Source: Ron
Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu
|
