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June
23, 2005
Hortiscope
Ronald C.
Smith, Horticulturist
NDSU Extension Service
Q: I just bought a
huge jade plant for my garden, but people are telling me that jade can’t
be planted outdoors. Is this true? (e-mail reference)
A: Jade plants sold
in 90 percent of the U.S. are intended for use as a houseplant because
of their intolerance to cold temperatures (40 degrees or lower). If
you live in a frost-free zone and have a good, protected location for
a jade, then go ahead and plant it outdoors. Most people will summer
their jade plants outdoors in dappled shade and then bring them inside
well before the arrival of any frosty nights.
Q: I have ti plant
cuttings that I partially put in water. The cuttings started to sprout,
but do not have roots. I put plant food in the water and the cuttings
became waterlogged. I put the cuttings in soil and I am hoping they will
take root. How do I fix this problem? Should I order new cuttings? (e-mail
reference)
A: You can grow
ti (Cordyline spp.) plants in water, but the water needs to be free
of fluoride and fertilizer. If grown in soil, the soil needs to be sterilized
or pasteurized and without added fertilizer. Roots should form in about
six weeks. Based on what you have told me, I would suggest ordering
new cuttings and starting over.
Q: We have a 14-year-old
dogwood. It had a mixture of reddish, flexible canes and brittle brown
canes. We pulled out or cut down all the brittle canes. There is green
at the base. Was this the right thing to do? In addition, do established
lilac bushes do well after transplanting? (e-mail reference)
A: You did the right
thing with your dogwood. Lilacs transplant well as long as they are
not coming into leaf; so transplant lilacs while they are dormant.
Q: A stalk on my bamboo
looks diseased and I see some black dots on the diseased area. The leaves
look good except a leaf is yellowing and drying out. What should I do?
I also have a Madagascar dracaena that I think is in need of repotting.
Is it OK to use a different type of soil? Is there much difference in
the type of soil people buy? (e-mail reference)
A: Cut out the diseased
area on your bamboo if you are sure it is diseased. If you are not sure
it is diseased, monitor it to see what else takes place. In the gardening
business, you get what you pay for, so get the best potting soil that
money can buy. Purchase a brand name product because the supplier has
a national reputation behind it. Be sure to follow the directions on
the label.
Q: My goldfish plant
has just started flowering. I’ve noticed little white bugs on the
plant that have formed cottony webs inside the buds. What are they and
what can I do to get rid of them? I’ve babied the heck out of this
plant and I’d hate to lose it now! (e-mail reference)
A: It is difficult
to say, but the bugs could be cottony cushion scale or spittlebugs.
Take a cotton swab or Q-tip, dip it in rubbing alcohol, and then carefully
dab it on the little critters. Try it on a few at first to make sure
there is no negative reaction to the treatment. If not, then we have
to come up with something that will do the job and not kill the plant,
which is probably a systemic.
Q: I live in Zone
5 and have several established beds of cyclamen hederifolium and cyclamen
coum. Within the next year or so, I will be selling my home and would
like to bring the plants with me. Is there a preferred season to dig the
tubers? Can they be stored indefinitely? Would you store them in peat
moss in an open carton? Is there a preferred season to replant them? Should
they be soaked in water prior to replanting? (e-mail reference)
A: This is a plant
that I have no experience with, so I am going to pass on attempting
to answer your questions. None of my references has the information
you asked for, so I hope some of our readers can provide some insight.
If I don’t hear from anyone, try to use good common sense. Most
plants are better transferred while dormant. Plant parts never can be
stored indefinitely. Dusting the stored tubers with sulfur or activated
charcoal would be a good inclusion with the peat moss. Rehydrating the
plants prior to replanting sounds like a good idea, but no more than
overnight. It works for other plant species brought out of storage,
so why not hardy cyclamens? That’s as far as I dare go with my
limited knowledge. If I learn anything more from valid sources, I’ll
let you know.
Q: My sister-in-law’s
fig tree has small, black, sticky egg like casings on the stems, but not
anywhere else. She did find a web hanging from one of the stems. Can you
tell me what is on her fig trees stems? What can she do to get rid of
it and keep it from coming back? (e-mail reference)
A: Your sister-in-law
has a fig tree that is infested with scale and spider mites. If it is
as bad as I think it is, she might be better off dumping the plant.
Sprays and wipe-downs, along with the possible use of systemics may
be needed to bring everything under control. However, very few people
will give up without a fight, so I have a few suggestions. Take a cotton
swab or cloth that is soaked in rubbing alcohol and wipe the scale spots
off the stem. Purchase some Fungicide 3, which is an insecticide, miticide
and fungicide. Spray all the surfaces of the plant. If that doesn’t
work, then bring in the heavy artillery, which is Orthene. This is a
system/contact product that kills on contact through internal absorption
into the vascular system of the plant. For step 3, I suggest having
the plant outdoors for the summer, if possible. If not, then just the
application of the systemic material.
Q: I purchased a columbine
plant from a catalog a few years ago. The plant did well the first and
second year. This year it has exploded. I’ve dug up at least 60
new plants in the last few weeks. After this last rain, I looked and plants
are everywhere! Is this normal or will I be fighting this flower like
I fight the spread of strawberries in my garden? (Brookings, S.D.)
A: Columbines typically
will self-seed, but will not be a problem from an invasive standpoint.
They typically weaken when they go to seed, so many of the seedlings
will not mature. I have had columbines in my backyard for many years.
We always get a good flush of growth and a few flowers. They eventually
die if they are not reseeded. You may have an ideal location for this
species to self-propagate, although I never have heard of it being a
problem. If this is creating something that you don’t want, then
nuke everything with Roundup before they have a chance to seed.
Q: Is it bad to pick
crab apples off a tree? (e-mail reference)
A: Who said it was?
If it were, there would be thousands of us who would be committing this
“bad” action! In what way is it supposed to be bad?
Q: I have a 5-year-old
hibiscus. It used to flower, but now it has grown into a tree with no
flowers. I have given it sunlight, a bigger pot and vitamins. What should
I do? (e-mail reference)
A: Have you ever
cut it back? Sometimes that is what is needed to push it to flower.
Perhaps the container you moved it into is too large, so it won’t
flower until it is pot-bound. Don’t make the mistake of fertilizing
it too much.
Q: I have a large
hackberry tree with a new lawn under it. This year I have tons of tiny
seedlings sprouting under the tree and throughout the lawn (too many to
pull out). Is there something that I can use that will get rid of the
seedlings, but leave the lawn and trees unharmed? (e-mail reference)
A: Just mow the
grass. Woody plant seedlings don’t tolerate mowing. When the seedlings
reach the height of the mower blade, the growing tip is cut off and
they will die.
Q: My yard is sodded
with blue grass. After the sprinkler system was installed a year after
the sod, the areas over the pipe are growing tall fescue from a possible
reseed. It looks terrible (color mismatch) and grows at a different rate.
What can I do? (e-mail reference)
A: Get out the Roundup
and spray along the lines where the tall fescue is coming up. After
that, cut the dead material out and resod with Kentucky bluegrass again.
Q: Many of my neighbors
are now mowing their lawns and bagging. They cut the grass short, but
it really greens up. Is this advisable at this time? (e-mail reference)
A: This often is
called a “cleanup mowing” that removes the top third of
the old grass and allows the sun to hit the crown and soil, which warms
up the soil and stimulates new growth. I just drop my mower down one
notch and bag whatever I cut. If you leave it alone, the grass also
will green up, but later. Scalp mowing, which many folks do, is tough
on the grass and the machine and opens the crown too much, giving the
weed seed an opportunity to sprout and grow competitively with the grass.
Those who do it this short should get their blades resharpened to do
a better job of cutting the grass during the summer.
Q: I think I have
Asian beetles (they look like ladybugs) in one of my flower gardens. I
was told to plant rosemary to get rid of them. Does this really help?
I had hundreds of them against the side of my garage when I was cleaning
out the flower garden last fall. I really would appreciate any info as
to how to get rid of these bugs. (e-mail reference)
A: I don’t
know of anything that will get rid of the beetles outside of normal
attrition. I have not heard that rosemary works to get rid of them.
Look at it this way; your garden should be free of aphids because of
the beetles.
Q: I have a row of
honeysuckle and a row of lilac trees. They are about 25 years old. They
have overgrown to the point that you can’t walk through them and
the branches are lying on the ground. Can they be trimmed or will they
die because they are so old? (Gardner, N.D.)
A: If they were
alive last year, chances are excellent that they still will be alive
now, with some dead branches thrown in. Cut them back to the ground
with a chain saw before they leaf out and then stand back! You will
get a surge of growth that will overwhelm you, but very few, if any,
flowers that year.
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
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