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September
1, 2005
Hortiscope
Ronald C.
Smith, Horticulturist
NDSU Extension Service
Q: I have a coleus
plant with burgundy or red leaves and green on the flowers. I watered
it the other day because it was drooping. It did well after watering,
but within days some of the leaves became pale or faded. What does this
mean? Will the plant die? (e-mail reference)
A: The plant likely
is in too much shade. Try giving it a little more light, but not too
much all at once.
Q: I have been growing
wave petunias for several years to plant in hanging baskets. Trying to
beat previous years, I have been adding more and more plants in the containers.
I placed 10 plants in a 14-inch basket and six plants in a 12-inch container.
They are not doing well even though I water them daily and fertilize weekly.
I suspect that I have too many plants in the containers. How many plants
should be placed in such baskets? (e-mail reference)
A: Good heavens!
I promise that four plants per container will do a fantastic job of
overflowing the basket. Each plant spreads 4 inches in every direction.
Q: I have cactus houseplants
for the first time. I know that if in doubt, do not water, but I must
water some time. How do I know when to water and how much? If some leaves
fall off, does that mean I’m overwatering, underwatering or is that
normal? I have had my plants for about three weeks and have watered once.
One plant is losing leaves. (e-mail reference)
A: Since there are
as many cacti as there are Smiths (almost!), I suggest you go to the
Web site www.fortunecity.com/greenfield/profit/262/caredir.html
and roam through all the cactus care tips based on the species you have.
Q: I have a Norfolk
Island pine that has started losing its branches and is turning a pale
color. I have added Miracle-Gro and put it under some trees to keep it
out of the sun. I am afraid I am going to lose the tree, which was given
to me by a good friend. What can I do to prevent more damage? (e-mail
reference)
A: Norfolk Island
pines are fussy about being moved, so this is a common problem. It sounds
like you have done all you can to help, so now the waiting begins. If
it continues to decline, do an air-layer on the top 12 inches of the
plant. That will at least keep the plant alive, but smaller, and will
give the pine a chance to adapt to your home environment.
Q: Is there a hosta
that will do well on the west side of my house? It would be planted under
a tree, but would get west sun around 4 p.m. until the sun sets. Thanks
for your help. (e-mail reference)
A: There is sun-tolerant
hosta, but I don’t know which cultivars. A visit to a local nursery
may solve the problem for you.
Q: I’m new at
growing fruit trees, so I have a lot of learning to do. I have Italian
and Stanley plum trees. My problem is I can’t get any fruit off
these trees. They won’t produce blossoms. The Stanley is at least
5 to 6 years old. The Italian is 4 to 5 years old. All I gave them for
fertilizer last year was a fertilizer stake per tree. This spring, I sprinkled
some compost around the base of the trees. (e-mail reference)
A: The trees probably
got their flower buds nipped by the cold in the dead of winter or by
the warming/freezing cycles in spring. Don’t waste your money
on fertilizer spikes because they will not get your tree to flower or
help it grow. Most fruit trees do not need fertilization unless you
are growing them for commercial purposes or they are growing on nearly
pure sand.
Q: What can I use
for fertilizer or weed control on strawberries? I planted them before
the rain last week. They are very hardy looking plants that were grown
here in North Dakota last year. (e-mail reference)
A: The best weed
control, unless you have more than a quarter acre of strawberries, is
hand weeding and mulching between rows. As to fertilizer, a broadcast
of 10-10-10 at a rate of 4 to 5 pounds per 100 square feet would do
the trick in the absence of a soil analysis. An application of Miracle-Gro
as they are attempting to get established would be even better.
Q: I bought four small
pontentilla bushes that bloom reddish pink flowers. What other plants
or bushes complement pontentilla and are low maintenance? (e-mail reference)
A: Why not visit
a local garden center and see what lights your fire? I don’t know
where you live, the kind of light exposure you have, the soil type or
what objectives you want to achieve in your landscaping, other than
low maintenance. A local garden center that employs a designer can help
you better than I can. You need to have a plan developed to have a cohesive,
functional and attractive looking landscape.
Q: What chemical will
control grass in our strawberry bed? (e-mail reference)
A: Garden strawberries
do not have a chemical recommendation for weed control. Hoeing and hand
pulling are the best suggestions. Herbicides should not be applied while
the plants are blooming, when runner plants are taking root or during
late summer/early fall while the fruit buds are forming. This makes
applying the right herbicide at the right time a tricky proposition
at best! Hence, herbicides mostly are limited to commercial growers.
Q: We will be placing
window boxes around one of our local buildings - on the east and west
side, easy wave petunias and the north side a mix of impatiens and begonias.
A watering system
is being installed to water each basket daily. How often should we fertilize?
Some say a low dose each day, while others say two doses of clean water
and feed on the third day. (e-mail reference)
A: A low dose every
day would be best, if you are good at making low doses. Miracle-Gro
fertilizer is about as good as it gets for this purpose.
Q: I am trying to
find out how to extract seeds from rose hips. (e-mail reference)
A: It’s a
piece of cake. Allow the hips to mature on the plant, cut them off and
when dry, simply cut or break them open to extract the seeds.
Q: I have a good-sized
dieffenbachia plant. The leaves on the bottom are growing upward rather
than fanning out. The leaves are at a perfect height for our dog (a boxer)
to walk under them and let the leaves rub over his head and back. He seems
to be seriously attracted to the plant. Is there anything about the plant
that could be poisonous to the dog? I’ve tried to do some research,
but haven’t been able to find much information. Yes, I know my dog
is weird. (e-mail reference)
A: Your dog is normal,
not weird. Dieffenbachia can cause death if the dog decides to take
a bite out of it. The common name for this plant is “dumbcane,”
which does not refer to an IQ level, but the fact that all parts of
the plant contain high levels of calcium oxalate. It can cause irritation
and swell the dog’s membrane tissues and tongue to the point of
possible suffocation. Understand that this is not a poison in itself
(spinach and Swiss chard also contain it to much lesser amounts). However,
the concentration of this crystalline substance is very high in dieffenbachia.
Perhaps your dog is smarter than you think. The dog may know intuitively
what the plant contains and simply is using the leaves to gently scratch
his head without ever intending to take a bite out of the leaf. Should
he ever do so, get him to a veterinarian because the effects can be
countered quickly with an injection.
Q: We have a problem
with bromegrass in our lawn. We are close to a fence line with bromegrass
in it that goes to seed each year and invades our lawn. Is there a way
to eradicate it other than reseeding? Would Siduron work? (Corsica, S.D.)
A: Siduron will
work if you have annual downy brome (Bromus tectorum). I don’t
know what is common in your area. In North Dakota, we are confronted
with perennial brome (B.inermis), which Siduron would not touch. If
it is a perennial, then the only control is Roundup.
Q: We need to know
the best way to revive a 40-year-old caragana hedge. (e-mail reference)
A: A caragana hedge
can be revived by cutting it back completely to the ground. Do it early
in the spring, before leaf-out occurs. Now would be too late, as the
major energy expenditure has taken place. The hedge possibly could be
too low in energy reserves to put out decent regrowth. The second, but
less dramatic, choice is to cut back a third of all the canes this year.
Cut the canes to the ground, starting with the oldest ones first. Do
this over a three-year period and you will have revived the hedge. Unlike
the first choice, you can do this while the hedge is in leaf because
the plants will have enough leaf cover to manufacture food for the rest
of the season and store some away for next spring’s surge.
Q: I have several
peony plants that must be at least 30 years old. They bloomed profusely
until last year. Now we are getting about six flowers per plant. Is there
something I can do or have these plants exhausted their life expectancy?
(e-mail reference)
A: Dig and divide!
If you do it this fall, they may outlive both of us.
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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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