|
July
14, 2005
Hortiscope
Ronald C.
Smith, Horticulturist
NDSU Extension Service
Q: In early November,
I planted many tulip bulbs. I was thrilled when every single one popped
up out of the ground earlier this spring, but I am concerned about the
leaves. They are twisty and do not lay close to the stem. I keep them
watered, but not too much. I read the description of tulip fire disease,
but I don’t think it is that because there is no brownness or gray
fungus. Is it normal for the leaves to be a little twisted? (e-mail reference)
A: It sounds like
a reaction to a herbicide that may have been used in the planting bed
or the adjacent turf area. Unless you have very dry and sandy soil,
you don’t need to water tulips once they are established.
Q: Are there maple
trees that do not produce seedlings (whirly birds)? I love maple trees,
but do not like the mess from the seedlings. (e-mail reference)
A: Many maples are
seedless. Go to any nursery and ask for a “male clone” of
the species of maple that you want.
Q: We bought a house
late last summer and discovered a pear tree. There were full-sized pears,
but they were bug-ridden and unusable. This spring I expected to see the
tree flowering, but it isn’t. Are there types of pear trees that
don’t flower? Are the pears edible? What should I do to keep the
bugs away so we can harvest the fruit? (e-mail reference)
A: Pear trees that
bore pears last year should be flowering this year. You didn’t
tell me where you live, but in North Dakota the pear trees are in flower.
To control insect damage to the fruit, a spray schedule and good sanitation
(picking up fallen fruit) are essential. The spray schedule starts with
a general-purpose fruit tree spray. This insecticide/fungicide combination
is available at most garden supply stores. The general schedule is to
spray at bud swelling, at petal drop and again about 10 days later.
Q: Is there any product
that can be used in flowerbeds to control or eliminate dandelions after
the perennials start growing? I have so many, but some physical limitations
prevent me from removing that many by hand. (Jamestown, N.D.)
A: Spot spraying
carefully with Roundup is the only alternative I can suggest at this
point.
Q: I have a curious
question to ask you about sowing lawn seeds. I am told that some seeds
should be buried and some exposed as long as they are firmed on the ground.
Can those exposed seeds germinate? (e-mail reference)
A: If the seeds
you are talking about are Kentucky bluegrass, ryegrass or creeping red
fescue, they simply need to be lightly dragged and firmed into the surface
of the soil. Most grasses need light for germination. If the seeds are
buried, germination will be slow. The moisture problem is solved in
part with a straw or virgin wood-fiber mulch spread lightly over the
top and the entire planting lightly irrigated three to five times a
day until germination is evident.
Q: I have a beautiful
lilac that greens up beautifully every spring and has many beautiful purple
blooms. They smell great! However, every year one stem of the bush seems
to die. All the leaves fall off and it looks dead. The next year it comes
back with green leaves and blooms. Then another one will lose its leaves.
I can’t figure out what’s wrong. (e-mail reference)
A: I don’t
have any idea what is causing the problem. Sorry!
Q: I have a schefflera
that is having some problems. I inherited it from the women who had my
apartment before me. It only has a few stalks that have grown out very
long and only have leaves at the ends. I have to tie up all the trunks
to keep them from splaying out. I am getting new growth on it, but it’s
only on the top. Do you have any recommendations on how to make it bushier?
Should I prune it back? Just recently, I started getting very bright yellow
spots in the center of some leaves that are starting to spread out. There’s
a light green “halo” around the yellow spots. The edges of
the leaves are still dark green and the undersides look normal. I have
searched the Internet, but can’t find any mention of this. Any idea
of what’s going on? My other schefflera is doing extremely well.
Almost too well because I can’t get it to stop growing! Nevertheless,
the other plant always has been a little peculiar. (e-mail reference)
A: Unlike a peculiar
relative that you can’t get rid of, the peculiar plant you describe
is hardly worth the time you need to put into it. However, I detect
a hint of a plant lover in your note, so the above advice probably is
not sitting too well. So, I’ll offer some alternative advice.
The plant needs stronger and more light. It also needs to be pruned
back. Those floppy stems are not going to improve with time. We can’t
take the 98-pound weaklings and turn them into pumped-up beauties! The
plant also has a fungus that got started in that particular leaf. By
cutting it back and disposing of the wimpy, sickly leaves, you will
or should be removing the inoculum. Once you have performed the above
tasks, I would suggest summering the plant outdoors or at least in an
area where there is bright, indirect light. If you place it outdoors,
do so under the canopy of a tree or on the north side of your building.
Q: Can you tell me
how to save my aglaonema or “silver bay”? There are several
firm, green stalks, but the leaves have died off. I believe they were
sunburned. I’d like to find a way to get leaves on the stalks again
or else I’m afraid it will die. (e-mail reference)
A: The Chinese evergreen
is one of the premiere shade-loving plants. All I can suggest is to
remove the remaining leaf stalks and maintain the plant as if it still
had leaves. Keep the plant in subdued light, not direct sunlight. If
no new leaves emerge in six weeks, then the plant likely is shot and
should be dumped.
Q: I want to plant
old-fashioned lilac bushes to be used as a screen. How far away should
they be set from an above-ground pool? I do not want them to grow under
the pool or to puncture the sides. (e-mail reference)
A: I would plant
the lilacs at least 15 to 20 feet away from the pool. The more distance,
the better.
Q: I am trying to
figure out the amount of peat to buy. Do the 5.5-cubic-foot bags of peat
fluff to more volume when it comes out of the bags or is that all there
is? (e-mail reference)
A: Yes, those are
compressed bails and the peat literally doubles in volume when it’s
broken up.
Q: I planted a lilac
bush about five years ago. The first year it bloomed and there were a
few flowers with a lilac color. Now, every year it blooms with white flowers.
The bush is beautiful. Is there anything that might be missing in the
soil to produce a lilac color flower? (e-mail reference)
A: No. Something
happened or you got a grafted plant where the scion wood was pruned
off or that part of the plant died, so the rootstock is now producing
the flowers.
Q: I would like to
grow peonies for drying. The colors I would like are red and dark pink.
Sometimes, the varieties that are too red turn black when dried. Do you
have any suggestions on specific varieties to try? (e-mail reference)
A: I don’t,
but you may want to visit my Web site at
www.ext.nodak.edu/extpubs/plantsci/landscap/h1037w.htm. There are
several methods listed for preserving flowers that may give you better
results.
Q: We recently purchased
a property that has a large strawberry patch. I don’t know very
much about strawberries, except that I like them. How do I clean the patch
in the spring? Do I remove all the dead foliage? Do they need fertilizing?
(e-mail reference)
A: I wish people
who write and ask me cultural questions dealing with outdoor seasonal
plantings would give me their location. It would help me answer the
question with greater accuracy. If your berries have not started growing
new foliage or even if they have, get in there and cut them back with
a lawn mower set as high as possible. Collect the cut foliage in a bagger
attachment. This normally is done in late fall to remove the foliage
that may be carrying disease and insects from the summer season. If
there are no flowers showing at this time, you probably still can do
it. Here are some Web sites that will give you a good background on
growing strawberries:
www.ext.nodak.edu/extnews/hortiscope/fruitveg/strwbrry.htm
or
www.ext.nodak.edu/extpubs/plantsci/hortcrop/h16w.htm.
If you have any more questions after reading through my two sites on
strawberries, get back to me and I’ll try to help you.
Q: I am looking for
a shrub to plant in our yard. I need a shrub that has a short root system.
The location of the shrub row is between a ditch and our septic system
drainage field. Unfortunately, this is in our front yard. I would like
to have this hedge serve as a fence and decoration. Do you know of a shrub
that would suit my needs? (Karlstad, Minn.)
A: Thanks for letting
me know where you are. Cotoneaster and honeysuckle come to mind. Visit
a local nursery to see which of the two you prefer.
Q: I was at a gardening
workshop and was told that bleeding heart plants like milk. They did not
go in to any details. It sounded crazy to me, so I did not ask for details.
Is this true? I have checked quite a few Web pages, but have not found
any information about it. I did a Google search and your page came up.
Since I used to work at NDSU, I thought I would drop you a note. (e-mail
reference)
A: I hope it wasn’t
one of my colleagues who made that statement! Milk is a liquid that
has many nutrients in it that can benefit any plant it is dumped on,
but why waste milk on a plant when it can get along perfectly well without
the milk. There are millions of bleeding heart plants across the country
that are doing fine, but have never had the “milk treatment.”
Watering and normal fertilization practices are all that are needed
for literally 100 percent of all horticultural plants, such as houseplants,
flowers, trees, shrubs, herbs and lawns. Any liquid that isn’t
toxic to plants, such as coffee, tea, beer or diluted urine, will benefit
plants in some way. Thanks for alerting me to this. I’ll keep
my ears open to find out the origin of the story.
Q: Could you provide
me with information on how to transplant African violets? Can I transplant
when they are in bloom? (e-mail reference)
A: Knock them out
of the pot, get fresh potting soil specific for African violets, and
get a slightly larger pot. Repot at the same depth they were in the
original pot and water it. African violets frequently are repotted while
in bloom. It doesn’t hurt the plant, but the blooming cycle usually
is truncated at that point. You may want to take the opportunity to
propagate these plants through vial leaf petiole cuttings to increase
your numbers and act as a hedge against any dying out in the future.
Q: I have a question
about a silver maple tree that was planted a few years ago on the south
side of our house. It is growing, but the leaves are always pale yellow
green and they dry up and fall off in late summer. It doesn’t seem
to follow the other silver maples in the area. What can I do to green
up the leaves and keep them on the tree to turn color and then fall at
the proper time? Thank you. (Moorhead, Minn.)
A: You very likely
have a seedling selection of silver maple that is not tolerant to the
alkaline soil in our region. You can try fertilizing with an iron-based
fertilizer to see if that corrects the problem, but in more cases than
not, it is a futile effort, with the tree eventually dying or needing
to be cut down. If you replace the tree, be sure to purchase a named
cultivar, such as northern acclaim thornless honeylocust. This and other
named regional trees have been tested for tolerance to our environment,
including the cold, heat, disease, insect, and soil conditions.
###
Source: Ron
Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu
|
