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July
7, 2005
Hortiscope
Ronald C.
Smith, Horticulturist
NDSU Extension Service
Q: I planted some
tulips for the first time last fall. They bloomed nicely, but all of the
petals fell off some of the plants. Will they rebloom or will I have to
wait for the next season? (e-mail reference)
A: Tulips bloom
once during a growing season and then gradually go dormant. They will
rebloom for you next spring, if you allow the foliage to die down naturally.
Q: I understand that
bonsai is a technique that helps a tree live longer. Some trees are much
easier to assist than others. Is a Norfolk pine one of these? I’ve
read that they are more delicate and pruning is more difficult. I have
a few seedlings and would like to try the root-over-rock technique. Is
it worth the effort? (e-mail reference)
A: I would say no.
Norfolk Island pines make beautiful houseplants, but they, unless you
have a lot of skill, make poor bonsai plants. Go for a juniper instead.
Juniper is the beginner’s choice because of its ease of establishment,
and tolerance to abuse and neglect, and it makes handsome bonsai specimens!
Q: I recently moved
to an area where I can have my two horses. The area I converted into pasture
has about six 10- to 12-year-old red maples in it. Last winter my horses
ate the bark off the trees. I pruned what didn’t look good or survive.
I can’t seem to find a definitive answer on how to treat the trees.
Should I wrap them and then put fencing around them? Should I spray the
trees with a deer repellant? Should I cut them down? Do they poison horses?
Every time I go to do one thing, someone tells me something different.
Do they need sunlight to grow new bark? (Wabasha, Minn.)
A: I strongly suggest
putting a fence outside the drip line of the trees so the horses cannot
get to the bark or foliage. According to my poison plant references,
at least two cases of livestock death involving cattle and horses have
been reported in West Virginia. As to the tissue damage where the horses
stripped off the bark, I would take a knife and cut back to where the
bark still is attached. The trees will heal on their own. You don’t
need to wrap the trees or treat them with any deer repellents because
the fence should take care of the problem.
Q: I have a staghorn
sumac that is sending shoots out in many places. Can I dig these up and
replant them in other places? I don’t want any more in the area
where the main tree is located. If these shoots can be replanted, what’s
the best way to do it? (e-mail reference)
A: Replant as early
in the season as possible and with as much of the root as possible.
Give them a good soaking after replanting and water them enough to keep
them from wilting.
Q: What can you use
for the control of insects on strawberry plants and when should I use
it? (Cavalier, N.D.)
A: You can use Malathion
before growth begins. Use Sevin or Endosulfan after growth has started
and the flower buds are just separating. Do not use insecticides during
the blooming stage! Use Sevin again, if needed, 10 to 14 days past blooming.
Check to be sure that the damage is not a slug problem. If you do suspect
the problem is slugs, carefully apply metaldehyde to the affected area.
Be careful that you don’t get the bait on the fruit.
Q: Can you please
tell me if there are certain varieties of tomatoes that have a low acidic
content? I’m trying to avoid getting canker sores. At the end of
last summer, my husband and I got canker sores for the first time in our
lives. After eating all of our tomatoes, we quit getting the sores. This
year we only want to plant varieties that won’t cause these painful
sores. (e-mail reference)
A: NDSU has done
some studies on the acidity of tomatoes. The pH does vary, but mostly
stays above 4.3. Some of the varieties that tested high for us (above
pH 5.0) are health kick (5.04),vita gold (5.09), La Roma (5.08), Russian
(5.09), super marzano (5.20) and classica (5.05).
People often mistake
the pink- or yellow-colored varieties as having a higher pH (lower acidity),
but that has not proven to be the case when looking at the research.
Generally, the lower acidity taste is due to a higher proportion of
sugar to acid in the fruit, so it is not as noticeable when eating.
I would suggest allowing the tomato to remain on the vine until it has
reached the maximum level of ripeness to allow for greater sugar accumulation
and lower acid taste.
It is often thought
that canker sores come from something like eating too many tomatoes,
but it is often a sign of some nutritional imbalance in the body. I
would suggest checking with a nutritionist, dentist or doctor to be
sure that there is no mineral or vitamin deficiency (especially B12)
in your system.
Q: I have someone
with bottom-rot on their tomatoes. Any idea of the cause? (e-mail reference)
A: Blossom-end rot
is a physiological disorder caused by an incomplete cell formation at
the time of fruit development on the blossom end. It is common on early-setting
tomato cultivars. It usually disappears when fruit develops. The way
to avoid a recurrence is to maintain an even soil moisture level as
much as possible and avoid dry/wet cycles. Don’t cultivate too
aggressively around the plants and damage the roots, and avoid overfertilization
with high-nitrogen material. The cell tissue breaks down due to insufficient
calcium and other minerals that go into cell-wall development, so rotting
pathogens then set in. The affected part can be cut out and the rest
of the tomato eaten, but the tomatoes would have to be discarded if
they are intended for market purposes.
Q: I was just on your
Web site to find out if I could start a rose bush from a clipping. You
said that it was easy, but you didn’t say how. Is there a certain
area on the rose where I should take the clipping? The bush I want to
take a clip from has been doing well for years. I’m new at trying
my hand at starting new roses, so any help is a big plus. (e-mail reference)
A: It’s a
piece of cake. Take cuttings from wood that is not in flower. The cuttings
should be at least 6 inches long. Stick the cuttings in a sand/peat
mix (50/50) that you can keep moist. The cuttings should be kept away
from direct sunlight. Mist several times a day to keep the cuttings
hydrated. They should set roots in six weeks or less. If the cuttings
wilt, then wait until the plants go dormant this fall and then take
the cuttings sometime before they leaf out the following spring. Rooting
hormone powder will help push things along. To learn more about plant
propagation, go to my Web site at
www.ext.nodak.edu/extpubs/plantsci/landscap/h1257w.htm.
You will find all kinds of information on the Web site about starting
plants from cuttings, grafting, budding, seed and tissue culture.
Q: Can a Madagascar
dragon tree plant that is a houseplant be taken outside for the summer?
I have had mine outside for about a week and now the leaves are turning
white. Will it be OK or will it die? (e-mail reference)
A: It can be moved
outdoors, but it can’t go from a 300 foot-candle light intensity
to a 10,000 foot-candle intensity without some damage to its tissue.
Place it outdoors after all danger of cold weather is past. Temperatures
of just 50 degrees at night can cause problems with houseplants. That
may have been what happened to your dragon tree. If the plant tissue
did not freeze and the main stem still is firm, then there is a chance
that it will recover in a few weeks. Just be patient and don’t
treat it any differently than you normally would.
Q: I planted a thunderchild
crab apple tree on my front lawn last year. At the time, it was flowering
and looked wonderful. This year the buds seem to be dry and brittle like
they’ve been through a drought. When I touch them, they feel hard
and there is no sign that a soft leaf is trying to poke through or open
up. (e-mail reference)
A: It sounds like
the parts you examined are dead. If this is true with the entire tree
and there are no buds emerging, then the tree is likely finished.
Q: I transplanted
a sand cherry bush. It probably was the wrong time of year to do so, but
I needed it moved. I did the same thing to this bush two years ago. The
roots stayed active and a new bush evolved. Can I do anything to kill
the roots? Will the roots of perennials eventually penetrate into my concrete
foundation? (e-mail reference)
A: The roots won’t
penetrate the foundation unless they are “superroots!” As
to the roots regenerating a new shrub, if you see new sprouts coming
up, spray or paint them with Roundup.
Q: I have a blue hydrangea
(endless summer variety) that I would like to fertilize with aluminum
sulfate to encourage blue flowers. How often should I fertilize? (e-mail
reference)
A: Fertilize it
once a month during the growing season.
Q: I had a producer
ask about evergreens that appear to have a lot of winter injury. The evergreens
are on the edge of town, so they are very visible. He is wondering about
using a liquid fertilizer to spray on the foliage. I told him that I would
be scared of burn. I suggested Mir-Acid, but he says he has too many trees
to use Mir-Acid. He feels liquid fertilizer would have the same effect.
I think liquid fertilizer is mainly nitrogen, while Mir-Acid has many
other nutrients in it. (e-mail reference)
A: He does not need
to spray the trees with fertilizer to get them to recover. He is better
off allowing nature to do its own repair work. If they are going to
recover, they will do it without extra nutrients being applied. Spraying
with a nitrogen-rich material may stimulate too much growth, subjecting
the evergreens to increased insect and disease problems. I have seen
mountainsides covered with evergreens with the same problem. When I
passed by them again two months later, most had greened up without any
human intervention. He’ll probably spray anyway because most people
are stubborn about this.
Q: I would like to
share a true story. I told a friend that if he ever divided his peony
I would like to have a part of it. The next time that I saw him, he handed
me a couple of stems from the bush. Not knowing what to say, I thanked
him and went home and planted the stems. Imagine my surprise when the
bush began to grow the following spring. Last spring, the bush was as
big or bigger than a bushel basket. (e-mail reference)
A: Thank you for
sharing that story! I’m sure the stems had some root part attached
to them and you obviously are blessed with a green thumb. Keep gardening!
Q: I just received
a small, potted gerbera daisy. I am concerned about how much and how often
I should water it. I have heard many cases of plants dying because of
overwatering. Also, should I be feeding it fertilizer? Should it be moved
to a larger pot? I plan to keep this plant in the house. (e-mail reference)
A: This is likely
one of the newer, compact cultivars. It shouldn’t need a much
larger pot. If you want to move it up to the next pot size, probably
a 3- or 4-inch pot, that would be the maximum needed. It needs liberal
amounts of water during the spring and summer seasons and to be on the
dry side in the winter. Allow the soil to dry down before watering again.
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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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