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August
5, 2004
Hortiscope
Ronald C.
Smith, Horticulturist
NDSU Extension Service
Q: I am trying to
grow plants near my garage. I have plastic and rocks on it, but it gets
quite wet. I want to plant something that has good color. (Gonvick, Minn.)
A: To help dry the
soil, get rid of the plastic and rocks. You need to make your selections
based on how much sun the area gets, what size plants you want and if
you want flowering woody plants or flowering herbaceous plants.
Q: We purchased two
greenspire lindens about three years ago. I would like to know about making
tea out of the flowers. Is there a better variety of linden to use or
is the greenspire a good choice? Do I pick the small flower clusters as
soon as they appear or wait until they dry? I have a dehydrator and need
to know how or what to do to make tea. (e-mail reference)
A: The flowers are
dried in a dehydrator. Harvest when fresh off the tree. Place one teaspoon
in a cup of boiling water and allow to steep for about 10 minutes. Store
the flowers in a clean, air-tight container in a cool location or freeze
in a ziplock freezer bag.
Q: I would like to
expand and reorganize my raspberry patch. I have seen raspberries growing
in about two-foot diameter clusters, but I can't find any information
on growing them this way. What is the best spacing and what is the best
way to bind the canes? (Fargo, N.D.)
A: Raspberries have
been grown just about every way possible. I suppose the best way is
the one that suits the individual gardener. Without control on a regular
basis, raspberries can become an invading, obnoxious weed! I have grown
them in rows with enough space to get my small tractor through with
a cultivator attached. I am currently growing a few in my backyard.
The plants are supported by wire attached to stakes at the end of the
rows.
Q: I have red bumps
on the leaves of my maple tree. Do you know what this is and how to fix
it? (e-mail reference)
A: Those red bumps
are caused by a small mite that lays eggs in the developing tissue early
in the spring. The bumps you see are the larvae hatching and starting
to feed. There’s nothing you can do about it, but the damage is
mostly cosmetic and not lethal. It usually shows up for a couple of
years. Weather extremes or natural predators usually take care of the
problem.
Q: I planted some
bulbs last April. They weren’t growing so I dug them up and found
a bunch of small little white worms in them. What are they? Some of the
bulbs are now starting to grow, but very slowly. (e-mail reference)
A: Some type of
insect laid eggs in the bulbs. The eggs hatched and the worms are now
in the larval (feeding) stage. They will eventually consume the bulb
to the extent that it will not produce much of a flower, if at all.
Your best bet is to dispose of them.
Q: I recently purchased
some plum trees, but one of them has a strange problem. On the sprouting
twigs and leaf stems, there are occasional little red nodules about the
size of a straight pin head. They look like small, but fat (quite protruding)
blisters under the skin of the plant. The nodules ooze a small amount
of clear liquid, which the ants like to drink. I sprinkled some diazinon
around the tree. The ants are now gone, but the blisters are still there.
I dug at one of the blisters with a fingernail and they are quite firm.
What do you think I should do? (e-mail reference)
A: From your observations,
it does not appear to be a borer working its way through the tree. It
could be some physical damage from shipping, hail or a bird pecking
into the bark. The ants were after the carbohydrate rich exudate emerging
from the nodules. My advice is to keep monitoring the tree to be sure
that none of the nodules turn out to be borer or bark beetle activity.
Q: I have a ficus
tree that I have had in my upstairs bedroom for about five years. I repotted
it about four months ago with fresh soil and a bigger pot. Now there is
sap running down the walls beside the tree and the leaves that fall off
are sticky. It sits close to a window for indirect sunlight and is near
a vent in the ceiling. Suggestions?
(e-mail reference)
A: Sounds like a
bad infestation of spider mites. Move the plant outdoors as soon as
possible. Visit a local garden center and pick up a miticide that is
safe for ficus plants. Treat according to label directions.
Q: I have 15 arborvitae
that were planted 10 years ago. Suddenly, most of them turned brown halfway
up and appear dead. Amazingly, only one side of the trees turned brown
and the other side (facing my neighbor’s house) is green! My tree
company says they did not spray anything harmful. Only 10 of the 15 trees
are brown. If they did spray something, I would think all the trees would
be brown. I don’t know if our rough winter had anything to do with
it. Is there anything I can do? (e-mail reference)
A: The tree company
may not have intentionally sprayed the trees with anything harmful,
but there could have been some residue from another client where they
did use something that would have been toxic. It may have been used
up by the time they got to the eleventh tree. Also, do you have a lawn
care service? Are the unaffected ones in the shade and the affected
ones in direct southwest sunlight? These are all only guesses. Don't
give up on the trees. I've seen some that I didn’t think would
make it, only to be pleasantly surprised at their total recovery.
Q: We have a mature
boxelder tree in our yard that looks sick. The leaves have black spots,
are smaller in size than past years and dropping from the tree. Any idea
what might be wrong? (e-mail reference)
A: It could be any
number of fungal diseases. Have an International Society of Arboriculture
certified arborist inspect the tree. There might be more than one thing
wrong with the tree. It is a good idea to get boxelders inspected on
a regular basis as they mature.
Q: The needles on
my creeping juniper have started to turn brown. I think the problem is
webworms, but I can’t find any worms. (e-mail reference)
A: It could be any
number of causes such as disease, environment or pollutants in the air.
Take a sample of the plant to a local, competent nursery. If they don't
know, contact the local state or county Extension office for some assistance.
Q: My roses have orange
stuff all over them. We have had them for 32 years, but this is the first
year this has happened. I figure it is a fungus, but would like to know
what to do about it. (e-mail reference)
A: You are right;
it is a rust fungus. At the first sign of this malady, pick off and
destroy the affected leaves. If it is too late for that, spray with
a fungicide appropriate for rust on roses such as lime/sulfur or one
of the many other products on the market. Repeat the treatment according
to label directions, which is generally every 10-14 days or when new
growth emerges. In the fall, pick up all fallen leaves and prune back
as you normally would. Next spring, prior to new growth, spray again
with lime-sulfur. Hopefully the wind and moisture sources will be in
your favor.
Q: I planted a silver
maple in my backyard in mid-April. I believe it is a silver queen. It
had a few leaves on it when it was planted. It did not produce any more
leaves and now the existing leaves are dead. Some of the small branches
seem very brittle. Any ideas? (Fargo, N.D.)
A: Planted too deeply?
This is a good cultivar that is adapted to our area. Take a branch to
the nursery where you made the purchase to see if they can help you.
Q: I recently found
out the beautiful tree in my backyard is a linden. I brought a branch
to my local tree spraying company and found out that the white spots on
the back of the leaves are cottony maple scale. I've noticed them on the
tree the last two years. What do you recommend as a treatment? Is there
another alternative to spraying? (e-mail reference)
A: Give your tree
company a chance to serve you since they identified the pest. There
are summer oils and insecticidal soaps that can be applied that will
help control this pest without polluting the neighborhood or putting
you or your children in danger. If they are a good, full-service company
with Certified ISA arborists, they should be able to offer you some
alternatives other than a highly toxic spray. Some action needs to be
taken because, if left unchecked, these pests will multiply and eventually
weaken the tree, predisposing it to further attacks from other insects
and disease organisms.
Q: Can I put my angel
wing begonia outside? I'm not sure which side of the house would be best.
South is probably too hot, but it's about the only side that gets decent
sun. Any advice? (Park Rapids, Minn.)
A: Give the angel
wing all the bright, indirect light available, but keep it out of the
south exposure or it will cook. Summering houseplants outdoors is like
going on vacation for most of them.
Q: My mother bought
us a nice hanging basket containing two cascadian bi-colored petunias
just over a week ago. In the last few days, the leaves in the middle and
around the edge started going limp and curling. Can you tell me what the
problem is and if I can rectify it? The plants get a lot of sun and I
water twice a day. At the moment, there are still plenty of healthy looking
flowers on the plant. (e-mail reference)
A: Most likely it
is Botrytis fungus getting started. To help clear it up, back off on
the watering to once a day. You may also want to spray the plants with
an all-purpose fungicide.
Q: Why would a lilac
bush not produce many flowers? (LaMoure, N.D.)
A: There are numerous
possibilities such as too much nitrogen, shade, immaturity and possibly,
too low a temperature, but that is unlikely where you are.
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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