Ronald C. Smith, Horticulturist
NDSU Extension Service
Q: I have the weed speedwell in my lawn. What can I use to get rid of
it? It has taken over a part of the country cemetery also. (E-mail
reference, Forman, N.D.)
A: All the speedwells I know in this part of the country are annuals,
so a pre-emergent that will control broadleaf annuals should do the job.
If the pre-emergence opportunity is missed, then Trimec should take it
out. Try to get the weed in the early stages of growth when it is most
vulnerable to herbicides.
Q: I want to take out a row of Caraganas around my home. Any suggestions
on how to best do this? (E-mail reference, Carson, N.D.)
A: I assume that they are old and large, so the task will not be easy.
I suggest cutting them back severely, and when new growth emerges, spray
them with Roundup to get a good kill on the roots, being sure to mix the
Roundup with ammonium sulfate for greater effectiveness. Then, with the
stumps that remain, you can either rent a stump grinder and grind them
down below the soil surface, or, if that isn't work enough, they can be
chain pulled out with a truck or winch.
Q: I had a patron stop in today who starts her tomato plants from seed.
Her question is, what are some of the best varieties of tomatoes to grow in
this area? (E-mail reference, Valley City, N.D.)
A: There are probably close to 100 varieties of tomatoes that can be
grown in North Dakota.
Celebrity is one of the best hybrids as it grows with few problems and
produces good sized (not jumbo) fruits. Others are: Sweet 100, Sweet
Million, Better Boy Hybrid, Burpee Hybrid, Early Girl, Stupice, Siberia,
and Better Bush Hybrid to name just a very few. Some are bush, some are
indeterminate; some are large and some are small, depending on what the
Good sources for the seeds are:
Catalog Fulfillment Center
335 S. High Street
Randolph, WI 53956
Tomato Growers Supply Co.
P.O. Box 2237
Fort Myers, FL 33902
Q: Would you please tell me how you put a shamrock to rest, how long it
should be in a rest period, and do you cut it down? (E-mail reference, Ayr,
A: I'm afraid that you've got me on this question. I know they need
some rest, but how much, I don't know. Usually six to eight weeks is a
sufficient rest period for many plants, and generally they are allowed to
dry down. I will stand corrected by anyone who will come up with more
concrete information than this.
Q. My 4-year-old apricot tree got lots of flowers in the spring but no
fruit at all. Do I need to plant another apricot tree to pollinate? What
should I do? I read an article in a magazine with pictures about apples that
are trained and kept short in the front yard but still bear a lot of fruit.
The thing is, they did not include how to train and prune them. Can you give
me some tips how they did it? (E-mail reference, Milpitas, Cal.)
A: First of all, thanks for identifying who you are and where you are
writing from. It helps me to focus on the problem a little better and
gives me a person to respond to instead of just a message. I wish
everybody did that! About your apricot tree. While it is not clear whether
or not apricots need another to cross-pollinate, it would be a good
measure of security to have another one for that purpose. Even if not
necessary, it will only make the fruit set better. I don't know your
climatic conditions in that part of California. In our part of the
country, the apricot is usually prevented from setting fruit by spring
frosts damaging the blooms. That could be the case in your territory as
well. The fact that you are getting flowers is encouraging; you could be
lacking in bee activity at the time the blooms are open, it could be too
windy, or too rainy. For now, try the additional tree. California produces
95 percent of the apricots sold in the U.S., so somewhere in the state
things are going right! What you likely read was about the art of espalier
-- a technique that has fruit trees pruned in a geometric form, generally
in two dimensions -- vertically and horizontally -- against a wall or
fence. Book stores or a local library should have information on that. If
that isn't it, then they were creating topiary plants that have unique
shapes. Again, local references should help.
Q: I have a number of African violet leaves started and it looks like a
number of plants coming on each leaf. It is best to trim out all but one, or
let them all grow? I have had an Annabelle hydrangea for about eight years,
but it has not blossomed. The last few years a few have started to form, but
do not continue to mature. I tried putting on miracid, but it did not help.
At the garden center they suggested a soil acidifier. I tried that last
year, but that did not seem to help either. Do you have any suggestions or
know what the problem could be? (E-mail reference, Bruce, S.D.)
A: I suggest letting the African violets grow for awhile. Once the
original leaf has died off and the plantlets have matured somewhat, you
can divide the crown into two, three or four plants.
Generally, the lack of flowering is due to either too much nitrogen or
not enough sunlight. If you are too good to the plant nutrient-wise, it
may just simply grow vegetatively and not produce flowers. I suggest
giving it some "traumatic stimulation" early this spring, by
taking a straight-edge spade and pushing it into the ground in about three
places outside the spread of the plant to sever some of the roots. Do this
before leaf-out takes place. This often pushes a reluctant shrub or tree
into flowering within a season.
Q: Do I really need to put fertilizer on my trees? If so, which one do
you recommend? (E-mail reference, Milpitas, Cal.)
A: Fertilization of trees is suggested only in response to a
deficiency. Generally, trees need little additional nutrients, since they
have an extensive root system to mine ample nutrients from the soil. If
you start to notice chlorosis (yellowing of the foliage) or shortened
internodes on the branches, then it might be advisable to add a complete
fertilizer like a 10-10-10 or one that contains microelements like iron
and copper. To know where your soil stands in nutrient content, I suggest
getting a soil test done. Have the pH, organic matter, N,P, and K and the
soluble salts checked.
Q: We have a grandson who wants to use plants for his science fair. I
have two geraniums; one has had natural light and is straggly, the other 16
hours of artificial light and is robust and beautiful. Can you give me some
suggestions as to how he can present the plants? Where would we find a light
meter? I went on line searching but came up with photography equipment. Any
clue as to what we would expect to pay for one? (Gwinner, N.D.)
A: Using a light meter would give some concrete data that he can make
reference to, like the robust plant receives 16 hours of light at a
footcandle reading of 1000 FC while the spindly plant receives only
diffused light, which varies between 50 to 150 FC per day. You can contact
Hummert International, located in Earth City, MO. Their phone number is
1-800-325-3055. They have a duo plant light and water meter for about $20.
The model number in their 2000 catalog is ID-1830, catalog # 65-6802.
While not a "professional" model, it should certainly be enough
to provide your grandson with the information and data that he needs for
Q: A lady called me today and said she attended the juneberry session at
Marketplace in Bismarck. During the session it was brought up that you
should not plant spruce by juneberries. Why would that be? I know of the
problems with junipers and apples, but have not heard of the spruce and
juneberry dilemma. (E-mail reference, Minot, N.D.)
A: Your client is confused or mistaken. There is no problem with
juneberries and spruce that I am aware of. There is cedar-apple rust where
the alternate hosts are juneberries and junipers, but not spruce.
Q: Last year I planted "Straight Eight" cucumbers in my back
yard garden. The cucumbers were bitter. I watered evenly and consistently
with the exception of one week that I was away and we did not receive any
rain that week. Could there be some type of deficiency in the soil? Should I
just try a different type of cucumber? (E-mail reference, Casselton, N.D.)
A: I am sorry to report that it was the dry week that caused the
bitterness. Cucumbers need 1 inch of water per week -- every week -- and
any water stress results in the fruits being bitter. Straight Eight is a
good variety, as I have planted it many time with good success. I would
encourage you sticking with that until something else catches your fancy.
Q: This coming spring I need to replace four American elm trees in our
yard. What do you recommend as replacement trees? (Rogers, N.D.)
A: I recommend polyculture rather than one species of tree. For
example, you could plant an Amur or Tatarion maple in your front yard, a
Japanese tree lilac or serviceberry in the back, and either laurel
willows, Manchurian ash or Ohio buckeye along the street.
Q: I am thinking about getting into commercial pumpkins. What are weed
control options for grassy weeds and broadleaves, specifically kochia and
milkweed. (E-mail reference, Linton, N.D.)
A: Roundup is labeled for pumpkins, but of course the spray must be
directed away from any pumpkin plants. This (actually Roundup Ultra) is
applied up to three days before seeding or transplanting. Dacthal is
another one that can control some broadleaf and grassy weeds, and it must
be applied to weed-free soil. Finally, there is good-old Poast which is
the ultimate grassy (emerged) weed control. In every instance, you are
responsible for following the directions and adhering to the information
contained on the label.
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 email@example.com.
Source: Ron Smith, (701) 231-8161, firstname.lastname@example.org
Editor: Gary Moran, (701) 231-7865, email@example.com