NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
October 12, 2000
Ron Smith, Extension Horticulturist
North Dakota State University
Q: Can you tell me what the enclosed weed is and how to eradicate it from a lawn? It grows on rather dry soil and I would like to know of a way to get rid of it without destroying the grass. (Braddock, N.D.)
A: What a nasty one! You sent me a sample of sandbur -- Cenchrus panciflorus -- a shallow-rooted summer annual. It is best controlled with a pre-emergence in the spring with a herbicide that contains Oxadiazon, Oryzalin, or a combination of Oryzalin and Benefin.
Q: My garden area was sprayed with Canada thistle spray in April by an airplane that was spraying the field next to it. Shortly after that I planted my garden and nothing came up and I couldnít figure out why. Now I am convinced it was from the spray. Will I be able to grow a garden there again? (Marion, S.D.)
A: Generally, unless excessive doses of herbicide were applied, the soil should support a healthy garden next year. I would suggest removing all crop residue this fall and discing the soil. Next spring, try not to plant the crops in the same spot -- locate the potatoes where corn was, etc.
Q. Could you tell me what kind of plant or weed this is? It grew by our house and I thought it might be parsley, but this year it has flowers and grew really tall and is going to seed. (Tripp, S.D.)
A: The plant was Queen Anneís lace, or wild carrot. It is a good sod-busting weed with a nice deep tap root. Some people in the prairie cultivate it as a flowering perennial; in the east they consider it a weed . For your records, it is known as Dacus carota, and the seeds are valued by birds.
Q: Enclosed is an example of a bush that is growing in my brothers yard that we seem to be unable to identify. It has blossomed twice this year, and after the flowers have dropped it starts berries which turn an orange color. The flower stage has white blossoms and form a flower on each of the berries (seeds?). It is a fast growing plant and seems to like itself as it does reproduce easily. As my brother said it will probably turn out to be a bad plant or a noxious weed as it is so hardy. If you could help us out with this we would be delighted to know its name. (Devils Lake, N.D.)
A: Wow! Are you ever thorough! If everybody sent me samples like you do, many of my ID problems would be solved. What you have growing is a European elder, Sambucus nigra. This is a rank growing shrub that produces an abundance of fruit which ripens to a black color in September. The birds relish the fruit! If you let this go unchecked, it will become a pest. However, if you prune it back hard in late winter the new growth will be attractive and manageable.
Q: We planted Colorado blue spruce in the spring of 1999 and in the fall of 1999 and we had no luck with them. Out of the 20 we planted there are only six alive. In the spring of 2000 we planted white fir, and none of them survived. What did we do wrong? Should we have used sand, mulching, or potting soil when we planted them? What kind of fertilizer should be used for these kinds of trees? How often do they need to be watered? (E-mail reference, Lehr, N.D.)
A: I don't know what you did wrong in the planting, but you did plant a species that is not hardy in our area -- the white fir. They will not survive no matter how much attention you pay to them.
You didn't state what size tree you planted. Small plants, 1 to 5 years old, ranging in size from 1 to 3 or 4 tall, have the greatest opportunity to survive. As the size goes up, the chance for root damage and non-adaptability to the site increases. Generally, we suggest nothing more than planting at the proper depth in native soil, and watering in well. Literally millions of trees have been planted that way and survived to live to a ripe old age.
Q: We just moved to a new house and it has raspberry and blueberry bushes. I have no experience working with either and was wondering how far back I should cut them before winter and when is the best time? (E-mail reference, Hillsboro, Ore.)
A: Both plant species should grow like weeds in your area! Raspberries have two cane types -- the primocane grows the first summer and normally remains vegetative or non-fruiting for that season. In the second summer, that same cane produces floricanes, or fruit bearing branches. Once the fruit ripens, the cane begins to senesce or die. New primocanes are produced each year, so fruit production is yearly. Once these fruit-bearing canes stop bearing, it is a good idea to remove them completely, and burn them. The longer they stay with the plant, the greater the opportunity for insect and disease problems to develop. Blueberries need only to have their weaker branches pruned. This is generally done in the early spring before the buds open. The important thing with blueberries is winter protection. Not knowing the winter extremes in your area, I suggest contacting your local extension horticulturist or other folks who have blueberries as well and see what their cultural practices are. Low pH (4.5), continuously moist soil, adequate fertility, and winter protection are the key factors in blueberry production.
Q: I repotted a peace lily about a month ago using Miracle gro potting soil. At the time, it had five beautiful white flowers but had outgrown its home. Since then, four of the five turned green, then brown. The fifth is still in the "green" stage. It has continued to produce new foliage although some of the lower leaves have some brown tips. It lives on my covered balcony which receives bright but indirect light. Here in northern Florida, the temperature reaches the mid-90s most days with mid to high humidity. Can you help me to regain the blooms and keep my plant healthy? It was a gift from my mother and grandmother in Tennessee and I really want it to thrive. (E-mail reference, Pensacola, Fla.)
A: It sounds like your peace lily could be suffering from a couple of troublesome environmental conditions. First, the fact that the spathe emerges green indicates that there is too much light, causing chloroplasts to form. Second tip browning is an indication of either over-watering, watering a plant in a non-free-draining container, or nutrient ion salt burn, such as chlorine or fluoride. I'd suggest moving it to a shadier location, making sure it is in a free-draining container and not over-watering, and try about two weeks of watering with distilled water to see if that improves anything. I suspect that your normal drinking water may be high in salts, or that your household has artificially softened water.
Q: I have a silver maple (20-30 yrs old) that drops a few discolored leaves most of the summer. These leaves have a scab on them. Other than this condition, the tree appears healthy, turns proper color in the fall and buds and leafs out normally in the spring. Can you enlighten me on this condition? (E-mail reference, Ellendale, N.D.)
A: There are fungal leaf spot diseases that hit many tree species at sub-lethal levels each growing season, causing leaf drop on the older leaves. I don't know whether or not it is worth the effort on your part to eliminate this since it poses no threat to the health of the tree. It's kind of like us catching a cold -- little harm done -- and your tree apparently has good resistance to this pathogen to keep it from becoming virulent and destructive. Normal fall sanitation -- picking up of leaf litter -- every fall sometimes does the trick, as well as a spray of lime-sulfur in the early spring before leaf out. This often kills the overwintering pathogen that is taking up residency in the bark tissue of the tree. In addition, keep an eye on the tree for dead twigs and branches, remove them when noticed, and try not to allow the tree to become drought stressed during the season. Water well once a week when rainfall is lacking.
Q: In 1996 I planted a cut leaf weeping birch. It grew into a straight, lovely tree. This year, the leaves gradually dried up and now the tree looks dead. Can fire blight hit birches? Can you tell me what is wrong with it and if it can be saved? (Aneta, N.D.)
A: I too, have a cutleaf weeping birch in my yard -- going on 15 years now. To me, they are one of the most beautiful trees nature produces! Concerning the apparent demise of yours, have you checked the buds or twigs to see if they are plump and green? If they are, chances are the tree will re-leaf next spring. If not, then it is firewood -- likely a victim of a root-rot fungus.
Q: I have several questions for you in regard to trimming and transplanting my 2- year- old Techny arborvitae and some other plants. Can you tell me when and how to trim them so that they are not too high or big around? Can I transplant my daisies this fall, and also my dianthus? Should they be cut down after blooming and if cut off will they bloom again in the same season? Can I move my aster now and transplant them? How do I go about digging up my bleeding heart and transplanting it and when? When can I trim my Vanhoutte spirea hedge? If I do it this fall will it hurt or delay their blooming in the spring? When should potentilla be trimmed or transplanted? (Hannaford, N.D.)
A: Wow! I suggest a course or two in horticultural practices. You asked a lot of questions so Iíll be brief to get all the responses in a reasonable space:
- Arborvitae -- prune in spring before new growth emerges. You can use a hedge shear (most people do!) or you can trim them by hand.
- Yes, on both the dasies and dianthus.
- Cutting them back after initial blooming will work with dianthus to give a repeat bloom; it may or may not with dasies.
- Move the asters in the early spring.
- Go ahead and transplant your bleeding heart. Locate the crown, dig carefully around it, lift and divide the crown into logical sections (two to four).
- Pruning the VanHoutte hedge now will eliminate most of the flowers next spring. Pruning right after they flower will not. Woody shrubs are best pruned selectively in the early spring to reduce stress and enjoy the flowers.
- Early spring on the Potentillas.
Q: Can you tell me why my Norway maple doesnít seem to be growing? It is about 5 years old and looks really healthy, but the branches donít seem to be growing. It sits on the east side of our house and is in full sun most of the day. Is there something we can do for it? (Gettysburg, S.D.)
A: Yes! Move it about 150-200 miles east and it will do better. Norway maples do not perform well in high pH (alkaline), poorly drained, or compacted soils. Now, having said all of that, you still have a problem. From the symptoms on the leaves you sent me, I think your tree is attempting to grow in a soil that is either high in salts or quite compacted. I suggest renting a core aerator and aerate beginning at the drip-line or canopy edge of your tree; run the aerator in ever increasing circles around the tree. This will improve the gas exchange in the soil. If this doesnít work then vertical mulching should be attempted.
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