May 17, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: Is it a good idea to fill in the low places in my yard? Do I need to do anything to the yard before I put the new soil down? (Kulm, N.D.)

A: Yes, you can "topdress" your lawn to even-out low areas. Seeding can then take place with a mix of Kentucky blue and creeping fescue. Mist or water lightly until germination is evident.

Q: Do you have any information on how to get rid of fungal black knot? I think this is what is infecting my chokecherry trees. (Ryder, N.D.)

A: A number of approaches can be used: Remove all knots by pruning about 3 to 4 inches below the knot. Spray with lime sulfur after knot removal. Remove any wild species harboring this pathogen. Realistically, unless this disease is caught in the early stage, it is totally debilitating, and it is best to remove the tree.

Q: We are raising basil in our greenhouse and having very good luck with it. We are wondering about various methods for preserving the crop. Can you direct us to a source to provide the information we need? (E-mail reference, Bottineau, N.D.)

A: Basil preserves best by freezing it. There, it will retain close to 100 percent of its essential oils. Blanch the leaves quickly in boiling water, dry them on paper towels and freeze them in sealed plastic bags. Or, for the short term, the crop can be preserved in oil; wash and dry, and place in a clean, dry glass jar (not a plastic one!). Sprinkle salt over each layer of leaves, and when the jar is full, fill with olive oil to cover the leaves. Close with a tight-fitting lid and store in refrigerator. They will be good this way for about a week to 10 days. You should realize that basil plants get woody as they age, so be sure to start with fresh plants when that begins to happen.

Q: I have a lawn with invading circles of brome or quack grass. I am planning to kill the present lawn with Roundup and reseed. I am considering using a slit seeder to avoid tilling the lawn. I need to know where can I rent a slit seeder and if that is the best option. (E-mail reference, Lisbon, N.D.)

A: I suggest trying a major rental store to see if they should have a seeder, but I doubt it. You may have to hire it done by a lawn service company. If that option cannot be found, I know it will work if you do the following: After everything has been killed off, scalp mow the entire lawn, collecting the clippings. Go over the area in two directions, perpendicular to each other, with a power rake. Spread the seed with a drop or cyclone spreader Drag in the seed with the back of a leaf rake or a piece of chain-link fence. I've done it several times with great success. The power rake is easier to find than the slit seeder.

Q: Do you have any solutions for night crawlers? Any advice for the white scale on evergreen trees? My wife is organically inclined when it comes to battling pests, but she will do whatever it takes to get results with these. (E-mail reference, Valley City, N.D.)

A: If the night crawlers are a big problem, I suggest applying a grub insecticide (everybody's lawn has grubs!) like Sevin. This will also control night crawlers. Be sure to follow label directions. Scale insects on evergreens is a touchy one. If they are on just a branch or two, you might be better off cutting those off now and disposing of them. Insecticidal soap can be used if you can catch them in the crawler stage in late May or early June. In the dormant stage of growth, try a horticultural oil spray (sometimes called dormant oil spray). This will kill the overwintering adults and perhaps control the outbreak further. Try your best to grow the evergreen in as vigorous and healthy manner as possible to discourage scale development. They usually attack plants that are in a weakened state.

Q: My mother has an upright juniper next to her house. It stands some 20 to 25 feet tall. The bottom growth is not bad, the middle is really bare and then the top isn't too bad. One side is rather thin all the way down. What she is wondering is, if we try to prune this should we severely prune it or would it be a waste of time and effort? Would we be better off trying to dig it out and start with something new there? We have kept it pruned over the years, but it really is starting to look really thin in some spots and really overgrown in others. (E-mail reference, Bismarck, N.D.)

A: I suggest removal. A juniper 20 to 25 feet tall right next to the house is overgrown for the site, unless it is a huge house on a large lot. Any "dress-up" pruning you may do will only be unsatisfactory, and you will end up taking it out anyway. Save yourself the frustration. Get it out of there and replant with something new.

Q: I am planning to do some xeriscaping in my front yard and had planned to use wood chips as mulch until a friend told me I would be risking an infestation of carpenter ants, which she told me would be very dangerous to my home. I've never heard of this problem around here. Should I be considering a different type of mulch? (E-mail reference, Moorhead, Minn.)

A: Plants attract bugs too, so should we eliminate plants around the home? Carpenter ants are not particularly attracted to wood chip mulch. Even if they were, they are easily controlled. I have used and recommended wood chip mulch for decades with no negative consequences like carpenter ants.

Q: I don't know a thing about lilacs, but my friend cut down a lilac bush and I took some of her cuttings. She told me to put them in a bucket of water and they should sprout. I have done that and now they are starting to bud. I asked my friend what I should do, but she doesn't know about the lilac bush she has. (E-mail reference)

A: You have taken, I assume, what are known as hardwood cuttings, which in general do not root well. The most easily rooted cuttings are the softwood type (new growth), which exist just before the end leaves mature. If your friend has any suckers sprouting from the cut back shrub, I'd suggest digging those out carefully and transplanting them where you want the shrub to develop. Water in well, using a water-soluble fertilizer.

Q: What's the best herbicide to kill out volunteer roses? A yard owner wants to take them out and replant to something else ( not sure what). Will Roundup do the job? How much growth does she need to get a good kill with it? Will Curtail or Stinger do them in without too much herbicide persistence? Is there a cultural practice that will work better than herbicide? (E-mail reference, Fort Yates, N.D.)

A: Roundup should do the job. Let the new growth mature fully, then give them a shot. I cannot answer your question on the other two herbicides as I don't know what the replanting intent is.

I know of no cultural practice that will get rid of them better than Roundup.

Q: I have a grapefruit plant I started from seed. I put it outside last summer and it bloomed! It is now 28 inches tall and I would like to cut it back just above where it bloomed so it will branch out more. Will this work? (Osage, Minn.)

A: Yes. Go for it!

Q: Last fall we noticed that our lawn had bulges all over with small holes. After a rain there are a lot of angle worms or earthworms on the sidewalk and patio. What remedy should we be using? (Carrington, N.D.)

A: Treat the lawn with Sevin, following directions on the label for grub control. A single application will control about one-third of the population.

Q: I received a rubber plant as a gift and now I need to know how to take care of it. How often do I water it and when do I fertilize? Can I use plant shine on the leaves? (Grafton, N.D.)

A: Water with care. The soil must be dried out somewhat between waterings. Make sure the water is tepid, or room temperature, especially during winter months. I don’t recommend leaf shine - simply a damp cloth will do. Fertilize once a month from spring (April) through fall (October), and not at all during winter. The biggest danger to this species is over-watering.

Q: I have a Christmas cactus that is just blooming. Should the spent blooms be removed? Will it help the rest of the blooms develop?

A: The flowers can be removed once they are spent. This saves energy in making seed, allowing more to be put into the blooming, which we all appreciate.

Q: What is the best "first" procedure for a lawn in the spring? My husband insists on mowing it as short as the mower allows (shaving it). He usually does this a couple of times. Last year the neighbor's lawns on each side of ours were thick and green and ours was still brown and thin. Please advise. He may listen to you! (E-mail reference, Fargo, N.D.)

A: I'm not sure I want to get into the middle of a husband/wife argument over lawn care. Let's see, what can I say that will keep both of you on my side and still do the lawn some good? Ok, here it is: Dormant scalp mowing does the following to a lawn: It removes the canopy cover, exposing the soil and grass crowns to sunlight. This in turn warms the soil and grass quicker, drying it out. It also risks damaging the crown of the grass plant, either weakening it severely, or killing it outright. The exposed soil also contains some weed seeds that need sunlight to germinate. Scalp mowing accomplishes that. The grass crowns not set back or killed outright will begin earlier growth, resulting in earlier and consequently more frequent mowing throughout the season. The first procedure for lawn care in the spring is to rake it up with a leaf or broom rake. This gets rid of all the litter and dead grass and helps to get the grass dried and warmed up a little faster. This is sometimes accomplished with a power rake. This is OK, as long as the power raking isn't too early and too severe. It should be set just deep enough to clean off the surface, not pull up any grass plants. Finally, mow the lawn high--2.5 to 3.0 inches. This encourages a deep root system, a dense canopy that shades the soil surface and helps to control weeds, and it aids in getting the grass through the hot dog days of summer.

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: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu