November 17, 2005

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I’m hoping you can help me with a problem I’ve never seen before. My daughter and I were outside looking at her cocoon (we found a giant green caterpillar in a cocoon). I told her it soon was going to be a moth. She wondered if it was the same type as the one she pointed to lying on the ground. As I looked at the moth on the ground, I saw some bees attacking it. The moth was alive, but partially eaten. I didn’t think bees ate other insects. (e-mail reference)

A: Bees don’t, so what you saw had to be members of the wasp family, Vesper spp. They eat other insects, especially as the days get shorter and we get closer to winter. This is a good opportunity to remind you and your daughter to be careful with open cans or bottles of pop, damp toweling or ripe fruit lying on the ground or meat sandwiches because the wasps are attracted to such things. Wasps have been known to venture into cans of pop to the painful surprise of the drinker!

Q: I have a gorgeous clematis growing on my trellis. It grows huge purple flowers that bloom late in the spring, but in July, the blooms die and the vines and leaves turn brown. Should I be pruning? Is this growing pattern normal? In the winter, should I prune the plant off the trellis? I was told not to do that by a relative, but it is ugly. (e-mail reference)

A: It is best to prune in the early spring. As to the decline in the visible quality of the plant, you might try moving it next spring, before new growth takes place, to an eastern exposure so the hot sun won’t cook the plant as much.

Q: I have petunias planted in two barrels. They were lovely until two weeks ago when they started to look yellow and the blossoms faded. I added some Miracle-Gro soil this year, but that is the only thing I did differently from other years. Should I pull them out? Also, we recently were in New England and saw a redbud and red twig dogwood. Are these trees hardy for central South Dakota? I read your column all the time. (e-mail reference)

A: If you have been using a container that is not free draining and just adding fresh soil to the barrels, you may have created a root rot disease problem. If that is the case, you might as well yank them out because they are not going to get better. Unless you live in a section of the state that is open prairie, redbud and red twig dogwood should grow well for you. Give them a try and thanks for being a loyal reader of the column!

Q: I have a small strawberry patch that was overtaken by grass. Other than pulling out the grass, is there an easier way of getting rid of it or do I have to face the fact that I will be on my knees for the rest of my life in the strawberry patch? (e-mail reference)

A: No, you don’t have to spend the rest of your life on your knees pulling grass out of the strawberry patch! There is a herbicide called Vantage that will keep the grassy weeds under control once you get them pulled out.

Q: Thanks for your work. I read your column every chance I get. What is the best seed to use on a two-thirds acre lot? I have heard native grasses are best because they need less water and don’t need as much care (less mowing and fertilizing). What would you suggest? The lot is in the middle of a growing development, so I am wondering if I should use native grasses, such as Kentucky bluegrass, or something else. (e-mail reference)

A: In a development, you are limited on what seed you can use without being ostracized by neighbors and possibly local authorities. Fairway crested wheatgrass is about the best choice for water conservation and low maintenance. It will need overseeding every few years to keep it nice and thick, but it is considered a low-input grass. Tall fescue is another possibility. I grew it for many years in my backyard. It was able to go a long time between irrigations and I only fertilized it once a year.

Q: Should new asparagus plants be watered or should I just let nature run its course? (e-mail reference)

A: If you are in the middle of a long, dry period, such as two weeks or more, give it a good dose of water. Sometimes Mother Nature’s course is harmful to certain plants being established.

Q: Why do the little pumpkin and squash fruits turn yellow and fall off, sometimes before the flowers open? My summer yellow squash does not have this problem! I try not to overwater, but the plants wilt in the sun, so a little splash of water revives them. (Fargo, N.D.)

A: The flowers were not fertilized because of the lack of bee activity in your area.

Q: We have an unusual problem in our strawberries. We have slugs in them. I have tried many ways to get rid of them. We had them last fall, so we put Diazinon in the soil before we planted the garden this spring, but the slugs were back after a few months. We have tried beer traps and were told to put bloodmeal around each strawberry plant to discourage them. Nothing has helped. I have laid a couple of boards out in the rows to “catch” the slugs. I gather the slugs each day and squash them. Is there something else that you could recommend? I’m getting frustrated. (Starkweather, N.D.)

A: Unless you have acres of strawberries that you are trying to make money on, the best advice I can give you, based on what you have told me, is to start over. Till the soil and allow it to lay fallow until spring. When you replant next spring, spread “Sluggo” among the berries. This organically approved, low toxicity material effectively controls slugs. The typical slug poison, metaldehyde, is quite toxic.

Q: I have a hoya plant that is doing very well, but I was told years ago that they are poisonous. I have a grandson who is now walking and into everything. Are hoya plants poisonous? If so, what parts? (e-mail reference)

A: Hoya is not listed in either of my texts on poisonous plants. However, it is a good idea to keep the plant out of your grandson’s reach in case there are compounds within the plant that may make him sick.

Q: We have been working on a large landscaping project in our backyard. When is the best time to plant a lawn, what is the best seed to use and where do we get it? Also, we have a European mountain ash that has what looks like holes from woodpeckers concentrated on the trunk of the tree about 30 feet off the ground. What can we use to deter the woodpeckers that won’t be harmful to other birds? How critical is it that we keep woodpeckers off the tree? Can they kill it? I enjoy reading your article every week and have learned a lot. (Cooperstown, N.D.)

A: Thank you for your loyalty and kind words. My Web site at
www.ext.nodak.edu/extpubs/plantsci/landscap/h1170.pdf will tell you more than you need to know about establishing a lawn. Establish a finish grade, apply starter fertilizer and then seed. Use a general-purpose mix of 55 percent or more Kentucky bluegrass and the rest split between creeping red fescue and perennial rye. There are dozens of outlets where this material is available. Woodpeckers will not kill a mature, healthy tree. Sometimes they get carried away, so a little Tanglefoot will discourage them. It is not toxic, but is sticky, which they don’t like.

Q: I have 10 acres of land. Ninety percent of the land has prickly pear growing on it, but I want it gone! I have put fertilizer on it, poured diesel and even put salt on it. I have sprayed with professional Roundup, but nothing seems to faze it. My friend told me to use Remedy, but it is far too expensive. On the Web, I found a moth that is a natural predator; however, the state won’t allow the moth. I am at my wit’s end. Do you have any suggestions? I’d really rather go natural, if I can. I am desperate. I did dig some up and burn it, but to do the whole field would take years. Can you please help me? Thank you so much. (e-mail reference)

A: I am sorry, but you have exhausted all the options I would have suggested. Perhaps someone who reads the column can give us some insight on something that will work.

Q: In one of your columns you suggested planting wildflowers. We live at Spiritwood Lake and the hill going down to the lake is very steep. My plans are to plant low ground-cover bushes and sprinkle wildflower mix. Does the wildflower seed have to be planted or can it be thrown out on the ground? What ground cover would you suggest? The hill is too steep to mow and faces south. Could you give me a listing of the garden supply stores that handle wildflower mix? (e-mail reference)

A: I don’t recommend planting a mix of ground-cover woody plants and wildflowers because they are not compatible. The wildflowers would overpower the ground cover, so your money would be wasted. Also, if you chose to do a burn off in the early spring, it would damage the woody plants. Go for the straight wildflower planting. You’ll love it! There are mixtures everywhere garden supplies are sold. Fall is a very good time to get them going because there is less competition from weeds. All they need is a place to lodge in the soil. Hard, bare soil will not work. Scratch the surface slightly, spread the seed and then water.

Q: Can you tell me the names of the longest blooming perennials? I’m in zone 3. I love roses and tall plants. (e-mail reference)

A: Look for Echinacea, lilies and daylilies. They are my favorites because of their long show of flowers.

Q: My sister-in-law is allergic to weed whackers (her words, not mine). She uses Roundp around the trees in her yard instead of trimming with a weed whacker or push mower. I accidentally sprayed the bottom of a tree with Roundup, but nothing happened because the leaves were not touched. Can my sister-in-law be doing long-term damage to her trees by using Roundup? They’re full-grown trees, which are mostly spruce, oak and fruit trees. In addition, do you remember me writing to you about my raccoon problems and telling you that zucchini worked for keeping them out of the sweet corn? Well, I’m told by a reliable source that buttercup squash is the best for that kind of raccoon defense. The vines must be pricklier. Also, we’ve had some grub worms in the yard and the raccoons (or maybe skunks) have been turning the sod on my lawn upside down looking for them. Sometimes in the morning, my yard looks like a war zone. Maybe I’ll put the whole yard into buttercup squash next year! (Kindred, N.D.)

A: Your sister-in-law is on safe ground spraying Roundup around the base of the trees. In fact, in the long-term, it is likely better for the trees because string trimmers are responsible for canker development and mowers inevitably are bumped into the trees, scarring the bark and leading to decline. Once the Roundup hits the soil, it is deactivated. It only works on green tissue.

Q: Can you use pine cones for mulch? I have many spruce trees in my yard that produce pine cones. I would like to use the cones for mulch around my maple trees. My husband says the cones are too acidic. Since our soil is so alkaline, I think it would be OK. What do you say? (Dickinson, N.D.)

A: Cones from spruce or pine trees can be used as mulch without harm. If the cones come from spruce trees, they are spruce cones, not pine cones. It’s a common mistake many folks make because we often think of pine cones as a generic term. Just don’t overdo the mulch. Some people get too carried away when they start adding organic mulch, thinking that if a little is good, much more would be better.

###

Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu

BeefTalk

Prairie Fare

Plains Folk

Hortiscope

Market Advisor:

Crop

Livestock

North Dakota State University
NDSU Agriculture Communication
NDSU Extension Service
ND Agricultural Experiment Station