Green Industry Resources
Hort Update- Seasonal Information for the Green Industry
Show Questions - April 5, 2012
1. This viewer had mealy bugs last year in their zucchini; they were treated with Sevin, which did not stop them. With the mild winter, will there be more insects and how do you get them under control?
a. Most likely, these were squash bugs not meally bugs -- squash bugs are very detrimental to squash and since they winter over as adults, you will have to vigilant. Check your garden regularly; the egg is a brick-colored lens shape. They are found in the juncture of the leaves. Treat as soon as they hatch with Bifenthrin, permethrin or even insectical soap.
2. When is the appropriate time to apply preemergant in the northeast part of the state and in Grand Island?
a. In a normal year it is the 1st week of May and the second week of May the further west you go. In Grand Island with the soil temperatures as high as they are this year now is the time to apply a preemergant. Consider using something that will contain dithiopyr (Dimension); this has limited post activity. If your crabgrass has three leaves showing on the plant this can knock it back with fairly good results. If you have not seen any germination, use the prodiamine or pendimethalin based products.
3. A Lincoln viewer has a white haze in the turf -- it looks like the turf was sprayed with white paint. Is it powdery mildew or is it too early?
a. If it has a dusty appearance on the leaf blade in a shaded area, it could be powdery mildew. There are some fungicides you can use or you can do some over seeding of the turf if it is thinning out. If it is appearing this early and they want to keep the turf they may want to look at a fungicide. Make sure quality management is being used to help minimize the disease.
4. With the unseasonably warm temperatures, is it okay to start planting your cool season crops?
a. Yes, but if we do have that threat of frost, make sure you are able to cover what has emerged.
5. A Papillion view has a 50 foot linden tree that had Japanese beetles last year -- what can they do now to eliminate the problem?
a. Japanese beetles are good flyers and love linden trees. Try a drench with imidacloprid like Merit -- applied by the first of June. This will be applied around the base of the tree and it will be translocated to the foliage. You can use a foliar spray but with the larger trees, a professional may need to be called.
6. How do you get rid of crown vetch, in and amongst other desirable plants?
a. If it is in other dicot plants, there is really no control. If it is in turf or in a roadside location, an aggressive treatment of the phenoxy type herbicides (like 2,4-D) will not it back. Mowing will also help to keep it controlled and suppressed. You'll have just as good results with mowing to keep it spressed.
7. An Omaha viewer planted a 4 foot lodgepole pine. As winter proceeded, the tips became reddish brown. They did water it throughout the winter season, but the brown tips seem to be increasing. Is this a tip blight problem or environmental?
a. If it is just established and they are seeing it all across the whole tree then it is most likely environmental. The new tree has a limited root system and with the drying winter winds you can could get some desiccation. Keep an eye on it -- it should come out of it.
8. A viewer in Ceresco has rhubarb -- with the cool temperature they are worried of toxins moving to the leaves.
a. Rhubarb leaves are poisonous regardless -- the cool temperatures are not really going to force the toxin down into the stalks. If we do get a freeze, the plant may be held back a bit but the toxins are always going to be in the leaves.
9. A Springfield viewer had white maggots 1/8 of an inch long in their peas. How do they control them this year?
a. They are most likely seed corn maggots -- they would have to use an in-furrow treatment with permethrin for that .
10. This is a viewer from Ravenna, they would like to know when and how to plant zoyza grass?
a. Zoyzia can be planted by both seed and plugs; however, the seed is a southern variety and will not grow here so we need to plant it by plugs. The recommendation is to plant on 12-inch centers -- however that will take several years to fill in. We don't recommend planting zoyzia, but if you must, we recommend planting it on 6-inch centers. Time for planting is late May or early June.
11. This is a viewer that has tip blight in Austrian pines. Do they spray just the tips? When and how?
a. If it is Sphaeropsis (Diplodia) tip blight, the needles that stop growing about half way and turn brown on the end -- that timing for a spray application is going to be when you have half needle elongation. If it is Dothistroma needle blight, the longer needles will be affected and it will generally show up on the lower part of the canopy. With the Sphaeropsis, you will have to get high in the tree; if it is Dothistroma, you can get away with only having to spray the lower canopy.
12. A viewer from Bennett would like to know what will happen to the plants if we get a freeze now?
a. A lot of the woody plants (trees and shrubs) could lose that set of leaves and blooms, but they are able to sometimes put on a second flush of leaves. For the herbaceous perennials (flowers), it depends where they're located, if they're further along than normal, and other factors like that.
13. We had a viewer call and say they already have worms on the pines.
a. They are right; normally they are out in the last week of April to early May. The pine sawflies are out; these are already a half-inch long, they are half grown. You need to check your pines; tap the worms off with a stick or treat with permethrin.
14. We have a viewer who has trumpet vine and wants to get rid of the suckers.
a. It is aggressive. You can catch it early and paint the stems with RoundUp or a RoundUp and 2,4-D mixture. Keep it off other plant material as you will injury it. Be persistent; that is the key. You will need multiple applications.
15. A viewer has two tree peonies -- one has blooms that dry up and don't open.
a. This is most likely botrytis -- it is a fungal disease. The first thing to do is avoid overhead irrigation and remove the infected blossoms. If you want to manage it with a fungicide spray, apply it at early bud development. But that would be a last resort.
16. This is a viewer who has access to well-composted horse manure -- they want to mix it with soil around grape vines. Are there precautions?
a. Make sure it does not have a lot of weed seeds in it -- certain manures have a lot of weed seeds and then you are putting more of a problem where you do not want it. Do not add too much -- it can be a bit rich. But yes, you can use it by the grape vines.
17. These viewers found grubs in the garden when they turned over their soil. Should they treat for the grubs?
a. It would help to know if these are annual grubs or three-year grubs. If they are three-year grubs, and if they're in that middle year, they will feed on the seeds, vegetables, and roots. They may want to put down a soil insecticide (permethrin or bifenthrin granules) at planting time. Fall tilling also helps to reduce the number of grubs and other soil insects.
18. A viewer thinks they have Bermudagrass in their Kentucky bluegrass. Two questions: does Bermudagrass grow here and is there a selective control of it if it does?
a. There is no selective control for Bermudagrass in bluegrass. The cold tolerant Bermudagrasses do grow here but we don't recommend them (it's very course and not attractive).
19. This viewer has something two inches long that looks like an unopened pine cone. It's dark brown and in the soil about 6 inches deep in the vegetable garden.
a. It sounds like some sort of fungus. If it is under mulch, some of the stinkhorn fungus will produce a large mass. Split them in half. If it has a gelatinous mass, it is a stinkhorn. If not, bring it to your local Extension office and we can see if we can get it identified.
20. Any advice on protecting hostas from freeze?
a. If you have not removed your winter mulch, you can cover them back up. If they do freeze, they may send up new sprouts. But that is probably all you are able to do.
21. Two years ago, a viewer used 20-Mule Team borax to control ivy. Now the grass will not grow.
a. We used to recommend this and then realized that boran is toxic to most plants. Physically excavate that soil, replace with different soil, or till it up and water it a lot to neutralize the soil. To test it, sew some seed and it if does not come up, you will have to wait.
22. A viewer has had fungal issues in their tomatoes. She would like to know if there is a soil treatment to eliminate the fungus in tomatoes?
a. There are not any chemical soil treatments to recommend -- if they would like to take a year off and do a solarization treatment on the area that would be a possibility -- but that will leave the areas fallow for a year.
23. This is a viewer that planted honeylocust in a windbreak. They thought they were thornless. Is there any way to prune out the thorns in honeylocust?
a. No -- unfortunately, what you have is what you've got. You can try to cut the thorns off, but you will be out there every year. Removing the trees and starting over is your only option.
24. This is a question about a bindweed gall mite. It's a European insect. Will it control bindweed? If so, where do you get it?
a. We would have to do research on that one. I have read about it. It does have some good potential for biologically controlling bindweed. I believe it will not over winter here -- you can introduce it, but it would die over the winter.
25. When do you control prostrate spurge with pre-emergent and what would you use?
a. First week of May--this year. It will be late April, early May in the panhandle area. The products to use are those containing pendimethalin or prodiamine.
1) A viewer had a gas meter put in and the soil has settled. What should they do?
a) You can put some soil back over where the trench is and plant what you want to plant
2) We have many viewers that think its okay to plant tomatoes now.
a) It is still early.
3) It is time to prune the forsythia?
a) Go ahead, as soon as it is done blooming.
4) This viewer saw azalea, heather, and pierisin at the box stores. Are those things to use in Nebraska?
a) Not if you want them to live long.
5) Is it time to plant potatoes?
a) Go ahead.
6) Is it time to cut back the ornamental grasses?
a) Yes, before they show
1) Are dry conditions worse or better for cedar apple rust?
a) They are better
2) Are there pine diseases you can treat later in the season?
a) No, control on those is upfront -- typically the third week of April. This year it would be now through the end of May
3) Spruce has interior dead branches.
a) Usually caused be needle cast diseases -- those should be managed the same time as pine diseases. You need to treat the older needles in the spring, the wet part of the year.
4) Are morel mushrooms up yet?
5) What are the white blotchy things on the trunk of junipers?
a) Those are cankers. They need to prune those out; remove three to five inches below the infected area.
6) Can you still spray your fruit trees?
a) Should have been done three weeks ago.
1) Is it time to seed your lawn?
a) No still early.
2) Is it too late for preemergant?
3) What can you spray crabgrass with if it is already up?
a) You can use a product called Drive or you can use the preemergant Dimension (control up to the three leaf stage)
4) How do you handle the weeds showing up in the buffalograss?
a) Do not spray the buffalograss with RoundUp in the spring -- you can spray it in the fall. Wait for it to green up and begin mowing it and that should get rid of most of the weeds.
5) Is it too late or early to aerate?
a) It is still a bit too early -- we do not want it to get a frost burn around the hole.
6) What about the blue flowers in the leaf axil and square stem?
a) That is creeping Charlie or ground ivy. It is up but not blooming much yet. Control with repeated applications of a 2,4-D; it is better controlled in the fall.
1) Little tiny ants in the kitchen, how to get rid of them?
a) Use some of the bait stations.
2) Where are the bees?
a) The hives came through the winter; so the bees are out in the landscapes. There are lots of flowering plants out right now -- the bees are not concentrating on one plant.
3) People are seeing wolf spiders in the house now.
a) They over winter as adults; it is warm and they want out.
4) What is the chemical Acelepryn?
a) It is a DuPont product used in turf and ornamentals. It is also found in Scotts GrubX
5) What to do about pine bark beetle?
a) You can treat the bark this time of year. Again, normally it would be in May. This is a spray on the trunk.