Green Industry Resources
Hort Update- Seasonal Information for the Green Industry
2012 Show Questions - August 23
1. What's going on in forty-seven states is West Nile Virus.
a. West Nile Virus waxes and wanes from one year to the next. With it being such a dry year, it's interesting that we have seen as much West Nile as we have. Again, it's sort of independent of the weather in many ways. So it is popping up all over the United States and here in Nebraska. It is a concern. It is transmitted by mosquitos. The best way to manage that disease is, in fact, to manage the mosquitos. This is best on a community wide basis. The State Department of Agriculture and the state entomology group are working on the mosquito control program. But there are things we can do in our landscapes. First, don't leave standing water around. Well, you think it's been a drought, and we don't have standing water. If you have flower pots and they have water underneath, that can breed mosquitos. If you are running your irrigation system, it can accumulate water. Keep those drained. Keep porch lights off. Those are drawing in mosquitoes. Stay in the house during the twilight hours when the mosquitoes are most active. If you are out, wear long sleeves and pants. If you must be out wear an insect repellent, up to but not more than 30% Deet. Bug zappers? They kill a lot of bugs, but don't kill mosquitos. That’s West Nile Virus in a nutshell.
2. Zach, you get the first picture, this is a viewer who wants identification on a berry. They want to make gooseberry wine. Are these gooseberries? Those were in the freezer so they look like frosty grapes.
a. It’s always hard to tell from a picture like that. It looks like pokeweed. And I believe many parts of pokeweed are poisonous. Be careful making wine. Use due diligence.
3. Is this poison sumac?
a. No, this isn't. This is gray dogwood. You find it near streams.
4. A viewer in Onawa, Iowa has a four-year-old apple tree, Honey Crisp. It is blighted. It hasn’t produced any fruit this year. The neighbor's tree doesn't have it, but he doesn't say if it is the same kind of tree. Is it resistant?
a. The other tree is highly at risk for the same. I don't know if we're talking about scab or blight. Scab, probably. We’re looking at a difference in resistance. Look at a fruit tree spray and start next year; schedule spraying to avoid problems. Don't do anything now.
5. This is a Murray, Kansas viewer. They have an American elm, which they planted this spring. There's a hole on the south side of the tree with something clear is coming out of it. Is it a borer?
a. They get what's called wet wood and elms are at risk for that. It's a newer tree, right? Usually we see that in larger trees. Where you have two branches forming a crotch area and water accumulation, that will come out. It would be wet wood. If it's smaller and you have a hole, see if there's debris being pushed out. If so, squirt some chemicals (Eight, permethrin) in there.
6. These viewers in Plattsmouth have two and half acres. They keep it mowed. They have a great mixture. They don't mow much or water. How do they bring back what was a beautiful lawn? Mow? Fertilize? There’s no weeds or crabgrass.
a. Water. Do your rain dance. That's the only thing that will help. You need to have it green up and in the fall, once it is green, you can fertilize. Until then we’re in a holding pattern. Hopefully we'll get the rain.
7. This is a viewer in rural Adams County. They have 10 semi-dwarf apple trees planted bareroot in 2010. They thrived and got some fruit. Is it okay to mix their own fruit spray? They want to be economical. They are not big enough to buy bulk from a supplier. Something like Captan, malathion, carbaryl mixture?
a. Many things can be tank mixed, but be careful. You may want to take a jar and do a jar test. Put them together at the suggested mix rates and see if it works. If you have separation or sediment and you can’t spray anything out of that, don't do it. Watch for burning with some of the products that carry certain surfactants. If you mix the wrong things and double up on the surfactants, you could burn the plants. Be careful. There is some risk. The label may say this can be tank mixed with other products. Try it. Use the labeled rates in a jar or something and go from there.
First off, if they planted this bare root in 2010, they should be taking off the apples. Don't let it produce in the first two or three years. It needs to put its energy to growing roots. Second, be careful using carbaryl (Sevin). Be careful. If you spray it, you will have a reduced fruit crop. Sevin is a mite-magnet. If you get into the season and start spraying with Sevin, you will have a spider mite problem. I wouldn’t put carbaryl into a spray mix. I might use it for caterpillars or something.
8. Sarah, you had something that came in on the eggplant. This is a Black Beauty; the yellowing is also occurring on globe eggplants. What causes the yellowing?
a. We have had some questions this summer, in some cases all the plants are affected and in others only some cultivars are affected. You can see the eggplant is firm, it is not soft or rotting, just the coloration of the skin is not what it should be. I don't know exactly what causes this. It is physiological. Not a disease or an insect; it is probably related to heat and water. Lack of water, plenty of heat. One of those two things is causing it. Keep the plants well watered, no drought stress. If you start to see the fruits going off color, just pick them off. And hopefully it will give you new, good fruit.
9. Fred, we talked about this last week. The viewer in Norway, Kansas has had these phlox since the 1930s. I found a sample in Lincoln that looks just like the photograph
a. Examining it, I see phlox plant bug damage. And they are probably gone this time of year, but the bugs did some damage. This is simply the spent blooms of the plant; just go out and deadhead the plants. They are not shedding. A lot of newer varieties of plants are self cleaning; the petals will drop if they start to fade. Older varieties don’t do that, but these stay attached.
10. Zach, a viewer From Milford planted plugs of Legacy buffalograss, and they think it doesn't need mowing or watering.
a. Legacy buffalograss, once it's established, you can determine how much water or mowing is needed. You can go without watering and manage it like tall fescue. Most folks mess up on their plug establishment or sod establishment; it is like any other grass, and it needs irrigation and regular mowing. And it needs mowing to help it spread. Mow or water? You can get by with a little of it. I have different stands in my landscape, some I never mow and some I treat like tall fescue.
11. This is a viewer with three different questions about arborvitae that’s turning brown and black. Is it heat, stress or fungal?
a. Any or all of the above. Look at the base to see if you can see ground rot. Inspect the base of the plant and look closely for crown gall. If you see specific affected branches, prune those branches out.
12. Sarah, a viewer in Valparaiso wants to know if it is time to cut back Knock Out® roses. Is it too early?
a. It is too early. You don't want to prune the roses and then have them start putting out new growth. If this new growth comes out, and we get an early cold spell, you could have die back on the new growth. Wait until they have lost their leaves and are dormant; do the pruning before the winter. Remember, Knock Out® roses don't need a lot of pruning any way. We wouldn't prune them like a hybrid tea.
13. This is from a viewer in Harlan, Iowa. This is the bug question. They have insect damage, they haven't seen the insects themselves; they don't water much. They want to know that did the damage and when?
a. We have to know what the insect is. It could be sod webworm, billbugs, or white grubs. If the damage is showing up now, take a spade and go between the damaged area and good areas, cut one or two inch samples, cut down and see what's down there. Once you find it, take it to a garden center or local extension office, and have them identify it. It could be a whole host of insects. And could be no insects at all; it could be an animal. It's hard to tell without a picture.
14. They are thinking about overseeding; what about treating the unwanted green turf with Roundup. They know it kills bluegrass, but it is dormant. Will it cause damage to the bluegrass if they spray over the top? If so, what's the reseeding time lapse?
a. This is typically what we recommend in the winter. One grass is green and the other is brown. The brown grass won't absorb Roundup. I would be cautious to do it now. There may be green in there. I would spot spray it. Or if possible, dig them out. I wouldn't spray the whole lawn and then reseed after Roundup is about 2 or 3 days. It allows the Roundup to translocate.
15. This is an Omaha viewer who has a bluegrass lawn and has a drainage area in the middle. They think they get a fungus in mid-July. They lost a quarter to a third of their lawn. They reseeded and it looks good. They don’t fertilize. This whole fungal issue, should they go back to bluegrass so they don't end up with fungus? It was bluegrass, but they reseeded with fescue.
a. They have more of a problem with fescue? They said it was bluegrass, they got a fungus and started reseeding with fescue. It's a preference. As far as fungal diseases, if it's a blighting disease, the fescue will be more prone to brown patch. But if you have drainage and it’s wet, you may see that in bluegrass as well. If it's a full sun area and you see rings or spots dying out, it's probably summer patch. Fescue is less susceptible to that. If you are not sure, take a sample for diagnosis. I would opt for tall fescue. I like it in omaha. It doesn't get summer patch. If you get brown patch, it rarely kills. You can reduce the annual nitrogen. And we never see grub damage. In Omaha, I like tall fescue. I like Kentucky bluegrass farther west.
16. We have a couple of questions about tomatoes. They are not getting ripe, even though the nights are cooler.
a. I have recently seen mine setting new ones again. In the worse of the heat they were not setting new flowers at all. Make sure your plants are staying well-watered. They can abort, even if not accompanied by high temperatures. If the plants are healthy, there's no reason they shouldn't be setting again. With some patience they should set. If you have green ones, they need more time to mature and ripen. Give it a wait and see.
17. Fred, they have a buffalograss lawn. They have chinch bugs eating it.
a. Would that be right? They wouldn't eat the roots. They feed on the crown. But now we're in the second generation. They are peaking. One of the bifenthrin products is the best. Apply now; again, it needs a little bit of moisture to get it down in the crown of the plant. Make sure it is cinch bugs. This product can also be applied to zoysia.
18. You get a picture on this next one. This is viewer who is having a nightmare time with their turf. They think it is K31 growing in clumps. It looks like popcorn balls. They want to reseed with Kentucky bluegrass and are wondering if fescue got in it. How do they do this for long-term renovation?
a. Number one, that looks like a fabulous lawn given the drought conditions. But that's not the question. It looks like Kentucky 31. It is green through a drought like this. It could be dug out because it doesn't spread, or spot sprayed with Roundup. And within a couple of days, rake it up and reseed back in there in 3 or 4 days, and I assume the rest of the lawn was bluegrass.
19. This is an Omaha viewer who has low growing junipers. They are seeing limbs turning brown, scattered throughout the plant. It’s been watered.
a. It could be a disease. One of the things we have seen in them is rodents. Follow the branches that are turning brown, follow them back and look for any areas that may have physical damage or something on it like a canker with a lot of sap. If it's the whole branch, it's a canker. Rogue it out. Rogue just the branch, not the whole plant.
20. We have an Omaha viewer with a silver maple that gets enough water but drops dry leaves all summer long and has done this for years. It's kind of a mess. Any thought on that?
a. I can't think of any reason why it is dropping dryish leaves if it is well established and healthy. Maybe some water uptake problem caused by a root issue. It maybe some kind of anthracnose. I don’t know. Maybe if we see a picture of it
21. Fred, an acreage north of Lincoln has hard shell insects with 2-4 yellow markings about ¼ inch in length. Need a picture?
a. I need one. It is some kind of a beetle.
22. We have viewer in Lancaster County with Cochise turf type blend. It has not been watered regularly. Now they’ve watered it regularly for about five days. But it's not coming back. They are wondering, is there hope?
a. If it’s Cochise, it is older tall fescue. Five days may not be enough. Have some more patience here. Maybe 10 days or more. It doesn't have the same drought survival as bluegrass. It may take a few more days. If not in two weeks, I would reseed.
23. We have a viewer who had mini sweet bell peppers planted in a container. All of the peppers got brown spots on one side. Disease or sunburn?
a. I would look at the position of the plant. If they are all one side it’s probably sunburn. Diseases will be more random. Not on just one side, typically.
24. An Omaha viewer has a Greenspire linden planted in 2003. The leaves are yellow from the interior out. They don't say if it's a new construction planting. They think that in 2 weeks there won’t be any remaining foliage.
a. What about spider mites? Not often in lindens. Lace bugs would be a possibility. Usually you will lose the leaves. If this is the only year it's happened and the tree has been healthy in the pass, I would say environmental. If they could send us a picture that would help us figure out what's happening. If this is between sidewalk and curb, make sure it stays watered for the rest of the fall and winter. Give it time to leaf out and see where it's at then. We have seen full leaf loss or random yellowing. Maybe related to the location of the plant, the cracks in the soil which some cases are pretty deep. I would look at the buds. Even if the branch has lost the leaves, if the buds are healthy---if you pull one away and see green tissue under it---then the buds are still alive and I think it has a good chance next spring.
1. When are the apples in Nebraska City going to be ripe?
a. Now. You can go down and start picking.
2. They have an Autumn Blaze maple that has a part of the top dying and the bottom is sprouting.
a. It was a poor plant selection, honestly, for the location. Maples can be problematic. If you only have sprouts coming from the base, get rid of it. Starting a new tree from a sucker won't work.
3. We have several viewers that have ash and crabapples that are dropping leaves. Cut them down?
a. No, don’t cut them down. It is heat or some kind of residual disease.
4. We have Nearly Wild roses that have 7-foot long canes.
a. It is probably shooting coming up from the roots.
5. Yews are brown on top. Is that disease or drought?
a. That's scorch.
And water? Yes.
1. We have some orange-ish pointed mushrooms.
a. These are stinkhorn mushrooms; some people will refer to them as eggs. They'll have slimy stuff around them. Not a problem.
2. Apple trees are losing their leaves.
a. It is most likely scab.
There’s nothing to do about it now, right? It’s too late.
3. There’s mold on the stem end of the tomatoes, not on the blossom end.
a. What's most likely on the end, where it is attached, is fruit rot. Could be anthracnose. It is fungal or bacterial.
4. Any way to keep squirrels from chewing on honeylocusts to keep them from cankering?
a. Prune that material out because there's a good chance it has infections.
1. This is a viewer who wants to overseed their K31 turf, but can only water Thursday, Friday, Saturday, Sunday.
a. Can't hurt to overseed, it's cheap now. It might not be successful.
2. A viewer in Creighton cleaned their garden out and wants to know how to prevent the fall weeds and not hurt the garden.
a. Turn it over and till it or use Preen.
3 Is there a preemergent without fertilizer?
a. It is. Also, you can use a low fertilizer. Yes, you can do that. If your lawn is dormant nothing will germinate.
4. A viewer thinks they saw ragweed, but not very tall. Is there little and big ragweed?
a. Yes, there are various types of ragweed, but it also germinates for a while.
5. Weed control in a crushed granite path?
a. Short term, you can use glyphosate. Long term gets to be a problem because it would be a residual product, depending on the particle size, it could move off there. Use Roundup.
1. Butterfly milkweed that's covered with aphids. Is that unusual?
a. No, aren't they gorgeous? Don't kill them.
2. When can we expect the invasion of the box elder bugs?
a. Good question. Any time now.
3. Should we treat for emerald ash borer now?
a. No. It's not in Nebraska.
4. Noticed a lot of fungus gnats inside. Are they outside too?
a. There are a lot of them. We don't notice them because they get blown away in the wind.
5. We have insects that are lime green and look like ladybugs. They have black stripes.
a. It could be one of the leaf beetles that feed on a variety of plants.
6. What's the deal with the earthworms in the drought?
a. They are deep. They are still there somewhere.