Green Industry Resources
Hort Update- Seasonal Information for the Green Industry
2012 Show Questions --- August 9
1. We had a viewer who sent a picture of what they thought was an insect; it was actually a pupa. They thought it was eating their potato.
a. A pupa that has a long handle, that is the mouth part of a future moth. It is either a tomato or tobacco hornworm. It might be feeding on the foliage but not causing much harm to the plant. Eventually the moth will emerge and it will be a “hummingbird” type of moth, which will come out at night and feed.
2. Zac, your question has to do with compacted soil around new construction. The ground is hard because they used ash as the base of the drive. What can they do to loosen the soil and they are concerned about the ph.
a. In any construction zone, be sure to remove whatever they have used to pour the concrete, pea gravel, etc, you cannot grow turf in any of that. With the drought, all the weaknesses in the lawn are showing up. I would go in and remove all the offensive stuff and replace it with good black dirt. Check the ph level: if it 5.5 to 7, which is usually what it is in Nebraska, it should not be a problem.
3. This viewer has grown several types of heirloom tomatoes. They are seeing some of the old culitvars shrivel and die. Is this a disease or due to extreme heat?
a. Heirloom tomatoes are wonderful to grow, but more succeptable to problems. If it is only one variety, then it is most likely a disease, possible wilt. Cut the stem and if you see black within the stem it is probably wilt. You can remove the plant and take it in to the extension office or diagnostic lab to have it checked to make sure what you are dealing with.
4. Elizabeth, a viewer has pumpkins that have turned orange already. They are wondering if they should leave them in the field or pick them now. The vines are still green.
a. When it comes to pumpkin, any of the winter squashes, the fruit is ripe when your fingernail cannot pierce the skin. You want to make sure you cure them. There is a good Neb Guide on curing vegetables.
5. This image shows little brown holes in the west side of a maple. What is causing them?
a. They are actually holes caused by birds. What is under the surface of the hole is a mature round headed borer or a pupa. The borers are preparing to exit and the birds are feeding on them. For the tree, try to spray; treating with Bithenthrin would be good and do two applications this year yet and for the next few years.
Another photo shows a hawk sitting in a birdbath, why?
These birds are very hungry and thirsty. In the heat, the temperature of the water can get very high, so make sure to change the water daily, morning and evening, to keep it fresh.
6. A viewer from Elgin has bluegrass that has gone dormant. It has spots of brome in it. Should they treat it?
a. Normally it would be ok to treat brome in dormant turf, but I would be careful doing it this early. I would either use a glove dipped in Roundup or spot spray with it. Don’t damage anymore turf than has already been harmed by drought.
7. We have a viewer who mulched with straw in their garden and they are wondering what they should do further. Should they till it in in spring or fall?
a. There is no evidence that straw harbors any disease. I would incorporate the straw in with organic material and till it in the garden.
8. A viewer wants to know what is causing apples to drop from the tree before ripening?
a. The drought is causing the apples to drop before ripening; they are not getting enough moisture. If the tree had a heavy fruit set this spring, it is overloaded and dropping fruit to survive.
9. Jim, we know that Emerald Ash Borer is in Kansas City. What can we do here to prevent it from reaching us?
a. The concern is that there has been a violation; someone brought ash firewood to the Kansas City area. It came from the eastern part of the United States where they had been. There is a lot of information available. Usually when a pest like this has been detected, it has been in the area for several years. The key is: don’t take firewood anywhere. Burn the wood where you obtain it and don’t move it across state lines. We don’t need to do anything here until the borer has been discovered here.
10. This is a question from a viewer about feeding their lawn on a regular basis. They know it is too hot for fertilizer and are wondering about using products with iron?
a. Iron is a great product for instant green. It won’t force any growth but also won’t harm the turf. The hard part is the application. It is hard to find it in the right formulation and it will stain decks and sidewalks. I would advise having a professional apply it if that is what you want to do. Generally I say to stay off lawns this time of year. Wait til September to apply fertilizer.
11. This picture is of watermelons. They are wilting, stunted, and yellowing. They dry up and die. This is on the later planting of the watermelons and a variety that is supposed to be resistant to wilt.
a. If the whole vine is wilting, it could be bacterial wilt. If it is resistant to wilt, then you might see some sort of cucumber beetle. Us good sanitation practices and possibley relocate next year. If the soil is heavy clay, it might not be ideal for watermelon growth. They tend to like more sandy soils.
12. An Iowa viewer wants to know how you can tell if a cantaloupe is ripe?
a. Cantalope will have a creamy spot on it. The skin underneath should be a golden color and the vine should slip away from the fruit and the biggest one should smell like a cantaloupe.
13. A viewer has a lot of dead cicadas on their porch and driveway. Another viewer says their turf is being harmed by cicada killers.
a. A lot of them are found dead, attracted to the lights at night. Their season is basically over with and we should not see much activity from them for the rest of the fall. The wasps will follow the dead ones. The killers dig tunnels and drag them in there and lay an egg on them and cover them up. They pose no risk unless you are in their flight path. It is better to let them be.
14. This viewer has a new planting of blue gramma/sideoats gramma/little bluestem. Should they use Tenacity to control puncture vine, sandbur, and velvetleaf?
a. I would not use Tenacity to control these weeds. Use a pre-emergent in the spring to control sandburs. A number of things will control puncture vine, 2,4-D will take care of it. I would recommend that we have a publication on our website called EC130. It covers all types of weed control in Nebraska and covers all sorts of weeds and crops in Nebraska.
15. An Omaha viewer had a diagnosis of anthracnose in ash. Should they try to treat it?
a. If you want to manage it, you really need to do it earlier in the year. You need to treat it at bud break in the spring. As far as protecting the ash or starting over, as to when the ash borer is here, it is a personal decision. You may want to start other trees. Always start others and don’t cut down the ones still living.
16. We have a viewer by the Cedar River. They want to be able to hold the banks. It is a northeast exposure. There is a 200’ by 20’ strip.
a. If you are trying hold the bank to keep it from washing away, sumac would be a good choice. If you are not worried about how it looks, reed canary grass will hold it. If we get a wet year it will survive. Swamp white oak will do well and sumac will also do well.
17. Jim, we have a question about a preventive for pine wilt. Anything to do as a preventative?
a. It’s not practical, not much to be done. You can't kill the adult beetle.
18. I’ve already asked this question in the lightening round, but I will ask again. Will the water collected from a dehumidifier harm the turf?
a. It's fine and cleaner than a lot of the water that we are putting on now. One drawback is hauling the bucket up from the basement. At least it's a little bit of water. And, we are recycling the water; that's great.
19. A viewer that has a shrub-form crabapple with small trunks and the branches appear dead and brittle. When it rains, it’s in a wet spot, but there hadn't been any. Is this disease or environmental or both?
a. There are a couple of things, but I can't tell for sure. With the crabapples and, in fact, any apple trees, we see fire blight. That would be a viral disease. Typically, they are black and those don't look dark. And, you will see fungal cankers. If you see swollen areas or anything that looks abnormal, I would prune 3 to 4 inches below that area. They don't like wet. It could be having an effect. This year we are drier so all of our fungal cankers are favored.
20. This is a viewer from Clarinda, Iowa who has peonies. They look yellow and in another row, some are brown, dead, yellow. They want to know if they can cut them down now or should they wait? Any other care recommendations?
a. Cut them down when the foliage is yellow. You want to try to leave the green. Good cleanup to keep the diseases out.
21. A viewer has spider mites on their green beans. They’ve tried water and soapy water. What else can they do?
a. The beans have a hairy outer layer. It's hard to get good coverage on the plant. Additionally, it's too hot for a horticultural spray oil treatment. That's a possibility when the weather gets cooler. Beans are an attractive plant to spider mites. They go crazy and take out the foliage. If you leave them in the garden they will affect other plants. They like a few hundred types of plants.
22. We have 60 degrees at night here in some locations; is it okay to spray broadleaf weeds?
a. There is no rush to spray for broadleaf weeds. The soil has to have some moisture and the lawn has to be actively growing. And a lot of our lawns are not. We have up to the 1st of November to treat broadleaf weeds. There's no rush to spray. Wait until mid-September to the middle of October.
23. We have two spruce questions from Lincoln. One is Black Hills spruce where the needles are turning black and purple and even shedding the green needles. In the second spruce, the top quarter of the tree is turning brown.
a. We mentioned that the cankers like dry conditions. Dipoldia canker is one that's common in spruce. Follow the damage down on the branch and look carefully. If it is a canker, you may see some pitch or resin coming out at the point it’s affected. You need to decide if you want to remove the canker or cut out the damage. It's not going to recover if it is canker. That portion will be dead. They still need the drink. Any spruce species are able to get cankers.
24. We have a North Bend viewer who has an ash tree. They had a wheelbarrow filled with cement and they rinsed it out around the tree. Are there any effects from that?
a. It won't be positive. Rinse it somewhere else; that's a good idea. Just because it may have rocks and gravel and you are putting it at the base of the tree. Even though it is moisture, everything else that goes with it is not positive. That’s one of the things we deal with at construction sites. We tell the contractors, don't do that.
1. We have a viewer that has cucumber that's turning yellow but not mushy.
a. It could be sunburn.
2. How long will apple trees live?
a. 20-25 years or more in the right situation.
3. Should they dead-head their annuals and should they?
a. Yeah, be careful if it is next to concrete with the reflective heat.
4. Can we get perennials to bloom for the fall?
a. You can cut them back. If you cut them back, the drought could get them. But, you can cut them back.
5. Leaves are falling off the birch trees. Why?
6. A viewer has a Green Gem Boxwood that is dying.
a. If you get them at certain box stores, they can be really root bound or they may not be the best cultivars. I would pull up the dead one, look at the root ball, and that will tell you whether or not they were root bound when they were put in.
1. Do we have brown patch now?
a. Yes, you could if you are watering.
2. How do you treat it?
a. Avoid overhead irrigation.
3. Is there any fungicide you could use?
4. Are there any diseases on yews that could cause a single branch to turn brown and die?
a. There are several cankers that could cause that.
5. And, you need to?
a. Rogue it out.
6. Could solarizing the soil kill whatever is causing crown rot in the garden?
a. It could. If you have everything out in the fall, you will get some affect. It is better to go for a whole year.
7. Are there any pathogens in the water from the dehumidifier? Somebody wants to use it to water their plants.
1. How deeply should they water before aeration in the fall?
a. Deep enough so they can get the tines into the ground. The tines will go in as deep as the lawn was watered. The deeper you go with the tines the better you are---2 to 3 inches.
2. Is there a need for pre-emergent application this fall? If so, what?
a. I would avoid them this fall because most of us will be over seeding. We prefer to use them in the spring in most cases.
3. There is concern about cheat grass in the central and western parts of the state.
a. That grass is a downy brome grass, a winter annual. I'm surprised it is out there right now. That will go away early in spring. I'm shocked it's out there. Maybe a misidentification.
4. This person has a new house. Can the sod farms even cut sod now?
a. Sure. The sod farms are irrigated and you can lay sod as long are you irrigate it after you lay it.
1. This person swears they got eaten alive by No-See ums. Are there No-See-Ums out there?
a. They are out there and also some black flies. You can see the black flies.
2. What about chiggers?
a. There could be some chiggers still out there especially in irrigated areas. They are found in areas where there's lots of tall grass, not in dead grass.
3. This viewer has a honeylocust that has holes oozing sap.
a. It could be bird or borer activity. I would check into that. I would be ready to treat in the spring.
4. An Omaha viewer had a leaf cocoon descend out of a tree. What could that be?
a. Maybe a bagworm that's moving to another place. They'll do that.
5. A viewer with a huge infestation of scale on euonymus, almost white.
a. Still a chance this August, because there's two generations. If you see crawlers, then treat with insecticide soap or a spray oil with good coverage and that will help to break that lifecycle.