1. This McLean, NE viewer has two questions and sent us a picture of a tomato leaf and an oak leaf. The viewer says early when the oak tree budded out, the leaves were deformed with some blisters, then they developed holes.  The new growth does not have this issue. The viewer wonders if they should be concerned about that.

Let's start with the oak, and it certainly looks like insect damage.  Probably caterpillars, or maybe spring cankerworm. But it looks to me like there is something more going on than just the caterpillar damage.

It also looks like there might be some environmental damage on the leaf. Sometimes early spring cold temperatures can damage leaves as they emerge, killing the tissue between the veins.  The dead areas will dry up and blow out of the leave.  The name for this condition is "oak tatters".

Obviously this is old damage. There isn't anything you need to do now in terms of the insect control, and not much you need to do from the environmental perspective either.  There are quite a few green tissues left there for good photosynthesis.  Over the long run I think it will be okay.

2.  The second photo from our McLean, NE viewer is of a tomato leaf. The viewer wants to know what is on the leaf. In addition, is there something they can apply to stop it?

The wet conditiosn that we have had this year really has been favorable for Early Blight in the vegetable garden. Early blight is one of one of several common fungal diseases we will see on tomato.  Many times, gardeners use overhead irrigation in the garden and it would be better not to do that.  My recommendation would be to try to mulch the tomato plants to eliminate soil splashing up onto the lower leaves and start watering from the base instead of overhead.

3. This Gering, NE viewer has a weed question. They sent in a picture and want to know what it is and how to control it. They say pulling it out of the grass is also a problem.

That is a common weed called prostrate spurge or spotted spurge. If you break a leaf or the stem, you will see white, milky sap. This is the time of year you really see it growing very quickly and it forms a mat.  If it's in a flowerbed you can hand pull it, or use very careful spot sprays of glyphosate (RoundUp).  This is a species that is easy to kill with herbicides.

4. It North Platte viewer has two trees, four to five years’ old, and about 40 feet tall. They were cutint them down and found these deformed leaves with purple dots on the undersides. They wonder if this problem will move to their 50 year old cottonwoods, which give them a lot of shade.  Fred, I think we decided this was insect damage rather than pathology.

Those are popular leaf aphids. They live on the leaves, and their feeding causes the leaf to curl around them.  You can see the discoloration they cause, the yellowing of the leaf. I would not worry about them at all. Generally, about this time of year the lady beetles and other predators come in, the temperatures go up, and the aphids cease to exist. Do not worry about it. Will they go to other trees? They might, but they really are not a serious pest.

5. This Bellevue viewer has an old-fashioned Quince on the southwest side of the house; it is a part of a foundation planting, so it is kind of the hot and dry. They are wondering whether this is a significant issue and whether they should worry about it. The photo just shows a handful of these leaves.

It does look like an chlorosis problem, probably iron, although sometimes we see manganese chlorosis. The shrubs look like they have been planted there for some time. Sometimes the ph of the soil at the foundation of the house could actually increase slowly over time. That may be why they are seeing it now for the first time in ten years.  They could try an iron treatment and see if they get a response. Alternatively, prune out the discolored branch sections back to green healthy tissue.  Quince is normally a very tough plant, so I don't think this will be a major issue.

6. Fred, this viewer says they're diligent about controlling squash bugs, but now they have another problem.  A squash plant is wilting and when they split open the plant stem they found this huge grub-like creature.

That's classic squash vine borer. It is probably the most serious pest next to squash bugs that I have in my squash in my garden.  The adult is a day-flying clear winged moth. It almost looks like a little bee or wasp. It will move around the squash. They lay their eggs right at the base of the individual vines. The eggs hatch and the borers go into the vine. As they grow, the pinkish, creamy-coloredcaterpillar will reach one inch in length.  They do the damage the viewer experienced.

There are a couple of things they can do. One, you can apply an insecticide, something like Rotenone, Neem Oil or carbaryl (Sevin) dust applied right around the base of the plant where the adults lay their eggs.   If there is a bit of minor damage, cut into the stem and remove the caterpillar.  The mound soil up over the crown of the plant. Sometimes plants will continue to grow and produce fruit regardless of a little squash vine borer damage. 

7. This western Nebraska viewer has bindweed in their evergreens, which are located between a lake and their yard.   They have tried painting RoundUp on the leaves in the fall. That really did not do much good. It really is getting out of control, so what can they do?

Try something stronger than just applying RoundUp to the leaves. One of the growth regulator herbicides, such as a combination of 2, 4-D and Tordon is something they can apply. If they use a product like 2, 4-D, I would wait until it cools down a little bit, maybe after the heat of August passes but before it gets too chilly out there.

When painting RoundUp on a weed, watch the concentration of the RoundUp because sometimes I think people can get the concentration too weak and they're not getting an effective dose into the plant. So a 2% solution of Roundup is probably what people should be doing in those instances.

8. This New Jersey viewer has cucumbers and tomatoes with some disease problems.  There has been an infestation of Late Blight in the Northeast and Mid Atlantic states.  Could this be the problem?  They grew these plants from seed. So any advice we can give them?

There are several different foliar fungal diseases that could cause the symptoms we are seeing; particularly on the cucumbers. It could be Early Blight, Late Blight, Septoria leaf spot or Anthracnose.

In any case, both of these plants will benefit from making sure you do not use overhead irrigation, which will favor the leaf spots on the tomato as well as the cucumber. That is the first thing I would recommend. The next step would be to try to do everything you can to reduce the time that the leaf is wet. Improve air circulation by thinning plants if necessary, or by doing some light pruning on surrounding shrubs.  The last step would be to start making regular applications of a fungicide labled for use on vegetables.  Be careful to check and follow the harvest interval requirements on the label. 

9. This viewer needs identification of the plant in this photo. A relative has this particular plant in Southeast Kansas on their sunny deck. Apparently, it is tolerating quite a bit of heat so they want to know whether it is something they can use here in Nebraska?

It appears to be a Mandeville Vine, because of the glossy leaves and tubular-shaped flower. We can grow them in Nebraska as an annual, but they are not hardy.  I commonly see them in containers, and they can be overwintered indoors in the container. There is light pink flower; this is a hot pink they have in the picture. They are a very pretty vine. Interestingly enough, I have never seen them not vining up a trellis so it is interesting to have it cascading.

10. Fred, this Pawnee City viewer has an old, wooden shed that has become a breeding ground for wasps. They are worried about them and have removed two nests. They buzz around the door, but so far no stings. He does not think he can make it bug-proof but he does not want to get stung!

These are paper wasps, sometimes called umbrella wasps because of the shape of the nests, and they are beneficial insects. They are excellent predators out in the landscape. They eat caterpillars and all sorts of things in our yards and gardens. Everything being equal we want to preserve them for their beneficial value.

Having said that, this is a wasp. As the season progresses, they will become more and more territorial and defend their nest. They have a very ferocious sting. So if that shed is way off and you do not ever go in there then leave them alone.  Otherwise, I would get rid of them. Go to a garden center and get a hornet &  wasp spray. It comes in a pressurized can and shoots a super cool stream of spray. Stand back about 10 feet and direct the spray over nest. Any insects hit by the spray will immediately drop and even if they sort of fly out, they are so disoriented, they will not sting. I would do that if there were any chance of folks encountering those nests later in the season. Get them now when they are small.

11. All right, Lowell and Loren, this is actually for both of you. This is a viewer in Holt County with grapevines and they have some questions about foliage.  The first picture shows curling on the new growth and they wonder if this is herbicide drift? They say they are 100 yards or more from the bean and cornfields, but the grapes also show major discoloration in the leaves. Pathological, herbicide or both?

I don't see anything that is suggestive disease.

The cupping on that sample is indicative herbicide injury, some of kind of growth regulator herbicide such as 2, 4-D, to which grapes are very sensitive. When daytime temperatures are warm, the growth regulators volatize and the gas can drift fairly long distances. The chlorosis on the leaves doesn't look like drift from a corn or soybean field.  The fields are a ways away and any of the other products, aside from 2,4-D, that would be sprayed on a commercial corn or soybean field would have to be particle drift to move that far. There would have to be serious wind to move the particles a hundred yards.

12. Loren, this one is for you, and then to Fred. These Rudbeckia plants have a pest and some spotting on the leaves. 

The spots are Septoria leaf spot, a common disease on this plant. Couple things you can do, first avoid overhead irrigation, a lot of times these are in flower beds that get hit by a sprinkler and any moisture on the leaves will promote this disease.  The disease will not kill the plant, but it will make it look somewhat unsightly.  If you want to manage it, then apply a fungicide, anything labeled for any ornamentals, and reapply the product as directed on the label.  Once you have a lot of disease it is difficult to get it under control, but the fungicide will protect any new growth.  Next year, start treating earlier in the season.

Those insects are immature assassin bugs. They are important predators in our landscape, so leave them alone.  Before you spray the fungicide, brush them away.

13. This Kimball, NE viewer has many different kinds of trees, mulberries, pines, and elms. They are all older trees that have not been under irrigation. They are wondering about installing an irrigation system and whether we feel that will injure those older trees.

Pulling the irrigation lines up will cause damage to the roots. There may be some damage to the roots but if the trees are otherwise healthy and vigorous, they'll re-grow the roots as long as there's not too much digging and tunneling.  Trenching to install the lines can be very damaging to tree roots.

If they are concerned about the additional water, and possible overwatering, that can occur with an in-ground irrigation system then they should be OK as long as they do not overirrigate and keep that soil continually saturated.  If there is turf under the trees, then don't run the irrigation system more than twice per week during the hottest parts of the year.  In spring and fall, don't run the irrigation unless it is needed.  Following those practices, it should be good for the trees, not bad for the trees.

14. Fred, these mature Austrian pines are in Colfax county, north of Schyler, in a farm windbreak. Notice the bottom half of the tree is green and upper half is brown. There are holes, sap, and all sorts of things on the trunk.  They are hoping we can give them help on this because they have Scotch pine which, of course, are experiencing pine wilt.

That is most certainly one of the Zimmerman Pine moth species.  There are a number of different species Dr. Mark Harrell has worked on. The caterpillars bore underneath the bark, usually on 10 to 15 year-old trees. You can see the damage there; usually it is at the bases of the limbs. That one tree you will probably lose because the top is dead. You can probably save the others.

The way to deal with this is with an insecticide application. There are two treatment windows. The first is the third week in April. This is to get the caterpillars as they are coming out of the overwintering stage.  You can use a product like permethrin or bifenthrin. Spray the entire trunk and bases of the branches to the point of runoff.  Make a second application the third week of August, which we are coming up on. 

Click here for publication on Zimmerman pine moth

15. Loren and Kelly, this is hops being produced for brewing beer in the Omaha area.  The plants have good vine growth and the viewer has been trimming them back because they think that will promote bigger flowers. They are seeing issues on the foliage now, and thought potentially, Loren, it was mosaic virus.  

Based the symptoms we are seeing on the pictures, we can rule out a virus. None of the symptoms suggest this vine has a virus.

It does show some symnptoms on the leaf margins that look like nutrient deficiencies. Kelly and I were talking about this.  It really looks like it could have a root rot because of wet soil.