Butterflies…Everywhere

Butterflies blog

As a nature-loving person, with major interests in plants and bugs, I love going outside in the warmer months of the year to enjoy all the plant and insect life outdoors. One of my favorite things to view would be the butterflies. I love the unique coloration patterns and flying abilities of butterflies. This year there is a bit of an increase in population of one particular butterfly, the painted lady butterfly.

The painted lady butterfly is a pinkish-orange butterfly with black blotches on the wings. The forewings have a white-spotted, black tip. This butterfly has a wingspan of 2-2.25 inches. They are often confused with monarch butterflies but painted ladies are more pinkish in color, not striped, and are smaller than the monarch.

Painted lady, Whitney Cranshaw, CSU, Bugwood
Painted Lady Butterfly, Photo courtesy of Whitney Cranshaw, Colorado State University, Bugwood.org

Painted lady butterflies are being seen this year in quite large numbers. Many of the callers are just curious as to why there are so many butterflies on the gravel roads or if these butterflies will do any damage to their plants. Some callers are just curious why the populations seem so large this year. These are all great questions as this year, the population is quite a bit higher than other years.

Painted ladies are one of the butterflies in the nation that migrate through Nebraska every year from the south and they do not overwinter here. This year there is an abundance of painted ladies in the south. The high population has built over many years of ideal conditions for the development of painted lady butterflies in the south. The weather has been less harsh and there is an abundance of host plants there, as well, to help increase the population. This higher population coupled with the wind currents this year have led to a very high population moving through Nebraska late this summer.

Painted Lady underside, N. Stoner
Underside of a painted lady butterfly

As a butterfly, the painted lady is a pollinator insect and therefore is beneficial to have around. So, the butterflies will not damage our plants they will in fact help us. However, as a caterpillar, they do feed on some of our crops. It seems there is an abundance of host plants for them this year so it looks like we could face one to two more generations of the painted lady butterflies in Nebraska this year before the frost occurs. The butterflies we are seeing now are laying eggs on different plants, including soybeans, that will emerge into caterpillars. When that happens, those caterpillars could feed on the leaves of soybeans as well as our vegetable garden crops. However, it is NOT recommended to apply pesticides to control adult painted lady butterflies, instead just watch in your fields and gardens and treat the caterpillars if necessary.

So, the abundance of these butterflies is a good thing for our pollinated plants. Remember only a couple of years ago we had a very high population of the periodical cicada, it is just another reason that nature is so unique and so enjoyable. All insects go through periods of increase and decline in their populations, it is mostly dependent on environmental conditions as well as food and host plant availability. Enjoy the butterflies while they are here, we don’t usually get to see so many all at once.

Poor Pollination

Poor Pollination, Blog post

Summer is a great time of the year. Our flowers are blooming and our gardens are growing. However, sometimes we have disappointments in the garden such as when our vegetable crops don’t produce viable fruits for us to eat. There are many reasons for that, but most of them we cannot help with. Just be patient and they will work themselves out.

Zucchini, squash, and cucumbers have been known to produce fruits that develop into only a small fruit that then falls off the plant. The reason for this is due to poor pollination. The plants in the cucurbit family have separate male and female flowers. This time of the year, only the male plants are present in the plants. To have a fully pollinated fruit that will develop to maturity, the plant needs the female flower to provide the fruit itself, but it needs to be pollinated by the male flower. A female flower is easily identified because you will see a small forming fruit behind the flower. Often times, people see the flowers on the plant and then get discouraged because a fruit doesn’t form, but both types of flowers are necessary to get fruits.

Poor pollination can also be caused due to lack of pollinators. Bees and other insects are necessary in cucurbits to ensure that the pollen is moved from the male flowers to the female flowers. Some years the weather isn’t desirable to the pollinators or we have a low number of pollinators present, which will lead to poor pollination causing the small fruits to drop off before fully developing. This year it has been quite rainy which leads to less pollination because bees don’t like to fly in the rain. Be careful when spraying for squash bugs and squash vine borers to help reduce injury to pollinating insects.

blossom end rot zucchini
Blossom End Rot on Zucchini

Blossom end rot is another reason that small fruits may not fully develop and then fall of your plants. Blossom end rot is an environmental problem that affects many of the plants in our garden including tomatoes, peppers, cucumbers, squash, zucchini, and watermelons. This is actually a calcium deficiency within our plants. Calcium is often found in adequate quantities in Nebraska soils, however, it cannot be moved throughout the soil and into the plant without even moisture. So, the problem isn’t due to lack of calcium, it is due to uneven moisture in the soils. In Nebraska, especially in the beginning stages of plant development, moisture is typically uneven due to heavy rains in between dry spells. Using calcium on your plants will not help this issue. Give the plants time and they should begin to develop normal fruits with no blossom end rot on them later in the season. Typically, we only see blossom end rot for the first couple of harvests in a season. You can still eat the fruits that develop with blossom end rot, you would just need to cut the rotten portion of the fruit off.

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Squash bugs on a Zucchini

Squash bugs and squash vine borer are coming to take over our gardens soon. This is the time of year to watch out for these problematic, common insects found affecting our cucumbers, zucchini, and the other cucurbits. Pay attention to your garden to help prevent damage. You can scout for the eggs of the squash bug. You will notice a group of tiny, copper colored eggs gathered near the intersection of the veins on the underside of the leaves. Remove and destroy the eggs as you find them to reduce the population. For squash vine borer, wrap the base of the plant in aluminum foil to stop the females from laying the eggs on your plant. You can use insecticides for both of these, just be careful to do it in the evening when the bees aren’t flying and don’t spray the flowers with insecticides to help with pollination.

Peach Leaf Curl

Lately, I have had quite a few community members come into the office with a problem on their peach tree. The leaves look funny and have a pinkish color to them. The same problem is being seen throughout the area and unfortunately, there is nothing we can do about it, at least not for this year. The problem many people are dealing with is Peach Leaf Curl.

Peach leaf curl is caused by the fungus Taphrina deformans. This fungal disease is one of the most common diseases in the home orchard and can affect the blossoms, fruit, leaves, and shoots of peaches and nectarines. (Cherries have a similar leaf curl diseases caused by T. cerasi.) Peach leaf curl is more severe following cool, wet springs; temperatures between 50 and 70 degrees F are ideal for infection, which is why we are seeing it so often this year.

Peach Leaf Curl, Paul Bachi, Univ of Kentucky R and E Center, Bugwood
Photo of Peach Leaf Curl is from Paul Bachi, University of Kentucky Research and Education Center, Bugwood.org

The primary symptom is a thickened, puckered area on leaves which will turn yellow to red or purple with the loss of chlorophyll. These leaves may prematurely drop, weakening the tree and making it more susceptible to other diseases, pests, and cold injury. The disease can also result in reduced fruit set, size, and quality.

A single fungicide spray applied while trees are still dormant (just prior to bud swell), thoroughly covering all branches, shoots, and buds will control peach leaf curl. Effective controls include Bravo, Ziram, and copper compounds.

At this time of year, most infection has already occurred, and fungicide sprays are relatively ineffective. Fruit on defoliated trees should be thinned to reduce stress and improve tree survival.

This information on Peach Leaf Curl came from Connie Fisk, a fruit tree expert for Nebraska Extension located in Cass County. Read more from Connie on her blog, Food Adventures with Connie

Another thing to think about this time of year, is what type of fruit tree to plant if you are thinking about planting new trees. You need to decide what type of fruit you prefer to grow, what you will be using your fruit for, and if the tree is self-fruitful or if you need to plant a pollinator tree nearby. It is also best to plant fruit trees that are resistant to the common diseases found in our fruit trees. For apple trees, select a tree that is resistant to cedar-apple rust and apple scab. For peach trees, choose a tree that is resistant to bacterial spot. For pear trees, choose one that is resistant to Fire Blight.

apples-A. Henneman flickr
Flickr image courtesy of Alice Henneman per CC license

For Apple trees, some good choices include Redfree, Johnafree, or Liberty. For Pear varieties, look at Moonglow, Luscious, Lincoln, Magness, or Seckel. For Peaches, choose Reliance, Red Haven, Contender, or Madison.

There are many other great choices for fruit tree varieties to use. Nebraska Extension released a NebGuide in July of 2016 called ‘Fruit Tree Cultivars for Nebraska’. It is a good guide that helps you to find the fruit tree variety or varieties you need for your fruiting wishes.

Tree Selection and Pruning

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Arbor Day is Friday, April 28th, 2017. Arbor Day is always an exciting day for me because I really appreciate trees and understand the real potential that can come from planting a tree. With Pine Wilt and the concerns of Emerald Ash Borer creeping closer it seems there is always a need to plant a tree, if not for you, then for future generations.

There are a lot of good trees to plant when you do plant a tree. The most important thing to remember when planting trees, is Diversity. When you go to purchase your tree, look around your yard and even your neighborhood. Try to avoid planting multiple trees of the same species, genus, or family of plants in the neighborhood and in your own landscape. You may enjoy Maples, but you want to make sure you plant other types of trees in your yard besides just maples to help avoid an issue that may arise should another pest come through like what we saw with Dutch Elm Disease or Chestnut Blight or now Emerald Ash Borer.

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Each year, ReTree Nebraska comes out with a new diverse list of trees that grow well in Nebraska and are often under-utilized. That list includes Baldcypress, Catalpa, Kentucky Coffeetree, Elm Hybrids, Hackberry, American Linden, Sugar Maple, Chinkapin Oak, Bur Oak, English Oak, Sycamore, Shantung Maple, Miyabe Maple, Gample Oak, Tree Lilac, Concolor Fir, Black Hills Spruce, and Ponderosa Pine. In 2017, ReTree Nebraska added Turkish Filbert including other nut trees such as Hickory, Chestnut, Pecan, Buckeye, and Walnut to the list of good trees to plant in Nebraska. There are a lot of other great trees to use in your landscape, this is just a short list.

Turkish Filbert is a unique, under-utilized tree in Nebraska. It grows up to 40-50 feet tall and 30-50 feet wide. It has large, bright green leaves that turn yellow in the fall. This tree has catkin flowers, like a cottonwood.  It has edible nuts that are produced in a cluster of 3-6 and have a spiny husk that covers the nuts. Often squirrels eat the nuts, but they can be roasted and eaten by humans. This tree is most commonly used as a shade tree or a specimen tree in a landscape.

Another thing to think about with our young trees, is pruning. Eric Berg, a community forester from the Nebraska Forest Service wrote a great article on pruning young trees. We need to start pruning our trees when they are young to minimize tree wounding and cause the trees to grow stronger, mature growth. A tree planted in a landscape setting, rather than being planted in a forested area, will grow out more than up and not develop a strong central leader. Often our trees develop multiple leaders that lead to weak growth that can easily be broken in storms. We saw the damage from weak branch attachments and poor growth in our ice storm this past winter.

pruning tools-K. Todd
Photo courtesy of Kim Todd, UNL Department of Agronomy and Horticulture

We can prune a tree when it is young to help prevent some damage in future storms. If you would like to learn more about pruning young trees, Graham Herbst, from the Nebraska Forest Service, will be in Beatrice to teach us about pruning young trees on Monday, June 19th from 6-8 pm starting at the Gage County Extension Office. He will cover how to set pruning objectives, determining a pruning cycle and dose, strategies for specific trees, and how to execute your plan with proper cuts. There will also be a hands-on pruning demonstration at the end of the classroom portion. If you are interested in this program, please call the Gage County Extension Office at 402-223-1384 to sign up.

Henbit?!

Henbit from canva

It’s spring, finally! I know our winter wasn’t terrible this year, but I always look forward to spring. That is such an exciting time of the year, all of our plants are greening up and the early blooming trees, shrubs, and bulbs are beginning to show us their beauty for the year. However, not everything about spring is fun and games. This is the time of the year I always get calls about that dreaded purple flowering weed in our lawns and gardens.

Henbit is the purple blooming weed that shows its ugly face very early in the spring. This is the weed that will cover crop fields early in the spring with large expanses of purple blossoms. This weed is also quite prevalent in our lawns and gardens.

henbit, steve dewey, Utah State Univ, Bugwood

Henbit is a member of the mint family, which means that it has square stems. It has leaves that are rounded with a scalloped edge and they are arranged oppositely along the stem. It has a small purple flower with darker colored purple spots on the lower petals of the flowers. Henbit is often confused with creeping Charlie or ground ivy, which is a perennial weed from the same family with purple colored flowers as well. The differences between the two are that creeping Charlie is a perennial so it blooms later in the year than henbit and creeping Charlie has flowers that are more blue and henbit flowers are more purple.

Henbit is a winter annual. This means that henbit only lives for one growing season, but it’s development is different from something like crabgrass which is a summer annual. A winter annual is a plant that germinates in the fall and grows a bit before basically becoming dormant for the winter months. Very early in the spring, henbit will start to grow again, produce flowers which produce seed for the growth to come next year and then it dies. A winter annual dies as soon as the weather starts to warm up in the late spring whereas a summer annual germinates in the spring and goes through it’s lifecycle through the summer months, dying with our fall frosts.

The problem with henbit is that by the time we see it, or rather see the beautiful purple flowers, it is too late to treat it this year. As I said, henbit dies when the weather warms up, so why spray it with a chemical when it is going to die in a few weeks anyway. The fact that it is noticed when it is blooming shows us that it is already producing seed for next year, so killing the existing plants does nothing for the future generation of this plant. However, pulling the plant would be a fine management practice in the spring months.

Henbit is a plant that tends to grow in the areas where grass typically dies out. Areas around sidewalks and driveways or areas where people tend to cut the corner around sidewalks are locations where the turf gets worn down and the henbit excels. Henbit is also often found along the foundation of a house or in a garden area with exposed soils. If we can do things to keep your grass growing in these locations or use other plants or mulch to cover the bare soil, the henbit will struggle. Using a pre-emergent herbicide for broadleaf weeds in the fall will also help reduce the seed germination. Finally, using any broadleaf post-emergent herbicide later in the fall after the henbit has germinated, such as 2,4-D, will kill henbit as well.

Nebraska Weather Effects on Plants

Crazy Weather blog

This year the weather has been crazy. We saw 70’s in February followed by 30’s and snow in the middle of March. The warm weather was great, but it got all of us in the mood for spring, including our plants. Now that we have seen such a cool down, our plants may be the ones most affected.

We have seen early budding in many of our shade trees and shrubs, which often happens with above average winter and spring temperatures. This can be problematic for the plant. If the swelling or opening up of buds occurs prior to a cold snap, it can cause damage to that particular bud. If those buds that were opening up were flower buds, we may lose the flowers on that shrub or tree for the year. However, if those buds were leaf buds, those plants may be set back on their emergence and growth for the year. If leaf buds were damaged, a healthy tree will set new, secondary buds to push growth but it will be later in the season than normal. As long as the tree is healthy it will be fine. But, there is nothing you can do to stop this condition.

Red maple, bugwood
Photo from: Chris Evans, Illinois Wildlife Action Plan, Bugwood.org

This warm up, cool down cycle is stressful to our plants. So, it is a good idea to help keep your plants otherwise healthy. Make sure your trees and shrubs are properly mulched and kept well watered in the absence of rain.

Another issue that we are dealing with this spring with the rapidly changing environment, is the advanced emergence from dormancy of spring bulbs prior to this latest cold snap. There is nothing you can do regarding this issue either. The bulbs that have already begun to bloom may lose their flowers early or have some freeze damage. These bulbs may also experience some leaf dieback. Tulips and daffodils are normally a spring blooming plant, so they are accustomed to normal spring freezes adapting to temperatures as low as the upper 20’s. However, if we see anything lower than that, these plants may exhibit freeze damage on the leaves, showing up as white, limp leaves. Do not cut back the damaged leaves until the foliage dies back on its own.

Finally, we have started to see many of our perennial plants emerging and greening up for the spring already. Much of this growth occurred before the cold snap last week. As for these plants, I would advise you to just leave them alone. If there is a forecast for very low temperatures, it would benefit the plants to add additional mulch or a row cover over them for the overnight hours, pulling that back during the day as the temperatures warm up. If you didn’t remove the plant material last fall, leave it there now until the spring, even as they green up below it. If you expose the crown of the plant that has been covered by the dead plant material all winter long, cold snaps will be more problematic for the plants. The dead plant material and extra mulch the plant has had over the winter months will protect it from freezing and thawing and from very cold temperatures this late in the season. It is best to wait until we are more consistently facing spring weather before removing this plant blanket they have had all winter.

Ice Storm Damage to Plants

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Many people do not like winter due to cold weather and the bad driving conditions such as snow and ice. Our plants are not much different in this respect, snow and ice can cause problems to our plants. The recent ice storm we saw covered our trees and shrubs in a thick layer of ice.

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Lawn covered in ice from winter storm Jupiter

As trees become covered with ice, problems can occur. The best way to avoid any problems from a heavy layer of snow or ice would be to let it melt naturally. Heavy snow or ice loads look damaging to the tree which makes people want to knock the ice off of the trees to help the plant. However, it is really better to leave it alone. The snow and ice will eventually melt off of the plants and they will spring back up to their normal form after a while. If you try to break ice off of a tree or shrub, it can break the branches or crack them, leaving them vulnerable to other problems.  Again, the ice will eventually melt off of the tree or shrub and it will be fine.

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Shrub covered in ice by 2017 winter storm

Many tree branches broke after the weight of the ice from the last storm proved to be too much. The best management practice for helping a tree that has broken branches due to snow and ice would be to go out and trim those branches to make them a clean cut rather than a jagged cut. Leaving a break rather than having a clean cut will prevent the tree from naturally healing the wound and this opening will lead to decay in the tree. This is much more damaging to the tree so it is best to prune the tree between the break and the bark collar or hire a professional to do this for you. If your tree split down the middle or lost a great number of branches, it may be time to to think about replacing this tree. It would be best to call a Certified Arborist in this case to assess the damage and give recommendations on the next steps for your tree.

 

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Broken branches due to ice storm, photo by Karen Rahe

Deicers are another plant consideration in the winter. They can cause damage to concrete sidewalks and to plants growing beside them. Many deicing agents contain salt substances, such as sodium chloride and potassium chloride. Because of the salt content found in these products, it can cause severe damage to our plants if too much is piled on them too often. Typical plant symptoms of salt damage include:

  • Desiccation (drying out)
  • Stunting
  • Dieback
  • Leaf margin and tip damage similar to chemical burns on the leaves

To avoid damage to concrete, remove the salt as soon as you can. Deicers are meant to make shoveling easier, not to completely melt away snow and ice. As soon as the salt melts through the ice and snow enough that it can be removed, go out and shovel it off of the concrete. When removing the snow, do it in a manner that protects the landscape plants growing in the yard. Do not pile the snow onto trees, shrubs, or flower gardens. If it has to be piled onto your landscape, move the salt onto the grass and try to do it in a manner that makes it more uniform on the grass surface. If too much salt continually gets piled up on the grass in one location, the turf can be harmed. If you are very concerned with the effect the deicers have on your plants, you can use alternate products for melting the ice, such as calcium magnesium acetate which contains no salt.