This is a collection about horticulture.

Yellow Pine Needles October 3, 2014

Filed under: Uncategorized — Elizabeth Killinger @ 3:06 pm
Tags: , , , , ,

Yellow inner needles

IMG_0600Cooler nights and falling leaves signal that fall is here. Pines in the area are starting to change colors too. Knowing the cause of the discolored needles will help to know if it is nature taking its course or if it is a disease infecting your trees.

Across the area, yellow inner needles in pine and spruce have just started to appear. Evergreen needles change color in the fall too, just like deciduous trees. It is a normal occurrence called natural needle drop. The older interior needles of pine and spruce are turning yellow and drop from the tree. The older needles that are lost are usually located closer to the inside of the tree or trunk. Factors that increase the stress on an evergreen can intensify the autumn needle drop. These stress factors can include drought, herbicide injury, root damage, or insect or disease damage.

White pine with natural needle drop

White pine with natural needle drop

Like many living things, evergreen needles also have a lifespan. Pine trees hold their needles for 2-3 or more years. Spruce trees hold their needles longer than pines, usually around 5-7 years. After the needles have lived their lifespan, they fall from the tree. Some trees, like the white pine, make it easy to see the needle drop.

The location of the discolored needles can determine if it is natural needle drop or if something else has infected the tree. If the tip of the branch was the only part affected this spring, fungus could be to blame. Cool, wet springs are ideal conditions for fungus, this spring was no exception. The Sphaeropsis tip blight fungus will infect the new growth as it emerges causing it to turn brown and hang on. If fungicides are applied, the best time to spray preventative treatments for Sphaeropsis tip blight fungus is April.

Sphaeropsis tip blight

Sphaeropsis tip blight

One of the most common pine diseases is also caused by a fungus and can also cause brown needles. Dothistroma needle blight causes reddish lesions found on individual needles. It causes the needle to appear to be half green and half brown on last years’ growth and mainly affects the lower half of the tree. Preventative fungicide applications can be made in mid-May and again in mid to late-June.

Pine wilt can also cause needles to change color. If the entire branch, or tree, turns brown and the needles hang on, it could be pine wilt. The cause of pine wilt is smaller than we can see with the naked eye. The pinewood nematode is a very small worm-like organism that attacks the tissues that move water and nutrients throughout the tree. The nematode doesn’t travel very far by itself, so it uses a ‘friend’ to help it move around. Nematodes hitch a ride on pine sawyer beetles and fall off when they reach a new tree to infest. The first symptom is the tree or a major branch will have a grayish green tint to it. As the nematodes progress and multiply the tree turns tan and then eventually brown. One important thing to remember is that the dead brown needles will remain on the tree for a year or more

Pine Wilt in Scotch Pine

Pine Wilt in Scotch Pine

One way to prevent needles from changing color next spring is through irrigating now. Moisture helps to promote root growth and reduces winter desiccation injury. Supplemental fall irrigation should be continued, when there isn’t precipitation, until close to soil freeze. When air temperatures in winter are above 40 degrees Fahrenheit apply water early enough in the day so it can soak into the ground before temperatures drop below freezing. This will help to avoid the water from freezing on the surface at night when the temperatures drop down. Apply enough water to moisten the soil eight inches deep under the drip line of the tree. Be sure to check the soil moisture before irrigating to avoid irrigating a saturated soil.

Proper identification of the culprit behind the color changing needles can help you determine if this is nature taking its course or if you have some action to take in the future.

For more information contact Elizabeth Killinger at, 308-385-5088, on Facebook, Twitter, her blog at, or visit the University of Nebraska-Lincoln Extension website:


Its ReTree Nebraska Week 2014! September 24, 2014

Filed under: Uncategorized — Elizabeth Killinger @ 6:11 pm
Tags: , , ,
Plant it forward.

Plant it forward.

Every good Nebraskan knows we are the home of Arbor Day. Did you know we also have another opportunity to celebrate trees? ReTree Nebraska week is dedicated to trees. Find out why we should re-tree Nebraska and how you can take part in this week long celebration from September 22st – 27th.

ReTree Nebraska is a cooperative initiative of the Nebraska Forest Service, Nebraska Statewide Arboretum, University of Nebraska Rural Initiative, University of Nebraska–Lincoln Department of Agronomy and Horticulture, and Nebraska Community Forestry Council. It is a 10-year cooperative initiative which will raise public awareness of the value of trees, reverse the decline of Nebraska’s community tree resources, and improve the diversity and sustainability of trees in communities across the state that will last for generations to come.

Severe weather, drought, poor planting practices or species selection, insects, disease and an aging tree population all have contributed to the decline in the number of community trees across the state. Planting new trees is an essential part of maintaining Nebraska’s community forest, and fall planting offers important benefits.

Just because we are a ‘Prairie State’ doesn’t mean that we don’t have or need trees. Across Nebraska, there are about 470,000 acres of community forests. These trees were planted by previous generations who understood the long-term benefits they would provide, such as cleaner air, healthier soil and wildlife habitats. Planting a tree provides much-needed shade during hot Nebraska summers, which helps reduce energy costs for homeowners, schools and businesses. Every dollar invested in the community forest returns an average of $2.70 in net annual benefits. Nearly $9.7 billion in environmental, social and economic benefits are provided by 13.3 million trees in Nebraska communities, but that’s half the number of trees that were present 30 years ago.

Fall is an optimal time for tree planting. “Fall is a great time to plant trees in Nebraska because there are fewer demands on the roots, allowing trees to establish their root systems and get a jump start on spring growth,” according to Jessica Kelling, ReTree Nebraska coordinator.

When selecting a tree species, Kelling recommends considering a couple of key factors. Plant a different species than what is already growing in adjacent areas. “Enjoy the two weeks of fall color your neighbor’s red maple provides, but select a tree for your yard that provides some variety in leaf texture, form and fall color to create a diverse landscape year round.” Kelling also urges homeowners to take a tree’s mature height and width into consideration when selecting a species for planting. “Go to the planting site and look up, down and around for conflicts with buildings, utility lines and even other trees.”

If you are looking for a good tree to plant this ReTree Week, ReTree Nebraska has “Fourteen for 2014,” a list of underutilized tree species. The trees are broken down by size and type and include:

Evergreen- Concolor fir—Abies concolor, Black Hills spruce– Picea glauca var densata, Ponderosa Pine—Pinus ponderosa

Small to Medium Deciduous Trees- Shantung maple—Acer truncatum, Miyabe maple—Acer miyabei, Gamble Oak- Quercus gambelii, Japanese or Pekin Tree lilac-Syringa reticulate (‘Ivory Silk’) or Syringa reticulate ssp. pekinensis (Copper Curls®)

Large Deciduous Trees- Kentucky coffeetree—Gymnocladus dioicus, Northern catalpa—Catalpa speciosa, Baldcypress—Taxodium distichum, Bur oak—Quercus macrocarpa, Chinkapin oak—Quercus muehlenbergii, English Oak—Quercus robur, Elm hybrids—Ulmus x (‘Accolade’, ‘Cathedral’, ‘Frontier’, ‘New Horizon’, ‘Pioneer’, ‘Triumph’, ‘Vanguard’), Black or Bigtooth Maple- Acer nigrum or Acer grandidentatum

We can work together to celebrate this week as well as support a grassroots, or rather tree roots, Nebraska initiative. To learn more about ReTree Nebraska, report a tree planting, or find out more about tree selection, planting and care, visit or email

For more information contact Elizabeth Killinger at, 308-385-5088, on Facebook, Twitter, her blog at, or visit the University of Nebraska-Lincoln Extension website:


Impatiens Downy Mildew September 15, 2014

Impatiens with downy mildew

Did your once gorgeous flowering impatiens turn into bare looking sticks by the end of the summer? If so you are not alone. Impatiens downy mildew is a fungal-like infection that has been reported across the state this year. Find out more about this disease, how it spreads, and what you can do in the future to prevent another infection.

The symptoms of the infections aren’t as easy to spot as you might think. The first symptoms are leaves starting to appear light yellow or stippled yellow and green. The leaf edges begin to curl downward and appear to be wilted. The tell-tale sign is the fluffy white growth on the underside of the leaves. Often these symptoms are over-looked until the plant begins to lose its blooms and leaves, leaving bare stems. Eventually, the entire stems will begin to collapse and turn soft and mushy. All varieties and hybrids of Impatiens walleriana, common bedding plant impatiens, are susceptible to impatiens downy mildew. New Guinea impatiens, Impatiens hawkerii, are highly resistant as are other bedding plants in different genera that aren’t related to impatiens.

Underside of the leaf. Photo courtesy

The development of impatiens downy mildew is highly influenced by the weather. Wet foliage, cool night temperatures, and moist air all contribute to ideal conditions for this disease development. Plants in heavily shaded locations where the leaves stay wet for extended periods of time will tend to have higher incidence and severity of this disease because moisture promotes infection. Impatiens downy mildew tends to be worse in locations where leaves stay wet for extended periods of time, beds that are densely planted, or in beds that receive overhead sprinkler irrigation, due to the leaves not being able to dry quickly.

It takes perfect environmental conditions for this disease to take hold. The pathogen can be introduced into a garden on infected transplants that aren’t yet showing the symptoms. Additionally, impatiens that are planted into beds that were infected the previous year may also become infected. A close cousin to the pathogen that causes impatiens downy mildew has been found to survive for 8-10 years in the soil.

Impatiens downy mildew can spread throughout the landscape. The pathogen produces spore-like structures called sporangia on the lower surface of the leaves of infected plants. These structures can be splashed short distances or become airborne and travel long distances on moist air currents and spread the infection. It only takes about four hours of a wet leaf surface for sporangia to form. Under hot, dry conditions, infected plants may not show symptoms of disease and produce sporangia on the lower leaf surface.

There are several management approaches for the landscape beds. Avoid planting Impatiens walleriana in those beds that had plants infected this past year. Consider alternative plants in those areas like coleus, caladium, begonia, or New Guinea impatiens. In beds with no history of impatiens downy mildew, I. walleriana can be planted, but take care to inspect and select disease free plants. Once a plant is infected, there isn’t a cure and it should be removed from the landscape. Also pick up any fallen leaves or blooms and consider removing neighboring plants. At the end of the growing season, completely remove all plant material to prevent the pathogen from overwintering.

Changing cultural practices can also help prevent this disease. If possible, reduce the amount of moisture and humidity that the plants are getting. Aim to water the plants in the early morning and provide deep infrequent irrigation to reduce the amount of time the leaves are wet. Space plants out so that there is adequate air circulation between the plants.

Fungicide applications are another option. Most fungicides can help prevent infection, but there aren’t any that will cure the disease once the infection has occurred.

Don’t let impatiens downy mildew stop you from enjoying these shade-loving annuals. Take precautions to ensure this disease doesn’t take hold of your landscape. But if it does, be prepared to try other interesting annuals.

For more information contact Elizabeth Killinger at, 308-385-5088, on Facebook, Twitter, her blog at, or visit the University of Nebraska-Lincoln Extension website:


Garden Weeds: A plant out of place… August 14, 2014

Filed under: Garden — Elizabeth Killinger @ 2:53 pm

All things considered, it’s been a good year for the home gardener. No doubt some of you with gardens are being buried by the amount of produce. Before too long the zucchini fairy will start leaving ‘gifts’ on the door steps of neighbors and friends. The weeds are thriving just like the rest of the garden and we still have a long garden season ahead of us. Find out what you can do to keep your garden weed-free up until frost.

The biggest problems for most vegetable gardeners include bugs, diseases, weather, and most commonly, weeds. A weed by definition is a plant out of place. In the vegetable garden, that can mean any plant that isn’t eaten eventually. Proper identification of the plant ensures that you are removing the ‘weed’ and not pulling up the garden crop you worked so hard to get to grow. The best time to control weeds is when they are seedlings, but that doesn’t always happen. It is important not to let the weeds go to seed, which can make future weed problems worst in the long run. One shepherd’s purse plant can produce 38,500 seeds in a single growing season and one redroot pigweed can produce 117,400 tiny seeds in a year.

There are several methods that can be used in the war on weeds. Mechanical control, chemical control, and mulching are three common methods used to combat weeds in the vegetable garden. Mechanical control can mean a wide variety of methods, all of which manually disrupt the growth of the weed. Rotary hoes, wheel hoes, powered garden tillers can work in those areas between wide rows and those areas where weeds are winning the war. Hand pulling or using hand tools may be needed closer to the crop. Pulling early and pulling often is the motto for most vegetable gardeners when it comes to weeds. If the weeds have gotten away from you and they are starting to set seeds, more drastic measures may need to be taken…the lawn mower. Mow off the weeds before their seeds fully mature. Mowing short on a hot summer day is enough to set the weeds back enough to buy some time for you to try to regain control, or even kill them in some instances.

Carefully selected herbicides are another option for weed control in the vegetable garden. An early season choice for the vegetable garden would include preemergence products that contain trifluralin, like Preen Garden Weed Preventer, or corn gluten meal, like in Preen Vegetable Garden Organic Weed Preventer. These products keep the weed seeds from germinating, or sprouting. Use caution in areas where you want to direct seed garden crops as they can also keep your garden seeds from germinating as well.

Herbicide control on already emerged weeds can get be a little more risky. Some post emergence herbicides like those that contain 2,4-D can volatilize into the air and cause damage to sensitive crops like tomatoes, peppers, and potatoes. If you do select a post emergent herbicide for the vegetable garden, be sure that the labeled for use in the garden and follow the label’s instructions.

Monitoring weeds before they get out of control is easier said than done. Watch for weeds, apply preemergence herbicides early in the season, scout throughout the season, and pull weeds often. If all else fails, just remember some weeds are edible making them a tasty addition to the garden.

For more information contact Elizabeth Killinger at, 308-385-5088, on Facebook, Twitter, her blog at, or visit the University of Nebraska-Lincoln Extension website:



Enjoy Roses: flowers, thorns, bugs, and all July 28, 2014

Filed under: Uncategorized — Elizabeth Killinger @ 1:00 pm

No doubts about it, roses were hit hard this winter. Whether you had hybrid tea roses or the tough-as-nails shrub roses, they all took a beating. Don’t let your roses suffer any more damage this summer, be on the lookout now and catch these common rose problems.

Japanese Beetles

Japanese Beetles

Japanese beetles are a common pest of roses. They will feed on most anything, but they have a love for roses. These insects are related to the May/June beetle and can be a major pest of roses. The immature form of the beetle is a grub that can do some damage to turfgrass. The adults hungrily devour roses and cause the most feeding damage. The front of this beetle is a dark metallic green and the wing covers are a dark tan or coppery color. The main identifying characteristics for these beetles are five small tufts of white hair along each side of the insect. They feed in clusters during the day on leaves or on the blooms. Adult Japanese beetles can cause the leaves to have a skeletonized appearance, ragged holes, or in some instances, the leaves are completely eaten.

Rose Chafers

Rose Chafers

Rose chafers are another beetle pest of roses. The adult beetles are slender, 1/2 inch long, and are light tan colored. They lack the tufts of hair that the Japanese beetles have. The long burnt-orange legs are the distinguishing characteristic that sets them apart, as they clumsily walk around. The adults feed on the foliage and flowers of roses, while the larvae feed on roots of grasses and alfalfa. Adults may feed together and can cause skeletonized leaves or ragged holes in the flowers.        

There are a few ways that you can control Japanese beetles and rose chafers on roses. If the infestation is light, hand picking is an option. Pick the beetles off in the early morning and drop them in a bucket of soapy water. There are also some deterrents that can be used like neem oil. Several insecticides are labeled for control of these pests with active ingredients like carbaryl, acephate, and chlorpyrifos. Keep in mind that these beetles are mobile and often new beetles take the place of those killed by insecticides. Try to avoid applying the products to the flowers or during times when bees are present because they can harm honeybees.

Black Spot on Roses- photo courtesy IANR Pubs

Black Spot on Roses- photo courtesy IANR Pubs

Some disease names lack imagination. Black spot of roses is one of those. This fungal disease causes the rose leaves to turn yellow then develop black spots, hence the name black spot of roses. The leaves that are affected might fall off, which can affect the appearance of the shrub. It can also reduce plant vigor, cause stunted growth, and increase the chance of winter kill. The fungal spores overwinter on fallen leaves and diseased canes. Rain splash or sprinkler impact easily spreads the spores onto healthy new plant material.    

Prevention is the best method for dealing with black spot. Following good sanitation practices like cleaning up rose beds in the fall will make sure to get rid of any old plant debris that could overwinter spores. Replacing old mulch with new, if black spot was a problem in the past in that location, as well as looking for and selecting rose varieties that are resistant to black spot will help to reduce or eliminate the need for a spray program.

Fungicides are another option for black spot control. For best results, most fungicide applications should be applied preventatively to healthy foliage to keep the leaves from becoming infected. Throughout the growing season, infected leaves should be removed as soon as symptoms begin to appear. On plants with a history of black spot, fungicides can begin to be applied as soon as the foliage begins to emerge in the spring and continued throughout the summer. Read and follow label instructions for application and reapplication recommendations. For best results, a fungicide should be used in combination with good cultural and sanitation practices.

With a keen eye, you can catch these issues before they become a pest in your rose bed.

For more information contact Elizabeth Killinger at, 308-385-5088, on Facebook, Twitter, her blog at, or visit the University of Nebraska-Lincoln Extension website:


Is that a Webworm or a Bagworm? July 14, 2014

Filed under: Insects,Trees — Elizabeth Killinger @ 2:00 pm

Webworms, bagworms, are they the same thing? If not, why does it make a difference whether you have a bagworm or webworms? It can make a big difference which insect you have to control and the damage that they cause. Correct identification is key to know how to control these pests.

Fall webworms or tent caterpillars are an occasional pest. They are sometimes called ‘bagworms,’ but using the correct common name will help clear up confusion. They appear as white webbed nests on the ends of branches in cottonwood, crabapple, walnut, and other trees. The caterpillars hide in the webbed nest during the day and feed on the trees at night. The caterpillars cause little harm to otherwise healthy trees. Tree health is not usually affected until more than 50 percent of the foliage is eaten. If there are enough nests, about one on every branch, the tree could be completely eaten. If you can safely reach the nest, use a broom to break up the bag of webworms. Follow up by spraying with a strong stream of water or an insecticide like permethrin (Eight) or Spinosad (Conserve). The nests can also be pruned out when possible. Trees that have heavy infestations this year won’t necessarily have a similar outbreak next year.   

Bagworms on a juniper.


Bagworms are a whole different story from webworms. Bagworms will feed on a wide variety of trees and shrubs, but they mainly prefer evergreens, especially junipers, cedars, and spruce. The reason that they are called bagworms is because they spin their own individual cases or bags around them for protection. As the bagworm grows, so does the bag that contains them. They will add leaf fragments to the outside of the bag for camouflage. The bags look like baseball bat-shaped ornaments hanging from the trees. There is one way to know if your cedar tree has bagworms. If you see little cone shaped things on your cedar tree, more than likely you have bagworms, because cedar trees don’t produce cones.

The earliest sign of bagworm injury on junipers is brown stressed needles at the tips of the branches. If the infestation is severe enough, the tree they are feeding on will have a brown tint to it. Heavy infestations of older bagworms are capable of completely defoliating a tree or shrub. This can cause stress to the plant or even kill it if damage is great enough. This is especially true if they have infested an evergreen which is unable to re-grow new foliage until next year. If you have bagworms on any deciduous plant, ones that lose their leaves every year, they are able to re-grow foliage if needed. Just be sure to pick up the leaves this fall and dispose of them.          

There are several options for controlling bagworms. Insecticidal sprays require thorough coverage to penetrate the canopy and contact the feeding bagworms. It is generally preferable to use ground equipment with higher spray volumes and pressures. Aerial applications may fail to provide thorough enough coverage resulting in less than satisfactory bagworm control. The spray has to completely cover the plant, almost to the point the product is dripping off of it. If the bagworms have made their home on a windbreak, the applicator has to be sure to have enough pressure to get product between the two rows of the windbreak. If this area is missed the bagworms that were hiding out there will move and re-infest the rest of the plant. Hand removal is another option for controlling bagworms. After removing the bags, place them in a bucket of soapy water.

There are several options available for insecticidal control of bagworms. Some of the reduced-risk options include Bacillus thuringiensis (Bt), spinosad, or azadirachtin (neem oil) are effective on young larvae and may be needed to be applied repeatedly. Additional insecticidal options include permethrin (Eight), bifenthrin (Talstar), cyfluthrin (Tempo), chlorantraniliprole, carbaryl (Sevin), dimethoate, esfenvalerate, fluvalinate (Mavrik), lambda-cyhalothrin, acephate (Isotox IV), and tebufenozide (Confirm). Depending on the product and size of the insect, secondary applications may be needed.

Be on the lookout now for webworms and bagworms and control them before they make a meal out of your plants.

For more information contact Elizabeth Killinger at, 308-385-5088, on Facebook, Twitter, her blog at, or visit the University of Nebraska-Lincoln Extension website:


Tomatoes vs. Herbicide June 17, 2014

Filed under: Garden — Elizabeth Killinger @ 2:43 pm
Tags: , ,

Tomato with herbicide damageYou say tomato, I say tomato…regardless of your pronunciation, tomatoes are a seasonal favorite in the backyard vegetable garden. Tomatoes have their fair share of seasonal issues and problems. Being observant can help you decide what route is best to take.

Weeds are nothing more than a plant out of place. Other people may have more choice words for these pests, but we all try to control them the best that we can. In the vegetable garden weeds seem to grow twice as fast as in the neighbor’s yard. There are several methods that you can use to help control the pesky weeds before they become a major problem. The simplest method that requires the least amount of equipment is hand pulling. This works best on the weeds before they reach full maturity. To make it easier on you, water the area before you try to pull up the weeds. The mud makes pulling easier and allows you to get a bigger portion of the root with each tug. Solarization of the garden is another non-chemical method you can try. Place clear plastic over the area where the weeds are an issue and secure the edges. Allow the weeds to ‘bake’ under the plastic for 45 days in the peak of the summer season, which means you miss out on this years’ gardening season.

Herbicides are another option for controlling weeds. Preemergence herbicides work best to help control pesky annual weeds. These herbicides will also keep garden seeds from sprouting and shouldn’t be used in areas where plants are direct seeded in the garden. Preemergence herbicides are best if they are used in areas that will be transplanted into, the plants have already sprouted and the herbicide won’t affect the transplants. If grasses in the garden are an issue, a product specifically designed to control grass, like Over-The-Top, or glyphosate product, like Round-Up, can help. Apply the products only to the weeds themselves, not the garden plants. Glyphosate is a non-selective herbicide and will damage whatever plant material it is applied to. Be sure to read and follow all label instructions prior to applying the herbicides. Make sure they are labeled for use on the weeds that you have and that they are labeled for use in the garden.

photo 4Use caution when using certain types of herbicides around the garden. Some broadleaf weed herbicides such as 2,4-D are volatile, especially during hot weather, and may drift across the yard or even from adjacent yards in concentrations sufficient to cause injury. If possible, avoid applying this herbicide for weed control during summer months to escape injury to non-target plants. Tomatoes are one of the more sensitive plants to 2,4-D injury. Herbicide drift on tomatoes appears as leaves that are cupped, thickened, distorted or leathery, and which develop an uncharacteristic fan shape. The youngest foliage is often the most sensitive to the drift and will show the symptoms before the older foliage. If herbicide is suspected, inspect other plants in the area. Herbicide injury will typically be found on more than one type of plant. Other herbicide-sensitive plants include potato, pepper, grape and redbud and they will also show twisting or distortion. Whether or not long term injury will occur is difficult to evaluate. There is no way to know how much herbicide the plant received. We cannot recommend that affected produce from vegetables is safe to eat if it was exposed to herbicide drift. This is especially true for those vegetables that were on the plant at the time of the exposure.

With a little bit of caution now you really can have it all. You can control weeds in the garden, have your tomatoes and eat them too.

For more information contact Elizabeth Killinger at, 308-385-5088, on Facebook, Twitter, her blog at, or visit the University of Nebraska-Lincoln Extension website:



Get every new post delivered to your Inbox.

Join 553 other followers