killingerscollection

This is a collection about horticulture.

Got Yellow Grass Instead of Bluegrass? August 24, 2015

Filed under: Uncategorized — Elizabeth Killinger @ 8:30 am
Yellow color in a bluegrass lawn.

Yellow color in a bluegrass lawn.

Timely rains this year may have kept many from running their irrigation systems, but they could have also done much more than that. Moisture has kept many lawns from going dormant and heavy rains are most likely the reason for many the weeds in the turf and in some cases, its yellow appearance.

Yellow colored Kentucky bluegrass has been spotted all around the region.   While we don’t know the exact cause of the yellow lawns, there are several factors that are known. The symptoms appear to only be affecting some cultivars of Kentucky bluegrass. It has not been seen in tall fescue or perennial ryegrass. The symptoms mainly appear only on the upper, young leaves. This discriminating coloration means that it probably isn’t a deficiency of nitrogen. Nutrients like nitrogen are mobile in the plant; if one leaf is affected, they will all be affected. Other nutrients like iron might be to blame as it isn’t as mobile in the plant, which can lead to spotty symptoms. On the turf that has been examined, there isn’t a notable lesion or spot on the leaf, which rules out many diseases and fungal infections.

The weather we have had this season might be playing a role in the yellow streak. The symptoms are most often seen in lawns that are mostly irrigated or received more than adequate amounts of rain. They also happen when the soil temperatures are at their seasonal highs during wet summers. There can be some similar yellowing symptoms in the spring, but they are attributed to denitrification, or loss of nitrogen, in the soil.

What can a person do? You will be happy to know that this sickly color only affects the visual appeal of the Kentucky bluegrass. It doesn’t seem to have any long term impacts on the overall health of the plant. No need to apply a fungicide, insecticide, or fertilizers with less than 0.5 pounds of nitrogen per 1,000 sq ft. Reducing irrigation for the short term should help with this coloration issue. If you wanted to try to green up your turf, you could try a low rate application of iron. This could give you back your green color, without the use of nitrogen fertilizer, which isn’t recommended in August. Mowing could also remove a majority of the discolored younger foliage which is higher up in the canopy.

Some longer term solutions might need to be considered if this turns out to be an annual occurrence. The main goal is going to include increasing drainage and reducing compaction. Core aeration is one way to increase drainage to lawns that are compacted, on heavy clay, or have heavy traffic. Another longer term option could include overseeding with a different cultivar of Kentucky bluegrass or possibly changing turfgrasses altogether. To get the best of both worlds, you can try both aeration and overseeding. Take advantage of the holes caused by core aeration and overseed at the same time. The rule of thumb is that for each week grasses are seeded before Labor Day, development is speeded by two weeks. The optimal window to seed cool-season turfgrasses is August 15 to September 15. Thin stands of Kentucky bluegrass should be overseeded with improved cultivars at .75 to 1 pound of seed per 1,000 square foot. If you are overseeding a tall fescue lawn, use a blend of improved turf-type tall fescue cultivars at a rate of 4 to 6 pounds of seed per 1,000 square feet. Ensure the seed has good seed to soil contact and irrigate frequently to for the best germination.

If your lawn has a yellow streak, don’t worry. A little time and a lot of patience will yield a greener appearing lawn.

 

Elizabeth Killinger is the Horticulture Extension Educator with Nebraska Extension in Hall County. For more information contact Elizabeth at elizabeth.killinger@unl.edu, her blog at http://huskerhort.com/, or HuskerHort on Facebook and Twitter.

 

The ‘F Word’ of the Year: Fire Blight August 17, 2015

Filed under: Uncategorized — Elizabeth Killinger @ 7:30 pm

This year has been a tough one on our landscapes. The fluctuating temperatures this winter caused death and dieback in euonymus and willow. Then the prolonged cool, wet spring has brought about fungal infections including ash rust and cedar/apple rust. Now a bacterial infection is rearing its ugly head in apple, crabapple, and their relatives. Find out what fire blight is, the symptoms to be on the look-out for, and what can be done to trees once infected.

Fire Blight on crabapple

Fire Blight on crabapple

Fire blight is the oldest and most serious bacterial disease of apple and pear. It has a wide host range including many species in the rose family. Apple, crabapple, pear, cotoneaster, hawthorn, firethorn, and mountain ash are the most common species infected in Nebraska. The infection enters into the plant through natural openings in blossoms and leaves or through wounds in the bark. Infections continue to develop until the spring flush of growth stops or until about a month after flowering.

The symptoms are fairly easy to recognize. The most common symptom are in the twigs and leaves. Infected leaves quickly wilt and turn brown or black, but the key characteristic is that they remain attached to the branches. The infected twigs often form a cane-like shepherd’s crook at the tips of the branches. The infection moves its way down from the blossoms and twigs to the older branches. Cankers show up as sunken-in, discolored areas on the branches. The bacteria may continue to spread into scaffold limbs and eventually into the main trunk. The severity of the disease is related to the cultivar and weather conditions at the time of the infection.

Unfortunately, there isn’t any cure for this disease, but there are things you can do to slow the spread of the pathogen. Prune and discard all infected twigs and branches that have cankers. Cuts should be made at least 12” below the infected area. The disease can also be spread through the use of contaminated pruning equipment and tools. Pruning tools should be disinfected after each cut by dipping the cutting surface into disinfecting solution of either 70% rubbing alcohol or a 10% bleach solution for at least 30 seconds. Ideally the pruning should take place when the plant is dormant to avoid spreading the bacteria.

Chemical controls are usually not successful and are more of a preventative treatment than a curative one. Copper-based fungicides and the antibiotic, streptomycin, are somewhat effective in controlling fire blight. The copper fungicides are best applied at the green tip stage to help reduce the inoculum produced in carryover cankers on branches. Control of blossom blight is done by spraying with streptomycin during flowering. Always read and follow label instructions and precautions.

There are some species or cultivars that are more resistant to fire blight. If you are selecting a new tree for the landscape, try to select those that are resistant. Most edible pear varieties are also susceptible, but the following varieties show some resistance: Kieffer, Garber, Seckel, Tyson, Lincoln, Dutchess, and Moonglow. The least susceptible apple varieties include Red Delicious, Golden Delicious, Dayton, Liberty and Jonafree. Because of the widespread occurrence of this disease on ornamental pear, homeowners may wish to consider an alternative tree for the landscape. Fire blight is highly infectious in the following ornamental pear cultivars: Aristocrat, Autumn Blaze, Capital, Fauriei, and Redspire. Bradford pear is moderately resistant to the disease, but has other issues in the landscape and should be avoided.

Fertilization of trees can promote this disease. Heavy fertilization promotes rapid, succulent plant growth, and increases the probability of fire blight and intensifies its severity. Generally, trees don’t require much additional fertilization. A tree in a location surrounded by turf will be provided with more than enough nutrients from what it can absorb from the lawn.

Be on the look-out for the tell-tale signs of fire blight in your susceptible species. Be prepared to do some pruning. Consider a replacement that is more resistant. Who knows maybe next year will be a ‘normal’ Nebraska year.

Elizabeth Killinger is the Horticulture Extension Educator with Nebraska Extension in Hall County. For more information contact Elizabeth at elizabeth.killinger@unl.edu, her blog at http://huskerhort.com/, or HuskerHort on Facebook and Twitter.

 

Grubs- Turf’s Summer Problem June 28, 2015

Filed under: Uncategorized — Elizabeth Killinger @ 9:00 am
Different grubs side-by-side

Different grubs side-by-side

Happy Summer! June 21st marked the start of the summer season. Summer means a good time for cookouts, picnics, swimming, and grub control. Not exactly what you had in mind for summer fun? Knowing the pest and its habits can help keep you from spending all of your summer fun time dealing with grubs.

White grubs are the larvae of a group of beetles called scarab beetles. There are many scarab beetles in Nebraska, but only a few can cause significant damage to turf. The more common ones include
the masked chafer, or annual grubs, and the May/June beetles, or three-year grubs. White grubs look very similar. They have C-shaped bodies that are cream or white colored, have reddish-brown heads, and three pairs of short legs right behind the head.

There are minor differences between the species, but they all have the same type of feeding
patterns. The grubs feed below the soil surface on the roots of all common turfgrass species. They are
capable of destroying the entire root system of the plant if infestations are heavy enough. The first signs
of grub damage include areas of pale, discolored, dying grass displaying signs of moisture stress. The adult
beetles of these grubs rarely cause much damage and are more of a nuisance than anything.
Damaged areas are small at first, but will grow rapidly as the grubs grow and enlarge their feeding
area. The affected areas may feel spongy and can be easily lifted from the soil surface or rolled like a
carpet. Another indicator that your lawn may have grubs is small areas that are dug up by animals like
raccoons, skunks, or moles foraging for the insects.

A few grubs in your lawn doesn’t necessarily mean that an insecticidal control is needed. There are
threshold levels that warrant insecticidal control. For masked chafers 8-10 grubs per square foot and 3-5
per square foot May/June beetles are the threshold levels. If you have more insects than that, a curative
treatment will be needed, usually around the first week of August. If you have had a history of grubs in
your lawn, a preventative insecticide application the third week of June through early-July will have the
insecticide in place when the eggs begin to hatch.

Products for grub control have changed over time. Before 1999 grub insecticides were used as
curative treatments. They were fast acting, had a short residual activity and needed to be applied within a
narrow treatment window. New types of insecticides are now available that offer the opportunity for
preventative treatments. These products are slower acting, but they have a much longer period of
residual activity and are available for a much wider treatment window.

There are a wide range of products that can be used to treat grubs. Chlorpyrifos (Dusban), carbaryl
(Sevin), isazophos (Triumph), Chlorantraniliprole (Acelyprin), Imidacloprid (Merit), and Halofenozide (Mach
2) are just some examples of the products that will work well to control grubs. Trichlorfon (Dylox) can be
applied for curative control if white grubs exceed threshold levels later in the season. Be sure to read and
follow the label instructions.

Keep in mind that no registered insecticide is 100% effective. On average they usually kill 75 to
90% of the grubs present in any given area. Re-applications may be necessary when grub populations get
very high.

Scouting early and catching the problem before the numbers get too high will help allow you to
have a worry free summer.

Elizabeth Killinger is the Horticulture Extension Educator with Nebraska Extension in Hall County. For more information
contact Elizabeth at elizabeth.killinger@unl.edu, her blog at http://huskerhort.com/, or HuskerHort on Facebook and
Twitter.

 

Common Turfgrass Mistakes June 26, 2015

Filed under: Uncategorized — Elizabeth Killinger @ 6:40 pm
Tags: ,

yellow turfA lush, green lawn free from weeds and pests is what most of us want in our backyard.   On your quest for the perfect lawn, there might be some mistakes you are making along the way. Don’t let one of these common mistakes hinder your progress towards that lawn you have dreamed about.

Mowing is a task that everyone with a lawn has to do. One of the most common mistakes is improper mowing height. While some grasses can be mowed at 1” or less, that doesn’t mean they should. Common cool season turfgrasses like Kentucky bluegrass and tall fescue actually do better and have fewer weeds when they are mowed closer to the 3-3 ½” in height. There is also a direct correlation between the height of the turf and the length of the roots. The taller the turf is mowed, the longer the roots and the more soil profile available for absorption of water.

Another common mowing mistake is removing too much leaf blade at any one time. The rule of thumb is to remove only 1/3 of the leaf blade during a mowing. Rains and fertilizing turf can cause the lawn to grow more quickly. Instead of sticking to a mowing schedule of only one day a week, let the turfgrass decide the mowing schedule. For cool season turfgrass, in the spring and fall consider mowing more often to accommodate the rapidly growing turf. During the summer, early spring, and late fall, mowing frequency can decrease as the turf isn’t growing as rapidly. Again the goal is to only remove 1/3 of the grass blade, not to only mow once a week.

Improper fertilization is another common turfgrass mistake. If a little is good, a lot will be better is not the rule to follow. Read and follow the label when it comes to applying any pesticide and especially fertilizers. Overfertilization can directly harm the turfgrass or contribute to diseases commonly seen in turf, not to mention the flush of growth it causes in the plant which often is compounded by improper mowing techniques. Timing is everything when it comes to fertilization. The turf needs to be fertilized when it can use it the most. Cool season grasses like Kentucky bluegrass and tall fescue are most active in the cooler months in the spring and fall. Warm season grasses are ramping up and actively growing when the weather gets warmer. Apply the fertilizers when the grass is actively growing; spring/fall for cool season grasses and summer for warm season grasses.

Turf needs water to grow. Whether it comes in the form of rain or if it is applied through a sprinkler, water is necessary for a nice looking lawn. Overwatering turf is a common mistake that many people make. Like with the mowing, let the turfgrass be the guide when it needs water. Instead of watering on a set schedule, take the weather conditions, soil type, and turfgrass type into consideration. If you have an automatic system, invest in a rain sensor. This will shut the system off when it detects ¼” of rain. Watering too frequently or for too little of time, discourages the turfgrass from developing a deep root system. The deeper into the soil the roots go, the more profile the roots have to pull water from. The goal is to water less frequently, but deeper into the soil profile.

The last common turf mistake is assuming that turfgrass will grow wherever you want it to. Areas with heavy shade, steep slopes, or with scorching heat might not be the ideal environments for all turfgrass. Do not try to make turf grow in an environment where it isn’t content because in the end, neither of you will be happy. Look at all landscaping options for locations. Don’t just focus on getting the turf to survive, pick a plant that will thrive in that environment.

There are several aspects to focus on, pay attention to mowing height and frequency, fertilize at the proper time and with the right amount, watch the watering depth and frequency, and try not to make turfgrass grow where it isn’t happy. By avoiding these common turfgrass mistakes, that picture perfect lawn of your dreams is much closer to becoming a reality.

Elizabeth Killinger is the Horticulture Extension Educator with Nebraska Extension in Hall County. For more information contact Elizabeth at elizabeth.killinger@unl.edu, her blog at http://huskerhort.com/, or HuskerHort on Facebook and Twitter.

 

Wildflower Week 2015 June 1, 2015

Filed under: Uncategorized — Elizabeth Killinger @ 6:40 pm
Tags: , , , ,
A great resource that helps to identify different wildflowers.

A great resource that helps to identify  wildflowers.

Please follow and bookmark my other blog http://huskerhort.com

Wildflower Week is in full bloom. What exactly is Wildflower Week and what is a wildflower? Wildflowers and native plants are very versatile plants that have multiple benefits in the landscape. Some wildflowers are a cut above the rest and are worth a try in your garden.

Wildflowers are an important part of any region’s identity. Nebraska Wildflower Week celebrates this “sense of place” through wildflower-related events and activities the first week in June, when many of Nebraska’s prairies and gardens

Nebraska Statewide Arboretum (NSA) serves as coordinator for Wildflower Week activities, bringing together organizations and individuals across the state that recognizes the value of wildflowers—not only for their beauty but also for what they imply and symbolize. “Where wildflowers are thriving, is a sign that the environment is healthy,” said Bob Henrickson, whose nursery production work with the Arboretum concentrates on native and regionally-appropriate plants. Opportunities for wildflower enthusiasts across the state include guided tours, presentations on wildflower plantings, exhibits, prairie runs, and much more. Events, photos and more information is available at the NSA’s website http://arboretum.unl.edu.

Wildflowers and native plants can be unique and interesting additions to the landscape. What is the difference between native plants and wildflowers? The terms “native” and “wildflower” are often used interchangeably, but there is a difference. Native plants in the Great Plains are generally described as those found growing in a defined area prior to European settlers. Wildflowers are described as flowering plants that grow with little or no human help. They can either be native or introduced, or brought in from other areas. Both wildflowers and native plants work well in low maintenance areas and in sites that need hardy, drought tolerant plants.

Top 5 wildflower picks of 2015:

Shell-leaf Penstemon, Penstemon grandiflorus– There are over 200 species of Penstemon, with nearly 24 native to the Great Plains. They are upright, multi-stemmed perennials that grow from 2-3 feet tall. Tubular flowers shaped like snapdragons are white to lavender. They prefer full sun and well-drained soil.

New Jersey Tea, Ceanothus americanus– This 2-4’ tall shrubby plant prefers sandy loam soils or rocky soils with good drainage. Clusters of showy, fragrant, flowers appear in May to July and are great for cut flowers. This drought tolerant plant does best in full sun to part shade.

Swamp Milkweek, Asclepias incarnata- As the name implies, these plants are tolerant to wet soils and swamps. The pinkish-rose flowers show up in July-August on 4-5’ tall plants. It is slow to leaf out in the spring so give it some time.

Blue Flax, Linum perenne– This easy-to-grow perennial is tolerant of a wide range of conditions and reseeds itself almost sounds too good to be true. The 1-2’ tall plants produce blue flowers in May-July. To extend flowering, cut some stems back by 1/2 mid-way through the bloom period.

Helen’s Flower, Helenium autumnale– Also known as sneezeweed, this clump-forming perennial produces yellow to maroon colored flowers in August- September. It is tolerant to wet sites, but prefers rich, moist soils. Divide clumps every 3-4 years to maintain plant vigor.

This is just a sample of my favorites, but there are many more interesting wildflowers to learn about. More information about wildflowers can be found in a Nebraska Extension NebGuide, a University publication, ‘Wildflowers for the Home Landscape’. Go to http://www.ianrpubs.unl.edu and search for the keyword ‘wildflowers’.

For more information contact Elizabeth Killinger at elizabeth.killinger@unl.edu, 308-385-5088, her blog at http://huskerhort.com/, HuskerHort on Facebook and Twitter, or visit the Nebraska Extension in Hall County website: hall.unl.edu.

 

Research Before You Retweet: Gardening in the Age of Social Media May 18, 2015

Filed under: Uncategorized — Elizabeth Killinger @ 3:59 pm
Blossom end rot on tomato. Maintain consistent moisture, try mulching tomatoes first. Don't reach for the Epsom salts.

Blossom end rot on tomato. Maintain consistent moisture. Try mulching tomatoes instead of reaching for the Epsom salts.

Without a doubt the interest in gardening and landscaping has been on the rise for many years. In order to find information on how to garden in the past, you had to know who to ask or what book to look in. Today the places to find information are endless. Pinterest, Facebook, Twitter and the internet all have gardening information that is easily shared among friends and followers alike. Sometimes these ideas are tried and true while others are more “too good to be true.” I might not be the first to say it, but you can’t believe everything you read on the internet.

Through my job with Nebraska Extension, I educate people using science-based information that comes from research. This ensures the information that I give out has been researched by numerous people and has been found to be consistent in a number of settings and conditions.

When searching online, it can be difficult to figure out the source of the information. Sometimes the information comes handed down or it comes from unreliable information observed by one or a handful of individuals. Other times the information comes from groups or individuals with an agenda for or against a certain thing. Whenever you see something online, be sure to do a little research before you add the practice to your own garden.

Land-grant universities are good sources of information. To make sure you get science-based gardening information, you can find university extension resources online. The easiest way to find university information while you are searching online is to add the command “site:.edu” or “AND extension” to your search.

One of the most common sources for misinformation is with homemade pesticide alternatives. Be sure to research the safety and efficacy of these products before applying in the landscape or garden. Epsom salts, a common homemade pesticide ingredient, should be used with caution in the landscape. Epsom salts are magnesium sulfate. A soil test should be performed prior to applying to make sure the soil is deficient in magnesium. In slightly alkaline pH soils, like in most of Nebraska, magnesium is readily available. Another reason to avoid over using Epsom salts in the landscape is because it leaches easily from the soil and can act as a potential water contaminate.

Vinegar, the wonder substance. It can multitask so well in the house; it must be useful outdoors too. There are many homemade recipes that use vinegar as a cure-all for one thing or another in the landscape. Vinegar is an effective weed killer, but not the household type. Household white vinegar is about 5% acetic acid. Household vinegar will burn the top back on the weeds, but has a difficult time killing the roots on larger plants. The weed killing vinegar, or horticulture vinegar, is 20% acetic acid. It works much faster, but also has a tough time killing the roots on larger plants. Caution has to be used with the 20% acetic acid. Vinegar is also not very effective to prevent or cure disease problems; it can burn back good plants just like weeds. It is not a good fertilizer either. Acetic acid only contains hydrogen and oxygen, elements the plant can get from the air. The only thing vinegar is really good for in the landscape is killing very young weeds.

‘Research it before you apply it’ should be the new motto to follow. Check reputable resources to make sure what you are reading is safe and tested for that particular problem. A little research upfront can save you from applying a mixture that won’t fix your problem…and save your vinegar for making pickles.

For more information contact Elizabeth Killinger at elizabeth.killinger@unl.edu, 308-385-5088, her blog at http://huskerhort.com/, HuskerHort on Facebook and Twitter, or visit the Nebraska Extension in Hall County website: hall.unl.edu.

 

The War on Weeds April 19, 2015

Dandelions

Dandelions

Spring has officially sprung. The crabapples and flowering pears are in full bloom. Tulips and daffodils are starting their flower show. Henbit and dandelions are looking gorgeous. Are the last two not quite the kinds of spring flowers you want in your landscape? If so, there are some things you can do. The key to knowing what to do when depends on the weed, but it all comes down to proper identification of the enemy and its life cycle.

Winter annual weeds bloom in the spring, produce seed, and die all before the temperatures get hot. One of the more common winter annual weeds is henbit. Henbit has scalloped leaves, a square stem, and little purple flowers at the tip of the stem. These weed seeds germinated last September or October. Henbit plants sat dormant throughout the winter just waiting for the right time to jump into flower and seed production. Post emergence, broadleaf weed, herbicides won’t do much good. Spraying might make you feel better, but it can cause the plant to produce and drop more seeds. If the area isn’t too large, these weeds can be hand-pulled. Increasing the density and health of the lawn in the thin areas can help too. Improve the lawn either by overseeding or by changing cultural practices to promote grass growth. If you choose to use preemergence herbicides, aim to apply in early September to control winter annual weeds. For the best selection of preemergence herbicides, consider purchasing them now and storing until fall.

Summer annual weeds germinate in the spring, grow throughout the summer months, and produce seeds and die before winter. One of the most common summer annual weeds is crabgrass. Crabgrass is an annual grass that often fills into areas where the turfgrass is thin. Crabgrass preventers, or preemergence herbicides, will help to keep seeds from germinating. These products aren’t effective for plants that are already growing, so they should be applied before the plants come up. Crabgrass needs a minimum soil temperature of 50 to 55 degrees to begin germination. Preemergence herbicides applied just prior to germination provide the longest period of control. If applied too early, some products are out of the soil profile before all of the weed seeds germinate. Now is the perfect time to apply the preemergence herbicides. Apply half the highest rate on the bag’s label now. A second application, again half the highest rate on the label, can be applied in 6-8 weeks to give extended weed control. Remember that these products need to be watered into the soil profile within 24 hours for best results.

Perennial weeds come back year after year. The common offenders include white clover and ground ivy, sometimes called creeping Charlie. Ground Ivy looks very similar to henbit, but the control methods are very different. Ground ivy also has scalloped leaves, a square stem, and purplish flowers, but the flowers are in the leaf axil, between the leaf and the stem, in comparison to henbit that flowers at the end of the stem. The best time to apply post emergence herbicides for perennial weeds is after a light frost in the fall with a combination herbicide that contains multiple active ingredients. These products will also work well to control other weeds like clover or dandelions in the lawn.

Positive identification is key to selecting the proper control method. With a little homework upfront, you can ensure that it is the daffodils and tulips you see rather than the dandelions and henbit in the landscape.

For more information contact Elizabeth Killinger at elizabeth.killinger@unl.edu, 308-385-5088, her blog at http://huskerhort.com/, HuskerHort on Facebook and Twitter, or visit the Nebraska Extension in Hall County website: hall.unl.edu.

 

 
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