Nov 2016

Hantavirus - A Mouse's Deadly Companion, Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#Hantavirus
 In Nebraska, deer mice can be carriers of Hantavirus. Cotton rats and rice rats are the culprits in Southeastern states, while the white-footed mouse is a carrier in the Northeast. 

Hantavirus - A Mouse's Deadly Companion

By Susan Harris-Bloomfield, Nebraska Extension Educator

As we gear up for cold weather, so are the rodents living around us.  Shelter with a winter’s supply of food is what they now seek, and guess what?  You have both in your rural home and outbuildings.  Unfortunately, mice are very good at finding indoor access and food.  But while you are supplying them with these amenities, they can be virus-carrying vessels that pose a serious risk to you and your family.  

Transmission
Rural settings offer perfect conditions for contracting Hantavirus (pronounced Hahn tuh virus), a virus that can progress to Hantavirus Pulmonary Syndrome (HPS).  Deer mice are the specific rodents in our area that can shed the virus in their droppings, urine, and saliva.  When stirred up, tiny droplets containing the virus get into the air and breathing in contaminated air will transmit the virus.  According to the Centers for Disease Control and Prevention, researchers also believe that touching something contaminated with the virus can make you sick.  Symptoms usually occur within two to four weeks, but it has been reported that symptoms can start as late as eight weeks after exposure.  Cases of HPS are rare, but have occurred in Nebraska. 

Symptoms
Kathy Beck, Office Manager in Gosper County’s Nebraska Extension office, experienced HPS firsthand several years ago.  Early symptoms include fever, fatigue, muscle aches (especially in the thighs, back, and hips).  Other symptoms could be headaches, dizziness, chills, and abdominal issues such as nausea, vomiting, or diarrhea.  Kathy had many of these symptoms.

“Regarding the headache – you know the number charts they show you in the hospital with 1 as ‘Feeling Great’ and 10 as ‘Feeling Terrible’?  Well, my headache was a 12.  An ‘I Couldn’t Move’ number 12 headache,” she recalls.

A few days after the initial illness sets in, there could also be shortness of breath and difficulty breathing as lungs fill with fluid, as Kathy’s lungs did.  Thinking it was the flu, doctors ran tests but could only come up with the possibility of a fast-growing cancer.  Four days in, after being air-lifted to Lincoln, Kathy was quite disabled.

“At this time, I was in and out a lot and didn’t know what was going on.  My brain was very foggy and I couldn’t formulate what I wanted to say very well – but I do remember I told my main doctor (one of 10) that we lived on a farm and had mice.  They always poo-pooed me and then would run another test.”

Hantavirus - A Mouse's Deadly Companion, Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#Hantavirus

Rural outbuildings provide protection for deer mice, which can transmit hantavirus. 

Twenty days in the hospital with breathing machines, fluid draining, and lots of tests helped to save Kathy’s life.  But it wasn’t until the day before she was released from the hospital that she happened to catch a television network’s story about Hantavirus.  She saw all the similarities of symptoms and told her doctor.  He finally agreed to run the test and eventually confirmed that indeed she had contracted Hantavirus, leading to HPS and near-death.

Diagnosis and Prevention
Diagnosis for this disease can be easily overlooked or confused with influenza.  However, two factors to consider if you develop early symptoms are:

  1. Do I have potential for rural rodent exposure?
  2. Do I have shortness of breath? 

If both answers are ‘yes’, be sure to mention the possibility to your physician.  Blood tests can determine if your body has created antibodies to a Hantavirus.

HPS can be fatal.  According to the CDC, the mortality rate is 38%.  There is no specific treatment, cure, or vaccine for Hantavirus infection. However, we do know that if infected individuals are diagnosed early and receive medical care, they will most likely do better because of oxygen therapy that helps them through the period of severe respiratory distress.  HPS is not contagious from person to person and pets are not known to carry Hantavirus.

Effective prevention:

  • Eliminate contact with rodents in all home and work areas by finding all gaps that a pencil will fit into and sealing them.
  • Set traps and remove dead mice using rubber gloves for both.
  • Spray urine and droppings with a disinfectant or mixture of bleach and water to soak thoroughly before removing with rubber gloves.
  • Do not sweep or vacuum droppings or nests - this will kick the virus to into the air where it will be breathed by humans.
  • Do not leave out food or pet food to attract more unwanted guests.
  • Elevate wood piles 12 inches from the ground and move them at least 100 feet from the home.
  • When opening an unused cabin, shed, or other building, open the doors and windows, leave the building, and allow the space to air out for 30 minutes.

Kathy encourages her family and friends to do that last one every time.  She makes a good point: “A little pre-planning and a little frustration of not being able to get at the job immediately is a whole lot better than being laid up – or even laid out.” 

For more tips and information about Hantavirus, Centers for Disease Control or contact:

Susan Harris-Broomfield
University of Nebraska-Lincoln Extension Educator – Rural Health, Wellness, and Safety
308.832.0645

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Reaching for the Light: How Trees Grow, Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#HowTreesGrow

Sycamore in fall color. Competition among trees for light creates tall straight trees with few branches. 

Reaching for the Light: How Trees Grow

By Eric Berg, Nebraska Forest Service

In most forested environments, the name of the game for tree survival is, “Who can capture the most sunlight, grow the fastest and tallest and eventually shade out any competition for sunlight, water and nutrients?” It is a competition that typically takes years to play out and often decades to see the full result. This competitive process generally results in tall, straight trees with few branches, most of which are strongly attached to the trunk at right angles.

Light As A Limited Resource
In a sense a tree is simply a collection of branches, with each branch serving as an independent subdivision, i.e. a tree on a tree. Branches manufacture their own food through photosynthesis and export a portion of that food to the trunk and root system below. As long as the branch continues to produce more food than it uses, it continues to grow and support the rest of the tree. The forested environment forces this system and process to be efficient, effective and ruthless. Trees or branches that are not able to capture enough sunlight don’t produce enough food and die back. This time-tested process of Mother Nature works well in forested environments.

An Overabundance of Light
But if you take that same tree from a tightly-packed forest and move it the “community forest,” the collective landscape of our cities and towns where the great majority of us live, the environment is very different. Whereas sunlight was one of the most limiting resources of the forest, sunlight is now one of the most abundant and, quite frankly, abused resources. That’s right, you heard it here first, our community trees have an overuse problem with sunlight, and we need to talk about that openly and frankly.

It’s important to talk about because trees provide valuable social, economic and environmental benefits in an urban environment. They shade our homes, provide food, slow stormwater, reduce flooding and protect us from winter winds, to name just a few. Perhaps even more important is that they create and define a sense of place. But urban settings are a tough place for trees that originated from a forest.

Trees that abuse and overuse sunlight are easy to spot; you probably have one in your very own yard. But you’re not alone. Most of the trees growing in home landscapes, on streets and in parks were planted individually rather than in groups. How do you know if your tree has a problem? If it’s short and wide with multiple stems and many competing, co-dominant branches, it isn’t growing “naturally.” If the branches grow at shallow angles of 45 degrees or less rather than being strongly attached at 90 degree angles, that predisposes them to stress or ripping out in strong winds or storms.

Managing "Sunlight Abuse" in Your Trees
All of this is preventable if we take the time to notice, mimic and manage like nature. This means grouping similar plant materials together, separating trees in mulched beds away from turfgrass and planting a diversity of woody plant materials closer together to force a more naturalized and structurally stronger growth pattern. With careful landscape design and management, we can create landscapes with trees that are healthier, stronger and more capable of withstanding the extreme weather of the Great Plains. So take a closer look at your trees and see if they’re suffering from “sunlight abuse.” If they are, take some steps to help them toward a more structurally sound future.

The Nebraska Forest Service strives to enrich lives by protecting, restoring and utilizing Nebraska's tree and forest resources.

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November Turf Tips, Nebraska Extension Acreage Insights September 2016. http://acreage.unl.edu/enews-nov-2016#NovemberTurfTips
Debris removal is an important task for fall lawn care. 

November Turf Tips

By John Fech, Nebraska Extension Educator - Horticulture

Two main activities are the focus of November lawn care – fertilization and dormant seeding - as well as a carryover from October – debris removal.

Fertilization
With most applications, a mix of slow and quick release nitrogen sources are recommended, to provide for the immediate needs of the turf as well as what is required for healthy growth over the next couple of months.  However, due to concerns of loss of nutrients and possible movement of nitrogen into water supplies, we focus on the short term with the last application of the year. 

Another difference between this application timeframe and others is the rate or dosage of nutrients.  At this time of year, 0.25 to 0.50 lbs of nitrogen per 1,000 sq. ft. is recommended.  The goal is to get the nutrients into the plant quick and to help with winter stress tolerance.  The low rate of quick release nitrogen will help accomplish the former; inclusion of potassium will cover the latter.  Look for a fertilizer product with a 1-0-1 analysis ratio, such as 19-0-17.  On a 10,000 sq. ft. lawn, 13 to 26 pounds of this type of product will be required.

Dormant Seeding
Early November is the best timing for the fertilizer application, whereas mid to late November is the timeframe for dormant seeding.  The rationale behind dormant seeding is to get the seed in place to take advantage of early spring weather, should it come our way in April.  The process is started just as for other seeding projects, with powerraking and loosening of the soil, except that we don’t want the grass seed to grow; instead, just to have it in place to grow once the warming temperatures of the sun work their magic in spring.  On average, a 50 to 75% success rate is usually realized.

Debris Removal
Debris removal is important whenever it occurs, but in fall, it occurs often.  In fact, if the site has a few well placed trees, it’s an ongoing process.  Two basic approaches can be utilized – or both; to mow and mulch the leaves, branches and seeds into the turf canopy or to pick it up and work it into the compost pile for future usage in the veggie garden.  Either way, the landscape will benefit, especially if done frequently.

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Fall Kaleidoscope, Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#FallKaleidoscope
 Shining bluestar, Ammsonia illustris, features brilliant golden yellow foliage in fall. 

Fall Kaleidoscope

By Karma Larson, Nebraska Statewide Arboretum

Over the span of a week or two—just a slight turn of the kaleidoscope—the color wheel changes. The rich greens of summer foliage, which haven’t browned thanks to moisture and cooler weather, have begun to shine yellow, red and purple in the fall landscape. For all the challenges the Midwest throws at us, seasonal changes are part of the payoff. It’s time to enjoy.

In terms of sheer volume, trees and shrubs are the most noticeable, but perennials are losing their chlorophyll-induced green as well. Yellow and orange pigments become more noticeable with the loss of chlorophyll; while vibrant red color results from a more complex mix of trapped glucose, bright sunlight and cool nighttime temperatures. In years with an early frost, leaves are more likely to simply dry up and turn brown. We’ll see what fall 2015 has in store for us, but below are some plants to brighten up our fall gardens in future years.

Yellow and Orange Fall Color

  • Bluestar, Amsonia, has tiny blue flowers in spring and in fall the abundant feathery foliage turns a brilliant golden yellow.
  • Solomon’s seal, Polygonatum, has bluish-black berries in summer that go beautifully with the yellow fall foliage. The variegated one with its ivory-streaked foliage is even more striking.
  • Other perennials for yellow fall color include gooseneck loosestrife, monkshood, hosta, balloonflower and ferns.
  • Pale grasses that will brighten barren landscapes include blue and sideoats grama, with interesting seedheads that focus attention on their soft buff colors. Others to consider include: Indiangrass; prairie dropseed in orange to light copper shades; switchgrass; and the very upright Korean and feather reed grass.
  • Trees for yellow fall color include cottonwood, baldcypress, birch, honeylocust, ginkgo, dogwood, ash and some maples and oaks.
  • Shrubs include witchhazel, spicebush, bottlebrush buckeye and native serviceberry, Amelanchier alnifolia.

Reds and purples

  • The common name bloody cranesbill makes it clear that perennial geraniums are great plants for crimson fall color.
  • Columbine, bergenia, coralbells, sedum and prairie smoke turn varying shades of red and purple; and the foliage of all these hardy plants often persists far into winter. They’re a beautiful contrast to muted mulches or bright white snow.
  • For grasses, little bluestem in cultivars like Dallas Blues offers vibrant blue and purple fall highlights. Shenandoah switchgrass has red and purple foliage. Indiangrass tends toward copper highlights.
  • In Nebraska, red fall color in trees can be extremely variable, but some of the maples and oaks, sweetgum and many others turn red to purple.
  • For shrubs, very few plants outshine the sumacs. Viburnums tend to have dark berries that contrast with their red foliage. Other reds include chokeberry, burning bush, some varieties of serviceberry and eastern wahoo.

Nebraska Statewide Arboretum is a nonprofit that works toward sustainable home and community landscapes through initiatives in education, public gardens and the environment. Plant and landscape resources at http://arboretum.unl.edu.

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Nebraska Extension Publications Provide Unbiased, Science-based Information for Private Well Owners

Nebraska Extension Publications for Private Well Owners Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#WaterPublications
Resources are available providing unbiased and science-based information for management of a private well system. Image by Sharon Skipton.

By Sharon Skipton – Nebraska Extension Water Quality Educator Emeritus and Bruce Dvorak - Nebraska Extension Environmental Engineering Specialist

You may have questions about your drinking water as you attempt to manage your private well system.  You might have a burning question or an immediate problem.  Our mission at the University of Nebraska – Lincoln (UNL) is to provide unbiased, science-based information to help you find answers to your questions or solve your problems.  Nebraska Extension drinking water publications have been developed with this goal in mind.  Information included is unbiased and science-based.  Publications were produced by Nebraska Extension faculty.  Authors collaborated with Nebraska Department of Health and Human Services staff, industry professionals, and others as appropriate.  Nebraska-specific information is included when possible.  Publications are reviewed and updated a minimum of every 5 years, but usually more often.  This assures that the latest research findings, public policy actions, and regulations are reflected in the documents.

Nebraska Extension drinking water and private well system publications can be accessed at the web site http://water.unl.edu/drinkingwater/publications. Publications available include the following:

Understanding Private Drinking Water Wells

  • G2149 Private Drinking Water Wells: Planning for Water Use
  • G2150 Private Drinking Water Wells: Water Sources
  • G2151 Private Drinking Water Wells: The Water Well
  • G2152 Private Drinking Water Wells: The Distribution System
  • G2153 Private Drinking Water Wells: Operation and Maintenance for Mechanical Components
  • G2154 Private Drinking Water Wells: Operation and Maintenance for a Safe Well

Wellhead Protection for Private Drinking Water Wells

  • G2049 Protecting Private Water Supplies: An Introduction
  • G2050 Protecting Private Water Supplies: Water Well Location, Construction, Condition, and Management
  • G2051 Protecting Private Water Supplies: Household Wastewater (Sewage) Treatment System Management
  • G2052 Protecting Private Water Supplies: Runoff Management
  • G2053 Protecting Private Water Supplies: Hazardous Materials and Waste Management
  • G2054 Protecting Private Water Supplies: Pesticide and Fertilizer Storage and Handling

Testing Drinking Water

  • G1614 Drinking Water: Certified Water Testing Laboratories in Nebraska
  • G907 Drinking Water: Testing for Quality

Drinking Water Contaminants

  • G1552 Drinking Water: Arsenic
  • G1826 Drinking Water: Bacteria
  • G1360 Drinking Water: Copper
  • G1376 Drinking Water: Fluoride
  • G1274 Drinking Water: Hard Water (Calcium and Magnesium)
  • G1714 Drinking Water: Iron and Manganese
  • G1333 Drinking Water: Lead
  • G1784 Drinking Water: Nitrate-Nitrogen
  • G1275 Drinking Water: Sulfur (Sulfate and Hydrogen Sulfide)
  • G1569 Drinking Water: Uranium

Drinking Water Treatment

  • EC703 Drinking Water Treatment: An Overview
  • G1488 Drinking Water Treatment: What You Need to Know When Selecting Water Treatment Equipment
  • G1492 Drinking Water Treatment: Sediment Filtration
  • G1489 Drinking Water Treatment: Activated Carbon Filtration
  • G1491 Drinking Water Treatment: Water Softening (Ion Exchange)
  • G1490 Drinking Water Treatment: Reverse Osmosis
  • G1493 Drinking Water Treatment: Distillation
  • G1761 Drinking Water Treatment: Shock Chlorination
  • G1496 Drinking Water Treatment: Continuous Chlorination
  • G1494 Drinking Water Treatment: Emergency Procedures
  • G1704 Chloramines Water Disinfection: Omaha Metropolitan Utilities District and Lincoln Water System

Indoor Water Conservation

  • G2190 Water Wise: Water Conservation in the Home
  • G2188 Water Wise: Managing Low-Capacity Private Drinking Water Wells During Drought

Miscellaneous

  • G1539 An Introduction to Drinking Water
  • G918 Water: The Nutrient
  • G1448 Drinking Water: Bottled, Tap and Vended
  • 1536 Drinking Water: Storing an Emergency Supply
  • G1471 Decommissioning Water Wells to Protect Water Quality and Human Health

We encourage you to check out any and all publications that may be of interest and assistance to you. 

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Grasses and Legumes Work Well for Horse Pastures

Grasses and Legumes Work Well for Horse Pasture, Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#HorsePasture

Horses graze differently than other livestock. They heavily graze specific spots and are pickier about what they eat.

By Monte Stauffer, Nebraska Extension Educator - Livestock

Horses are popular throughout the area.  If planning a new horse pasture, be sure to plant the right things.  Horses graze differently than other livestock.  They heavily graze specific spots and they are pickier about what they will eat.

Cool-season Grasses & Legumes
Two grasses that are popular for horses are timothy and bluegrass.  Unfortunately, these cool-season grasses produce low yields and lack persistence in Nebraska.  A better choice for the area is a mixture of orchardgrass and smooth bromegrass.  Add a little red clover, some white clover, and alfalfa to this mixture and you will have an excellent feed resource.  In western Nebraska, intermediate or crested or western wheatgrass might be a better choice since they are more adapted to dry climates.

Warm-season Grasses
Native warm-season grasses also can provide good summer pastures for horses.  Warm-season grasses that horses graze well include bluegrama, big bluestem and sand bluestem, sideoats grama, sand lovegrass, and indiangrass.  A mixture of three to five of these grasses will make good summer grazing.

Avoid switchgrass and little bluestern for horse pastures.  Horses do not graze these grasses very well.  However, both switchgrass and little bluestem are consumed well as hay if they are planted in mixtures with other grasses and harvested before seedheads emerge.  They can be used for horse hay even if they make poor horse pasture.

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Fall Windbreak Site Preparation and Ordering Tree Seedlings

Fall Windbreak Site Preparation and Ordering Tree Seedlings, Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#Windbreak
Pine wilt has caused death of many trees in this windbreak, resulting in the need for renovation. 

By Sarah Browning, Nebraska Extension Horticulture Educator 

Diseases, insects, drought and age take a toll on windbreak plantings throughout Nebraska, resulting in the need for renovation or tree replacement. Late fall is a good time to assess your windbreak plantings and order trees for spring planting. Most windbreaks, even those with a few gaps, can be renovated to maintain or enhance their effectiveness. 

Fall Windbreak Site Preparation 
Site preparation should begin this fall for next spring’s windbreak, wood lot or wildlife plantings.  Proper site preparation can mean the difference between a successful tree planting and a total failure.

Fall soil preparation is beneficial in several ways. It increases soil capacity to store water from winter precipitation. It also allows the soil to settle and pack better around tree roots, and reduces weed and grass competition next spring.  And it makes spring planting much easier.

Site Preparation Tips
The best method for site preparation depends on the terrain, existing vegetation, soil type and erosion hazards. Glyphosate works well to kill existing grass, weeds or cover crops and has very little soil residual.  New plantings can be made in areas treated with glyphosate after a 10-day waiting period.

  • Former crop areas - In areas that have been cultivated for crops, little or no preparation is needed.  If many weeds are present, the land may require a single disking before planting. Otherwise, plant directly into the previous year's crop stubble. Avoid exposing erodible soils to the wind. If erosion is a threat over the winter, plant a fall cover crop. The following spring, treat the existing vegetation with herbicide, and plant the windbreak directly into the cover crop residue.
  • Grassy areas - On sites with heavy grass sod, preparation begins with herbicide application while the grass is actively growing. The site is then tilled or plowed in the fall and disked the following spring just prior to planting. On relatively flat sites in eastern Nebraska the site should be plowed or disked so soil is in the same condition as if row crops are to be planted.
  • Slopes - On sloping land, tilling tree-planting strips is a site preparation technique used to prevent unnecessary erosion. Delay disking or tilling until just before planting to conserve soil moisture, control early spring weeds, and reduce the potential for erosion damage.
  • Erodible areas - In rangelands where erosion may be a major concern, kill existing vegetation with glyphosate. To assure complete control, apply the chemicals in the spring, at least two weeks before tree planting and when the grass is actively growing. Planting directly into the dead sod reduces the chance of soil erosion, however, replanting costs may be higher since the matted sod, even though the grass is dead, may cause competition for the establishment of tree roots.
  • Residential windbreak planting sites benefit from fall preparation, too. Since windbreak plantings are spaced more closely together than trees or shrubs in landscape plantings, it is beneficial to till tree-planting strips. This eliminates grass competition, allowing the new tree seedlings to be more vigorous in the early years following planting, makes mowing easier, and minimizes mower to damage young trees. Drip irrigation can be installed to make watering easier. Finally, after planting apply 3-4 inches of wood chip mulch the entire length of the tree-planting strip.

Purchasing Trees
Deciding on plant species and purchasing plants is a critical step in the establishment of a windbreak. This is your best opportunity to avoid plant species susceptible to insect or disease problems. Key points to keep in mind when purchasing tree seedlings include:

  • Purchase your stock from a reliable source. Bare-root windbreak tree seedlings are available through your local Natural Resource District (NRD) office. November is the time Nebraska ’s NRD offices begin taking orders for windbreak seedlings to be delivered next spring. Over-the-counter tree sales are typically taken until March 1, 2017 or as long as supplies last.  Locate your local NRD office and look for the Conservation Tree Program. 
  • Bare-root tree and shrub seedlings can also be purchased from some nurseries. Your seedlings should come from nurseries using locally collected seed or seed from Northern origins. This ensures plants are well adapted to local growing conditions.
  • Choose plant material that is suitable for your soils and can survive the environmental extremes of your site.
  • Select insect and/or disease resistant plants whenever possible.
  • Don't be too quick to buy the cheapest seedlings; they may not be the best value in the long run.
  • When ordering trees from your local NRD office, a minimum order of 25 seedlings is required; plant species are sold in bundles of 25 each. If 25 of one species is more than you need, then talk with your neighbors.  Maybe you can place a joint order and split the bundles.  Plants cost approximately $0.90 cents each, plus tax and handling. You must pick up your tree seedlings when they arrive at the NRD office in spring.

Plant species available vary between NRD office, but commonly include the following.

  • Evergreen trees - Eastern White and Ponderosa pine; Eastern red cedar; Colorado Blue, Norway and Black Hills spruce, and Concolor fir.
  • Deciduous trees – American elm; Hackberry; Bur, Northern Red, Chinkapin and Swamp White oak; Black Cherry; Black Walnut; and Sugar maple.
  • Shrubs - American plum; Hazelnut; Redosier dogwood; Chokecherry; Black and/or red chokeberry, Serviceberry; Elderberry; Common lilac; Amur maple; Skunkbush sumac.

 Usually, windbreak seedlings are two years old and 12-24 inches tall, with full healthy root systems.  Bare-root seedlings must be handled carefully to ensure good survivability and performance.

Many NRD offices also offer, at a minimal cost, machine planting for large orders.  Preparation of the land prior to planting is the responsibility of the landowner.   Contact your local NRD office for a list of additional services offered in association with windbreak tree plantings.

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Sweet Potato, Nebraska Extension Acreage Insights November 2016. http://acreage.unl.edu/enews-nov-2016#SweetPotato

Sweet potatoes are a tropical plant and need a long growing period, usually 100-110 days. 

Sweet Potato: My Favorite Thanksgiving Vegetable

By Sarah Browning, Nebraska Extension Horticulture Educator 

Yam or Sweet Potato?
Sweet potato, Ipomoeas batatas, is a member of the morning glory family native to Central and South America. The term “yam” was coined by the Louisiana sweet potato industry in 1937 as part of a national marketing campaign to differentiate their moist, orange-fleshed sweet potatoes from those grown on the east coast at that time, which had white flesh and a drier texture. White-fleshed cultivars of sweet potatoes are relatively uncommon in the U.S. today. The term “yam” is an English version of the African term “nyami”, which refers to the starchy root of true yams in the Dioscorea genus. 

These days the terms yam and sweet potato are used interchangeably in the U.S., although the U.S. Department of Agriculture does require the label "yam" always be accompanied by "sweet potato", unless of course the vegetable in question is truly a yam. True yams are native to West Africa and Asian, and have a rough scaly outer skin. Their flesh may be white, yellow, purple or pink when mature and is starchier and drier than that of sweet potatoes. True yams are also relatively uncommon in the U.S.

Growing Sweet Potatoes
If you’ve never tried growing sweet potatoes in your garden, it’s definitely worth a try.  Since they are tropical plants, sweet potatoes like hot weather and do little in the garden until soil warms to 65°F or higher. They will be injured by any amount of cold weather, so monitor your soil temperature and wait to plant until the soil has warmed. Check your local soil temperature in spring at Nebraska Extension’s Hort Update web site or measure it yourself at a 4” depth using a soil thermometer.

Sweet potaotes also need a long growing season, usually 100-110 days depending on the cultivar you choose. Some common cultivars are listed below. Plants do sprawl out more than Irish potatoes, so if your garden is small look for bush types with more compact growing habits. Once established, sweet potatoes are tolerant of hot, dry weather and have few pest problems.

  • Beauregard - 100 days to harvest, light purple skin, dark orange flesh, extremely high yielder from Louisiana State University
  • Bush Porto Rico - 110 days, compact vines, copper skin, orange flesh, heavy yield
  • Centennial - 100 days, orange skin and flesh, good keeper, resistant to internal cork and wilt
  • Georgia Jet - 100 days, red skin, orange flesh, somewhat cold tolerant
  • Jewel - 100 days, orange flesh, good yield, excellent keeper  

Planting
Sweet potatoes are grown from plants or slips. Purchase bunches of slips from your local nursery or grow your own.

To grow your own slips, place a sweet potato root in a container and cover it with moist sand. Place the container in a warm location and give it about six weeks for the root to develop new growth shoots. Keep the sand moist during this time, but don’t allow it to become waterlogged. Pull shoots from the root or cut them off about 1” above the soil line when they reach about 6-8" tall. Cutting the shoots prevents rot diseases from entering the root while it continues to produce additional shoots. Slips do not need roots before they are planted in the garden. They will quickly develop roots of their own once planted in warm, moist soil.

Planting in ridges of loose soil 8-12” high allows the soil to warm faster in spring, improves drainage, and gives the roots room to expand. Ridging also makes harvesting easier when digging. Space rows at least 3 feet apart, and plants 12” apart in the rows.  If you only plant a few sweet potatoes, creating mounded hills of soil works well too. Vines may spread 6-8 feet wide.

Sweet potatoes grow best in moderately fertile soils. Avoid excessively rich or highly fertilized soil. Plants grown on light sandy soil will benefit from 1 to 2 sidedress applications of nitrogen during the growing season. Apply phosphorus and potassium only if a deficiency is indicated by a soil test.

Hoe as needed early in the season to control weed growth. Dense vine growth will suppress most weeds later in the season.

Plants are well adapted to hot, dry weather, but a good deep soaking in August during dry periods will improve your harvest.

Harvest
Harvest as soon as the roots reach eating size and before frost. If vines do get frosted, dig them immediately. Decay in dead vines passes down to the roots. If immediate digging isn’t possible, vines should be cut away and loose soil thrown over the rows to protect roots from the cold. Digging is easier if the vines are first cut off.  Do not allow the roots to become chilled in cold soil or after they are dug. Temperatures below 55°F can cause chilling injury.

Ideally, the roots are cured at 85°F and 90-95% relative humidity for 4-8 days before storing. But keep in mind that if air temperatures are lower than 85°F, it will take longer for cuts on the roots to heal. After curing, store your sweet potatoes at 55-59°F and 85-90% relative humidity.

Why not try growing sweet potatoes in your garden next year and you could be enjoying sweet potatoes from your own garden at Thanksgiving!

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