Flood Recovery

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Photo of breached Levee in 2019 Flooding along the Missouri River, Photo by John Wilson, Nebraska Extension Educator

Many parts of Nebraska have faced flooding issues recently that have done a great deal of damage to homes and properties. Flooding has also caused damage to our landscapes and garden spaces.

Trees in the floods

Floods can do a lot of damage to our trees, depending on the length of time the trees were under water. According to the University of Wisconsin Extension, most plants can tolerate a few days of flooding during the growing season. Now that flood waters have or are receding take time to look at your tree and assess the damage.

When assessing the damage to your tree, make sure the roots remain at the same level in the soil and remove debris from around the tree roots. Hire an arborist to remove broken branches and check the stability of any leaning tree. If the tree is now leaning toward a building or other damaging location, have the tree removed. Do not fertilize your trees for at least a year to avoid further damage or disruption to re-establishing roots.

Garden space in the floods

Vegetable Gardens would be a concern due to food safety reasons. Floodwaters are not clean and they can carry bacteria and other harmful debris and pollutants with them as they move across the land. Fortunately, the floods came through before our gardens were planted, but there is still a concern with the soils and what crops we will plant. Spring garden crops and crops with edible parts coming into contact with previously flooded soils would be the most concerning.

According to John Porter, Urban Ag Program Coordinator for Nebraska Extension:

The recommendation depends on whether or not the crop comes in contact with the soil.  For crops that do not have direct contact with the soil, such as tomatoes, peppers, beans, etc. the waiting period between flooding and harvest should be at least 90 days. For crops that do have direct contact with the soil, such as lettuce and leafy greens, squash/pumpkins, and root crops such as potatoes and carrots the waiting period should be at least 120 days.  If the crops that don’t typically make contact with the soil are allowed to make contact, like tomatoes that aren’t staked, the 120 day recommendation should be followed.

Food safety concerns wouldn’t be present to gardens that were not affected by the floods. We can still plant our gardens into the soil during the 90 or 120 day waiting period, but any mature harvest should be discarded until after that waiting period for food safety. This means that we should opt out of spring gardening in areas where the floods impacted our vegetable garden spaces. Most of our summer crops would be fine, but you may want to use a trellis for cucumbers and use container gardening for things like zucchini to be on the safe side.

Turf in the floods

Lawns are resilient in flooded areas. It is best to stay off of wet lawns to avoid compacting the soil. Wait until it has dried out before mowing, driving equipment over, walking excessively over, and cleaning up the debris that may be on the lawn. Turfgrass can survive 4-6 days submerged, according to Missouri Extension. Most of our localized flooding receded quickly, so the lawn should survive. Also, because the flooding happened during the dormant period for the turf, the injury will be less than if it occurred during the warmer growing season. In areas that are still under water, when the floods do recede soil work, clean-up, and overseeding will be necessary. We may also see an increase in lawn diseases this summer due to the high amounts of rain and floodwater that affected them this spring. View this Turf iNfo on Turf Recovery after Historic Flooding for more information.

For more Flood Resources, visit: flood.unl.edu

 

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Spring Yard Clean Up

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Image by Rudy and Peter Skitterians from Pixabay

Now that spring is officially here, we can really start to think about outdoor activities. Don’t get ahead of the weather though, that could cause more harm than good or cause us to have to do more work later. But now that spring is here, I thought I would help you with your to do list and when to do those things.

Lawncare

This is the time of the year when we start to see green in our lawns again. We begin to think it is time to fertilize, overseed, and use crabgrass control. Don’t get started on your lawn too early. It has been quite cold this winter and even this spring. If you get too ahead of the weather it can cause some plants to develop freeze damage or die. Overseeding can be done in April, but anytime by the end of April to the early part of May is still fine for overseeding. I would suggest waiting until at least the middle of April this year. According to Purdue University, the optimum air temperature for germination of Kentucky bluegrass seed is 59-86 degrees, for Tall fescue it is 68-86 degrees. So we can wait until it warms up more consistently before overseeding the lawn.

Fertilizer also can be left until later in the spring before it is applied. You can apply a fertilizer application as needed in mid to late April. Wait to see how the lawn greens up to determine if a spring application is necessary. If a lawn has a medium green hue in late April, skip the typical Arbor Day application in favor of one in late May to early June.

It’s also a good time to clean the lawn from winter debris. Branches and leaves may have fallen during the winter, now’s the time to rake these up and remove them before mowing begins. It’s also be a good idea to clean pet waste from your lawns. Pet waste tends to build up over winter and can become a pollutant in water when it runs off your lawn and into storm drains.

Crabgrass Control

fertilizer spreaderDon’t get started with crabgrass control too soon this spring. The soil temperatures are still in the low 40 degree range. Crabgrass preventer should not be applied until the soil temperature is consistently at 55-60 degrees Fahrenheit. Even if a few early warm days cause crabgrass to germinate, if these days are followed by freezing temperatures, any crabgrass that germinated will die from cold temperatures. If you apply crabgrass preventer too early in the spring, it will break down too early causing more crabgrass to germinate later in the year.

Spring vegetable gardens

Vegetable gardens can be worked in the spring as soon as the ground is dry and workable. Cool season crops such as peas, potatoes, carrots, raddish, kohlrabi, lettuce, and spinach can be planted now. Asparagus beds can be cleaned up now and new asparagus patches can be started. Make sure that the soil is dry before you work the garden or plant any vegetables. Planting into mud can compact the soil and disrupt the growth of plants.

Wait to plant warm season crops such as tomatoes, cucumbers, peppers, eggplant, and beans until Mother’s Day, or until after our average frost free date, which is the end of April for the Beatrice area.

Cleaning up perennials

If you didn’t clean your perennial beds last fall, wait until mid-April before you begin cleaning them this spring. Those plants have been protected from the plant debris from last year’s growth, removing that now would expose the crowns and could kill the plant if cold temperatures return. You can begin to refresh your mulch anytime now. Apply 2-3 inches of mulch around your flower beds to protect them from weed competition and to keep the roots at a uniform temperature with added moisture.

 

 

 

 

Landscaping Around a Tree

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This photo shows a good example of landscaping under a tree. Notice the wide, thin mulch rings.

The winter is a great time to start thinking about spring gardens. One of the gardens you might think about for improvement or development is around trees. There are things you can do around trees to help improve the overall look of your landscape, but be careful, some things may be harmful.

Exposed Tree Roots

Exposed tree roots are often a problem in landscapes. Some trees will pop their roots up and out of the ground which makes it difficult to mow around and can be a trip hazard. Unfortunately, there is not a good fix for this problem. If you were to cut the root to remove it from above the ground, you would severely injure the tree and possibly kill it, depending on the size of the root. Adding more soil around the root to try to cover it up is also a bad idea. Adding more soil to the existing grade of a tree can suffocate the roots and kill the tree.

Raised Beds around Trees

One idea many people want to use around their trees is to add a raised bed around an existing tree. Adding the soil necessary to make a raised bed around a tree can kill the tree. If the tree is correctly planted into an established raised bed after the raise in soil grade is complete, that would be fine. However, adding this bed around an existing tree will severely damage the tree and could lead to tree death. Trees are slow to react to these things, so your tree may live just fine for 5-10 years, but then the damage will begin to show up as the canopy starts to thin or die.

Turf under Trees

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Thin turf under a tree, photo from John Fech, Nebraska Extension Educator

Another issue around trees that many people ask about would be thin turf growth or constantly bare soils under a tree. Turf is a sun plant and it will not grow well in shade. There are shade mixes in the market, but those are designed for light shade. Underneath a full grown, healthy tree is often too much shade for the turf to grow in.

A better option instead of thin turf for underneath the tree would be to just mulch the area. Mulch helps to keep the weeds down, retains moisture, keeps the roots cool, and keeps the lawn mower and weed trimmer back away from the tree trunk to reduce the incidence of damage from this machinery. Keep the mulch at a flat layer of 2-3 inches deep and don’t create a volcano of mulch around the tree. The mulch ring should be at least a 3 foot diameter around the tree, but it can be as wide as the dripline.

You can mimic mother nature and provide a nice growing environment for your tree by utilizing mulch and shade plants under the tree. You can plant shade plants into the area around your tree as long as you don’t add soil to put them in. In nature, trees grow great on their own with little input from humans. A big part of that is the growing conditions they are placed in. Trees in nature grow with leaf litter and smaller plants growing all around them. The leaf litter acts as a mulch and the shade plants thrive in the shade of the large trees.

Planning Your Garden

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*Reference to commercial products or trade names is made with the understanding that no discrimination is intended of those not mentioned and no endorsement by University of Nebraska–Lincoln Extension is implied for those mentioned.

In January the seed catalogs begin to arrive in the mail. Each of these catalogs is a promise that spring will come again. In all the cold, snowy weather, I like the excitement of planning my garden for this year. When you are planning your garden, keep in mind things like sunlight, location, and water availability. Planning is important for the vegetable garden as well as for flowers, trees, and shrubs.

Planning a Vegetable Garden

It is always hard not to get overwhelmed with all the fun, new plants available to us. But when planning your garden, look at the location available first. If you are planning for a vegetable garden, you need to have at least 5 hours of sunlight per day but 8-10 hours per day is ideal for vegetables, preferably more sunlight in the afternoon. If you don’t have the correct sunlight, look for shade loving plants. The garden should be in a location that is fairly level and has good soil for best growth of the plants. Be sure to plant your garden near a water source to ensure the plants get watered sufficiently through the growing season.

Also, be sure to have the proper spacing allowed for your garden plants. We tend to plant vegetable plants too close together because they are small when we plant them. Remember to space them according to the label directions. If plants are too close together it can lead to more disease and insect problems when they grow too large and overlap one another.

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Black Walnuts Photo courtesy of Paul Wray, Iowa State University, Bugwood.org

Black Walnut Trees

Another important aspect of your garden to keep in mind, would be to keep your garden at least 50 feet away from Black Walnut trees. Black Walnut trees produce juglone, which is a type of plant produced toxin that works as a weed barrier around the tree. Juglone will hinder growth and sometimes kill many different types of plants. Tomatoes are very susceptible to juglone. There are also a lot of other trees, shrubs, and perennials that are susceptible to the juglone. If you are planting near a black walnut tree, be sure to check if your plant choices are tolerant of the juglone. If you are unsure about a nearby tree, bring a sample of the tree to your local Extension Office for identification and they can help you determine which plants will do well planted near your black walnut tree.

Mulch

Mulch is a necessity for your garden. Whether it is a vegetable garden, a perennial bed, or trees or shrubs, mulch is vital to help keep weeds down and to retain moisture around plants. Mulch can be either wood chips, straw, grass clippings, or another form of organic mulch. Inorganic mulches are not the best option due to the fact that it is very hot around the roots of plants and does not retain moisture. Make sure that your mulch layer is not too deep, keep it around 2-3 inches deep and keep it uniform around the tree, avoid mulch volcanoes.

Plant Size

Make sure you always read the growing requirements and full size of the plant before planting it in your landscape. It is most economical to plant things that fit in the space in your landscape, rather than pruning or removing it later. Often times, trying to keep a plant in a space that is too small for it will lead to death and costly removal fees. So it is best to start with a plant that will grow no larger than the space available to have a long-lasting plant for that area of your landscape.

Have fun when searching through your garden catalogs and find something fun and interesting to try. The 2019 Pantone Color of the Year is Coral, try to use that in your garden this year. Check out the All-American Selections for new varieties that have been tested in real garden settings, many of them were tested in Omaha and Lincoln with help from Nebraska Extension.

Volunteer to Garden

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After the holiday season, winter gets long and exhausting. We can’t go outside to do any of our fun outdoor activities like gardening. This is the time of the year that the winter blues begin for many of us, and it’s understandable since we can’t garden. However, we can use this time indoors to educate ourselves in the best practices for gardening. One way to learn more about gardening in the winter and help the community during the growing season, would be to become a Master Gardener Volunteer.

The Nebraska Extension Master Gardener program is a horticulture related volunteer training program based in many counties throughout the state. It has been part of Nebraska Extension since 1976. Master Gardener volunteers are trained by UNL Extension faculty and staff and then they take that knowledge gained to volunteer in their community. They contribute time as volunteers working with their local Extension office to provide horticulture-related information to their community. Participants are required to complete 40 hours of training and 40 hours of volunteer service throughout the first two years of their involvement in the program. Master Gardener volunteers retain their certification through 10 hours of annual training and 20 hours of volunteering each year.

Each year the Master Gardener program is held throughout the state, including many locations in southeast Nebraska. The programs are held from 6:30-9:00pm on Tuesday nights at the Gage County Extension Office in Beatrice. This year the programs run from February 5-March 12. The schedule for the classes is as follows:

February 5- Introduction & ‘Do you know Plants?’– Nicole Stoner

February 12- Wildlife in the Landscape – Dennis Ferraro

February 19- Weather Ready Landscapes – Elizabeth Killinger

February 26- Secrets of Service for Master Gardeners – Terri James

March 5- Lawn Weeds & Pesticides – Nicole Stoner

March 12- Tree Hazard Awareness & EAB – Nicole Stoner

This class will also be provided in Wilber following the same schedule on Wednesday afternoons from 1-3:30pm. It will run from February 13-March 20 at the Saline County Extension Office. There are also many other opportunities and locations to take the Master Gardener Classes. Please contact Nicole if you are interested or if you would like to find another location for the classes.

The Master Gardener program is a great way to learn about gardening, help your community, and make good friends who share your love of gardening. For volunteer service, most of the Master Gardeners in the area participate in management of many of the gardens in your community. Look around the landscapes in public areas the next time you drive around town, there are signs to show many landscapes the Master Gardeners help to manage. They do a great job and really help keep our communities looking nice.

The cost of the Master Gardener program is $160 for the first year, which includes a book, t-shirt, and nametag. For returning Master Gardeners the cost is just $15. Please contact Nicole at the Gage County Extension office at 402-223-1384 to sign up for the program. The deadline for enrollment into the class is January 31, 2019.

Protect Plants from Winter Problems

Now that November is here, we can begin to prepare our plants for the winter conditions. Some of those preparations are to get plants ready for cold weather and some are to protect them from wildlife.

My beautiful picture

Wildlife Damage

During the winter months we can see plant damage from deer, rabbits, and voles. Deer can chew off the ends of small twigs and bucks can rub their antlers on the trunk of smaller trees. Rabbits can also chew on smaller plants, sometimes chewing small plants off at ground level. Rabbits and voles can also gnaw on the thin bark of our young trees to feed on the green, inner bark areas. There is no cure once it happens, so it is best to protect our plants prior to damage.

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Rabbit Protection Fence, Photo from Lancaster County Extension

Exclusion is the best defense but is sometimes a difficult task. There are fences that can be utilized but they need to be at least 8 feet tall for deer damage. Rabbits can be managed with a fence that is 2 feet tall. Voles can be controlled by removing tall grass and weeds from around the trunk of trees and by avoiding mulch layers deeper than three inches around trees. Placing hardware cloth around tree trunks will also prevent vole feeding. The commercial spray repellants available for deer or rabbits are not very effective and would need to be reapplied often.

Winter Mulch

Winter mulch can be applied now, or within a few weeks when temperatures are consistently dropping down to the twenties each night. Winter mulch is the heavier layer of mulch we apply to herbaceous perennial plants and strawberries to keep them from having temperature fluxes throughout the winter. Any plant that may be prone to frost heaving, the plant being pushed up out of the soil by a constant freeze and thaw condition, or plants that were just planted this fall could also benefit from winter mulching. This mulch can be up to four inches deep, which is deeper than we usually advise but is needed for winter protection. It is better to use coarse wood chips or leaves for winter mulch rather than grass.

Winter Watering

Winter watering is essential in dry winter years. Winter desiccation commonly occurs on evergreen types of trees and shrubs. All trees are still transpiring, or losing water, throughout the winter months, evergreen trees are transpiring at a higher rate than deciduous trees. Winter desiccation occurs when the amount of water lost is greater than the amount of water the evergreen takes in throughout the winter months. The damage from winter desiccation is brown needles out on the ends of branches. However, the damage from winter desiccation will not usually show up in our trees until early spring, so they will stay green through the winter. Drought effects can damage deciduous trees as well. Especially newly planted deciduous trees. All of our trees may need to be watered throughout the winter months if natural precipitation or snow cover is absent.

Winter watering should occur during the day on days when the temperature is 40 degrees Fahrenheit or above and is only necessary 1-2 times per month until spring. It is a good idea to test for soil moisture with a long screwdriver or soil probe prior to watering to determine if watering is necessary. If the screwdriver goes into the soil easily up to 18 inches, watering is not necessary. However, if pushing the screwdriver into the soil is very difficult, watering would be necessary.

Hot Weather and Plants

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Drought lawn photo from John Fech, Nebraska Extension Educator in Douglas/Sarpy Counties.

It’s hard to say what normal Nebraska weather is. However, this year has been particularly difficult for our plants. The quick change from cool to hot has caused some lasting effects on our plants. Some of the common problems we have been seeing this year include: leaf scorch, drought problems, and poor pollination.

Leaf Scorch

Leaf scorch can happen on the leaves of our trees, vegetable plants, and other garden plants. Leaf scorch causes the tips of leaves of many plants to turn brown and crispy. The abrupt change in our environment from cold to hot and humid left even the most well-adapted plants struggling to stay green. Even plants that are not in full sun will be affected from the high temperatures, such as hostas that are planted in shade.

When the plant is unable to take up enough water, the leaf tissue that is farthest from the major veins will dehydrate first causing leaf margins to scorch first. Leaf scorch is not necessarily caused from lack of water, it is because the plants cannot take in enough water to compensate for what is being lost through transpiration. The moisture may be present around the roots, it just is not entering the plant as fast as it is leaving it.

Do not automatically go out an water the plants that are showing scorch. Watering may be necessary, but don’t overwater. Ensure that the plants have mulch around them and check the soil moisture before watering.

Dry Conditions

In these dry conditions we have faced through most of the growing season, it is important to remember to water your plants. But, it is always a good idea to check soil moisture before watering to help reduce the problems with overwatering. Most of our plants need about 1 inch of water per week, if they don’t receive that from precipitation, they need it from irrigation. If a screwdriver or dowel pushes into the ground easily moisture is sufficient around the plant. For trees the screwdriver should go down 12-18 inches, for perennials it should go down 6-8 inches and for turf and vegetables it should go down 4-6 inches.

Poor Pollination

The heat we are facing is also causing some slight problems with poor pollination and there are problems we could face later as our fruits begin to develop, abnormally. In this heat there is a condition called blossom drop that can occur. It is when the flowers abort and fall from the plant rather than developing into a fruit. This can also be due to drought conditions, which we are also facing. When temperatures reach 93 degrees F, pollen becomes sterilized, so even if they get pollinated, they are not fertilized and fruits will not develop.

The heat and drought we have been dealing with can also cause small fruit development and sunscald. Sunscald happens in high temperatures when our fruits develop without leaf cover. Don’t prune tomatoes too heavily or it can leave your fruits open to damage from sunscald.

We could also have problems with bitter tasting cucumbers this year. Cucumbers produce a chemical called cucurbitacin, which is bitter in flavor. Most cucumbers that we eat now have low amounts of this chemical, but they can produce more due to environmental stress. Uneven watering, drought issues, and high temperatures can all lead to the build-up of cucurbitacin. It is likely this year we may have a problem with that, and there is no way to fix it. Just be sure to try out your cucumbers while you are cutting them up for your recipes.

The leaf scorch information for this article came from Kathleen Cue, Dodge County Extension Educator.