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www.uky.edu/hort

May - June

2017

Spring Lawn

Care Tips by Paul Rideout

Springtime always brings with it a renewed interest in maintaining a healthy lawn. Spring is the time to prepare your lawn for the rest of the year. There are many good management practices that will help you keep a healthy lawn throughout the season. Mowing at the proper height is a great start. The recommended mowing height for tall fescue is 2.5 to 3.5 inches, and for Kentucky bluegrass the height is 2 to 2.5 inches. Mowing at the best height for the grass encourages a deeper root system, discourages weeds, and helps reduce watering. Setting up your mower is a relatively easy task. Park your mower on a concrete or other hard surface and measure from the blade to the surface to get the proper height. There is no need to be exact but within ¼” inch is great. Following recommendations for mowing height and frequency will make your lawn care duties easier and result in a more attractive yard. A good sharp blade throughout the mowing season is also very important. Surgeons use very sharp instruments so the cut will heal quickly. When your mower blade cuts the tip of the grass blade, the wounds are susceptible to infections and insects. The sharper the blade, the quicker you grass will recover. Another tip is to mow often so that only one-third of the grass blade is removed at any one time. During the spring, the lawn may need to be mowed more than once a week. Mowing off more than 50 percent of the leaves at one time causes scalping, which results in an increase in weed competition and in the death of some grass plants during the hot summer. A good fertility program for your lawn should be based upon a soil sample. Most of the time, you should not apply nitrogen in the spring. Nitrogen promotes top growth and will only increase your time on the mower. For most lawns, nitrogen should be applied in the fall to help develop the roots, increase density, and prepare the plant for the spring green up.

Leaving grass clippings on the lawn saves time, money, and energy, since you don’t have to stop and empty the bagger or buy trash bags. Clippings also add free fertilizer to the lawn, possibly as much as 25 percent of the lawn’s annual nutrient needs. Grass clippings do not significantly increase thatch. Clippings contain 75 to 85 percent water and decompose quickly. Thatch is a tight, intermingled organic layer of dead and living shoots, stems, and roots that develops between the green leaves and soil surface. A little thatch is good, since it helps moderate temperature extremes at the soil surface and provides a cushion effect on the surface. Weeds can be a big problem in home lawns. Good weed management starts with a healthy lawn, so make sure you are mowing at the proper height and fertilizing correctly before attacking your weeds. There are two types of weed control: pre-emergent control and postemergent control. Pre-emergent is the best way to control the most common home lawn weeds such as crabgrass, dandelion, and many others. Most pre-emerge products come in combination with a fertilizer, so make sure the nitrogen content is very low for spring application or you will be mowing more than you planned. Timing your pre-emerge application is important. You must make sure that you get it applied before the weeds you are trying to control start growing. As soil temperature increases this spring, your weeds will start to germinate. Instead of monitoring your soil temperature, there are “indicator” plants that will let you know when you need to apply your weed control. A good indicator plant for pre-emerge application is the forsythia. When you see the bright yellow flowers starting to bloom, it is time to apply your preemerge. Make sure to follow all label directions when applying control products. These tips are just some basics. Different grass varieties and soil types require unique management practices. The Extension Office has detailed information on home lawn maintenance and can take your soil samples to help you customize your lawn maintenance.

While mowing the lawn, what should be done with the grass clippings? The answer is: leave the clippings on the lawn.

after gh that footprints are left ou en y dr is n law the til un Water long If you have to water, wait n is just beginning to wilt. law the t tha ow kn u yo let ll ies walking on it—this wi Water again after the soil dr ce. rfa su the on ng mi for begin ble root enough to allow puddles to will create the deepest possi e tic ac pr is Th e. ibl vis ain and footprints are once ag erance. nts in terms of drought tol system and the healthiest pla


Tomato

Support

Fruit & Veggie Garden

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by David Koester Without doubt, tomatoes are home gardeners favorite vegetable to grow. After preparing your soil, selecting the best variety and planting, comes providing support. There are many ways to grow tomatoes, but in a small garden, upright supports are often used to save space. This method provides other benefits as well as saving space. When tomatoes are grown off the ground, they will not be damaged by ground rots and will be out of reach of some insects. They will be easier to harvest and easier to treat for insect or diseases and will produce fruits that are cleaner and larger. For those who want to avoid as much pruning and tying as possible, the tomato cage is the best method of plant support. A tomato cage is a cylinder or wire mesh that holds the stems upright as they grow. Generally, concrete reinforcing wire with a 6-inch mesh is excellent because it gives good support and the squares are large enough to reach through to pick tomatoes. Reinforcing wire will rust, but you will get at least 10 growing seasons from each cage. Galvanized fence wire can also be used. Some nurseries and garden centers have ready-made cylinders available for use, but these are often inferior to those you can make. Healthy tomato plants should fill a cylinder about 4 or 5 feet high and 2½ feet in diameter. To make a cage about 2½ feet in diameter, cut the wire of the selected height in sections about 7½ feet long. When this is rolled into a cylinder and fastened together, it provides the 2½ foot diameter. The wire cage should be anchored to the soil in some way. A stake to which it is fastened will often do the job. You can cut the bottom of the cylinder leaving 6 inch spikes, which can then be inserted in the ground, helping to anchor the plant. Tomato plants may be either determinate, semideterminate or indeterminate. The determinate and semideterminate varieties develop short bushy plants that stay fairly low. For these types, lower cages may be used, because the cage serves mainly to support the plant

only enough to keep the fruits off the ground. Indeterminate varieties are those that continue to grow upright all summer and, therefore, require taller cages. Little pruning is required for tomatoes grown in cages. Shoots that hang outside the cage may either be pushed back inside or cut off. When growth becomes extremely dense in the cage, some thinning to increase light penetration and air circulation will reduce chances of disease build-up. Tomatoes grown on stakes require more pruning and some extra time for tying. Wooden stakes may be used and should be at least 6 feet in length. Strength is important since a heavy load of fruit near the top of a stake may cause the stake to break during a summer storm. Two-by-two lumber, commercial metal stakes, metal fence posts, or sections of concrete reinforcing rods can all be used. Place each stake about 4 inches from the plant and drive the stake into the soil at least 10 inches or until firm. At this time of year, plants should be growing vigorously, with pruning and tying often required weekly. After fruits have set and are developing, the growth rate slows and less frequent tying is necessary. Use soft cords, strips of cloth or other materials that will not cut into the stem. For gardeners with plenty of space, tomatoes may be allowed to sprawl without support. To avoid the development of fruit rots, a thick straw mulch can be beneficial. Mulch will also increase production of staked or caged tomatoes by keeping down weeds and maintaining a more uniform soil moisture.

lcium uptake. It disorder related to poor ca al gic olo ysi ph on mm co fruit a Blossom end rot is calcium movement into the nt cie uffi ins d an n tio iga irr ic with careful usually results from sporad er can largely be prevented ord dis is Th . eam str on ati via the plant’s transpir water management.


Flowers Planting Native Flowers

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for Pollinators by Faye Tewksbury

Need a reason to plant more flowers? How does supporting local agriculture, ensuring the availability of healthy fruits and vegetables, and protecting thousands of plant and animal species sound? By planting flowers that sustain pollinators, you are accomplishing all of this, as well as making your yard more attractive. Pollinators, which include bees, butterflies, moths, wasps, hummingbirds, and bats, make reproduction possible for more than three-fourths of the flowering plants on earth, including many of the fruits and vegetables we eat every day.

Of all the pollinators in the world, bees are the best. While almost everyone is familiar with European honey bees, fewer people are aware of the vast variety of native bees found in North America. These include bumble bees, sweat bees, miner bees, and mason bees, all of which are valuable pollinators of crops as well as native flowering plants. Alarmingly, populations of both honey bees and native bees are in decline.

Reasons for bee decline include disease and parasite infection, habitat loss, and stress caused by pesticide exposure and malnutrition. As gardeners, we have a critical role to play in reversing this alarming trend. One of the most important things we can do to preserve and support pollinators is to plant flowers. Bees gather nectar and pollen from flowers to feed themselves and their offspring. To stay strong and maintain healthy colonies, bees need a season-long supply of flowers that have not been contaminated with pesticides.

Many of our native bees specialize in feeding on native plants. Including native plants in your landscape will support the widest range of pollinators. When planting flowers to support pollinators, aim to have at least three different types of flowers in bloom during each season, from early spring through late fall.

Flowering perennials are among the best nectar sources for bees. Recommended perennials native to our region that are available from most garden centers include spring bloomers such as spiderwort (Tradescantia ohiensis), Coreopsis species and varieties, wild indigo (Baptisia species), Wild geranium, beardtongue (Penstemon species), and bluestar (Amsonia species). Some of the best native summer-blooming perennials for pollinators include coneflowers (Rudbeckia and Echinacea species), phlox, lobelia, butterflyweed and milkweed (Asclepias species), Stoke’s aster (Stokesia laevis), bee balm (Monarda species), mist flower, liatris, and mountain mint (Pycnanthemum species). To provide late-season nectar sources, plant a variety of native asters (Symphyotrichum species), goldenrods (Solidago species), joe pye weed (Eutrochium species), ironweeds (Vernonia species), and perennial sunflowers (Helianthus species).

and perennial flowers Some non-native herbs age for bees and other also provide excellent for include borage, cosmos, pollinators. Some of these , comfrey, rosemary, sunflowers, basil, zinnia no. lavender, thyme, and orega


Trees & Shrubs

Spruce Dieback

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Needle Cast Disease May be To Blame by Kimberly Leonberger and Nicole Ward Gauthier

Blue spruce and Norway spruce are popular landscape plants in Kentucky. However, many factors can cause spruce trees to cast (shed) needles. Casting may be the result of environmental stresses (heavy soil, poor drainage) or fungal diseases. In Kentucky, Rhizosphaera needle cast is the most common disease of spruce. This disease causes needle drop on lower branches, resulting in a distinct thinned appearance. Stigmina needle cast is a less common disease of spruce, but also causes symptoms similar to Rhizosphaera needle cast. Management options for both diseases include reduction of plant stress, good sanitation practices, and timely use of fungicides. Rhizosphaera and Stigmina Needle Cast Facts: • Symptoms become evident in summer when needles on lower branches turn purplish or brown (Figure 1). Needles fall within a few weeks and lower limbs are left bare (Figure 2).

Figure 1: Needles infected with Rhizosphaera turn purplish brown during summer. (Photo: Julie Beale, University of Kentucky)

• In order to determine whether Rhizosphaera or Stigmina needle cast is present, infected needles should be inspected with a hand lens. Look closely for the type of fungal fruiting body emerging from stomata (pores in needles) to confirm diagnosis. Rhizosphaera needle cast - Small, dark fruiting bodies (pycnidia) appear as tiny raised, grayish bumps topped with white waxy caps (Figure 3). While most easily recognized with a hand lens, they may also be visible with the naked eye.

Figure 2: Needle drop and thinning of lower canopy are classic symptoms of Rhizosphaera needle cast in spruce. (Photo: Minnesota Department of Natural Resources Archive, Minnesota Department of Natural Resources, Bugwood.org)

Stigmina needle cast – Fungal fruiting structures (sporodochia) appear as tiny, brown to black, brush-like tufts emerging from needles (Figure 4). • Rhizosphaera needle cast is caused by the fungus Rhizosphaera kalkhoffii. Stigmina needle cast is caused by multiple Stigmina species.

Figure 3: Rhizosphaera pycnidia appear as tiny raised, grayish bumps topped with white waxy caps. (Photo: Paul Bachi, University of Kentucky)

• Spread by water splash or wind-driven rain; moisture is needed for infection. • If defoliation occurs over 3 to 4 consecutive years, branch death is likely.

Figure 4: Tiny, brown to black, brush-like tufts emerge from infected needles through stomata of needles infected with Stigmina. (Photo: Paul Bachi, University of Kentucky)

Management Options: • Stressed trees are more sus ceptible to infection than he althy plants, so take steps to vigor. maintain plant • Properly space plants to im prove air circulation, thereb y encouraging rapid drying • Practice good sanitation of needles. habits. •Homeowners can apply fun gicides that contain chloroth alonil, copper, or mancozeb emergence (mid-April). Du during needle ring rainy seasons or in pla nti ngs with a history of diseas may be applied 2 consecuti e, fungicides ve years during spring when fungi are most active.


Trees

Give your Trees

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the Best Start! by Adam Leonberger

As I looked out at my yard this past week and saw the grass grow at lightning speeds, I decided that I need a few more trees in the space. With Earth Day and Arbor Day just past, I doubt I’m the only one thinking about planting a few more of those beautiful wood sculptures in my yard. While we are looking for the just the right tree, we should be thinking down the road a bit and consider if the tree is going to fit the space. The first thing to consider is the tree’s hardiness. Some trees are adapted to survive the cold winters of northern Canada, but whither under our summer heat, while others give up at the first mention of freezing temps. In Kentucky, we range in USDA cold hardiness zones 6a to 7a. So, look for trees and shrubs that are hardy to at least those zones.

You’ll want to look at the space in the ground, too. Trees need at least as much root space as their canopy to thrive. Avoid planting trees right next to roads and sidewalks. As the tree grows, the roots will make the pavement uneven and dangerous. You’ll also want to be careful planting over any septic fields, as the roots can clog the system. After you’ve chosen the tree and the space, be sure to plant the tree correctly!

We’ve all seen, and complained about, those “Pac-Man” trees that the utility companies have trimmed to maintain the right away. We need to think about where they will be planted. The first thing is to make sure there is enough space for the mature tree. To keep them looking beautiful for years, only plant small trees and shrubs (less than 25 ft. max height) within 15 ft. of overhead lines. I suggest medium trees (26 – 50 ft.) be planted near to homes to help shade the house during the summer, but be sure to plant them at least 15 ft. from the foundation. Larger trees are better planted farther from the house, since they have wider branch and root spread.

*Photos by: Adam Leonberger

Power companies across th e state contract with tree co mpanies to keep main lines clear of overhanging limbs . They do not maintain vege tation around the secondar lines, the ones that connec y t the house to the utility po le. That maintenance is th homeowner’s responsibility, e and keeping large, mature trees pruned every few years can be costly. Planting a sm aller tree or shrub instead of a towering shade tree ca be a win-win situation that n could ultimately save mon ey.


Upcoming

Horticulture Events MAY May 1 Attracting Pollinators 270-765-4121 Hardin County Extension Office (Elizabethtown) May 2 Miniature Container Gardens 270-554-9520 McCracken County Extension Office (Paducah) May 6 Native Plant Sale 270-388-2341 Lyon County Extension Office (Eddyville) May 8 Sunflowers 859-572-2600 Campbell County Extension Office (Highland Heights) May 9 Medicinal Botany 270-821-3650 Hopkins County Extension Office (Madisonville) May 11 4-H Mother’s Day Flower Pots 270-388-2341 Lyon County Extension Office (Eddyville) May 15 Growing Gourds and Pumpkins 859-572-2600 Campbell County Extension Office (Highland Heights) May 16 Tree ID Walk 859-873-4601 Woodford County Extension Office (Versailles) May 16 DIY Concrete Leaf Casting 606-679-6361 Pulaski Co Extension Office (Somerset) May 18 Introduction to Ferns 859-572-2600 Campbell County Extension Office (Highland Heights)

Upcoming Events 6

May 18 Herbs by Becky 502-633-4593 Shelby County Extension Office (Shelbyville) May 20 The Plant Fair 270-527-3285 Marshall County Extension Office (Benton) May 20 Wild Mushroom and Plant Identification 859-873-4601 Buckley Wildlife Sanctuary (Frankfort) May 22 Monarch Butterfly Waystations 270-821-3650 Hopkins County Extension Office (Madisonville) JUNE June 6 Perennial of the Year 270-765-4121 Hardin County Extension Office (Elizabethtown) June 8 Carnivorous Plants 859-572-2600 Campbell County Extension Office (Highland Heights) June 15 Perennials for Shade Garden 859-572-2600 Campbell County Extension Office (Highland Heights) June 15 Critter Ridder Class 502-633-4593 Shelby County Extension Office (Shelbyville) June 20 Common Garden Insect Pests and Beneficials 859-873-4601 Woodford County Extension Office (Versailles)


Upcoming

Horticulture Events JULY July 10 Flower Arranging 859-572-2600 Campbell County Extension Office (Highland Heights) July 13 Weed Management for the Landscape and Vegetable Garden 859-572-2600 Campbell County Extension Office (Highland Heights) July 18 Managing Perennials through Pruning 859-873-4601 Woodford County Extension Office (Versailles) September 14-15 2017 Kentucky Master Gardener Conference Scott County Extension Office (Georgetown) LATER MONTHS August 10 Water Garden Management 859-572-2600 Campbell County Extension Office (Highland Heights) August 15 Common Yard Tree Problems 859-873-4601 Woodford County Extension Office (Versailles) August 24 Toxic Plants 859-572-2600 Campbell County Extension Office (Highland Heights) September 12 Growing PawPaw Trees 859-572-2600 Campbell County Extension Office (Highland Heights) September 19 Home Lawns 859-873-4601 Woodford County Extension Office (Versailles)

Ucoming Events

October 17 Nuisance Wildlife 859-873-4601 Woodford County Extension Office (Versailles) November 21 Winterizing your Garden 859-873-4601 Woodford County Extension Office (Versailles) December 19 Wreath-making with Fresh Greenery 859-873-4601 Woodford County Extension Office (Versailles)

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State Horticulture Newsletter  

Spring Lawn Care Tips by Paul Rideout Tomato Support by David Koester Planting Native Flowers for Pollinators by Faye Tewksbury Spruce Dieba...

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