www.uky.edu/hort
May - June
2016
Spring Lawn
Care Tips by Andy 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 to 3 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 and minimize potential disease infections. 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. While mowing the lawn, what should be done with the grass clippings? The answer is, leave the clippings on the lawn. 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. Remember, grass clippings are not accepted in the garbage. Grass clippings do not 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 post-emergent 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. 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. 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.
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Fruit & Veggie Garden
2
Successfully Transplant
Vegetables
by Rick Durham
With springtime finally here, we turn our attention to the vegetable garden. Getting your transplants up and growing will give you some delicious homegrown produce in the months to come. Transplanting gives a plant more space to develop, but it will temporarily stop growth, not stimulate it. Therefore, for successful transplanting, try to interrupt plant growth as little as possible. Whether you grow your own transplants or purchase them, these eight steps can ensure successful transplanting into the garden. 1. Transplant on a shady day in late afternoon or in early evening to prevent wilting. 2. Ensure transplants are well watered and their roots are thoroughly damp an hour or two before setting them in the garden. 3. Handle the plants carefully. Avoid disturbing the roots. Try removing plants from their containers by knocking them out in an inverted position rather than tugging on the plants. Plants growing in peat pots may be planted with the pot intact.
4. Dig a hole large enough to hold the roots. Set the plants to the lowest leaf at recommended spacings. Press soil firmly around the roots. 5. Pour 1 cup of a solution of soluble plant food and water mixed according to the label’s directions. 6. Put more soil around each plant, but leave a slight depression for water to collect. Break off any exposed parts of peat pots so that they will not act as wicks and pull water out of the soil. 7. Shade the plants for a few days after transplanting on a very hot day by putting newspapers or cardboard on their south sides or cover them with a woven cotton fabric such as cheese cloth. 8. Water the plants every 2-3 days during the next week. For more gardening tips, visit the Garden, Lawns and Landscapes section at www.extension.org.
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Bearded
Iris
Flowers
3
by Lori Bowling
The bearded irises are a common old-fashioned flower found in many gardens and landscapes throughout Kentucky. They are very easy to grow perennials that do best in full sun and well drained soils. There are several classifications of the bearded iris from miniature dwarf, standard dwarf, intermediate and tall. The tall varieties are the largest group having thousands belonging to it. While they are easy to grow, they still can have a few problems if not cared for properly. The iris borer larvae can invade the rhizome by tunneling through it allowing for bacteria to enter. This bacteria usually will result in bacterial soft rot, a very pungent smelling disease. To prevent bacterial soft rot, it is important to use an insecticidal spray of Sevin or Malathion in the spring when the plants are about 3� tall and repeat spray weekly for 2 weeks. Sanitation is also key to keeping this disease under control. Foliage should be cleaned up in the fall to prevent laying of eggs by the adult iris borer moth for the next year. It is also important to note that the iris prefers to be grown in a bed without mulch covering it, so it would be very beneficial to use a pre-emergent weed control regularly. To help keep the iris rhizomes healthy it is
important to remove declining blooms to keep seed from forming. If seed is allowed to form then the rhizome will have less production of stored food that can decrease the bloom production the following year. Irises should be fertilized yearly in the spring when the foliage starts to grow. A general rule of thumb is to fertilize with a complete fertilizer such as 10-10-10 or 12-12-12 at a rate of 1-2 pounds per 100 sq.ft. This spring fertilization is the only one needed to help have a healthy rhizome. Spring blooming irises can be divided in August/September if they are getting to thick in the area you have them. If you are an iris enthusiast check your area to see if there is a local iris society or a Master Gardener group that may have a member that is into raising irises to get some varieties you may not have – if they are willing to share their rhizomes. Also, many Master Gardener groups and local garden clubs sponsor spring and fall plant exchanges so you may want to check those out to see if there are any irises at these events to add to your garden collection.
the foliage to yellow Once blooms fade, leave flower bed. As with before removing from the e foliage is sending many spring blooms, th r next year’s flowers. nutrients to the rhizome fo parts of iris care, as This is one of the difficult mediately remove many gardeners wish to im ne. foliage once flowering is do
Trees & Shrubs
Growing Hydrangeas
4
in Kentucky by Michael Boice and Lauren State
Primarily known as a source of summer color flowering June through August — long after most shrubs have finished. Hydrangeas’ interesting bark and flower heads can also provide winter texture when left untrimmed until spring. Four species are commonly used in Kentucky landscape plantings. Big Leaf Hydrangea is the most widely used hydrangea species. Its large flowers range from white to pink to blue. While white cultivars remain white, pink or blue cultivar color is determined by soil pH and availability of aluminum. A soil pH range between 5.0 to 5.5 will generally produce the blue flowers, and a pH of 6 and above inspires pink flowers. Most cultivars of this species bloom on the previous season’s wood. If temperatures drop too low, the flowers for the next season will be lost. New selections like “Endless Summer” bloom on current season’s growth, providing blooms even if flower buds are killed by late spring frosts. Smooth Hydrangea is popular for its large, white blooms from June to September every year on new growth. Removing the flowers as they turn brown will encourage a second flush of flowers in August. Part shade is best in locations where the weather is generally hot and dry. This hydrangea grows three to five feet tall, making it a possible choice in smaller landscape spaces. There are several good cultivar selections, but the most popular is “Annabelle.”
Panicle Hydrangea is one of the larger shrubs growing six to ten feet tall and six to ten feet wide depending on the cultivar. This plant will grow best in full sun. Enjoy the white to purplish-pink flowers from June to September. Blooms can be pruned when they turn brown or during the winter. One popular selection of this species is “Limelight” with large, light green flowers that mature to white. Oak Leaf Hydrangea, native to the southeastern United States, is known for its large, oak leaf-shaped foliage, and is a popular landscape choice for areas with part shade. The white to purplish-pink flowers are four to twelve inches long with three- to four-inch wide panicles. The flowers are abundant and fragrant. In the fall, the foliage turns to shades of red, orange-brown, and purple, adding additional color to the landscape.
A lot of plants struggle wh en the ground is not prope rly fertilized, but a lot of over fertilize the ground wh gardeners ere they plant their hydra ng ea flowers in an attempt to the color of the flower. So change me of the more common fertilizers that are used ha concentration of nitrogen ve a high in them, and nitrogen is a great way to boost the gro plant, but it will put all of wth of your its energy into creating fol iage instead of flowers.
Pests
Controlling
Mosquitoes
5
by Lee Townsend
Controlling mosquitoes is challenging to say the least. You may even think you are fighting a neverending battle. With mosquito-borne diseases, like the Zika virus, becoming more prevalent, it’s even more important to know how to take control of these pests around your home environment. Learning to do a few simple things could help protect you from more than the itchiness of a mosquito bite. All mosquitoes need standing water to develop through their larval stages and that doesn’t necessarily mean a lake or pond. It also includes bird baths, kiddie pools and even discarded soda pop cans. The key to controlling them around your home is to stop them from breeding in the first place. Some things you can do include: • Drain and remove trash, bottles and any debris that holds water. • Recycle any unused containers that could collect water, especially old tires. • Change water weekly in bird baths, wading pools, watering troughs and animal bowls. • Fill in holes, depressions and puddles in your yard.
draining properly. • Check and clean out clogged gutters to ensure drainage. • Keep ornamental ponds stocked with fish. • Fix leaky hoses and faucets. • Drain water from flowerpots and garden containers. • Turn over wheelbarrows, buckets and other items that collect water. • Adjust tarps covering woodpiles, boats and grills to remove standing water. • Encourage natural enemies of mosquitoes, such as warblers, swallows, martins and other insect feeding birds. It’s a good idea to start these practices early in the season. Just because the mosquitoes aren’t biting yet, doesn’t mean that they’re not developing. For more information about mosquito control, visit http://www.uky. edu/Ag/Entomology/entdept/faculty/Brown/index_files/Page601.htm.
• Make sure your culverts and ditches are
Bug Zappers: Though the satisfying sizzle you hear from this modern day ins torture device will convinc ect e you it’s working, don’t expect much relief from backyard mosquitoes. Bi ting insects (including m osquitoes) generally mak up less than 1% of the bu e gs zapped in these popular devices. Many beneficial insects, on the other hand , do get electrocuted.
Upcoming
Horticulture Events May 19, 2016 Backyard Wildlife 859-586-6101 Boone County Extension Office (Burlington) May 19, 2016 Edible Kentucky Series Begins 270-842-1681 Warren County Extension Office (Bowling Green) May 21, 2016 Naturalist May Day 859-873-4601 Woodford County Extension Office (Versailles) May 21, 2016 – 10am-2pm Garden Shed Herb Day (606) 739-5184 or http://boyd.ca.uky.edu/ Franks Extension Facility located at the Boyd County Fairgrounds May 23, 2016 Raingarden Workshop 270-886-6328 Christian County Extension Office (Hopkinsville) June 4, 2016 – 9am-12pm Master Gardener Plant Exchange and Sale (606) 739-5184 King’s Daughters Medical Center lot located at the corner of Bath Ave and 24th street in Ashland, Ky (under the big white tent) June 14, 2016 Vegetable Field Day and Tour 270-886-6328 Christian County Extension Office (Hopkinsville)
Upcoming Events
6
June 23, 2016 Horticulture Open House 270-261-9467 University of Kentucky Research and Education Center (Princeton) July 27, 2016 Rain Garden Workshop 859-572-2600 Campbell County Extension Office (Highland Heights)
The Southeast Center for Agricultural Health and Injury Prevention (SCAHIP) would like to collect some feedback from all those who work in areas that come into contact with agricultural industries. Below is a link to a short survey to find out what you consider to be the top health and safety concerns agricultural workers and their families encounter in the 10 state (KY, TN, GA, AL, MS, NC, SC, VA, WV, FL) Southeast Center’s region. This survey is 100% anonymous so please be direct and honest with your responses. Please forward the link to others who may be interested. Once submitted, you may enter to win a Visa Gift card.
http://bit.ly/SoutheastCenterSurvey