By The Yard. Peonies a Springtime Favorite HORTICULTURE NEWSLETTER QUICK TIP. Fayette County Extension MAY, 2017

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1 Fayette County Extension MAY, 2017 Cooperative Extension Service Fayette County Extension 1140 Harry Sykes Way Lexington, KY Phone (859) By The Yard HORTICULTURE NEWSLETTER Peonies a Springtime Favorite Inside this issue: Recipe: Spinach Slaw 2 Pests of Boxwoods 3 Carpenter Bees 4 Defoliation of Spruce 5 Quick Tips for May 5 QUICK TIP Good choices for low -maintenance annual flowers include Vinca Periwinkle, Begonia, Coleus, Impatiens, Ornamental Peppers, Blue Salvia (Mealycup Sage), Creeping Zinnia, Gomphrena (Globe Amaranth), Ornamental Basil, Polka-dot Plant, Cleome (Spider Flower), Dusty Miller, elampodium and Abelmoschus. Peonies are one of those spring time perennial flowers that are an old time favorite. These flowers are often fragrant, make for great cut flowers, and come back year after year. They come in many colors including cream, coral, crimson, pink, purple, rose, scarlet, black, white, and yellow. Peonies generally grow two to four feet in height, thriving in full sun and well-drained soil. Their sumptuous blooms will be coming to us shortly in the months of May and June. The two types of peonies generally grown are the garden peony or Paeonia hybrids and Paeonia suffruticosa, better known as the tree peony. The main difference you will notice between the two is that the garden peony will generally die back to the ground over winter, while the tree peony will retain woody growth through the cold months. Garden peonies are herbaceous perennials that are generally grouped into five categories based on their flower shape: single, semidouble, double, Japanese, and anemone. The tree peonies produce large numbers of flowers on the comparatively taller shrub-like plant. Peonies do well in cooler environments and are suitable to the Kentucky climate. Older peony varieties do best further south because newer varieties require a certain number of chilling hours each winter. As peonies are coming up this spring and shoots get to about three to four inches in size, one may apply a complete fertilizer such as or , or organic fertilizer such as 5-5-5, at the rate of 3 to 4 pounds per 100 square feet of bed area. A single application of fertilizer each year is generally adequate to maintain good plant growth and flowering throughout the season. Peonies multiply through tuber growth, which means that the plant will require occasional dividing. This division allows easy propagation to share with friends and family. Once a clump has become crowded, division of the peony is recommended. To do this, dig and separate the tubers being sure each one has three to five eyes. Remove any damaged tubers, or those showing signs of disease. In general, peonies usually do not Continued on page 2

2 By The Yard Page 2 Peonies a Springtime Favorite, con t. need to be divided for 10 to 15 years. If you find your peonies or other perennials in need of division, fall is a great time to perform this task. If you are looking to plant peonies for the first time this spring, you may find them in nurseries sold as potted plants. Otherwise, tubers are generally planted in the fall. When planting garden peony tubers, select a site in full to part sun where peonies have not been planted before. Set the tuber so that the eyes are one to two inches below the soil s surface. For tree peony tubers, they should be planted so that the soil is covering the graft union, generally four to five inches. After planting, make sure to water the tubers well. When planting in the fall it is best to mulch with two to three inches of straw, wood chips, or leaves. This layer of mulch can help to insulate your new planting over winter while adding organic matter. For more information on peonies and their availability, visit your local nursery. Source: Tracey Parriman, University of Kentucky

3 By The Yard Page 3 Pests of Boxwoods Boxwood Leafminers Boxwood leafminers feed and develop within plant leaves. Heavily mined leaves usually turn yellow and may drop prematurely, but the leaf drop usually doesn t have a significant impact on otherwise healthy plants. Management Natural enemies can be effective in managing infestations. If this insect has been a problem, application of insecticides such as carbaryl (Sevin), cyfluthrin (Bayer Multi-Insect Killer Concentrate, or permethrin (Bonide Borer Miner Killer, and others) about the time of Weigela bloom should provide preventive control. Products containing acephate (Orthene and others) can give some control if mines are developing. Boxwood Psyllids Boxwood psyllids are flat, green, sap-feeding insects that cause spring terminal growth to cup (Figure 3). The damage is especially noticeable on American boxwood. While the small nymphs (Figure 4) blend well with the foliage, the white waxy strands that they produce are very easy to see (Figure 5). These insects affect the appearance of the plant but are not a threat to plant health or vigor. Fortunately, distorted leaves usually fall off in about a year and the plants can recover. More information is available in Boxwood Psyllids (EntFact-454) Source: Lee Townsend, University of Kentucky, Extension Entomologist Figure 1. Light areas on undersides of leaves are signs of boxwood leafminer activity. (Photo: Lee Townsend, UK) Figure 2. Lower leaf tissue were removed from this leaf in order to show the boxwood leafminer larva (a maggot). The insect pupates and the adult (a small gnat) emerges in late April to early May. (Photo: Lee Townsend, UK) Figure 3. Cupped leaves are a classic symptom of boxwood psyllids. (Photo: Lee Townsend, UK) 2017 Community Benefit Every May, the Down to Earth Garden Club holds a special plant sale community fundraiser. The plants are grown, nurtured and generously donated by each club member. This wonderful community benefit will be held rain or shine. Natives, Herbs, Fruits, Vegetables, Perennials, Wildflowers, Grasses, Hostas, Shrubs, Trees, Annuals, Container Gardens, Succulents, Irises, Decorative Containers, Gardening Books, and many plants for sun or shade will be available for purchase during this spring event. Come support your community while adding beauty to your garden! The 2017 sale is on Saturday, May 13 th, from 9 A.M. to 12 P.M. at Woodland Christian Church, 530 E. High St. in Lexington, KY. Please visit our website for more information:

4 By The Yard Page 4 Carpenter Bees Are Good Pollinators, But... Male and female carpenter bees are becoming active after spending winter in last year s tunnels. These large yellow and black bees have shiny, bare abdomens (Figure 1) in contrast to the hairy ones of bumble bees (Figure 2). Female carpenter bees can sting if handled roughly, but they do not aggressively defend their nests or otherwise pose a threat. They focus on developing nesting tunnels and collecting pollen. Males, recognizable by the yellow spot on their face, stay near nesting sites and often investigate intruders who enter their space. While an intimidating sight, they do not have stingers. Carpenter bees are important wild pollinators. However, their nesting habits can cause unacceptable damage to structures. They nest in plant material; the soft or weathered wood of structures provides a desirable resource for them. Females use their strong mandibles to chew 1/2-inch diameter entry holes into soft, dry wood and then turn 90 o to chew along the grain. A season s work result in 6 to 10 inches of tunnel and can contain 6 or 7 cells in which individual larvae develop. Each cell is stocked with a ball of pollen, which is food for the grub-like larva. Over the years, galleries may become several feet long. While carpenter bees are solitary, many can accumulate over time in wood that meets their requirement or is near good pollen sources. Management Carpenter bee control is a challenge. Their tunnels may be in inaccessible places or so abundant that it is impractical to treat all of them. The best tactic is to initiate control early when the overwintering insects are just beginning to prepare their galleries for the season s brood. Dust formulations of insecticides applied into tunnel openings has been the traditional option. In this approach, bees are exposed to the dust as they enter and leave the gallery. They may ingest the product during grooming or the insecticide may enter through thin areas of the exoskeleton. Example dusts include boric acid dust, or products such as Bonide Termite & Carpenter Ant Dust (deltamethrin). Diatomaceous earth and combinations of dusts with desiccants are also possibilities. Insecticide sprays can be applied in tunnels, but bees may not pick-up of the dried residue as rapidly as dusts. Example sprays include Bayer Home Pest Control Indoor & Outdoor Insect Killer (cyfluthrin), Bonide Total Pest Control Outdoor Formula (permethrin), Bonide Termite & Carpenter Ant Killer Ready to Use (deltamethrin), Spectracide Bug Stop (l-cyhalothrin). About a week after treatment, plug tunnel entrances with a piece of dowel rod so these sites are not used next season by bees looking for nesting sites. Source: Lee Townsend, University of Kentucky, Extension Entomologist Figure 1. Carpenter bee with shiny abdomen. (Photo: Lee Townsend, UK) Figure 2. Bumble bee. (Photo: Lee Townsend)

5 By The Yard Page 5 Needles drop from the bottom of the tree first The black spots on the bottom of the needles are part of the fungus. Defoliation of Spruce There has been an increase in the number of questions received regarding spruce trees. The common complaint is that the spruce trees seem to be losing their leaves from the bottom up. One cause for this type of problem is a fungal infection called Rhizosphaera. This disease causes needle drop beginning on lower branches, resulting in a distinct thinned appearance. Management options include reduction of plant stress, good sanitation practices, and timely use of fungicides on infected trees. This disease becomes most evident in summer when needles on lower branches turn purplish or brown. The needles fall within a few weeks and lower limbs are left bare. If you suspect this disease, look on the back of discolored needles with a magnifying glass or hand lens. Small black spots (fruiting structures of the fungus) appear in rows in the infected needles. Green needles may also show these small black fruiting structures. Rhizosphaera overwinters in infected needles that remain on the tree and on those that have fallen to the ground. The fungus is spread by splashing and dripping water beginning in spring and continuing into the fall. Newly emerging needles can become infected during wet spring weather. A stressed tree is more susceptible to infection than a healthy one. Steps should be taken to maintain plant health such as proper fertilization and mulching. Be sure to use the correct spacing when planting to improve air circulation. This will encourage rapid drying of needles. Homeowners can apply fungicides that contain chlorothalonil, copper, or mancozeb during needle emergence in April and May. A follow-up application of fungicide can be applied a month later. For more information, go to: planthealth-spruce-defoliation Source: Amanda Sears, University of Kentucky, Madison Co. Extension Agent for Horticulture Quick Tips for May Mulch beds for weed control and moisture retention. Make sure to keep mulch away from tree trunks and the bases of shrubs. Use liquid products for lawn weed control. Most granular weed control products contain fertilizer which should not be applied to lawns this time of year. Monitor evergreens for bagworms. Carbaryl is effective as a control if you catch the larvae while small. Do not wait for the large bags to appear, as control will be difficult on older insects. Plant and seed vegetable gardens. Most warm season vegetables can be planted early this month and heat-lovers like peppers, squash, and sweet potatoes can go in later in the month. Replace pansies and other cool season plants with appropriate summer choices. Plant flowers. We should be frost free and good to go, although vinca will appreciate warmer temperatures later in the month. Divide and fertilize pond plants that have become overgrown. Move house plants outdoors late this month. Make sure you place them in a shady spot or they are likely to sunburn. Prune evergreens now through August. Don t forget to register for Gardener s Toolbox Classes, For a complete class descriptions and registration information visit our website at: ers_toolbox_2017.pdf

6 2017 GARDENER S TOOLBOX REGISTRATION FORM Name: Phone: Address: City: State: Zip: TOTAL Amount Enclosed $ IMPORTANT REMINDERS! Sign up early for classes to avoid being turned away because class is full. ALL classes are PRE-REGISTRATION only. If you need to cancel, you must do so 2 weeks prior to the class time to receive a refund or credit for a different class. If handouts and/or plants are not picked up 3 days after class, items will be donated. Please make check payable to: Fayette County Master Gardener Association Mail To: Gardener s Toolbox ~ Fayette County Extension Office (new address) 1140 Harry Sykes Way Lexington, KY ~ 2017 GARDENER S TOOLBOX CLASSES ~ Class and Cost Class and Cost 5/4: Growing Great Tomatoes, Cost: 6:00 p.m., West 5/4: Veggie Gardening for Beginners, Cost: Free, 6:30 p.m. 5/11: Hardy Hibiscus, Cost: 6:30 p.m. 5/16: Hens & Chicks, Cost: 6:30 p.m. 6/8: Elephant Ears, Cost: 6:30 p.m. 6/15: Perennials CLASS for Shade FULL Gardens, Cost: 3:00 p.m. 6/20: Veggie Gardening for Beginners Part II, Cost:: 6:30 p.m. 6/29: Oyster Mushrooms, Cost: 6:30 p.m. 7/6: Making Perennials Work, Cost: 3:00 p.m. 7/13: Fall Vegetable Garden, Cost: 6:30 p.m. 7/18: Weed Management, Cost: 6:30 p.m..8/3: Renovating Lawns, Cost: Free 6:30 p.m. 8/10: Crape Myrtle, Cost: 3:00 p.m 8/22: Hydrangeas, CLASS Cost: FULL 6:30 p.m. 9/7: Autumn Crocus, Colchicums, Cost: 6:30 p.m. 9/14: Saving Flower Seeds, Cost: 6:30 p.m. 9/19: Peonies, Cost: 6:30 p.m. 10/5: Storing Winter Bulbs, Cost: 3:00 p.m. 10/12: Minor Bulbs, Cost: 6:30 p.m. 10/17: Daffodils, Cost: 6:30 p.m. 11/2: Lilies, Cost: 6:30 p.m. 11/7: Stump the Hort. Agent, Cost: 6:30 p.m. 11/16: My Favorite Garden Tools, Cost: 6:30 p.m. 12/5: Holiday Greens, Cost: 3:00 p.m.

7 Saturday, May 6, 2017 Fayette County Extension Office 1140 Harry Sykes Way, Lexington, KY Attend demonstrations and take home one FREE Garden Kit containing plants, seeds and vegetable gardening book. DEMONSTRATIONS: Using Your Fresh Produce Container Gardening Soil Prep Planting Maintaining Your Garden FREE GARDEN KIT All materials while supplies last. First come first served basis. LIMIT ONE GARDEN KIT PER FAMILY

8 NONPROFIT ORG US POSTAGE PAID Fayette County Cooperative Extension 1140 Harry Sykes Way Lexington, KY Lexington, KY PERMIT 112 RETURN SERVICE REQUESTED Newsletter Enclosed Fayette County By the Yard Jamie Dockery County Extension Agent for Horticulture Cooperative Extension Service Fayette County Extension Service 1140 Harry Sykes Way Lexington, KY (859) UNIVERSITY OF KENTUCKY, KENTUCKY STATE UNIVERSITY, U.S. DEPARTMENT OF Educational programs of Kentucky Cooperative Extension serve all people regardless of economic or social status and will not discriminate on the basis of race, color, ethnic origin, national origin, creed, religion, political belief, sex, sexual orientation, gender identity, gender expression, pregnancy, marital status, genetic information, age, veteran status, or physical or mental disability. To file a complaint of discrimination, contact Tim West, UK College of Agriculture, ; Terry Allen or Patty Bender, UK Office of Institutional Equity and Equal Opportunity, ; or the USDA,