May - July

Transcription

1 May - July 2018 Hydrangeas Blue or Pink? You Decide. By: Kelly Jackson Hydrangeas grace the landscape with beautiful flowers in the spring and summer. The most colorful hydrangeas are bigleaf hydrangeas, Hydrangea macrophylla. Their flowers are usually either pink or blue. Flower color depends on the ph of the soil, a measure of soil acidity. Soil ph can be raised by applying lime. Some hydrangeas will respond to a higher ph (between 6.0 and 6.5) with pink flower color. To lower ph, apply aluminum sulfate. A lower ph (between 5.0 and 5.0) often results in blue flower color. A soil test will determine the existing ph and you can change your soil with the appropriate amendment to get the resulting flower color you want. Hydrangeas grow best in moist, well-drained soil and partial shade. When planted in full sun in our summer heat, they have a tendency to wilt. The north side of a house or a location where the plant receives afternoon shade is best. There are two flower forms of bigleaf hydrangea - mophead and lacecap. Mophead types make a full, large, round ball of sepals. The showy parts of the flower are the sepals, which surround the flower bud. The lacecap type has flower buds surrounded by showy sepals along the outside edge of the flower head. The inside of the flower head has buds but lacks the showy sepals. The type of flower head a plant produces depends on the cultivar. Most bigleaf hydrangeas bloom on previous season s growth. Part of last year s growth may be injured by cold weather during winter. As buds begin to show green in the spring, you will be able to determine how much wood is still living. The dead wood should be pruned out. Stems can be pruned lower as long as there are still some live buds below the pruning cut. Flower buds are more sensitive to cold temperatures than leaf buds. Until your plant begins to flower, it will be hard to know if all the flower buds are living. Recently new cultivars called re-blooming hydrangeas have been released with the advantage of blooming on old wood and new growth. Endless Summer (Hydrangea macrophylla Bailmer ) (released in 1998) is a true re-blooming hydrangea. It has a mophead flower type up to 8 inches in diameter with pink or blue color, depending on ph. The plant is 3 to 4 feet tall. Another new hydrangea is Lady in Red. This cultivar has three seasons of color. The stems and leaf veins are red. In the fall, the foliage turns a reddish-purple. It s lacecap flowers open pinkish white or bluish white, depending on ph. As they mature, they become deep burgundy rose. This plant is compact forming a 2 foot wide and 3 foot high mound. A popular cultivar for blue flowers is Nikko Blue. This plant grows 5 to 6 feet in height and spread. Although its mophead flowers will be blue in lower soil ph, they still become pink if ph is higher. Blue Wave, a lacecap flower type with lilac to pale blue sepals in low ph, also has sepal-less fertile dark blue flower buds in the center of the head. This plant reaches 4 to 6 feet tall and wide. Remember that most big leaf hydrangeas bloom on old wood. Pruning should be delayed until new growth appears in the spring. However, as we discovered this year, sometimes the worst injury can occur during a late frost in March or April. If your hydrangea doesn t bloom, its sensitive flower buds were likely killed by cold temperatures. When you take soil test samples, keep in mind that a few ounces of soil are being tested to determine lime and fertilizer needs for what may be several thousand pounds of soil in the lawn or garden area. It is absolutely necessary to take care to assure that the soil sample you send to the laboratory accurately represents the area sampled. Soil samples can be collected through much of the year, although fall (September to December) or spring (February to April) are the best times. Fall sampling will often result in a faster return of results and recommendations. Perennial Flowers Sample the top 6 to 12 inches of soil. Don t take samples too close to foundations, sidewalks, driveways or limestone graveled areas, unless these are treated as separate problem areas.

2 Harvesting Blueberries & Blackberries for Full Flavor By: John Strang It s almost summer, and that is prime harvest season for blueberries and blackberries, both of which have the potential to grow very well in Kentucky. Blueberries, which are native to North America, are ready to harvest from early June through early August. Blackberries are ready to harvest from mid-june to early October. These delicious fruits offer health benefits, but best of all, they capture the essence of summer in their sweetness. Fruit & Veggie Garden 2 Blueberries can be excellent choices for both home and commercial growing. They have the advantage of being as long-lived as fruit trees, with few pests or diseases. They also have a late blossom time, so frost rarely causes damage on well-chosen sites. Blackberries also have a long fruit-bearing life and will produce for a decade or longer in Kentucky. Blueberries require an acidic soil, which means that most soils in Kentucky will need to be amended to properly suit their needs. They also require a high organic material content, so peat moss should be mixed with the soil at the time of planting. Do not substitute with other materials. Irrigation is necessary during the summer because blueberries have a shallow, limited root system. Insufficient irrigation can compromise both this year s and next year s crops. Blackberries need to be pruned, fertilized and irrigated. Pruning varies, depending on the type of bramble; for specific information on the proper pruning for your blackberry canes, see the University of Kentucky s publication, Growing Blackberries and Raspberries in Kentucky. It s available online at pubs/ho/ho15/ho15.pdf or by contacting your local office of the UK Cooperative Extension Service. Blueberries in a cluster do not ripen at the same time, and only fully ripe berries should be picked. Fruit need at least one to two days after turning blue to develop full flavor and can be left on the bush for up to 10 days without a loss in size. Flavor does not improve once the fruit is picked; consequently, blueberries should be left on the bush for as long as possible to develop sweetness and flavor. For best results at harvest, pick carefully, rolling blueberries from the cluster with the thumb into the palm of the hand. Handle as little as possible to avoid rubbing off the bloom (the light waxy finish on the skin) and reduce bruising. Harvest only when berries are dry. Refrigerate promptly to slow ripening and decay. Blackberries picked for commercial sale are picked firm ripe, but home growers have the luxury of picking soft, fully ripe and juicy fruit. Pick fruit twice a week, and during hot, rainy weeks, every other day. Harvest after the morning dew has dried. Pick carefully to avoid bruising the fruit, and, as with blueberries, refrigerate quickly to limit fruit rot. The sweetest, best tasting fruit is produced during dry, sunny weather when nights are cooler. Harvesting in shallower containers are generally better: blueberries can handle being stacked fairly deep in buckets, but other berries, like blackberries and raspberries, are more delicate and shouldn t be, so a large shallow container will give you more room to work with. Additionally, consider bringing not only a bucket, but also planning to wear a belt or bring rope so that you can tie the bucket to you so you can pick berries with both hands.

3 When Thatch is a Problem By: Paul Rideout Lawncare 3 In Kentucky, we often struggle with quality lawns for many reasons. Cool season grasses do not perform well with a hot summer and warm season grasses are not as pleasing during the cooler months when they are dormant. Good overall maintenance practices play a critical part in our success. Aerifying and dethatching could be important to your specific lawn needs. Thatch is a tightly intermingled organic layer of dead and living shoots, stems, and roots that develop right at the soil surface. This layer develops when organic matter is produced more quickly than it can break down. Most of the time, thatch build up is not a problem with low maintenance lawns and more of a problem with higher maintenance lawns. It is important to note that some thatch is important as it helps moderate soil temperature. Typically, we like to see less than ½ inch of thatch. Managing thatch build up is important. Earthworms help out with this process as they help break down the organic matter. The more earthworms present, the less problems you should have with thatch build up. Mechanical thatch removal is an option. Many local rental yards offer a de-thatcher for rental. These machines have vertical blades that cut through the thatch layer bringing up the dead material to the surface. Often, depending on the amount of thatch present, it will be necessary to cover your lawn in two or three directions to sufficiently remove thatch. Remember that cool season grasses such as fescue and KY bluegrass are stressed during the warm months, so dethatching should be performed in the spring or late fall. Aerification is another option for controlling thatch with the added benefit of reducing compaction. This method involves removing cores 2-3 inches deep from the lawn. The cores are deposited on top of the grass and naturally break up over a week or two. Thatch reduction occurs because the extracted soil mixes with the dead organic matter speeding up the decomposition. Core aerifiers are often available from local rental yards, but sometimes more difficult to find than a de-thatcher. Consider contracting this service with local lawn care companies. As with de-thatching, aerifiying in two or three directions is preferred. Most aerifying equipment will allow several different size tines. Use the largest tine available; most often ¾ or 1 will be standard. De-thatching or aerifying your lawn is just one more practice that will increase the health of your lawn. Good fertility, mowing regularly and at the correct height, and keeping a sharp blade on your mower will also help. Following best practices with your lawn before the hot, dry summer will pay big dividends! To determine if your lawn has an excessive amount of thatch, you can look at, feel and even measure the thatch layer. What you re looking for is a thatch layer that s thicker than 1/2 to 3/4 inch, which usually means it s time to dethatch. If the turf feels springy and spongy underfoot this could mean too much thatch. Measure the thatch layer by taking a core sample of your turf by opening a vertical slice of it with a shovel and measuring the thatch layer with a ruler.

4 Tips To Reduce Potential Mosquito Breeding Sites In Ornamental Pools & Landscape Fish Ponds By Lee Townsend If you have an ornamental pool or landscape fish pond, you might be wondering how to reduce mosquito populations in these particular situations. Ornamental pools and landscape fish ponds are potential breeding sites, but they don t have to be. Below are some mosquito management tips for these pools and ponds. Some of these tips also apply to birdbaths. Check for mosquito larvae and pupae at least once a week so you ll know if mosquitoes are thriving and you need to start control measures. Simply kneel down by the edge of the pool, pond or birdbath and carefully watch the water for the distinctive wiggling of larvae and tumbling pupae. They are most likely found in warm, shallow areas. Since larvae and pupae must regularly come to the surface to breathe, just get comfortable and watch for a while. One mosquito management practice is to stock the pond with fish. Healthy, hungry topfeeding fish can help control mosquito larvae and pupae. Smaller goldfish or koi generally will eat larvae and pupae, especially if the fish are hungry. If you notice wiggling larvae, stop feeding fish for a few days to see if the immature mosquitoes disappear. Don t over-feed your fish. Hungry fish make better mosquito predators. Also, by not over-feeding you won t have leftover food to encourage algae growth. Manage aquatic plants to keep them from providing mosquito hiding places. Plants in contact with the water surface might shelter mosquito larvae from fish or other predators. Thin plants or remove some so fish can swim around and through this Continued on Page 5 Tips for limiting mosquito breeding sites around the home Pests 4 1. Dispose of old tires, buckets, aluminum cans, plastic sheeting or other refuse that can hold water. Empty accumulated water from trash cans, boats, wheel barrows, pet dishes, and flower pot bottoms. If possible, turn these items over when they are not in use. 2. Clean debris from rain gutters and unclog obstructed downspouts. Clogged rain gutters are one of the most overlooked breeding sites for mosquitoes around homes. Remove any standing water on flat roofs or around structures. Repair leaking faucets and air conditioners that produce puddles for several days. 3. Change water in bird baths and wading pools at least once a week and keep swimming pools cleaned and chlorinated. Ornamental pools can be aerated or stocked with mosquito-eating fish. Aeration / water movement helps, because mosquitoes prefer quiet, non-flowing water for egg-laying and development.

5 Tips To Reduce Potential Mosquito Breeding Sites In Ornamental Pools & Landscape Fish Ponds Cont. By Lee Townsend Pests 5 vegetation. Avoid thin-leaved plants because they provide excellent shelter for larvae. Mosquito larvae generally do well in stagnant water because they feed on the microorganisms. So periodically remove organic matter such as leaves, fruit and dropped flowers or buds that have fallen into the water. Excessive organic matter can require more oxygen than the pond has available for decomposition. The bacteria that grow in this situation discolor water and give it a foul odor. Another mosquito management practice is to trim surrounding landscape plants away from the water surface so they won t provide a base for algae growth as well as shelter for larvae. Another reason to prune landscape shrubs or trees is that all ponds and pools need some sunlight. Pruning reduces shade cover, thus enabling some light to reach the water. Finally, avoid contamination from fertilizers, pesticides, herbicides or muddy runoff. Fertilizers can cause rapid algae growth in the pond. Many pesticides and herbicides used for yard pests can be very toxic to fish. If the yard will be treated for pest control, cover the pond for protection, or don t have that part of the yard treated. If you re refilling or adding a large amount of water to the pond, consider whether the new water contains chlorine or chloramines. Contact a pet store that sells fish and nursery where you bought aquatic plants for advice on neutralizing these compounds. Generally, you can add small amounts of water, less than 10 percent of the volume, to your pond without a problem. Most larvicides sold to homeowners contain either the active ingredient methoprene or a toxin produced by the soil bacterium Bacillus thuringiensis israelensis (Bti). Methoprene prevents adult emergence by disrupting the development of mosquito larvae. Bti toxin attacks the digestive tract. It is lethal only to mosquito wrigglers and the larvae of some aquatic gnats and black flies. Neither methoprene nor Bti toxin is harmful to fish, waterfowl, pets, or humans when used according to label directions.

6 Prevent Rose Diseases Source: Nicole Ward Spectacular blooms and diverse types and varieties make roses a favorite of many Kentucky gardeners. However, warm, humid growing conditions create an ideal environment for serious problems each year with black spot and powdery mildew. Gardeners can nip these fungal diseases in the bud by planting resistant or tolerant varieties and creating an unfavorable environment for disease development. It may be necessary to use fungicides throughout the summer, especially on susceptible varieties. Your local Cooperative Extension Service has materials on resistant and tolerant varieties. Nursery catalogues also publish this information. To reduce foliar diseases, try to avoid conditions where rose leaves remain wet for an extended period of time. Do not wet foliage when watering plants and allow sufficient time for leaves to dry before nighttime. Prune out shading vegetation from overhanging trees and provide space between rose bushes to improve ventilation and sunlight penetration. Sanitation also is important for managing rose diseases. If you have not already removed and destroyed old leaves, winter-damaged canes and debris, do it as soon as possible. These items are a source of disease-causing organisms. Many fungicides are labeled to control rose diseases. Always check the label to be sure the product controls black spot and powdery mildew and read and follow application instructions. To maintain disease suppression, repeat fungicide applications at 10- to 14-day intervals throughout the growing season. Black spot produces dark, circular spots with fringed borders on the top or bottom side of leaves. Infected leaves often turn yellow and drop, reducing flower numbers and quality. White, powdery fungal growth is a sign of powdery mildew. It is easy to locate on such plant surfaces as leaves, stems and flower buds. Infected leaves may be small and deformed. Flowers 6 Two other important, but less common, foliar diseases of roses are downy mildew and rust. Downy mildew produces lesions that are an off-color, later turning purplish brown. It leads to defoliation. Rustcolored spots on leaves and stems indicate the disease, rust. Severely infected leaves may shrivel and turn brown. Another summertime disease is rose rosette, which affects roses throughout Kentucky. It is not a fungal disease. This disease is spread by a microscopic mite. The primary host is multi-flora rose, a thorny plant native to the Orient and introduced into the United States as a conservation plant and living fence. The disease also affects cultivated roses. Early symptoms are increased growth of shoots, which appear more succulent than normal and develop excessive thorns, and distorted, dwarfed leaves. The affected shoots are not winter hardy and produce few blooms. Rose plants eventually die. Early disease detection is essential to keep rose rosette from spreading. Remove and destroy any infected roses to keep the disease from healthy plants nearby. Carefully remove diseased plants to avoid scattering disease-carrying mites to other plants. Since multi-flora roses might be a disease reservoir, remove and destroy any located within one-eighth of a mile from the rose bed. Encourage More Rose Blooms To ensure good rose blooms for the next cycle, we must now deadhead all spent blooms. It will take an average of 49 days for most roses to hit their next bloom cycle. Some roses will bloom sooner, and others will take longer to rebloom, sometimes up to 60 days for roses with many petals.

7 Upcoming Horticulture Events Upcoming Events 7 MAY May 8 Growing Dahlias May 10 Rain Gardens May 16 Growing Summer Squash Hopkins County Extension Office (Madisonville) May 17 All About Hydrangeas May 17 Growing Hostas Marshall County Extension Office (Benton) May 18 Hypertufa May 19 Annual Plant Sale Marshall County Extension Office (Benton) May 19 Garden Shed Herb Day Boyd County Extension Office (Catlettsburg) May 24 Rain Barrel Workshop Franklin County Extension Office (Frankfort) May 29 Garden Photography for the Smartphone JUNE June 5 Preparing Exhibits for the County Fair McCracken County Extension Office (Paducah) June 15 Photography Basics and How to Submit Entries June 18 Floral Design Workshop Franklin County Extension Office (Frankfort) June 21 Amending Marshall County Soils Marshall County Extension Office (Benton) June 23 Garden Open House June 25 Raising Monarch Butterflies June 27 Growing and Cooking with Herbs

8 Upcoming Horticulture Events Upcoming Events 8 JULY July 9 Gardening for Pollinators July 10 Carnivorous Plants July 19 Growing and Using Culinary Herbs Marshall County Extension Office (Benton) July 19 Herb Appeal McCracken County Extension Office (Paducah) July 25 Flower Arranging SEPTEMBER September 17 Early Apple Tasting September 21 Tree and Shrub Care OCTOBER October 5 Fall Favorites for the Landscape October 15 Late Apple Tasting July 27 Tomato Class AUGUST August 24 Home Lawn Care