Contact: Tom Woods, Brunswick County Master Gardener Volunteer Coordinator

Date May 7, 2012

Contact: Tom Woods, Brunswick County Master Gardener Volunteer Coordinator

ALUMINUM IS THE KEY TO CHANGING HYDRANGEA BLOOM COLOR

Often purchased as a gift plant, bigleaf hydrangea can be transplanted in landscapes and enjoyed year after year.
Bigleaf hydrangea prefers morning sun, afternoon shade and moist, well-drained soil. It will grow in locations with afternoon sun, but will probably wilt and need more supplemental watering.
They don't like full sun
Do not expect the plant to take full sun. The large leaves of hydrangea result in more water loss in the heat of summer. So, hydrangeas perform best when given a break from the sun.
Bigleaf hydrangea can be easily grown in containers and make an excellent patio plant. An advantage of growing the plant in a container is that it can be moved indoors on a cold night.
Also called French, Japanese or snowball hydrangea, the plant is known for its flower colors that can be changed from pink to blue or from blue to pink by adjusting the soil pH. The color variation is due to the presence or absence of aluminum compounds in the flowers. If aluminum is present within the plant, the flower color will be blue. If it is present in small quantities, the color will be in between, or violet, and if it is absent, the flowers will be pink.
Aluminum affects bloom color
Soil pH indirectly affects flower color by affecting the availability of aluminum in the soil. When the soil is acidic, pH 5.5 or lower, aluminum is generally more available to the roots. When the soil is neutral or alkaline, pH 7.0 or higher, aluminum levels are decreased.
To gradually change flower color from pink to blue, broadcast one-half cup of wettable sulfur per 10 square feet and water it into the soil. To make the flowers pink, broadcast 1 cup of dolomitic lime per 10 square feet and water it into the soil. Granular products can be applied anytime throughout the year. However, it takes patience to change hydrangea flower colors, as it can take a year to see a noticeable change.
A quicker way to change flower color is through liquid soil drenches applied in March, April and May. To make the flowers turn blue, dissolve 1 tablespoon of aluminum sulfate in 1 gallon of water. To make the flowers turn pink, dissolve 1 tablespoon of hydrated lime in 1 gallon of water. Drench the soil around the plant with the solution. Avoid getting the solution on the leaves.
It is not hard to change hydrangea flower color; simply decide which method best suits you. With the right care and materials, you can have hydrangeas of your color choice.

Date: For May 14, 2012

Contact: Tom Woods, Brunswick County Master Gardener Volunteer Coordinator

Pine Bark Beetles

Nearly every resident of Brunswick County has a pine tree(s) of some variety on or near their property. The county is an attractive environment for pine bark beetles of several varieties and every year the Brunswick County Extension office receives calls from residents concerned about southern pine beetles killing their trees. On the site visits I have made, I have not yet observed Southern Pine beetles. However, I have observed Black Turpentine beetles. While removal of the tree is recommended for Southern Pine beetle infestations, Black Turpentine beetle infestations are not normally fatal to a tree. Knowledge of the various varieties of beetles we will encounter will aid in taking theappropriate action. This article is intended to provide some basic characteristic and infestation symptom information about the pine bark beetle varieties we are most likely to see.

The three pine bark beetle varieties of major concern are the Southern Pine beetle, the Black Turpentine beetle, and three species of Ips Engraver beetles. The Southern Pine beetle receives the most attention for killing large numbers of trees. However, Black Turpentine beetles and Ips beetles are more frequently encountered.

Identification and Detection

Though there is a size difference, the three Ips beetles are similar in appearance and are easily distinguished from other bark beetles in that the rearward end of the abdomen is scooped out and has spines (4 to 6 spines on each side). The Southern Pine beetle and Black Turpentine beetle have a rounded abdomen. The Black Turpentine beetle is the larger of the two, being about 1/4 inch long. The Southern Pine beetle is about 1/8 inch long. All of the pine bark beetles are roughly cylindrical and dark brown to black..

Location of Attack and Pitch Tubes

One of the quickest methods of detecting and identifying bark beetle attacks is to note the point of attack and the type of pitch tubes created. Pitch tubes are masses of congealed resin that ooze out of the tree around the entrance hole of a bark beetle.

The Black Turpentine beetle usually attacks the lower part of a tree from ground level up to 8 or 10 feet. The pitch tubes are an inch or more in diameter and often appear purplish.

Southern Pine beetle and Ips beetle attacks usually start well up the tree and then spread up and down the main bole. The pitch tubes of both are dime-sized and white to yellow. Though generally a little smaller, these pitch tubes resemble popped popcorn in color and shape. A pair of binoculars can be a great help in detecting Ips and Southern Pine beetle pitch tubes, especially for early attacks high in the tree. Severely stressed trees may not produce pitch tubes, in which case, the only signs of early attack will be the entrance holes and brown boring dust on the bark and around the base of the tree.

Gallery Patterns

Unfortunately, Ips and Southern Pine beetle pitch tubes and location of attacks are almost identical. However, the egg galleries constructed by the adults between the outer bark and sapwood are different. To examine these galleries, peel off a section of the outer bark with a machete, draw knife, or other suitable tool.

The egg galleries of Ips beetles radiate from a central nuptial chamber and follow the grain of the wood. Usually 2 to 5 females construct galleries from each nuptial chamber, and the resulting pattern is roughly "Y" or "H" shaped and are free from boring dust.

Southern Pine beetles create wandering S-shaped egg galleries in the inner bark. The galleries frequently crisscross and are packed with boring dust.

Examination of Black Turpentine beetle egg galleries is seldom needed for identification, since the pitch tubes and location of attack are distinctive. It is important to keep in mind that since Black Turpentine beetles attack the lower part of the tree and construct 12- to 18-inch egg galleries downward, the developing brood may be present below the soil surface, which can hinder chemical control efforts.

Needle Symptoms

Ips and Southern Pine beetles carry a blue stain fungus with them that causes rapid tree mortality. This fungus causes the needles of trees successfully attacked by Ips or Southern Pine beetles to fade, changing from green to light green to yellowish to reddish brown. Unfortunately, the beetle's life cycle can be as short as 30 to 40 days, and, by that time, many beetles may have developed and gone to neighboring trees. To prevent brood development, bark beetle attacks must be detected while the trees are still green. Infested trees should be removed before the brood develops and new adults emerge.

Control

Where infestations are severe, a preventive treatment may be applied to nearby un-infested trees. Protective sprays for living trees are expensive and should only be considered for valuable specimen trees. Two pesticides that can help protect living trees from infestation are; permethrin (trade name Astro) and bifenthrin (trade name Onyx.) These pesticides will provide from 3-12 months protection and should be applied by professionals.

The black turpentine beetle does not carry blue stain fungi and kills trees primarily by girdling (blocking the tree’s vascular system flow in the cambium layer.). Therefore, by detecting black turpentine beetle infestations early, remedial chemical control can often be used to save the tree. Contact your regional Extension agent for specific chemical recommendations.

Prevention

All bark beetles, especially the Black Turpentine and Ips beetles, are attracted to damaged or weakened pines. Trees can be damaged or weakened by construction, mechanical injury, fire, wind, drought or age. Preventing injury and immediately removing severely damaged trees will aid in reducing pine bark beetle infestations.

Date: April 30, 2012 for week of May 21

Contact:Tom Woods, Brunswick County Master Gardener Volunteer Coordinator

Stopping Blossom End Rot

Blossom end rot is common on tomatoes and squash, especially during hot, dry weather.

Avoiding this problem relies on carefully managing water andfertilizer applications, and testing

your soil to make sure soil pH is not too low. All fruits showing these symptoms should be

removedfrom the plant.

Are the bottom ends of your tomatoes or squash turning black or leathery, or failing to develop

properly? This problem, known as blossom end rot, is most common on tomatoes and squash,

though it may also occur on peppers, eggplants, melons, cucumbers and zucchini. Blossom end

rot is not a disease and does not spread from one plant to another. Instead, it is classified as a

physiological disorder and is caused by a lack of calcium in the developing fruit. There are

several factors that can lead to calcium deficiency in vegetable plants, all of which must be

managed to prevent blossom end rot from developing at anytime during the harvest season.

Causes of Blossom End Rot

Plants absorb the nutrients they need to grow from the soil. Some soils are naturally low in

calcium and vegetables grown in these soils will often develop blossom end rot. In southeast NC

low soil calcium is not a common cause of blossom end rot. Instead, blossom end rot is most

often caused by dry weather, several days of hot temperatures, long periods of wet soil

conditions, or low soil pH. In acidic soils, where the pH is below 5.5, some nutrients are locked

up chemically so plants cannot absorb them even if they are present in plentiful amounts.

Calcium is one of the nutrients that become less available to plants under acidic conditions. To

find out if your soil is acidic or low in calcium, submit a sample for free testing to the

Cooperative Extension office. The pH of acidic soils can be raised by adding lime, but this

should only be done if soil test results indicate it is needed. Many soils in our area are high in pH

and adding more lime to these soils will increase nutrient deficiency problems.

Another common cause of blossom end rot is over fertilization with high nitrogen fertilizers

such as soda. Nitrogen promotes rapid, dark green, leafy growth. Plants that are growing very

quickly often cannot move enough calcium into fruits to support proper development, leading to

blossom end rot. In addition, any conditions that cause root damage can lead to poor nutrient

absorption and blossom end rot. The most common causes of root damage in vegetable gardens

are wet soils following heavy rainfall and hoeing too close to a plant's root system.

Preventing Blossom End Rot

To prevent blossom end rot have your soil tested to make sure calcium and other nutrient levels

are adequate and your pH is in the correct range of 6.0 to 6.5. If your pH is low, sprinkling lime

on plants or on top of the soil will not help, since lime must be mixed into the soil to raise pH. To

affect pH, lime should be tilled into the soil 6" to 8" deep at least three months before planting.

The same is true for gypsum, sometimes referred to as land plaster, a substance that supplies

calcium without raising soil pH.

In addition to making sure your soil can supply calcium, it is equally important to maintain even

growth of your vegetable plants through careful fertilization and watering.To prevent blossom

end rot, keep plants evenly moist by watering during dry weather and mulching around

plants. Vegetables require between an inch and an inch and a half of water each week from

rainfall or irrigation to grow well. When rainfall is lacking, water plants once or twice a week.

Soaker hoses are wonderful for watering vegetables and other plants because they apply water

directly to the ground, instead of wetting plant leaves, which can make disease problems worse.

Also, avoid using high nitrogen fertilizers, such as those in which the first number on the bag

is higher than the rest of the numbers. Instead base fertilizer applications on your soil test results

and use slow release fertilizers such as pelleted, time release products or organic fertilizers.

Date: For May 28, 2012

Contact: Tom Woods, Brunswick County Master Gardener Volunteer Coordinator

Harvesting Potatoes

Potato harvesting season is here - when the tops start to die down, you will know it is time to harvest. One issue you may see on newly harvested potatoes are brown scab like wounds. This is a disease called scab. The potatoes are still fine to eat - causes of the problem and how to prevent it in the future are discussed here:

Common Scab: This disease is caused by the bacteriumStreptomyces scabies, which persists in the soil for long periods. Brown corky scabs or pits occur on potato tubers. These spots enlarge and merge together, sometimes covering most of the tuber. Leaves and stems are not affected. Scab is most severe in dry soil with a pH above 5.5, and in soil low in nutrients. Tubers infected with scab are edible, however, when blemishes are removed, much of the tuber may be wasted.

Prevention & Treatment:Soil pH should be between 5.0 and 5.3. Therefore, avoid alkaline materials such as lime and wood ashes. Scab is favored under low soil moisture conditions, so the garden soil must be kept moist during the active growing period of the tubers (particularly 4 to 9 weeks after planting). Although potatoes are heavy feeders, high nitrogen levels can increase scab severity. Additionally, high ratios of calcium to potassium can increase disease. Do not use manure on potatoes, because the bacterial spores can pass intact through the digestive tracts of animals. Plant potatoes in the same area only once every three to four years. Do not plant Irish potatoes after beets, carrots, radishes, parsnips, rutabagas and turnips, which are also susceptible to scab. Use certified seed pieces that are resistant to scab. The following potato varieties are scab tolerant: Superior, Goldrush, Red LaSoda, Red Gold, Caribe, Dark Red Norland, Butte, Carola, Russett Burbank, and Sebago. There is no reliable chemical control.

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