Some familiar evergreens such as Colorado Blue Spruce may be susceptible to environmental stress. The recent pattern of summer drought, milder than usual winters and cool spring temperatures combined with wet conditions in the northeast have favored development of a fungal disease known as “needle cast”. Early detection and proper diagnosis is important in the treatment of this fungal disease and to ensure the health of your plant.
The best proactive means for preventing needle cast disease is to plant your Blue Spruce in the proper location and provide proper care. Blue Spruce prefer to be located in a well-drained soil in an area of full sun, meaning the plant should be receiving at least six hours of sunlight daily. A southern or western exposure suits this best. Prevent irrigation from directly spraying on the foliage of the plant. Constant moisture on foliage or over-watering can be a direct invitation for needle cast. Drip irrigation is recommended where possible, allowing the soil to dry between watering. Proper planting height is of course also necessary. Plant the tree at grade or slightly above the grade so that the root flare is visible. Do not plant too deeply. It is best that the lower branches have some air circulation above the ground.
The type of needle cast affecting Colorado Blue Spruce in the northeast is mainly Rhizosphaera needle cast (caused by the fungus Rhizosphaera kalkhoffii). While some browning and dropping of older needles in spruce is common, needle cast disease is noted by a distinct brownish-purple discoloration which appears on needles (usually towards the bottom of the tree) mostly in late summer, followed by the eventual death and dropping of older needles. In addition, the presence of black fruiting bodies on new growth in early spring is a sure sign. Typically, infections start near the bottom of the tree where foliage dries more slowly and progresses upwards. Lower branches may lose so many needles that growth at the tips stops, resulting in the death of the entire branch (photo below). Newer current growth may show no signs of the disease until during autumn and into spring.
Should your tree show signs of early needle cast, it is treatable. Needle cast can be effectively controlled with fungicides containing chlorothalonil. For moderate to severe Rhizosphaera needle cast, two properly-timed applications per year for at least two consecutive years (sometimes three) are required for control. After initial treatment, additional applications should occur when new needles are half elongated (around Memorial Day depending upon location) followed by a second application three to four weeks after the first. The timing of the two applications should be the same for the second and third year. Since needle cast is fungal and spread through spores, removal of branches showing early signs can prevent further infection, but the tree should still be treated with a fungicide and monitored on a regular basis.
The best method of preventing needle cast starts with proper planning, planting and monitoring. Early detection of any kind of disease leads to better results and remedies any further issues down the road. These tips also apply to dwarf forms of Blue Spruce, such as Picea pungens ‘Globosa’ (Globe Blue Spruce). Norway and Serbian Spruce are less likely to be damaged by needle cast and ‘Hoopsii’ and ‘Fat Albert’ cultivars of Colorado Blue Spruce are more resistant to the disease.
The Spotted Lanternfly (Lycorma delicatula) is a new invasive insect that is native to China, Bangladesh and Vietnam, and introduced to Japan and Korea where it has become a major pest of grapes. Spotted Lanternfly primarily feeds on tree of heaven (Ailanthus altissima) but can also feed on a wide variety of plants such as grapevine, hops, maple, walnut and fruit trees, which has posed a great threat to these industries. This invasive pest was first discovered in Pennsylvania in 2014 and has since been found in New Jersey, Delaware and Virginia. In New York. A dead insect was found in Delaware County in the fall of 2017. In 2018, insects were reported in Albany, Monroe, Yates and Suffolk counties. Following these reports, the DEC and Department of Agriculture and Markets immediately began extensive surveys throughout the area. At this time, no additional insects have been found.
The Spotted Lanternfly adult is approximately 1 inch long and 1/2 inch wide at rest. Immature stages are black with white spots and develop red patches as they grow to maturity. Nymphs are black with white spots that turn red before transitioning into adults. Spotted Lanternfly can be seen as early as April and adults begin to appear in July. Their forewings are grayish with black spots. The lower portions of their hindwings are red with black spots and the upper portions are dark with a white stripe. In the fall, adults lay 1-inch-long egg masses, which when first laid are are smooth and brownish-gray with a shiny, waxy coating. Older egg masses appear as rows of 30 to 50 brownish seed-like deposits in 4 to 7 columns on the trunk, roughly an inch long. Spotted Lanternfly is capable of jumping and flying short distances and is spread primarily through human activity. They can spread to new areas when they lay their eggs on vehicles, firewood, outdoor furniture and stone.
Attacked trees will develop weeping wounds which appear wet, while leaving a greyish or black trail along the trunk. The sap may give off a fermented odor and will attract other insects to feed, notably wasps and ants. To destroy egg masses, scrape them off, place them into alcohol or hand sanitizer and double bag. It is important to collect specimens of any life stage and report sightings of egg masses, nymphs, or adult spotted lanternfly to your local DEC or Cooperative Extension for further verification.
Plans are in place for the detection and prevention of Spotted Lanternfly in the New York area. Extensive trapping surveys will be conducted in high-risk areas throughout the state as well as inspections of nursery stock, stone shipments and commercial transports from infected areas. The DEC and partner organizations encourage everyone to be on the lookout for this pest.
Sources: Pennsylvania State University Cooperative Extension and NY State Department of Environmental Conservation
Alocasia, also known as The Elephant Ear, is a large tropical looking plant displaying large, deep green arrow-shaped leaves, resembling the ears of an elephant. Planted as a tuber, the magnificent foliage of the plant can reach up to 9 feet (3 meters) in height with leaf spans up to three feet long! Alocasia are warm climate plants, cold hardy in USDA hardiness zones 7 through 11, depending on the species. They are commonly grown as annuals in colder climates and make wonderful focal points in the garden, serving nicely as accent pieces, especially when grown in containers.
Growing Elephant Ear plants is simple with very little maintenance necessary. Most of these plants prefer rich, moist soil and can be grown in full sun, but they generally prefer partial shade. The tubers can be placed directly outdoors once there is no threat of frost or freezing temperatures, which occurs around mid-April here in my zone 7a garden. Plant the tubers about 2 to 3 inches deep, blunt end down in a rich, organic potting soil. I use a large container (at least 16-20 inches in diameter) and plant just one plant. It will take several weeks for the first foliage to appear, but once the roots are established, the plant will rapidly grow throughout the summer months.
Your Elephant Ear plant will continue to grow to its maximum size, which will occur around July or August. It is recommended to keep your plants well-watered and to feed them once a month with an organic slow release fertilizer (such as bone meal) to maintain their vigor. As the plant matures and older foliage fades, simply remove any undesirable stalks at the base and new shoots will form. Planting around the perimeter of your large planter will add additional interest. In this planter I used a combination of Sweet Potato Vine and Morning Glory surrounding the large leaves of the Alocasia.
Elephant ears cannot survive winter outdoors. When autumn arrives, along with freezing temperatures, the plants must be dug up and stored indoors. After the first frost, cut the foliage back to about a couple of inches and carefully dig up the plants. Allow the tubers to dry out for about a day or two and then store them in peat moss or shavings in a cool, dark area such as in a garage or basement to overwinter. Repeat planting the following year!
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Have the temperatures been rising and are you yearning to go out into the garden? Spring is here and it is a time to start planning and prepping the garden for a successful start to the planting season. There are some recommended maintenance tips for getting your garden underway. Here is a list of common gardening tasks to be performed in late winter/early spring. (I recently posted this article on my other blog A Guide to Northeastern Gardening, but felt it was also fitting for here.)
True or False? Any dead material remaining from last year should be removed from your garden now. True. It is best practice to remove dead material from the garden in fall to prevent possible pests and disease in your garden. If you have left annuals or perhaps perennials for winter interest, now is the time to tend to them, along with any weeds that might have survived the winter. Pull out any dead remaining annuals and prune perennials back to the ground to encourage new growth. If cold temperatures are still to be expected, push mulch up around the crown of the plants to protect them from temperature fluctuations.
True or False? New mulching should be applied now before the ground thaws.False. Mulch acts as an insulator and applying mulch before thawing would actually inhibit warming as temperatures rise. Allow the soil to warm, then apply two to four inches of natural pine mulch. When applying, keep mulch several inches away from tree and shrub trunks to prevent oxygen loss and rotting. Mulch benefits plants by reducing water evaporation, preventing weeds, adding organic matter to the soil and also acts as a buffer, preventing drastic changes in soil temperatures.
True or False? Nitrogen based lawn fertilizer can only be applied after April 1st. True. According to the EPA, the prohibition on application of fertilizer between December 1st and April 1st applies to products that contain nitrogen (N), phosphorus (P), or potassium (K). If a product does not contain any of these nutrients, it could be applied during the winter months without violating this law. Explanation: If the ground is frozen, there is a greater danger of runoff and possible contamination of groundwater. Fertilizers applied when the ground is thawed and porous are absorbed and utilized by plant material and go through a natural filtration process before reaching the aquifer system. Please note that there are a variety of organic, natural fertilizers on the market that are more environmentally friendly. Success rate depends on brand and application.
True or False? Spring flowering trees and shrubs should be pruned in late winter/early spring. False. General rule of thumb is to prune flowering plants AFTER they flower. Early spring flowering trees and shrubs including rhododendron, azalea, forthysia, magnolia, plum, Eastern Redbud and cherry form their buds from the season before and should be not be pruned until after flowering. Pruning them now will remove flower buds that have already formed, resulting in a loss of blooms.
True or False? Summer blooming shrubs such as Spirea and Buddleia should be pruned in spring. True. Mid and late summer flowering shrubs such as Spirea and Buddleia (butterfly bush) prefer a spring pruning to promote fullness and blooms. Prune Spirea slightly for shaping. If the plant is overgrown to the point it is unsightly, it can be pruned more drastically to rejuvenate it now in spring. Buddleia benefits from an early spring pruning and should be pruned all the way back in late winter/early spring to promote fuller plants and better blooms in late summer. This practice is best performed once you see signs of life on your plants.
True or False? The best time to prune evergreens is in early spring. True. Evergreens can be pruned anytime when there is no threat of extreme temperature changes that would cause undue stress; however, the best time is either in early spring before they push out new growth, or afterwards once new candles form. When pruning evergreens that form candles, such as white pine, it is best to cut candles in half to keep the plant more compact.
True or False? Liriope and grasses should be cut back and divided now in spring. True. Liriope and ornamental grasses can be cold sensitive. Exposing the crown of the plant could be the reason for snow and cold damage. It is best to leave liriope and grasses alone in fall and to prune them back in early spring to allow for new growth. Spring is also the time to divide and move other perennials that have become overgrown. It is recommended that most perennials be divided every four years for best bloom. Dig up and divide with a sharp clean spade just as new growth appears, replant and add a sprinkle of slow release plant food in with the soil to help root promotion. Water in thoroughly.
True or False? Knock Out Roses should be pruned back in early spring. True. Wait until your roses are sprouting new shoots and showing some signs of life. Then, prune off dead wood or overgrown branches back about one third the size of the plant to promote strong growth and blooms. Be careful to watch while pruning so that you achieve a nice rounded shape for your plant. Early spring is also a good time to apply an organic slow release rose fertilizer mixed in with the soil at the base of the plant to ensure a successful start to the growing season. I would also recommend a regular watering schedule from the base of the plant, since roses do not fair well with constant water on their foliage.
True or False? Summer blooming bulbs should be planted in late spring. True. While spring blooming bulbs such as crocus, hyacinths, tulips and daffodils are planted in fall, late summer blooming bulbs such as Dahlia, Canna and Gladiolus are planted in spring. Amend the soil with compost or manure to insure them a good start and plant in a well-drained area to prevent rotting. Generally, bulbs are planted at a depth of three times their diameter, and specific instructions are usually supplied on the packaging. Once planted, water your bulbs thoroughly and be sure they get watered regularly. Applying bone meal will give your bulbs energy during the growing season, but do not mix in too closely to the roots.
Will the unpredictable weather we have been having across most of the U.S. and other areas harm my garden? I have been getting asked this question quite a bit over the past couple of years. Generally, plants are pretty resilient. Buds that are forming on the trees early are sparked by the warmer temperatures in daytime but slowed down by the colder nighttime temperatures, which tends to balance out their progress. If there is severe cold for a prolonged period of time, buds could freeze and get damaged, but the tree produces enough buds to still have a bloom. More sensitive plants like old fashioned hydrangea ‘Nikko Blue’ that bloom on old wood are more susceptible to cold and time will tell. If there is die back on your plant, prune out the dead wood and apply a dose of a high phosphorus fertilizer. It could help to boost larger blooms from any undamaged buds. Hydrangea varieties that bloom on new wood, such as ‘Endless Summer’ and ‘Pee Gee’ should winter alright.
Some of my evergreens are a bronze color. Should I be concerned?Winter bronzing is normal on evergreens near the end of winter while temperatures are cold. Once the temperatures rise and new growth is stimulated, the foliage will turn back to a more vibrant green. Broken or dead branches are different in that they are completely dried out and brown. Those branches should be pruned off the tree in late winter/early springtime to prevent any further damage. Any falling or divided tree leads can be arbor tied to secure them and encourage upright growth. Split branches can also be arbor tied together, and if caught in time the cambium growing layer of the tree can mend. In the photograph above, the center upright Western Arborvitae are displaying bronzing and there are no signs of broken branches. As you can see the trees are healthy.
Have you heard about my new book,Landscape Design Combinations? My first bookA Guide to Northeastern Gardening covers recommended plants for zones 3-9 with topics including butterfly gardening, deer resistant plants, shade gardening, perennials, trees and shrubs, evergreens, general maintenance tips and more.
Landscape Design Combinations is a continuation of the previous publication, with greater emphasis on design, including numerous numbered and labeled photographs of successful landscape plans. Topics include elements of landscape design, designing for the seasons, how to build a natural stone patio or walkway, simple container combinations and garden styles throughout the centuries.
Both A Guide to Northeastern Gardening and Landscape Design Combinations were written to provide you with the tools needed to help you to create a successful garden. Click on the links below for more information and previews. I hope to inspire you!
Spring has arrived and there is much to do in the garden. As the temperatures rise up into the 50’s and 60’s here on Long Island here are some April maintenance tips to get your garden off to a good start.
(1) Clean up garden beds and remove debris from over the winter. Allow foliage from daffodils, crocus and hyacinths to yellow and brown before removing so that energy can go back into the bulbs for next year.
(2) Pinch back cool weather blooms such as pansies to get maximum bloom span.
(3) Remove germinating weeds before they start to flower and re-seed.
(4) Divide and transplant perennials such as hosta, liriope and lilies once you see 3-4 inches of new growth. Dig a larger hole to transplant into, apply a slow release plant food and water in thoroughly.
(5) Re-Edge and mulch all beds. Prune spring-flowering trees and shrubs soon after bloom.
(6) It’s time to uncover fig trees or to bring them outside once the threat of freezing temperatures is over.
(7) Start cold weather vegetables such as peas, lettuce, carrots, beets, spinach and turnips.
(8) Apply pre-emergent crabgrass killer to lawn in mid to late April (after forthysia bloom) and fertilize.
(9) Fertilize roses. There are many rose foods on the market. A slow-release granular form is recommended.
(10) Begin planting new perennials towards the end of the month.
A little pro-active garden maintenance goes a long way in maintaining the vigor of your plants and beauty of your garden. Now that the chill is out of the air it is time to get out into the garden and enjoy all that it has to offer.
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