Cornus kousa ( Kousa Dogwood )

Characteristics

Cultivar:	n/a
Family:	Cornaceae
Size:	Height: 0 ft. to 30 ft. Width: 0 ft. to 20 ft.
Plant Category:	shrubs, trees,
Plant Characteristics:	decorative berries or fruit,
Foliage Characteristics:	deciduous,
Foliage Color:	green, red to burgundy,
Flower Characteristics:	long lasting, showy,
Flower Color:	creams, whites,
Tolerances:	slope,

Requirements

Bloomtime Range:	Late Spring to Early Summer
USDA Hardiness Zone:	5 to 8
AHS Heat Zone:	1 to 1
Light Range:	Shade to Full Sun
pH Range:	4.5 to 7
Soil Range:	Some Sand to Some Clay
Water Range:	Normal to Moist

Plant Care

Fertilizing

How-to : Fertilization for Established Plants

Established plants can benefit from fertilization. Take a visual inventory of your landscape. Trees need to be fertilized every few years. Shrubs and other plants in the landscape can be fertilized yearly. A soil test can determine existing nutrient levels in the soil. If one or more nutrients is low, a specific instead of an all-purpose fertilizer may be required. Fertilizers that are high in N, nitrogen, will promote green leafy growth. Excess nitrogen in the soil can cause excessive vegetative growth on plants at the expense of flower bud development. It is best to avoid fertilizing late in the growing season. Applications made at that time can force lush, vegetative growth that will not have a chance to harden off before the onset of cold weather.

Light

Conditions : Full to Partial Sun

Full sunlight is needed for many plants to assume their full potential. Many of these plants will do fine with a little less sunlight, although they may not flower as heavily or their foliage as vibrant. Areas on the southern and western sides of buildings usually are the sunniest. The only exception is when houses or buildings are so close together, shadows are cast from neighboring properties. Full sun usually means 6 or more hours of direct unobstructed sunlight on a sunny day. Partial sun receives less than 6 hours of sun, but more than 3 hours. Plants able to take full sun in some climates may only be able to tolerate part sun in other climates. Know the culture of the plant before you buy and plant it!

Watering

Problems : Creating a Water Ring

A water ring, sometimes called a water well, is a mound of compacted soil that is built around the circumference of a planting hole once a plant has been installed. The water ring helps to direct water to the outer edges of a planting hole, encouraging new roots to grow outward, in search of moisture. The height of the mound of soil will vary from a couple of inches for 3 gallon shrubs, to almost a foot for balled and burlapped trees, especially those planted on a slope. Mulch over the ring will help to further conserve moisture and prevent deterioration of the ring itself. Once a plant is established, the water ring may be leveled, but you should continue to mulch beneath the plant.

Conditions : Moist and Well Drained

Moist and well drained means exactly what it sounds like. Soil is moist without being soggy because the texture of the soil allows excess moisture to drain away. Most plants like about 1 inch of water per week. Amending your soil with compost will help improve texture and water holding or draining capacity. A 3 inch layer of mulch will help to maintain soil moisture and studies have shown that mulched plants grow faster than non-mulched plants.

Planting

How-to : Planting Shrubs

Dig a hole twice the size of the root ball and deep enough to plant at the same level the shrub was in the container. If soil is poor, dig hole even wider and fill with a mixture half original soil and half compost or soil amendment.

Carefully remove shrub from container and gently separate roots. Position in center of hole, best side facing forward. Fill in with original soil or an amended mixture if needed as described above. For larger shrubs, build a water well. Finish by mulching and watering well.

If the plant is balled-and-burlapped, remove fasteners and fold back the top of natural burlap, tucking it down into hole, after you've positioned shrub. Make sure that all burlap is buried so that it won't wick water away from rootball during hot, dry periods. If synthetic burlap, remove if possible. If not possible, cut away or make slits to allow for roots to develop into the new soil. For larger shrubs, build a water well. Finish by mulching and watering well.

If shrub is bare-root, look for a discoloration somewhere near the base; this mark is likely where the soil line was. If soil is too sandy or too clayey, add organic matter. This will help with both drainage and water holding capacity. Fill soil, firming just enough to support shrub. Finish by mulching and watering well.

How-to : Planting a Tree

Dig out an area for the tree that is about 3 or 4 times the diameter of the container or rootball and the same depth as the container or rootball. Use a pitchfork or shovel to scarify the sides of the hole.

If container-grown, lay the tree on its side and remove the container. Loosen the roots around the edges without breaking up the root ball too much. Position tree in center of hole so that the best side faces forward. You are ready to begin filling in with soil.

If planting a balled and burlaped tree, position it in hole so that the best side faces forward. Untie or remove nails from burlap at top of ball and pull burlap back, so it does not stick out of hole when soil is replaced. Synthetic burlap should be removed as it will not decompose like natural burlap. Larger trees often come in wire baskets. Plant as you would a b&b plant, but cut as much of the wire away as possible without actually removing the basket. Chances are, you would do more damage to the rootball by removing the basket. Simply cut away wires to leave several large openings for roots.

Fill both holes with soil the same way. Never amend with less than half original soil. Recent studies show that if your soil is loose enough, you are better off adding little or no soil amendments.

Create a water ring around the outer edge of the hole. Not only will this conseve water, but will direct moisture to perimeter roots, encouraging outer growth. Once tree is established, water ring may be leveled. Studies show that mulched trees grow faster than those unmulched, so add a 3"" layer of pinestraw, compost, or pulverized bark over backfilled area. Remove any damaged limbs.

Problems

Pest : Thrips

Thrips are small, winged insects that attack many types of plants and thrive in hot, dry conditions (like heated houses). They can multiply quickly as a female can lay up to 300 eggs in a life span of 45 days without mating. Most of the damage to plants is caused by the young larvae which feed on tender leaf and flower tissue. This leads to distorted growth, injured flower petals and premature flower drop. Thrips also can transmit many harmful plant viruses.

Prevention and Control: keep weeds down and use screening on windows to keep them out. Remove or discard infested plants, keep them away from non-infested plants. Trap with yellow sticky cards or take advantage of natural enemies such as predatory mites. Sometimes a good steady shower of water will wash them off the plant. Consult your local garden center professional or county Cooperative extension office for legal chemical recommendations.

Pest : Aphids

Aphids are small, soft-bodied, slow-moving insects that suck fluids from plants. Aphids come in many colors, ranging from green to brown to black, and they may have wings. They attack a wide range of plant species causing stunting, deformed leaves and buds. They can transmit harmful plant viruses with their piercing/sucking mouthparts. Aphids, generally, are merely a nuisance, since it takes many of them to cause serious plant damage. However aphids do produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface growth called sooty mold.

Aphids can increase quickly in numbers and each female can produce up to 250 live nymphs in the course of a month without mating. Aphids often appear when the environment changes - spring & fall. They're often massed at the tips of branches feeding on succulent tissue. Aphids are attracted to the color yellow and will often hitchhike on yellow clothing.

Prevention and Control: Keep weeds to an absolute minimum, especially around desirable plants. On edibles, wash off infected area of plant. Lady bugs and lacewings will feed on aphids in the garden. There are various products - organic and inorganic - that can be used to control aphids. Seek the recommendation of a professional and follow all label procedures to a tee.

Fungi : Powdery Mildew

Powdery Mildew is usually found on plants that do not have enough air circulation or adequate light. Problems are worse where nights are cool and days are warm and humid. The powdery white or gray fungus is usually found on the upper surface of leaves or fruit. Leaves will often turn yellow or brown, curl up, and drop off. New foliage emerges crinkled and distorted. Fruit will be dwarfed and often drops early.

Prevention and Control: Plant resistant varieties and space plants properly so they receive adequate light and air circulation. Always water from below, keeping water off the foliage. This is paramount for roses. Go easy on the nitrogen fertilizer. Apply fungicides according to label directions before problem becomes severe and follow directions exactly, not missing any required treatments. Sanitation is a must - clean up and remove all leaves, flowers, or debris in the fall and destroy.

Fungi : Leaf Spots

Leaf spots are caused by fungi or bacteria. Brown or black spots and patches may be either ragged or circular, with a water soaked or yellow-edged appearance. Insects, rain, dirty garden tools, or even people can help its spread.

Prevention and Control: Remove infected leaves when the plant is dry. Leaves that collect around the base of the plant should be raked up and disposed of. Avoid overhead irrigation if possible; water should be directed at soil level. For fungal leaf spots, use a recommended fungicide according to label directions.

Diseases : Anthracnose

Anthracnose is the result of a plant infection, caused by a fungus, and may cause severe defoliation, especially in trees, but rarely results in death. Sunken patches on stems, fruit, leaves, or twigs, appear grayish brown, may appear watery, and have pinkish-tan spore masses that appear slime-like. On vegetables, spots may enlarge as fruit matures.

Prevention and Control: Try not to over water. If your climate is naturally rainy, grow resistant varieties. In the vegetable garden, stake and trellis plants to provide good air circulation so that plants may dry. Increase sunlight to plants by trimming limbs. Prune, remove, or destroy infected plants and remove all leaf debris. Select a fungicide that is labeled for anthracnose and the plant you are treating. Follow the label strictly.

Pest : Scale Insects

Scales are insects, related to mealy bugs, that can be a problem on a wide variety of plants - indoor and outdoor. Young scales crawl until they find a good feeding site. The adult females then lose their legs and remain on a spot protected by its hard shell layer. They appear as bumps, often on the lower sides of leaves. They have piercing mouth parts that suck the sap out of plant tissue. Scales can weaken a plant leading to yellow foliage and leaf drop. They also produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface fungal growth called sooty mold.

Prevention and Control: Once established they are hard to control. Isolate infested plants away from those that are not infested. Consult your local garden center professional or Cooperative Extension office in your county for a legal recommendation regarding their control. Encourage natural enemies such as parasitic wasps in the garden.

Diseases : Blight

Blights are cause by fungi or bacteria that kill plant tissue. Symptoms often show up as the rapid spotting or wilting of foliage. There are many different blights, specific to various plants, each requiring a varied method of control.

Miscellaneous

Conditions : Slope Tolerant

Slope tolerant plants are those that have a fibrous root system and are often plants that prefer good soil drainage. These plants assist in erosion control by stabilizing/holding the soil on slopes intact.

Glossary : Large Shrub

A shrub is considered large when it is over 6 feet tall.

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