Fraxinus latifolia or Oregon Ash is a large, deciduous tree. It forms a rounded, broad spreading crown with glossy, pinnate, dark green leaves turning yellow in the fall. Leaves are up to 6 to 12 inches long, with up to 7 to 9 oval, tapered leaflets. An excellent specimen tree for woodland or coastal gardens. Grow in fertile, moist, but well-drained soil. Native of W. North America.Important Info : Large tree unsuited to small gardens. Can be affected by pests and diseases.
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Size: Height: 0 ft. to 80 ft.
Width: 0 ft. to 50 ft.
Plant Category: trees,
Plant Characteristics: low maintenance, spreading,
Foliage Characteristics: deciduous,
Tolerances: rabbits, slope, wind,
Bloomtime Range: not applicable
USDA Hardiness Zone: 6 to 8
AHS Heat Zone: Not defined for this plant
Light Range: Sun to Full Sun
pH Range: 5.5 to 9
Soil Range: Sandy Loam to Clay Loam
Water Range: Normal to Moist
FertilizingHow-to : Fertilization for Young Plants
Young plants need extra phosphorus to encourage good root development. Look for a fertilizer that has phosphorus, P, in it(the second number on the bag.) Apply recommended amount for plant per label directions in the soil at time of planting or at least during the first growing season.
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.
LightConditions : Low Light for Houseplants
Place low light houseplants within 5 to 8 feet of a sunlit window or within 2 feet of a northern exposure window.
Conditions : Types of Pruning
Types of pruning include: pinching, thinning, shearing and rejuvenating.
Pinching is removing the stem tips of a young plant to promote branching. Doing this avoids the need for more severe pruning later on.
Thinning involves removing whole branches back to the trunk. This may be done to open up the interior of a plant to let more light in and to increase air circulation that can cut down on plant disease. The best way to begin thinning is to begin by removing dead or diseased wood.
Shearing is leveling the surface of a shrub using hand or electric shears. This is done to maintain the desired shape of a hedge or topiary.
Rejuvenating is removal of old branches or the overall reduction of the size of a shrub to restore its original form and size. It is recommended that you do not remove more than one third of a plant at a time. Remember to remove branches from the inside of the plant as well as the outside. When rejuvenating plants with canes, such as nandina, cut back canes at various heights so that plant will have a more natural look.
Conditions : Light and Plant Selection
For best plant performance, it is desirable to match the correct plant with the available light conditions. Right plant, right place! Plants which do not receive sufficient light may become pale in color, have fewer leaves and a "leggy" stretched-out appearance. Also expect plants to grow slower and have fewer blooms when light is less than desirable. It is possible to provide supplemental lighting for indoor plants with lamps. Plants can also receive too much light. If a shade loving plant is exposed to direct sun, it may wilt and/or cause leaves to be sunburned or otherwise damaged.
Conditions : Full Sun
Full Sun is defined as exposure to more than 6 hours of continuous, direct sun per day.
WateringProblems : 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.
Problems : Waterlogged Soil and Solutions
Waterlogged soil occurs when more water is added to soil than can drain out in a reasonable amount of time. This can be a severe problem where water tables are high or soils are compacted. Lack of air space in waterlogged soil makes it almost impossible for soil to drain. Few plants, except for bog plants, can tolerate these conditions. Drainage must be improved if you are not satisfied with bog gardening. Over-watered plants have the same wilted leaves as under-watered plants. Fungi such as Phytophthora and Pythium affect vascular systems, which cause wilt.
If the problem is only on the surface, it maybe diverted to a drainage ditch. If drainage is poor where water table is high, install an underground drainage system. You should contact a contractor for this. If underground drains already exist, check to see if they are blocked.
French drains are another option. French drains are ditches that have been filled with gravel. It is okay to plant sod on top of them. More obtrusive, but a good solution where looks aren't as important, think of the French drain as a ditch filled with gravel. Ditches should be 3 to 4 feet deep and have sloping sides.
A soakway is a gravel filled pit where water is diverted to via underground pipes. This works well on sites that have compacted soil. Your soakway should be about 6'wide and deep and filled with gravel or crushed stone, topped with sand and sodded or seeded.
Keep in mind that it is illegal to divert water onto other people's property. If you do not feel that you can implement a workable solution on your own, call a contractor.
Tools : Watering Aides
No gardener depends 100% on natural rainfall. Even the most water conscious garden appreciates the proper hose, watering can or wand.
- Watering Cans: Whether you choose plastic of galvanized makes no difference, but do look for generous capacity and a design that is balanced when filled with water. A 2 gallon can (which holds 18 lbs. of water) is preferred by most gardeners and is best suited for outdoor use. Indoor cans should be relatively smaller with narrower spouts and roses (the filter head).
- Watering Hose: When purchasing a hose, look for one that is double-walled, as it will resist kinking. Quick coupler links are nice to have on ends of hoses to make altering length fast. To extend the life of your hose, keep it wound around a reel and stored in a shady area. Prior to winter freezes, drain hose.
- Sprayers: Are commonly thought of as devices for applying chemicals, but can really be a step saver for watering houseplants or small pots of annuals rather that dragging out a hose or making numerous trips with a watering can. The backpack sprayer is best suited for this. Take care not to use any kind of chemical in tanks used for watering!
- Sprinklers: Attached to the ends of garden hoses, these act as an economical irrigation system. Standing Spike Sprinklers are usually intended for lawns and deliver water in a circular pattern. Rotating Sprinklers deliver a circle of water and are perfect for lawns, shrubs and flower beds. Pulse-jet sprinklers cover large areas of ground in a pulsating, circular pattern. The head usually sits up on a tall stem, except for when watering lawns. Oscillating sprinklers are best for watering at ground level in a rectangular pattern.
Conditions : Regular Moisture for Outdoor Plants
Water when normal rainfall does not provide the preferred 1 inch of moisture most plants prefer. Average water is needed during the growing season, but take care not to overwater. The first two years after a plant is installed, regular watering is important. The first year is critical. It is better to water once a week and water deeply, than to water frequently for a few minutes.
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.
Conditions : Outdoor Watering
Plants are almost completely made up of water so it is important to supply them with adequate water to maintain good plant health. Not enough water and roots will wither and the plant will wilt and die. Too much water applied too frequently deprives roots of oxygen leading to plant diseases such as root and stem rots. The type of plant, plant age, light level, soil type and container size all will impact when a plant needs to be watered. Follow these tips to ensure successful watering:
* The key to watering is water deeply and less frequently. When watering, water well, i.e. provide enough water to thoroughly saturate the root ball. With in-ground plants, this means thoroughly soaking the soil until water has penetrated to a depth of 6 to 7 inches (1' being better). With container grown plants, apply enough water to allow water to flow through the drainage holes.
* Try to water plants early in the day or later in the afternoon to conserve water and cut down on plant stress. Do water early enough so that water has had a chance to dry from plant leaves prior to night fall. This is paramount if you have had fungus problems.
* Don't wait to water until plants wilt. Although some plants will recover from this, all plants will die if they wilt too much (when they reach the permanent wilting point).
* Consider water conservation methods such as drip irrigation, mulching, and xeriscaping. Drip systems which slowly drip moisture directly on the root system can be purchased at your local home and garden center. Mulches can significantly cool the root zone and conserve moisture.
* Consider adding water-saving gels to the root zone which will hold a reserve of water for the plant. These can make a world of difference especially under stressful conditions. Be certain to follow label directions for their use.
Conditions : Normal Watering for Outdoor Plants
Normal watering means that soil should be kept evenly moist and watered regularly, as conditions require. Most plants like 1 inch of water a week during the growing season, but take care not to over water. The first two years after a plant is installed, regular watering is important for establishment. The first year is critical. It is better to water once a week and water deeply, than to water frequently for a few minutes.
How-to : Reduce Watering
This plant requires less watering during winter months, so reduce watering from late November through early March.
PlantingHow-to : Pruning Trees After Planting
It is critical to prune trees correctly from the beginning to assure proper growth and development. Young trees can be transplanted in a number of forms: bare root, balled & burlap and in containers. The more stress the plant undergoes in the transplant process, the more pruning that is required to compensate.
Deciduous trees like maples (those that loose their leaves in the fall) can be dug up and sold with their bare roots exposed. Because most of the root system is lost in digging, sufficient top growth should be removed to compensate for this loss. This may be done at the nursery before you buy the plant or you may have to prune at the time of planting. Select and head back the best scaffold branches, i.e. those branches which will form the main lateral structure of the future mature tree. Remove all other extraneous side branches. If the tree seedling does not have branches, allow it to grow to the desired height of branching then pinch it back to stimulate the lower buds to form branches.
Ball and burlap trees are dug up with their root systems somewhat intact. This was mostly done for conifers and broadleaf evergreens, but has become common for deciduous trees as well. Since some root mass is lost in the digging stage, a light pruning is generally called for. Head back the plant to compensate for this loss and to promote branching.
Trees that are grown in containers generally do not loose roots in the transplanting phase. Therefore you do not generally have to prune them unless there is some root injury or limb damage in the planting process.
Once you have your trees planted, be patient. Do not remove shoots from the trunk early on as these allow the tree to grow more rapidly and also shade the tender young trunk from sun-scald. Wait a few years to begin training the tree to its ultimate form.
How-to : Staking Trees
Staking is done differently depending on the size and flexibility of the tree, and the windiness of the planting site. Generally only trees that are planted in windy, exposed locations need to be staked. For most trees, a low stake is preferred, to let the tree move naturally. For windy areas or flexible trees, use a high stake. For trees more than 12 feet tall, use two low stakes on opposite sides of the tree or several guy ropes. The ties used need to accommodate growth and not cause bark damage with friction. Buckle-and-spacer ties can be found at garden centers, they are expandable and have a protective spacer. Ties without spacers should be formed into a figure eight to create padding. Latest studies have shown that when staking a tree, provide enough leeway so that the tree can move back and forth in the wind. Stronger roots will develop this way. If the tree can not move back and forth, these important roots will not develop and the tree might fall over during a storm, once stakes are removed. When planting a tree, stake at the time of planting if staking is a necessity.
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.
ProblemsFungi : Rusts
Most rusts are host specific and overwinter on leaves, stems and spent flower debris. Rust often appears as small, bright orange, yellow, or brown pustules on the underside of leaves. If touched, it will leave a colored spot of spores on the finger. Caused by fungi and spread by splashing water or rain, rust is worse when weather is moist.
Prevention and Control: Plant resistant varieties and provide maximum air circulation. Clean up all debris, especially around plants that have had a problem. Do not water from overhead and water only during the day so that plants will have enough time to dry before night. Apply a fungicide labeled for rust on your plant.
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.
Pest : Leaf Miners
Leaf Miner is actually a term that applies to various larvae (of moths, beetles, and flies) that tunnel between upper and lower leaf surfaces, leaving a distinctive, squiggly pattern. A female adult can lay several hundred eggs inside the leaf which hatch and give rise to miners. Leaf miners attack ornamentals and vegetables.
Prevention and Control: Keep weeds down and scout individual plants for tell-tale squiggles. Pick and destroy these leaves and take advantage of natural enemies such as parasitic wasps. Know the Growing Degree Days (GDD)* for your area to target insecticide sprays when most beneficial for controlling the specific leaf miner. Seek a professional recommendation and follow all label procedures to a tee. *GDD numbers should be available from your local Cooperative Extension office.
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.
MiscellaneousConditions : Rabbit Tolerant
As cute as they are, rabbits can really damage a vegetable garden. Young, tender lettuce plants seem to be their favorite. If a free-roaming dog is not a possibility for you, consider installing raised vegetable beds and covering tender shoots with netting. If you have ample room, you can opt to plant enough for you and the bunnies. Scents don't always repel animals, as they get used to them and are often washed off in the rain.
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.
Conditions : Wind Tolerant
Plants that are wind tolerant usually have flexible, strong branches that are not brittle. Wind tolerant plants often have thick or waxy leaves that control moisture loss from whipping winds. Native plants are often the best adapted to not only wind, but also soil and other climatic conditions.
Conditions : Fall Color
Fall color is the result of trees or shrubs changing colors according to complex chemical formulas present in their leaves. Depending on how much iron, magnesium, phosphorus, or sodium is in the plant, and the acidity of the chemicals in the leaves, leaves might turn amber, gold, red, orange or just fade from green to brown. Scarlet oaks, red maples and sumacs, for instance, have a slightly acidic sap, which causes the leaves to turn bright red. The leaves of some varieties of ash, growing in areas where limestone is present, will turn a regal purplish-blue.
Although many people believe that cooler temperatures are responsible for the color change, the weather has nothing to do with it at all. As the days grow shorter and the nights longer, a chemical clock inside the trees starts up, releasing a hormone which restricts the flow of sap to each leaf. As fall progresses, the sap flow slows and chlorophyll, the chemical that gives the leaves their green color in the spring and summer, disappears. The residual sap becomes more concentrated as it dries, creating the colors of fall.
Glossary : Low Maintenance
Low maintenance does not mean no maintenance. It does mean that once a plant is established, very little needs to be done in the way of water, fertilizing, pruning, or treatment in order for the plant to remain healthy and attractive. A well-designed garden, which takes your lifestyle into consideration, can greatly reduce maintenance.
Glossary : Specimen
A specimen can be a tree, shrub, ground cover, annual, or perennial that is unique in comparison to the surrounding plants. Uniqueness may be in color, form, texture, or size. By using only one specimen plant in a visual area, it can be showcased. Specimen plants are accents in the landscape, just as statues, water features, or arbors.
Glossary : Sandy Loam
Sandy Loam refers to a soil that drains well, with excellent air space, and evenly crumbled texture when squeezed in the hand. A good workable garden soil that benefits from added fertilizer and proper watering. Dark gray to gray-brown in color.
Glossary : Clayey Loam
Clayey loam refers to a soil that retains moisture well, without having a drainage problem. Fertility is high and texture good. Easily forms a ball when squeezed in the hand, and then crumbles easily with a quick tap of the finger. Considered an ideal soil. Usually a rich brown color.
Glossary : Deciduous
Deciduous refers to those plants that lose their leaves or needles at the end of the growing season.
Glossary : Tree
Tree: a woody perennial with a crown of branches that begin atop a single stem or trunk. The exception to this rule is multi-trunk trees, which some may argue are really very large shrubs.
Glossary : pH
pH, means the potential of Hydrogen, is the measure of alkalinity or acidity. In horticulture, pH refers to the pH of soil. The scale measures from 0, most acid, to 14, most alkaline. Seven is neutral. Most plants prefer a range between 5.5 and about 6.7, an acid range, but there are plenty of other plants that like soil more alkaline, or above 7. A pH of 7 is where the plant can most easily absorb the most nutrients in the soil. Some plants prefer more or less of certain nutrients, and therefore do better at a certain pH.
Glossary : Landscape Uses
By searching Landscape Uses, you will be able to pinpoint plants that are best suited for particular uses such as trellises, border plantings, or foundations.
Glossary : Soil Types
A soil type is defined by granule size, drainage, and amount of organic material in the soil. The three main soil types are sand, loam and clay. Sand has the largest particle size, no organic matter, little to no fertility, and drains rapidly. Clay, at the opposite end of the spectrum, has the smallest particle size, can be rich in organic matter, fertility and moisture, but is often unworkable because particles are held together too tightly, resulting in poor drainage when wet, or is brick-like when dry. The optimum soil type is loam, which is the happy median between sand and clay: It is high in organic matter, nutrient-rich, and has the perfect water holding capacity.
You will often hear loam referred to as a sandy loam (having more sand, yet still plenty of organic matter) or a clay loam (heavier on the clay, yet workable with good drainage.) The addition of organic matter to either sand or clay will result in a loamy soil. Still not sure if your soil is a sand, clay, or loam? Try this simple test. Squeeze a handfull of slightly moist, not wet, soil in your hand. If it forms a tight ball and does not fall apart when gently tapped with a finger, your soil is more than likely clay. If soil does not form a ball or crumbles before it is tapped, it is sand to very sandy loam. If soil forms a ball, then crumbles readily when lightly tapped, it's a loam. Several quick, light taps could mean a clay loam.
Glossary : Tolerant
Tolerant refers to a plant's ability to tolerate exposure to an external condition(s). It does not mean that the plant thrives or prefers this situation, but is able to adapt and continue its life cycle.
Glossary : Fertilize
Fertilize just before new growth begins with a complete fertilizer.
Glossary : Pruning
Now is the preferred time to prune this plant.