Rhamnus purshiana ( Cascara Sagrada )

Characteristics

Cultivar:	n/a
Family:	Rhamnaceae
Size:	Height: 10 ft. to 40 ft. Width: 10 ft. to 30 ft.
Plant Category:	shrubs, trees,
Plant Characteristics:	decorative berries or fruit, low maintenance, medicinal,
Foliage Characteristics:	deciduous,
Foliage Color:	dark green,
Flower Characteristics:	unusual,
Flower Color:	creams, greens, yellows,
Tolerances:

Requirements

Bloomtime Range:	Late Spring to Early Summer
USDA Hardiness Zone:	4 to 9
AHS Heat Zone:	Not defined for this plant
Light Range:	Part Shade to Full Sun
pH Range:	5.5 to 7
Soil Range:	Sandy Loam 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 Shade

Full shade means there is little or no light in the growing zone. Shade can be the result of a mature stand of trees or shadows cast by a house or building. Plants that require full shade are usually susceptible to sunburn. Full shade beneath trees may pose additional problems; not only is there no light, but competition for water, nutrients and root space.

Partial shade means that an area receives filtered light, often through tall branches of an open growing tree. Root competition is usually less. Partial shade can also be achieved by locating a plant beneath an arbor or lathe-like structure. Shadier sides of a building are normally the northern or northeastern sides. These sides also tend to be a little cooler. It is not uncommon for plants that can tolerate full sun or some sun in cooler climates to require some shade in warmer climates due to stress placed on the plant from reduced moisture and excessive heat.

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

Conditions : Moist

Moist is defined as soil that receives regular watering to a depth of 18 inch deep, does not dry out, but does not have a drainage problem either.

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.

Problems

Fungi : 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.

Pest : Caterpillars

Caterpillars are the immature form of moths and butterflies. They are voracious feeders attacking a wide variety of plants. They can be highly destructive and are characterized as leaf feeders, stem borers, leaf rollers, cutworms and tent-formers.

Prevention and Control: keep weeds down, scout individual plants and remove caterpillars, apply labeled insecticides such as soaps and oils, take advantage of natural enemies such as parasitic wasps in the garden and use Bacillus thuringiensis (biological warfare) for some caterpillar species.

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 : 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.

Miscellaneous

Glossary : Bird Attracting

The term bird attracting applies to any plant that has flowers, fruit, nuts, or structure that attracts birds. Most plants on ""bird attracting"" lists have favorable fruits or flowers that serve as food, but the trunks, limbs and foliage cover that trees and shrubs provide should not be overlooked as they add shelter for raising young and protection from foul weather.

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 : Pacific Northwest

Pacific Northwest refers to plants native to parts of or all of the northwestern region of the United States, including Northern California, Oregon, Washington and British Columbia.

Glossary : Deciduous

Deciduous refers to those plants that lose their leaves or needles at the end of the growing season.

Glossary : Small Shrub

A small shrub is less than 3 feet tall.

Glossary : Large Shrub

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

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