Oenothera acaulis ( Evening Primrose )

Characteristics

Cultivar:	n/a
Family:	Onagraceae
Size:	Height: 0 ft. to 0.5 ft. Width: 0 ft. to 0.67 ft.
Plant Category:	landscape, perennials,
Plant Characteristics:	low maintenance,
Foliage Characteristics:	medium leaves,
Foliage Color:	green,
Flower Characteristics:	night blooming, single,
Flower Color:	pinks, whites,
Tolerances:	drought, heat & humidity, pollution,

Requirements

Bloomtime Range:	Early Summer to Late Summer
USDA Hardiness Zone:	5 to 9
AHS Heat Zone:	1 to 12
Light Range:	Sun to Full Sun
pH Range:	5.5 to 8.5
Soil Range:	Mostly Sand to Some Clay
Water Range:	Semi-Arid to Normal

Plant Care

Fertilizing

How-to : Fertilization for Annuals and Perennials

Annuals and perennials may be fertilized using: 1.water-soluble, quick release fertilizers; 2. temperature controlled slow-release fertilizers; or 3. organic fertilizers such as fish emulsion. Water soluble fertilizers are generally used every two weeks during the growing season or per label instructions. Controlled, slow-release fertilizers are worked into the soil ususally only once during the growing season or per label directions. For organic fertilizers such as fish emulsion, follow label directions as they may vary per product.

Light

Conditions : Full Sun

Full Sun is defined as exposure to more than 6 hours of continuous, direct sun per day.

Watering

How-to : Xeriscaping

Xeriscaping is a method of planting which promotes naturally drought tolerant plants and water saving methods. Much consideration is given not only to the plants chosen for the design, but the design itself. Lawns are greatly decreased in size and usually located in the center of plantings at a lower grade as to catch any runoff. Shrubs requiring the most water, are conservatively used and thoughtfully placed, where they may be easily watered, preferably from runoff, and moisture conserved. There is a strong emphasis on using native plants, which a purist will do exclusively. At the very least, improved cultivars of natives are highly recommended.

Irrigation maybe used to supplement watering, but takes a creative turn in the form of drip systems and recycled catch water. Organic mulches in the form of compost, straws, and barks are also used to retain as much water as possible. In extremely dry areas, it is not uncommon for gravel and rocks to serve as the mulch.

A xeriphytic landscape is one that takes your particular site into consideration. A plant that maybe considered low water usage in one area of the country, may not be in another area, due to climatic stresses.

Conditions : Dry

Dry is defined as an area that regularly receives water, but is fast draining. This results in a soil that is often dry to a depth of 18 inches.

Conditions : Normal

Normal is defined as regular watering to a depth of 18 inches, but periodically dries out in the top 7 inches between waterings.

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.

Planting

How-to : Preparing Garden Beds

Use a soil testing kit to determine the acidity or alkalinity of the soil before beginning any garden bed preparation. This will help you determine which plants are best suited for your site. Check soil drainage and correct drainage where standing water remains. Clear weeds and debris from planting areas and continue to remove weeds as soon as they come up.

A week to 10 days before planting, add 2 to 4 inches of aged manure or compost and work into the planting site to improve fertility and increase water retention and drainage. If soil composition is weak, a layer of topsoil should be considered as well. No matter if your soil is sand or clay, it can be improved by adding the same thing: organic matter. The more, the better; work deep into the soil. Prepare beds to an 18 inch deep for perennials. This will seem like a tremendous amount of work now, but will greatly pay off later. Besides, this is not something that is easily done later, once plants have been established.

How-to : Planting Perennials

Determine appropriate perennials for your garden by considering sun and shade through the day, exposure, water requirements, climate, soil makeup, seasonal color desired, and position of other garden plants and trees.

The best times to plant are spring and fall, when soil is workable and out of danger of frost. Fall plantings have the advantage that roots can develop and not have to compete with developing top growth as in the spring. Spring is more desirable for perennials that dislike wet conditions or for colder areas, allowing full establishment before first winter. Planting in summer or winter is not advisable for most plants, unless planting a more established sized plant.

To plant container-grown plants: Prepare planting holes with appropriate depth and space between. Water the plant thoroughly and let the excess water drain before carefully removing from the container. Carefully loosen the root ball and place the plant in the hole, working soil around the roots as you fill. If the plant is extremely root bound, separate roots with fingers. A few slits made with a pocket knife are okay, but should be kept to a minimum. Continue filling in soil and water thoroughly, protecting from direct sun until stable.

To plant bare-root plants: Plant as soon as possible after purchase. Prepare suitable planting holes, spread roots and work soil among roots as you fill in. Water well and protect from direct sun until stable.

To plant seedlings: A number of perennials produce self-sown seedlings that can be transplanted. You may also start your own seedling bed for transplanting. Prepare suitable planting holes, spacing appropriately for plant development. Gently lift the seedling and as much surrounding soil as possible with your garden trowel, and replant it immediately, firming soil with fingertips and water well. Shade from direct sun and water regularly until stable.

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.

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.

Miscellaneous

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 : Rock Garden

A rock garden is a garden that mimics an alpine area, having dwarf conifers, low-growing sub-shrubs, perennials and ground cover. Often, the soil itself tends to be gravelly or rocky.

Glossary : Perennial

Perennial: traditionally a non-woody plant that lives for two or more growing seasons.

Glossary : Seed Start

Seed Start: easily propagated from seed.

Glossary : Night Blooming

: plants that begin blooming late in the afternoon or early evening, closing no later than mid morning.

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.

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