Habitat Design on School Grounds

HABITAT DESIGN ON SCHOOL GROUNDS

By Lisa Albert
4-H Wildlife Steward for Deer Creek Elementary School

WHY SHOULD WE USE NATIVE PLANTS?

Beautiful
Adapted to our climate and soils
Provide food and shelter for native wildlife
Restoration and preservation
Educational

Native plants are plants indigenous to an area. They were not imported when settlers arrived. The parameters for determining what is native can be broad or narrow depending on the area the writer is focusing on. After all, every plant is a native somewhere. This manual defines natives as those plants that occur naturally in the Pacific Northwest region, primarily Oregon and Washington from the Cascades to the coast.

Within this range there are many different types of climate, soils and growing conditions. Some areas are riparian; their soils are high in organic matter, which provides a moisture retentive growing environment. Other areas are upland; high above the water table, with sandy soil that drains quickly and dries out thoroughly during the summer. There are meadows, mixed deciduous forests, and deep dark conifer forests. These areas will all support different plant species. It's best to choose plants that match your location’s conditions, even on a small scale, if you can.

The plant kingdom is divided into various classifications but knowledge beyond genus and species is generally not necessary. Beyond species, plants may additionally be subdivided by variety name. For example, Red Flowering Currant’s botanical Latin name is Ribes (genus) sanguineum (species). It has many named varieties, some of garden origin and some are naturally occurring. Ribes sanguineum ‘King Edward’ is of garden origin. Ribes sanguineum ‘Icicle’ is a naturally occurring variant. Why is this important to know? For the horticultural trade, plants are bred and selected for aesthetic reasons; perhaps to have larger flowers or fruit, a longer bloom season, more color variety and many more reasons. Because of this process, these varieties may not be as useful to wildlife as a natural variant or the straight species form of the plant. A change in bloom or fruit season, flower size and form, fruit size and form may not coincide with wildlife needs. For instance, the plant may not produce nectar, making it a poor food source for rufous hummingbirds and bees. Additionally double flowers may prevent access to the nectaries. If your primary purpose is to sustain wildlife, avoid named varieties if you can't determine their origin or wildlife impact.

To learn more about natives in your area, go for walks in natural areas during all seasons; notice what conditions are like throughout the year and which species tend to grow together. For example, red huckleberry tends to grow on nurse logs and establishes much more quickly and easily when these conditions are replicated by adding decaying wood to the planting hole.

It is also helpful to determine your region's climatic zone. Climate zone is an area in which a common set of temperature ranges, humidity patterns, and other geographic and seasonal characteristics allow certain plants to succeed and others to fail. Climate is the accumulation of weather effects in your area throughout a cycle of seasons. Sunset Western Garden book can help determine the Sunset zone and most gardening resources will help determine the USDA zone. The USDA zone is more commonly used while the Sunset Garden book breaks our region into many more distinct climatic zones.

When choosing plants for your schoolyard garden you can choose to use only natives or you can choose a mix of natives and non-natives (often called exotic) plants. Many non-natives will provide habitat for our native wildlife, though rarely to the extent of our native plants. Native plants and wildlife have co-evolved over millenia to create a wonderful web of life. While a non-native plant species may feed a few birds, a native species may directly and indirectly serve up to 50 species of fungi, insects, invertebrates, and other organisms. When choosing non-natives, select plants that provide habitat, suit your site, co-exist well with natives and are not invasive in our natural areas.

Once you learn to treasure native plants in your garden and you appreciate their value in our natural areas, a logical next step is to eradicate from your garden non-native plants that threaten our natural areas.

You may have heard the phrase “Noxious Weed”. This is a legal definition for plants that were originally brought in for horticultural purposes and escaped the boundaries of gardens, wreaking havoc in natural and agricultural areas. In Oregon, it is the Oregon State Weed Board that gives plants this designation, making it illegal to sell, propagate and transport these plants. In addition, the board regulates tax dollars and control measures to contain the spread of Noxious Weeds. These plants supplant native species at an alarming rate, they are considered destructive and competitive, and generally have little wildlife value. Many were given the classification because they have detrimental value on agriculture but with the recent listing of English ivy, this may be changing to include plants destructive in natural areas as well. Examples of Noxious Weeds are Scotch (or Scot’s) Broom, Purple Loosestrife, Himalayan blackberry. For more information, visit Oregon Department of Agriculture’s website at:

http://oda.state.or.us/Plant/Weed_control/NoxWeedQuar.html

The term “invasive plant” is more subjective and often dependent upon the speaker or writer’s viewpoint. Some will classify various native plants, such as fireweed, as invasive because they self-sow prolifically. This manual uses the term in regards to plants that are not legally classified as Noxious yet threaten our natural areas and wildlife habitat. They have many of the same characteristics as plants on the Noxious Weed list but are excluded for various horticultural and agricultural reasons. The English ivy listing was fought for many years because it is an excellent cash crop for the agricultural industry. Plants considered invasive include English laurel, English holly, butterfly bush, Black locust and Yellow flag. An excellent resource for this is a list called Alien Plant Invaders, produced by Berry Botanic Garden.

When choosing plants for a garden on school grounds, a plant’s toxicity should be considered and toxic plants should be avoided. Both native and non-native plants can have toxic properties, which can cause problems either by ingestion, mechanical injury (thorns), skin contact or allergens. These toxic properties, often a defense mechanism for the plant, can vary from plant to plant within the same species, from genetic variation of the same plant, from season to season or plant stage, from different plant parts, and can even be affected by soil type. For example, Red elderberry and Blue elderberry are closely related native plants. Red elderberry fruit is toxic to humans at all times. Unripe blue elderberry fruit is toxic. Fully ripe fruit is not toxic, though it is not very palatable. In addition, while ripe Blue Elderberry fruit may not be poisonous other parts of the plant are quite toxic. The stems, bark, leaves and roots of both red and blue elderberries are toxic.

What is poisonous for us isn’t necessarily poisonous for wildlife for many reasons. For instance, birds swallow fruit without chewing and the seed, which generally contains the toxin, passes through their system without releasing the toxins. The mechanical action of chewing releases the toxin in the seed, thus poisoning us. Another reason is that wildlife has had millennia to develop immunity to a plant’s toxins; we have not. NEVER assume that if wildlife can eat something that we can, too.

Older adults, young children and those with impaired immune systems are more susceptible to a plant’s toxins. Common toxic non-native garden plants include foxglove, lily of the valley, daphnes, wisteria, datura, hydrangeas, golden chain tree, azaleas, rhododendrons, hellebores, and nicotiana. Regardless of whether a plant is toxic or not, one rule of the habitat garden is that children should not touch a plant or put a plant part in their mouth unless instructed to do so by a knowledgeable, trained person and the plant’s identity and toxic properties are known.

For more information on toxic plants, see the suggested resources listed at the end of this manual.

The natives included in this manual are divided into four plant communities. Assess your school garden and determine which plant community its environment is most similar to and select natives from this list for your garden. Many of the plants listed for one community will also work in a similar plant community increasing your list of native plant possibilities. Proper plant selection is one key to a successful school garden. Adequate soil preparation for the specific plants’ needs, proper watering for the first one or two seasons to establish the plantings and yearly mulching to maintain even soil temperatures, prevent water loss and prevent weeds are the other keys to a successful planting.

The last bit of advice is to always purchase native plants and seeds from ethical reputable sources. Do not purchase illegally salvaged plants.