Conservation Landscaping & Habitat Restoration

HB-Sweetbay Magnolia RG at HB

EcoScaping, RainScaping, BayScaping, GreenScaping…

It’s All About Conservation Landscaping and Habitat Restoration!

(Excerpted from Ecoscaping Back to the Future…Restoring Chesapeake Landscapes, by Zora Lathan and Thistle A. Cone.)

Conservation landscaping—using native plants, removing invasive plants, conserving water, eliminating or reducing chemical fertilizers and pesticides to reduce pollution and conserve resources, shaping the ground for better infiltration and erosion control, and enhancing aesthetics and wildlife habitat—is beginning to be implemented on a regional basis nationwide.

Principles of Conservation Landscaping

The following principles detail some of the most important considerations for conservation landscaping. The more of these principles you can incorporate into your landscaping projects, the better off the Chesapeake Bay watershed and all of its living elements will be.

▪ Avoid the use of and remove and replace invasive plants
Although we encourage planting as many local native plants as possible, it isn’t necessary to remove all plants that are non-native. Some people choose to plant a favorite plant from elsewhere, or a cultivar that they just have to have. If the plant is known not to be invasive, this shouldn’t be a problem.

Most invasive plants are “exotics.”  That is, they have been brought here from another ecosystem, frequently from another continent. That often means that they arrived here with few or no natural enemies to control them and hold down their numbers. Those that get completely out of control cause huge problems to wildlife and the plants they displace, agriculture, and the livelihood of many people. Sometimes people have deliberately imported these plants as an ornamental or to provide some particular presumed benefit, like kudzu, which was supposed to help control erosion. Sometimes the plants are brought in accidentally with nursery stock or with other items shipped from elsewhere. Either way, if these aliens find an environment with insufficient checks and balances, then their populations may spread like wildfire.

Some invasive species, such as bamboo have vigorous growth habits that, if unchecked, can quickly overwhelm a landscape. Beware of planting invasives such as English ivy, purple loosestrife, butterfly bush, Norway maple, or Bradford pear. These can actually still be purchased at nurseries, despite their known bad habits.

▪Use regionally native plants
Native plants are species that are indigenous to a specific region, for example, the Chesapeake Bay watershed. They are adapted to the local soil and climate. As people moved from the Old World to the Americas, they brought exotic plants, and frequently changed the landscapes to resemble those that they knew in Europe and elsewhere. The result of the tendency to try to reproduce plants and plant arrangements from other countries is that thousands of acres of turf grass and many alien invasive species have been introduced.

Native plant benefits include:

  • Best adapted to local conditions, for example, no need to use chemical fertilizers.
    Water conservation, that is, once plants are established in the right place, no need for supplemental watering.
  • Reduced maintenance over the long run. While native plants are not maintenance-free, if they are placed in the landscape based on their preferred conditions, they require less care than non-native species.
  • Won’t harm natural areas, e.g., won’t become invasive.
  • High habitat value provides food, shelter, and nesting areas for wildlife.
  • Great variety of species for all conditions.
  • Create a “sense of place.”

▪Place plants in appropriate growing conditions
It is important to select the appropriate plants for existing light, soil, and moisture conditions. Some plants prefer dry soil, others prefer moist soil, while some can handle a range of conditions from dry to moist.

There are many good references on the growing conditions preferred by specific plants. Evaluate your site and select plants that will work well for the given conditions. Successful gardeners know that the old adage, “right plant, right place” will save you time, energy, and money. Moreover, your plants will be healthier, and more resistant to diseases, pests, and other problems—without the need for added fertilizer or pesticides. If a plant is not happy, and is doing poorly in a particular location, try moving it.

▪Minimize the use of supplemental watering

  • 30% to 60% of urban freshwater is used for watering lawns (depending on locale).
  • A 1,000 square foot lawn requires 10,000 gallons of water per summer to maintain a “green” look.

A tremendous amount of water applied to lawns and gardens is never absorbed by the plants and put to use. The greatest waste of water is applying too much too often, resulting in runoff. In addition to over-watering plants, excess irrigation leaches nutrients from the soil. Runoff caused by excess watering can carry polluting fertilizers and pesticides to streams, rivers, and the Bay. Water is also wasted through evaporation. In general, if you have to water, it is best done early in the morning to conserve water for your plants, yet still allow the water to evaporate from leaves and avoid promoting diseases for plants prone to such problems. The beauty of using native plants is that once they are established in the landscape (which can take approximately two months for herbaceous perennials), they shouldn’t need supplemental watering.

Water waste and excessive plant and weed growth can be reduced by providing water only when needed and only where the landscape requires moisture. Recent advances in irrigation technology allow for precise delivery of water with very little waste. Drip irrigation systems and micro-emitters are cost-effective when evaluated against rising water costs. The real benefit of these systems is that the water is used only for growing the plants desired, while helping prevent nutrient-consuming and waste-generating weed growth in other areas.

Rain water running off buildings can also be conserved and used in roof collection systems such as rain barrels and cisterns attached to drip irrigation lines, or mitigated by the use of “green” vegetated roofs.

▪Minimize the amount of lawn
Although lawns can prevent erosion better than bare soil, most other types of landscape plantings provide more benefits to the environment than does a lawn. Many lawns have become very compacted, too full of toxic chemicals, and a drain on our time, energy, and financial resources. They can be almost as bad as impervious surfaces in causing rapid runoff. For example, a thick, green lawn can be up to 90 percent impervious according to the US Environmental Protection Agency.

In most cities and suburbs, lawns are the most prominent type of vegetation. Lawns are also the most resource-consuming, as well as polluting form of landscaping. Americans spend over $30 billion annually on lawn care. Lawns consume more supplemental water, fertilizer, and pesticides than any other type of landscaping. Although lawns become stressed during periods of drought, most lawns receive twice the water they require for a healthy appearance. Less frequent, deep watering of lawns is best. Reducing the size of lawns and using common sense to maintain them will reduce the quantity of water and other inputs needed.

An emerald green carpet may seem desirable, but at what cost?  That emerald carpet is difficult to sustain without the application of numerous chemicals and large amounts of water. Children, pets, and the environment especially stand to gain health benefits from reduced amounts of lawn and more re-sponsible lawn care. Determine the minimum amount of lawn you absolutely need for recreation or other purposes, and then eliminate the excess. Consider some of the many beneficial alternatives presented in this guide. These will provide you, your family, and the environment with better solutions.

▪Reduce or eliminate the use of chemical fertilizers and pesticide

  • 80,000,000 pounds of synthetic pesticides are used on U.S. lawns each year.
  • When pesticides are regularly applied, 60-90% of earthworms are killed. Earthworms are invaluable for soil health.
  • Over 100 million tons of fertilizers are applied to residential lawns and gardens annually.

Before using fertilizer in your landscape, it is important to test the soil to see if it actually needs amending. A laboratory will give you detailed results and suggestions on amendments, and simple kits from a gardening store will give you a rough idea about certain nutrients. Don’t add fertilizer if you don’t need it. It will not be used by the plants and could cause significant problems as it runs off into the nearby waters. Algae blooms and fish kills are caused by too much fertilizer running off lawns and other landscapes.

Commercial fertilizer is costly and is frequently made from petroleum products. If you choose to amend your soil, after testing it, try to use organic fertilizers, slow release products, or compost. Remember that if you “grass-cycle” or leave clippings on your lawn, it will reduce the additional nitrogen requirements by 25%. Make sure no fertilizer remains on driveways or sidewalks, where it will wash into surface waters via storm-drains. If your lawn is unhealthy due to poor soil structure, compacting, slopes, poor drainage, pests, disease, improper pH, or shade, adding fertilizer will not help. If you have a lawn that you believe needs to be fertilized, we suggest you contact your local Cooperative Extension for suggestions on grass types and fertilizer requirements.

Pesticides, like fertilizers, should only be used as a last resort. If used improperly, they can be very dangerous to your health and the health of the surrounding environment. They can kill other things besides the intended species, such as worms, beneficial insects, birds, and other animals. They frequently make pest problems worse, because they tend to eliminate the beneficial insects which are trying to take care of the problem. Pest populations frequently recover faster from a pesticide application than the “good guy” insects who help keep them in check. This makes for a vicious cycle of dependence on chemicals to try to control a worsening problem.

Instead, try using integrated pest management (IPM). This technique entails simple preventative measures and using the least dangerous chemicals only if necessary, such as insecticidal soaps and oils. Using native plants that are adapted to the region and the specific site, and resistant to local diseases and pests, is the best approach. A wide diversity of native plants will attract many beneficial insects to your garden and may be all you need to keep pests in check. Using barriers, traps, and vigilant hand removal of pests can also help. The simplest aspect of IPM is accepting that a certain amount of damage will be done by pests. Having tolerance will help gardeners not to panic and apply pesticides where they are unneeded and problematic. Given overall healthy conditions, many problems are self-correcting.

“Most chemical pesticides represent a very crude form of knowledge about insects…. Even though this knowledge has been produced by Homo sapiens wearing lab coats, it is not nearly as sophisticated or precise as the knowledge a ladybug, say, possesses on the subject of aphids. The ladybug is not smart, but she knows one thing exceedingly well: how to catch forty or fifty aphids every day without hurting anybody else. If you think of evolution as a three-and-a-half-billion-year-long laboratory experiment, and the gene pool as the store of information accumulated during the course of that experiment, you begin to appreciate that nature has far more extensive knowledge about her operations than we do. The trick is to put her knowledge to our purpose in the garden.” –Michael Pollan

▪Compost to reduce yard waste and to use as a soil amendment
Composting is the natural process of decomposition and recycling of organic material. Nature’s recycling system is efficient, completing the cycle-of-life process. Leaves that fall to the forest floor form a moist mulch layer that protects the roots of plants and provides a home for nature’s recyclers—bacteria, insects, and worms that feed on the mulch, turning it into compost. As the mulch decomposes, nutrients essential to plant growth are released into the soil and are absorbed through plant roots.

Compost contributes to good soil structure, which allows soil to retain nutrients, moisture, and oxygen for long periods of time. When we remove yard waste from the landscape where it was produced, we deprive plants of their own natural fertilizing source. Like the natural composting process in the forest, we can create compost in our yards and gardens by placing yard waste in a suitable spot in bins or piles.

Yard waste alone accounts for approximately 18 to 20 percent of municipal solid waste, and during peak seasons, can account for 25 to 50 percent (US Environmental Protection Agency). Backyard composting saves valuable landfill space. It also saves taxpayers the additional costs to collect, haul, and manage yard waste.

▪Reduce the use of power landscape equipment

  • Gas powered garden tools emit 5% of the nation’s air pollution.
  • The average homeowner spends 40 hours per year, the equivalent to a one-week vacation, mowing the lawn.

We have choices about how we spend our time and money, use our energy resources, and impact our air quality. Given the above statistics, gas-powered lawn care may not be how you choose to use your resources. Consider lawn reduction, electric tools, and hand tools as alternatives. Have you ever seen someone using a large gas-powered lawn mower on a 10 foot x 10 foot postage-stamp size lawn?

One of the most wonderful side benefits to reducing turf grass in your yard is the reduction in noise pollution. Turf grass maintenance is not only costly and time-consuming, but it often entails the use of rather noisy equipment. Anyone who has heard the many-decibel onslaught from a neighbor or lawn company mowing or leaf-blowing their way across the lawn knows how disturbing the noise can be. The impacts in terms of stress, hearing impairment, and the disturbing of wildlife have not been adequately considered in many areas. Some communities have begun to regulate the use of such equipment, including which hours of the day they are allowed to be used and limits on decibel levels.

 ▪Utilize native trees to reduce heating and cooling needs
Another way to reduce energy use, besides reducing power equipment on the lawn, is to enhance the beauty and energy-efficiency of a home or other building by thoughtfully planting trees and shrubs in appropriate places.

  • Evergreen trees on the north side will shield buildings from winter winds. By breaking the wind, such trees will reduce your heating costs in winter.
  • Deciduous trees on the south and west side will provide shade in summer, reducing summer air conditioning costs. For example, air temperature is up to 25% cooler under trees; while deciduous trees allow the sun to warm buildings in the winter. Because such trees will drop their leaves in winter, they won’t deprive your home of sunlight when you need it. Remember to check on the final height trees will attain before planting to anticipate the possibility of interfering with power lines, roofs, etc.
  • Shrubs used as foundation plantings can reduce heating costs, creating an insulating, dead air space around the home. Plant the shrubs a few feet away from the building foundation.

▪ Purify the air and water by planting native trees, shrubs, and perennials
Forest buffers, rain gardens, and other conservation plantings provide many water quality benefits, including reduction of stormwater runoff, water purification, water cooling, and groundwater recharge. Another great benefit of such plantings is the improvement of air quality. Air pollution is a particular concern in the Chesapeake Bay region, since some of the worst levels in the nation have been found here.

American Forests lists the following air quality benefits of trees, for example: “Air pollution in our cities, and even our suburbs, is a serious concern as we enter the twenty-first century. The burning of fossil fuels has introduced a steady flow of deadly pollutants into our atmosphere, yet very few urban areas can meet national clean air standards. Luckily, we are surrounded by efficient air cleaning machines—trees. Trees sequester many pollutants from the atmosphere, including nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), carbon monoxide (CO), and particulate matter of ten microns or less (PM10).”

Trees, shrubs, and other perennials, especially when planted in layers, can provide advantages besides direct air pollution removal. Evapotranspiration—the process of drawing water up through the roots and plant and evaporating it from the leaves—cools surrounding air temperatures. Their shade can also help cool local temperatures in urban areas, which can reduce ground-level ozone formation. This helps reduce smog and the “heat island effect.”

▪Reduce the amount of impervious surface and install rain gardens to recharge groundwater and reduce runoff
Impervious surfaces, such as paved areas, roofs, and other structures which do not allow water to infiltrate into the ground, cause great problems for nearby waterways. Impervious surfaces cause runoff to be rapid, carrying pollution and overheated water to our streams and rivers. Thoughtful design of buildings, roads, paths, and parking areas, and choosing alternatives to traditional paving methods can help reduce the amount and improve the quality of water that reaches our waterways.

There are various innovative paving materials now available which will allow water to pass through them instead of running off. Using pervious pavers, gravel, and other more permeable materials in parking areas and driveways can help with this process. Paths made of mulch, or with brick or stone pavers set in sand or mulch, instead of cement, may permit more water to pass through into the ground. These methods help reduce the problems of flooding, water pollution, and groundwater depletion prevalent in areas with too much impervious surface. Rain gardens, rain barrels, and green roofs are also techniques to reduce the impact of too much impervious surface.

▪Reduce runoff and soil erosion and stabilize slopes by planting native trees, shrubs, and perennial ground covers in swales and on terraces, in addition to level and raised areas
Reducing stormwater runoff, erosion, flooding, and sediment buildup is a major benefit of practicing conservation landscaping techniques in the Chesapeake Bay watershed. Turf grass tends to form a partially impervious barrier to water flow; while shrubs, trees, and other types of gardens improve the ability of water to filter down and recharge groundwater supplies. The more water that is held in land areas, that is not rushing down to swell streams and rivers, the less flooding we will have.

A simple way to help slow and purify stormwater runoff is to create  swales, instead of berms or isolated “islands” in parking lots and other areas of impervious surface. A swale is simply a depression in the ground, not separated from rain water runoff by a curb or other obstruction. A swale can contain vegetation and act as a type of rain garden—a saucer-shaped depression—or bioretention area. Shaping the land in this fashion imitates nature by creating contours throughout the land. The human tendency is to level the landscape, not understanding the environmental impact of this type of grading. Rain gardens have the added benefits of reducing flooding and increasing groundwater supplies. Many people get their water from underground aquifers. The replenishment of groundwater—which is particularly important in times of drought—depends upon the absorption of rainwater into the ground.

Stabilizing slopes is also important for reducing erosion. If you have tried to grow grass on them, you know that steep slopes are not always easy to plant and maintain in lawn. There are many native plant alternatives which will do well on slopes and require much less maintenance. Reducing or eliminating mowing on a steep slope can be a huge time savings and safety advantage as well. Try native groundcovers, trees, or shrubs instead. Terracing can also help to stabilize slopes, reduce rain water runoff, and provide more manageable planting beds.

▪Provide wildlife habitat by planting native species
Water, food, shelter (including nesting spots), and space to live out their lives in a fairly undisturbed way are the basic things all animals need. The more of these elements we can provide in our suburban and urban landscapes, the better off wildlife will be. If we provide a diversity of habitats which include native plants, and few if any pesticides, more of the locally-evolved species will be able to coexist with us.

We are not talking about attracting wolves and elk, which were in the area in ancient times. We are, instead, hoping to attract small creatures that you will enjoy observing occasionally, if you are lucky. The most common will likely be birds, from robins and mockingbirds, to hummingbirds and hawks. There may also be small mammals like raccoons, opossums, foxes, and field mice. If you are outside a lot, you may get to see the occasional reptile, like a small snake or turtle. Amphibians like toads, frogs, and salamanders will be around if there is water nearby where they can lay eggs. Butterflies and other pollinating invertebrates will be attracted if you plant wildflowers and other native plants. There is nothing like a garden full of butterflies to put a smile on a wildlife gardener’s face.

▪Mulch to conserve water, suppress weeds, improve soil structure, and to lessen erosion
Mulch is an organic or inorganic layer of nonliving material covering the soil surface around plants. The benefits of organic mulch, such as shredded leaves or pine are manifold:

  • Helps to hold soil in place and minimizes erosion.
  • Minimizes evaporation and retains moisture for plants, allowing considerable water savings and reduced maintenance, especially during dry spells.
  • Keeps soil cool in the summer and warm in the winter, maintaining a more uniform soil temperature, which can improve plant growth.
  • Provides protective cover until plants mature (be careful not to bury seedlings).
  • Decomposes naturally to add nutrients and organic matter to soil.
  • Helps suppress weed growth, which can significantly reduce maintenance.
  • Enhances the aesthetics of a landscape design–a great top dressing that provides instant impact.

Avoid the use of too much mulch. Because mulch has so many benefits, some folks imagine “if a little is good, then a lot must be better” and create mulch volcanoes around trees. This type of excessive mulching creates unhealthy conditions.

▪Learn to appreciate nature and tolerate some imperfection in the garden
When trying to restore natural landscapes, remember that nature doesn’t design in straight lines, nor in lollipop shrubbery row arrangements. Adding curves to the landscaping beds and pathways, planting in “drifts” instead of rows, and avoiding drastically-pruned shrubs will add to the “natural” look of your gardens.

As noted in the section on reducing pesticides, learning to tolerate a bit of insect damage or a few dandelions in the lawn, for example, is part of the aesthetic in conservation landscaping. A better understanding of the lawn or garden as part of a larger ecosystem, will result in little or no fertilizer and/or pesticide use. Try to discover exactly what type of organism is causing the blemish on your plant, and see if you can outwit it with gentle means. If not, show tolerance if possible.

▪Protect existing natural areas and the watershed’s “sense of place”
Just like doctors try to “first do no harm” to their patients, conservation landscapers must try to protect intact natural areas. In other words, if there are functioning natural systems on or near your property, try to protect and enhance them; but certainly don’t damage them with your efforts. If possible, add buffers around them to extend the wildlife habitat they provide.

Another pitfall to avoid, is the temptation to dig up wild plants to expand a native plant garden. Sometimes a plant is locally or regionally rare and your removal of one or a few plants could endanger or wipe out the local population. Unless you have special permission from a landowner to remove native plants on a construction site where they will be destroyed, you should rely on reputable nurseries for your plants. Be sure that they have propagated their plants from nursery stock or from plants legally rescued from the wild.

Native plants are key to establishing a “sense of place” for the region. Our pride in what is local and historically unique should include the indigenous plants. Our children—and landscapers—should be taught which plants form the unique flora that was here before people arrived from around the world, bringing exotic plants with them. The more we include native plants in public and private locations, the more residents will begin to recognize and admire their intrinsic beauty.

One of the most wonderful human benefits of planting native plants, is the opportunity to discover a keen “sense of place” regarding what types of plants developed and belong here. Each region is unique in its combination of soil, climate, and other conditions which influence what can grow there successfully. Wouldn’t it be wonderful if the same enthusiasm we show for the local sports teams or for our home town could be shown for the plants that are native to that area?  Native plant gardens can help provide that pride in things local and precious. The more we plant and publicize native plants, the more people will recognize their beauty, their value, and the important role they play in the local ecosystem.

▪Maintain native plant gardens and plan for the long term
“It’s hard to imagine the American landscape without St. John’s wort, daisies, dandelions, crabgrass, timothy, clover, pigweed, lamb’s-quarters, buttercup, mullein, Queen Anne’s lace,  plantain, or yarrow, but not one of these species grew here before the Puritans landed. America in fact had few indigenous weeds, for the simple reason that it had little disturbed ground. The Indians lived so lightly on the land that they created few habitats for weeds to take hold in. No plow, no bindweed.” –Michael Pollan

Disturbing the soil—creating a haven for weeds—obliges us to maintain it. Develop a regular garden care and maintenance schedule for your garden. Like other types of gardens, the initial needs of native plant gardens will be watering to help plants become established, and weeding to keep down the competition. Take heart; if you maintain your landscape, the amount of weeding needed should lessen each year as more and more weeds are removed and the disturbed area stabilizes. Adding mulch once or twice a year may also be needed since organic mulch (which is the best kind) breaks down over time. Plants may need to be moved, replaced, and thinned as they grow, spread, or die. Figuring out who will complete these tasks for the long term is just as important as the planting of the garden.

Long term planning is essential before installing trees and shrubs, which should be thoughtfully located in the landscape due to their long life, possible substantial size, and the resulting effects they create in the landscape. Many variables exist that may influence your installation and maintenance plans, including time, available help, budget, and season. It may not be feasible to turn the property into a conservation landscape overnight. You may need to install your planting plan in stages and plan for long-term improvements, phased in over time. Remember, maintenance will be ongoing. Conservation landscapes are living, dynamic ecosystems that evolve and are ever changing.