The ideal Maine home for many people is on the waterfront. The occupants of those dream homes look out on the blue of the water, maybe a dock and a boat or mountains in the distance.

Unfortunately, pretty a picture as this is, such homes and their landscapes often damage the body of water they abut, be it ocean, river or lake. This column is based on a workshop I attended that focused on lakeside homes, but the landscaping strategies we were taught apply to other bodies of water, as well.

The notes for this bit of writing have been sitting on my computer desktop since almost a year ago when I, along with several dozen others, attended the class sponsored by the Maine Landscape and Nursery Association. But shortly after the gathering, the world turned upside down, and my columns took a different direction. Now, as gardening season approaches and Mainers are being vaccinated, including those lucky enough to own waterfront property, the topic again seems timely.

While acidification, mercury and invasive aquatic species are among the many threats to water quality, phosphorous causes the most damage, Roberta Hill, invasive species program manager for the Lake Stewards of Maine, told the group. That’s because, even a relatively small amount of phosphorous can result in algae blooms, she said. Those algae blooms are ugly; more importantly, they use up the oxygen in the water, which can kill the fish and beneficial aquatic plants.

Because phosphorous — coming from septic systems, fertilizer, animal feces, decaying organic matter and sometimes even simple soil erosion — sticks to small pieces of soil, it easily gets washed into lakes when it rains. The wide-open views that many waterfront homeowners desire exacerbate the problem, because unobstructed views probably mean there are no plants to slow the runoff of the polluted water.

What can those landscaping a waterfront home do to keep the water healthy and clean? The answer depends partly on the condition of the property when they start, Hill said.

For property owners building a new waterfront home on undeveloped land, “Doing nothing is the best thing you can do,” Hill said, making an exception for the removal of invasive species such as bittersweet, honeysuckle, Norway maple trees and knotweed.

The existing trees will provide shade for the home, and their leaves will slow the rainfall, resulting in less erosion. They’ll require no maintenance and no fertilizer, factors which will both help keep the lake clean and save money for the homeowner.

But doing nothing may not be practical. If nothing else, the property owners will want a path to get to the water so they can swim, boat or fish. They’ll also want a view of the water, even if it isn’t the unobstructed view they originally envisioned. There are a few compromises between the desires of the humans and the requirements of the natural world.

Keep in mind that clear cutting the property is not only environmentally harmful, but also results in a lack of privacy. Sound travels easily over water so the more a property is cleared, the more its occupants will be hear what others say or do on the water – and vice versa. Compromise with trees that frame or provide glimpses of the lake.

If you buy an existing waterfront home that has a lawn, stop mowing and raking to see what happens, Hill suggested. If you don’t like the results, “add some hydrangeas, which aren’t native but are friendly,” she said. You can also opt to reduce the size of the lawn, eliminating the sections on slopes, which produce more runoff than elsewhere and are harder to mow. Plant the slopes with ground covers or other herbaceous perennials instead.

For the path, avoid straight lines, which promote erosion. A curved path slows runoff and is more attractive. If the path ever gets too packed down, move it by planting shrubs where you don’t want people to walk and opening up spots where you’d like them to walk.

Hill also suggests creating a rain garden for the runoff from the roof of a house, running a hose from the downspout to a depression in the landscape. “Rain gardens can be small, colorful, shallow, and they capture and clean the runoff,” she said.

Another idea is to create what landscapers call garden rooms. Create an open outdoor area with chairs, tables, a barbecue and such, and surround it with trees and shrubs, such as highbush blueberries, hazelnuts, sweet woodruff and wild strawberries. For more plant ideas, Hill said that Native Plant Trust, Wild Seed Project and similar groups have extensive lists.

But as long as the plants you’re thinking of don’t require fertilizer and do slow down runoff, they will do their job.

Tom Atwell is a freelance writer gardening in Cape Elizabeth. He can be contacted at: tomatwell@me.com