Can Native Plants Help a Coastal Property in PEI?

Native plants can help a coastal property in PEI by binding loose soil at the top of a bank, slowing runoff before it cuts gullies, and holding dunes and salt marsh together. They cannot stop waves from undercutting a cliff or a storm like Fiona from taking metres of land in a day, so planting works best as one part of a plan for the site.

How Fast Is PEI's Coast Eroding?

The province's State of the Coast report puts the Island-wide average at 28 cm per year from 1968 to 2010 and 40 cm per year from 2000 to 2010. Those averages hide a wide range: exposed cliffs retreated about 24 cm per year over the longer period, while cliffs in sheltered estuaries lost about 5 cm per year.

The PEI Coastal Property Guide treats less than 30 cm per year as low risk, 30 to 90 cm as moderate and more than 90 cm as high. It also notes that a single storm can do far more, with Fiona taking up to 12 metres of land in a day in some places.

What Can Roots Do at the Top of a Bank?

Deep-rooted native plants help hold the loose soil near the top of a bank. The province's interim coastal policy recommendations suggest salt-tolerant, native, deep-rooted species for binding unconsolidated soil and restoring buffer vegetation to stabilize banks, and the province's 2024 update adds that living vegetation helps bind sediment and reduce bank erosion.

Plants also help where water runs off the land toward the bank. The Coastal Property Guide explains that gullies form where stormwater is not absorbed by the ground or slowed by vegetation at the edge of a bank. The 2024 update also points out that property owners can simply stop mowing or clearing in the buffer zone and let vegetation grow back on its own.

Why Can't Plants Stop a Cliff From Eroding?

Cliff erosion on PEI is driven mostly by what happens on the cliff face and at its base, out of reach of roots at the top. The State of the Coast report names frost wedging, water freezing and expanding in cracks, as the main process breaking down the Island's cliffs, while waves undercut the base until the top gives way and saturated soil can slump.

Planting along the top edge cannot reach the cliff face or the base, where those processes do their work. The Shoreline Management Plans handbook adds that erosion depends mainly on the land's natural geology, along with wave exposure, tidal range and bank height.

How Do Plants Hold Dunes and Salt Marsh?

On dunes, the roots and underground stems of marram grass form what Parks Canada calls a living net that holds the sand in place. In salt marsh, the State of the Coast report says vegetation stabilizes the shoreline against erosion and traps sediment, which lets a healthy marsh build up as sea level rises.

A marsh can only keep pace with the sea if it has room to shift inland. The same report describes coastal squeeze, where development or hard structures behind a marsh stop it from shifting inland and it slowly drowns.

When Is Planting Not Enough?

Nature-based approaches, which rely on or copy natural processes such as vegetation and sediment, are better suited to shorelines with low to moderate wave energy, according to the Shoreline Management Plans handbook. On higher-energy shores, it describes hybrid approaches that combine natural features with built structures.

Planting is also slow to pay off, and the Coastal Property Guide notes that nature-based solutions take time to establish and may not work in every setting. It is just as clear that hard armouring has drawbacks of its own, including blocking the natural movement of sand and increasing impacts on neighbouring properties.

Can Red Earth Help Plan Coastal Planting?

Red Earth Restoration's restoration work focuses on shoreline and coastal planting. No planting can guarantee a property's protection, so an enquiry starts with the site itself, with the location, the type of shore and photos of the bank or dune.

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