The coast offers a beautiful but challenging space for landscaping. Sandy, nutrient-poor soils, harsh, salty winds, and high humidity can easily frustrate our efforts to establish and maintain an attractive coastal landscape design.
This means that a low-maintenance approach is vital for successful coastal landscaping, but how do we implement this approach in practice?
Low-maintenance coastal landscaping involves the use of plants that require minimal care and that are adapted to withstand exposure to high levels of wind, salt, sand, and humidity, combined with design and management practices that mitigate the impacts of these environmental stresses.
Appropriate low-maintenance plant selection and management practices are vital for establishing a viable and beautiful coastal landscape. Let’s look more closely at some of the plants that grow easily in a coastal setting, and some management techniques that can keep the landscape design looking its best.
Coastal Landscaping: Challenges And Solutions
Coastal environments offer an appealing natural setting for landscaping, but they present considerable challenges for landscapers.
High wind levels are probably the biggest challenge for landscaping in coastal environments. Strong winds can erode soil, break plant limbs, and even uproot plants. Coastal gales can also damage plants through sand abrasion and can dessicate leaves and shoots, resulting in loss of foliage, shoot die-back, and stunted growth.
Salt poses another major challenge for coastal landscaping. Coastal winds coat plant surfaces with a salty residue that can result in stunted growth and the loss of foliage. Salt carried by coastal winds is also deposited on the soil, where it can create serious problems for plants that don’t tolerate excess soil salinity.
Humidity in coastal areas can also pose a considerable challenge, most notably by creating conducive conditions for the proliferation of plant pests and diseases to proliferate. Fungal diseases like powdery mildew and rust are among the most common and pernicious plant pathogens encountered in coastal environments.
Coastal soils also tend to have high alkalinity, as well as being low in nutrients. Indeed, the lack of fertility in coastal soils is exacerbated by their alkalinity, because important nutrients like nitrogen and iron get locked out in high pH soils. This makes it difficult to establish and maintain plants that prefer nutrient rich, low pH soils.
To overcome these environmental challenges, coastal landscaping design and management should prioritize a low-maintenance approach. This approach is based on the use of hardy plants that tolerate harsh coastal environments, combined with the use of management practices to mitigate the stresses of excessive wind, salt, and humidity.
Low-Maintenance Plant Selection For Coastal Landscaping
In general, low-maintenance indigenous plants adapted to the local area offer the most effective choice for landscaping in coastal areas. Indigenous coastal plants have very low maintenance requirements, while also having strong aesthetic appeal when used in context.
Of course, non-indigenous plants can be successfully integrated into coastal landscape designs as well, provided that they can tolerate the environmental conditions and stresses prevailing in coastal areas.
Plants that do well in coastal landscaping tend to have at least some of the following characteristics:
- tough, glossy foliage,
- flexible, sturdy stems and branches,
- low growing habit,
- low nutrient needs,
- low water needs,
- tolerant of high pH soil,
- tolerant of high salinity levels,
- tolerant of high humidity (resistant to fungal diseases).
The table below presents a variety of plants that tolerate full exposure to wind, drought, salt, and that grow well in nutrient-poor, alkaline soils.
|Cape honeysuckle (Tecoma Capensis)
|Coastal, perennial shrub, evergreen, flowers year-round.
|9 to 11
|Coprosma (Coprosma ripens)
|Perennial shrub, medium size, evergreen, flowering,
|8 to 11
|Creeping juniper (Juniperus horizontalis ‘Wiltonii’)
|Perennial groundcover, evergreen, specimen plant
|3 to 9
|Bulb, rapid spreading, short- lived flowers in summer.
|3 to 9
|Dune Aloe (Aloe Thraskii)
|Coastal single-stemmed Succulent, tall (2m), winter flowering
|9 to 11
|Gazania (Gazania rigens)
|Coastal ground cover, flowers year-round.
|4 to 10
|Hornbeam (Carpinus betulus)
|Large tree (+12m), deciduous, flowers in spring
|5 to 7
|Lavender (Lavandula angustifolia)
|Perennial herb, flowers year-round,
|5 to 9
|Maritime pine (P. pinaster)
|Coastal tree, medium-sized, evergreen, flowers in spring
|New Zealand broadleaf (Griselinia littoralis)
|Coastal, multi-stemmed tree, large (up to 10m high), evergreen, spring flowering,
|6 to 9
|Sea buckthorn (Hippophae rhamnoides)
|Coastal, multi-stemmed perennial, highly nutritious berries, nitrogen-fixing.
|3 to 8
|Sea oats (Uniola paniculata)
|Ornamental coastal grass, perennial, tall (+1m)
|7 to 11
|Sea pink (Armeria maritima)
|Coastal groundcover, evergreen, flowers in spring and summer
|4 to 8
|White poplar (Populus alba)
|Broad canopy tree, large (+12m), deciduous
|4 to 9
Wind Breaks For Low Maintenance Coastal Landscaping
Integrating windbreaks into coastal landscaping designs is probably the most effective way to mitigate problems caused by extreme wind pressure. Among other benefits, properly designed windbreaks:
- provide shelter to the landscape (and people),
- reduce the need for landscape maintenance,
- increase the variety of plants that can be grown successfully in the landscape.
Windbreaks aim to slow wind down, rather than stop it entirely, so windbreaks should be designed to ensure that wind can pass through them. In contrast, solid structures make for poor windbreaks because they merely redirect winds without reducing their force.
The position of windbreaks is crucial to their effectiveness. They must, of course, be sited perpendicular to the direction of prevailing coastal winds. At the same time, their positioning must contribute towards the overall landscape design, rather than detract from it.
In general, a properly designed windbreak will give protection to a horizontal distance roughly equivalent to ten times its vertical height (though the level of wind reduction decreases as one moves further away from the structure). However, for maximum protection, windbreaks should be positioned at a distance of two to five times their height.
In highly exposed locations with intense wind pressure, landscapers can use two windbreaks positioned in parallel, which will provide a double-layer of wind protection.
Living or softscape windbreaks in the form of hedges and tree rows are perhaps the most attractive option. While softscape windbreaks take months or years before they provide meaningful protection from extreme coastal winds, they can be just as effective at reducing wind as hardscape windbreaks.
Plant selection is of paramount importance for establishing effective living windbreaks in coastal landscaping. Given that living windbreaks are positioned in the most exposed locations in the landscape, they should be composed of hardy, low-maintenance plants capable of bearing the full force of coastal gales.
Another important principle is to use plants of different heights. Living windbreaks that combine low-growing shrubs with medium and tall trees can provide wind protection right down to the ground level (where trees tend to be less effective as windbreaks).
In addition to the trees and shrubs mentioned in the table above, some reliable plants to use for living windbreaks include:
- Cotoneaster (Cotoneaster franchetti),
- Darwin’s barberry (Berberis darwnii),
- Daisy bush (Olearia macrodonto),
- Hawthorn (Crataegus monogyna),
- Rose dog (Rosa canina).
Mulching For Low Maintenance Coastal Landscaping
There are simple low-maintenance management practices that can greatly increase the chances of success in coastal landscaping. One of the most important methods in this regard is mulching.
Mulching is crucial for protecting soil and plants in coastal landscaping, and thus for reducing the time, effort, and money required to maintain the landscape.
Mulch is highly effective for:
- reducing soil moisture loss,
- maintaining stable soil temperatures,
- preventing salt build-up in soils,
- preventing soil erosion from strong coastal winds.
There are a wide variety of materials that can be used for mulching, from garden trimmings to straw, woodchips, stones, gravel, and plastic sheeting.
Organic mulches can add fertility to nutrient-poor coastal soils if adequate moisture is present. However, this means they don’t last very long. Lighter material like leaves and straw can also easily be blown away by strong winds, especially if they dry out. Organic mulch can also look untidy, and might detract from the broader landscape design.
The best types of mulch for coastal landscaping are durable, aesthetically pleasing materials such as gravel, stone, and seashell. These kinds of mulches also have the advantage of staying in place even in gale-force winds.
Aesthetic considerations are also crucial when selecting a mulch material. Mulch layers are incredibly effective for coastal landscaping, but their color, form, and texture should enhance rather than undermine the broader landscape design.
Watering For Low-Maintenance Coastal Landscaping
Watering practices can make a big difference in coastal landscape management. During the hottest parts of the year, even low-maintenance plants need to be watered at least occasionally to ensure that they thrive and look their best.
Drip irrigation is generally recommended for coastal landscaping. This method enables more efficient water use, while also greatly reducing the risk of fungal diseases because water is delivered directly to the soil rather than being sprayed over plant foliage.
The time of day that plants are watered is also crucial for lowering the risk of fungal disease in coastal landscaping. Morning time is generally recommended, while the middle of the day is probably the worst time to water, as the soil moisture evaporation will increase humidity levels around the plants, thereby increasing the risk of fungal disease.
Having said that, there may be situations when overhead watering can be beneficial. For instance, during sustained periods of high winds, most plants will benefit from a thorough weekly rinse to remove excess salt residue that might otherwise cause them damage.
Hardscape Ideas For Low Maintenance Coastal Landscaping
Some additional methods for low-maintenance coastal landscaping include the use of durable hardscape elements throughout the design. Selecting objects and materials that are aesthetically pleasing when weathered by natural elements can be a clever way to incorporate beautiful, low-maintenance hardscape elements into the landscape.
Rocks are excellent for this purpose. Artful placement of different-sized rocks can greatly enhance the aesthetic appeal of any coastal landscape design, and they require no maintenance whatsoever.
Wood is also an effective hardscape material for coastal landscaping. Rough, bare wooden poles and old railway sleepers lined along walkways can serve practical functions while also evoking the look and feel of coastal settings. Crucially, these wooden, hardscape elements offer a low cost and low maintenance addition to coastal landscape designs.
Another simple but effective technique for low-maintenance coastal landscaping is to use maritime and coastal-related artifacts. Not only are these items appropriate for the design context, but they are also the epitome of low-maintenance, given that they were intended for use in and around the ocean.
Low Maintenance Coastal Landscaping In Inland Areas
Coastal landscaping doesn’t have to be limited to coastal areas. The low-maintenance coastal aesthetic style can be successfully utilized in inland settings, and landscapers have the advantage of not having to deal with the challenges of harsh coastal conditions.
The coastal style can easily be replicated by following some of the guidance presented in this blog. Appropriate plant selection and arrangement are the foundation for creating an impression of being in a coastal setting. The strategic use of iconic coastal plant species alone can potentially transform an inland landscape into a coastal landscape.
Coastal landscapes can also be effectively replicated through the judicious use of ocean-themed artifacts like shells, stones, old rope and fishing nets, driftwood, and anchors. Using bright colors like light white, blue, and yellow is another easy but very effective way to recreate a coastal setting and atmosphere without being at the coast.
Recreating a coastal landscape inland also requires that the overall design should be relatively informal, with flowing organic lines. Neat geometric angles and lines tend to dispel the illusion of being in a wild coastal environment, and therefore should be used sparingly if at all when designing coastal-inspired landscapes.
Like any successful landscape project, coastal landscaping should be informed by the natural context of the site being developed. Observing and working with (rather than against) the local climate and soils are essential for establishing an attractive, low-maintenance coastal landscape.
This means every coastal landscape design should be different and should express the coastal aesthetic style and atmosphere in a way that is unique to the local area.