Gardening along the coast presents even the most skilled gardeners with challenges not encountered elsewhere. Natural conditions along the coast create a very hostile environment for garden plants. Wind, salt spray, dry sandy soils as well as actual sea water can make gardening along the coast difficult. All of these factors can cause problems for landscape plants and effect how they grow. In fact, few plants can survive full exposure to the ocean so site preparation and plant selection is perhaps even more critical here than anywhere else. Despite these difficulties, however, there are techniques and guides you can follow to create a more favorable environment for your favorite plants.
Building windbreaks as protection from the elements is essential to creating hospitable garden spaces along the coast. Windbreaks should be planted with indigenous seaside plants. Here in Massachusetts, Rosa rugosa, bayberry and eastern red cedar have developed along the coast and have proven their ability to survive the harshest of seaside conditions. They also create more diversity in the garden as well as a habitat for native wildlife. Find out what grows naturally in along the coast in your area and use those plants to create a protected garden space. Begin the screen with a planting of lower growing shrubs such as the above mentioned bayberry and rosa rugosa. This will be the first line of defense against the ocean winds and salt spray. Next, plant rows or massings of taller evergreens such as eastern red cedar, this will dampen the winds even further. Though the goal is to provide protection and create a retreat and from the harsh seaside winds, design a planting plan which still allows for beautiful views.
Along with wind and salt, dry and sandy coastal soils can present gardeners with a challenge. Sandy soils are very well drained and don't hold enough moisture to satisfy the needs of most plants. This holds true for some distance inland as well. In order to remedy this situation till the soil and add a fairly large amount of compost, manure and peat moss. This will help the soil retain the moisture necessary for plants to survive.
Follow standard planting practices. Dig holes for trees and shrubs about twice the diameter of the root ball and just as deep. Place the plant in the hole being careful not to disturb too many of its roots. Also, always plant so that the top of the root ball meets the existing grade of the garden. Planting too high or especially too low will result in early plant decline. Begin backfilling the hole, at about half way fill the hole with water and let it settle. I usually do this twice to make sure there are no air pockets. Finish backfilling the hole then create a saucer around the trunk of the plant, mulch well and water again.
When planting a lawn along the coast the sandy soils create the need for extensive site preparation. For lawns to thrive the soil requires a certain amount of water retention. For best results, begin with 6" of topsoil. Topsoil holds moisture well, provides necessary nutrients and will prevent the leaching of fertilizers. When seeding, use a mix of Kentucky bluegrass, fescue and rye. However, use a higher percentage of the drought resistant varieties of turf such as fine fescue, red fescue and hard fescue. Be sure to water your lawn deeply. Shallow, frequent watering leads to weak root systems which remain close to the surface. An alternative to a vast lawn is to allow native grasses to grow into a meadow, just be sure to mow them at least once each season to prevent trees and shrubs from taking hold.
With proper planning, tree and shrub selection and planting technique, seaside gardens can thrive. Gardeners along the coast will find the work involved in overcoming difficult site conditions well worth their time and effort, after all the greater the challenge the greater the reward.