Planting on the Beach

Gardening editor Carolyn Ernst advises on successful techniques for planting a thriving garden beside the seaside. Tips on soil and salt resistance make for the perfect result.

June 13, 2018
Pacific Island Living

Pacific Island Living

June 13, 2018

Water is essential to life and as fresh clean water in the 21st century becomes an increasingly scarce commodity, our fascination with and love of water increases. The seaside house, either as your main residence or your holiday getaway, is becoming ever more popular. However if you are into gardening this choice needs to be thought through and you need to understand the compromises you will need to make. Seaside gardens, to varying degrees, come with issues, both in the form of soil type (or lack of) and salt exposure. These both limit the range of plants you can grow. If this limitation does not sound like you then perhaps a riverside or sea view property might be more to your liking. I went through this process and decided that I wasn’t really a seaside person and my gardening was more important than the accessibility of the five or six swims I had each year. I ended up with the best of both worlds; my property is bordered by a fresh water stream that does not flood and on the horizon I have sea views.

If you are a keen gardener, then the location of your new garden or home is very important. There are several things other than longitude and latitude that affect how you can garden and what sort of plants you can grow and will have a lot to do with the decision of what sort of garden you will have – a big thumbs down to an alpine garden in the tropics. Mind you, once you have mastered the art of growing things, most gardeners relish the challenge of growing something, when told it is not possible.

Understanding your location is the secret to a happy garden. If moving to a new area and starting a new garden or even renovating an old one, then the old advice of having a good hard look in the gardens around you stays true. If renovating an old garden, start by having a good look at what is flourishing and what seems to be struggling or just not doing its best. There are many reasons a plant will not be looking its best, sometimes it is just the season, maybe it just does not have the space or light that it requires, it might just not be in the right place for it at all. The question is, can this problem be fixed, or is it worth the effort? If the answer is no, then the plant should be replaced or moved.

Beside the seaside

Most seaside gardens have the problem of soil quality to some degree. This does not mean that you cannot grow anything. Deciding on a natural look on the very edge of the sand beach is often the best decision. Beach lilies are very happy here but watch out for the caterpillar that comes around about once a year. If you have nothing else Mortein works, although the better solution is a good drenching of organic caterpillar spray. Most beach lilies will survive even the most vicious of attacks, but can be extremely unsightly for long periods of time while they are first ravaged and then recover.

Golden cane do well, but will grow much slower in sandy soils. This can be improved by digging an extra-large planting hole and filling it with good soil and organic matter that will boost the initial growth. Other plants that survive in this harsh coastal strip are frangipani, allamanda and oleander, they come in many beautiful shades and make colourful additions to your garden. Remember they are all poisonous to some degree – mostly it is the sap, if care is taken then there is very little risk, just make sure the leaves and branches are not put in your mouth. Coconuts and sea frangipani (cerbera manghas) both do well in this coastal area as does the large spider lily.

More sensitive plants can be grown in the lee of your buildings but please take a good hard look at your soil to begin with. Given time and much effort you can build up your soil quality and quantity, but in the beginning you may need to import enough soil to build your garden beds. Remember the old saying, a $10 plant needs a $100 hole. The understanding of the basic requirement of a plant to be able to root and grow and draw its food from an adequate area is absolutely vital. I use a minimum of 20cm of reasonable soil for grass and very small plants. Larger palms and trees will require a 1 cubic metre hole for long-term health. Do not skimp on the basics. This is laying down the foundation of your garden and long-term plant health. Remember that shallow-rooted plants will suffer more in the dry season and, while this can be solved by watering, the water restrictions in many areas do not allow this, so what water you are allowed to use should be saved for your very special plants.

Remember to shade

Always remember to plant you precious delicate plants somewhere close where you can really appreciate the special effort you take with them. This will also make it easier for you to spend the extra time that it takes to look after them and monitor them for any issues. Entrance gardens and courtyards are good places for them.

If buying soil make sure you know the type of soil you are getting. If you have a seaside garden, go for a heavier organic soil, this will mix with your existing lighter, sandier soil and benefit your soil’s water retention and overall soil health. Some alluvial soils tend to be a little light and do not add much benefit to your sandy soils.

Salt exposure is the other main problem with seaside gardens. Understanding the trade winds and salt spray spread is important. There can be huge differences in salt issues within small distances. Properties near reefs, in trade wind-vulnerable locations will have real issues with salt damage.

Seashore trees offer the only protection from salt exposure. There is an increasing desire to remove trees on the shore line for the panoramic view; people are greedy, they want to see it all, but they should appreciate the importance of the framing effect and protection these trees give. Judicial pruning and removal of damaged or weedy trees is good but please consider the time and effort these trees have taken to grow in the often inhospitable soil and they are very hard to replace. Consider the benefit of the shade they cast and the importance of the tree roots in preventing coastal erosion.

It is important to leave as many trees as possible on the shore to try and block some of the damaging salt load. There are trees like Tamanu, Sea Oak (Casuarina) and Pandanus that seem to cope with even the worst location.

Tamanu is a very beautiful tree, lovely green shiny leaves and, for a tree that survives to a very great old age, it is also quite fast growing. The beautiful old trees seen around the shores in Vanuatu are absolutely stunning, many having their own special personality that is derived from the many storms and experiences they have survived. Unfortunately the latest problem most of them are facing is the erosion of coastal areas caused by sand mining and the stupidity of people that light fires in the buttresses under them. If you are lucky enough to grow a Tamanu tree you could make your own healing Tamanu oil.

Wind in the leaves

Pandanus is stunning and can be cultivated in two ways. They may be left to grow tall and stately, removing the suckers that grow underneath. Nothing is more beautiful than a pandanus loaded with big round fruit silhouetted against the tropical sunset. Pandanus can also be kept short and used as a screening plant; this is done by allowing the under suckers to grow and removing the older plants as they get too tall. Many people try to save money and use the wild pandanus – these are OK to use if you want the tall stately look and are also very easy to transplant (given the right equipment). However, if you want the shorter screening look or want to start with younger plants, be aware of the danger to you, your family and visitors of the sharp serrated leaves.

Sea oaks are perhaps not a tree most people would plant but they are very quick growing and will grow in the most desolate of soils. They are easily pruned and I have seen them used as a hedge or even topiaried. The noise of the wind through their leaves is something you either love or hate.

Also in your garden make sure you make the space for all of the seasons. If your garden is open to the trade winds then you will want to make the space for a nice area that is protected from the gales during this time of the year. These multiple living areas are important for you to maximise the use of your garden. Having a nice shady space to sit and relax at lunch time could be very different to the sunny position that you enjoy when you are having your morning cup of tea.

Subscribe to our Newsletter

Pacific Island Living