By Hayley Tia
As cruisers, many of us have left a wholesome green garden patch behind when we moved aboard. With the challenges of limited space, salt water, wind, and waves- a boat hardly seems a solid base to spread your roots. But then we wouldn’t be cruisers if we weren’t resourceful people! There are a number of healthy boat gardens sailing around the world and one such technique that always seems to yield a strong success rate is hydroponics. Within a vertical garden space spanning just 3ft, you can grow and harvest more than two dozen bundles of green goodness in just 4-6 weeks- all without the mess and weight of soil.
What is hydroponic gardening?
Hydroponics is essentially a garden without soil, using a nutrient solution to provide a balanced diet for the plant to reach its full genetic potential.
Why grow hydroponically?
Produces a higher yield- This is a technique that is highly efficient, with plant growth rates between 30-50% quicker than those grown in soil. Since adequate water and nutrients are delivered straight to the plant’s roots they are able to put more energy into growing above the ground rather than below the surface seeking the nutrients they require.
Better-quality produce- By feeding the plants this balanced nutrient-rich ‘diet’ you streamline the whole lifecycle for larger, more nutrient-dense crops, far more quickly.
Maximize space, minimize weight- Hydroponic gardens require far less space to grow than those in soil. Without the need for large root systems, each plant requires only a small reservoir of liquid to survive and happily grows in a vertical stacking system.
Conserves water- It may seem counterintuitive, but growing plants hydroponically uses up to 98 percent less water than those grown traditionally in soil. With a correctly functioning system, very little water is evaporated and there is no water runoff waste.
Less labor- Without the need for weeding, herbicide, and insecticide application, there is a huge reduction in labor but also in health risks associated with pest management and soil care.
Setting up your Hydroponic System Aboard
It’s important to spend some time assessing the best location for your hydroponic garden patch.
The key factors you need to consider relate to the obvious natural elements you are battling:
Wind: Finding a spot that is out of the direct wind, might mean under the dodger, above the transom, the aft deck or maybe you have some space indoors in a well-lit berth or head.
Sun: It’s no surprise that this garden will need plenty of natural daylight to yield a successful crop. Many hydroponic gardening landlubbers offer this via artificial lights but for many of us, this is unrealistic for our power consumption. Instead, why not make use of a resource that we already have plenty of uninterrupted access to! The best sun is indirect sunlight.
Waves: Position your system high enough that they don’t get salty splashes on a regular basis. On the rare occasion you have excess salt spray, give your plants a quick spray with fresh water to remove any salt that may be deposited on the leaves.
We have had great success with our hydro system positioned under our solar panels on our davits. It provides adequate protection from the wind, indirect sunlight and is high enough to avoid any salty splashes.
The Style of System
We have researched a number of different systems but the style that we have had the most success with is our PVC pipe system. We used 50mm PVC pipe, with 40mm holes drilled into one side at approximately 120mm apart, capping the ends. This allows you to have a reservoir of space that is not exposed to natural sunlight given the pipes opaque color, reducing any algae or mold growth but it is also easily cleaned, creating a very sterile environment which is paramount for successful growing.
There is a variety of mediums you can use to hold the plant in place; (using small baskets filled with either coconut coir, perlite, clay pellets, gravel, or Rockwool). We trialed a few varieties but found that a standard pool noodle works the best. They are readily available, easily cut to size, mold perfectly to the plant as it grows, eliminates evaporation, successfully plugs the holes to prevent sloshing water whilst sailing, AND can be used again and again.
With regards to oxygen and movement in the water, this is one such area that we have never had issues with. Being a constantly moving vessel our hydroponic system enjoys the natural movement of the boat all day, every day! We did, however, add some battens to ensure the movement of water wasn’t too great. These battens were off cuts of pool noodle positioned at regular intervals along the pipe to stop the water from gaining too much momentum whilst sailing.
Types of plants
The joys of sailing mean we often find ourselves in a variety of different locations and therefore a variety of different climates and weather patterns. For this reason, it is important to select plants that are already thriving in the area that you are cruising. These plant species clearly already enjoy these conditions and will have the best chance of growing aboard.
One way to find which species are in season in your region is to head to the local farmer's markets to check out what is in abundance. In warmer climates, these might include Asian-style greens like Bok Choy, Morning Glory, Amaranth, Brazilian Spinach, Thai Basil, and Cilantro. In cooler climates, it might be a variety of lettuces, Kale, Oregano, Rosemary, Thyme, and Mint.
We tend to opt for greens and herbs rather than fruiting plants as we gain a far higher yield of produce and they also tend to be a little hardier for this style of system. Anything that grows up rather than out struggles in this constant state of movement- but this is not to say it is impossible!
Sprouting greens for your garden
By far the easiest option to get your garden underway quickly is to propagate or ‘clone’ greens you already have on hand. Many plant varieties that work well in a hydroponic system are also very easy to clone from cuttings. Basil cuttings from its ‘growing tip’ can be kept in a glass of 25% strength nutrient solution in diffused low light in a warm humid environment and before long adequate roots will form, at which stage it can be added to your hydroponic system. Cuttings should be approximately 3” to 5” long and include no more than two sets of leaves. This method means you not only reduce any replanting shock (given you are shifting from one water source to another) but you will get to enjoy your harvest in as little as a few weeks from planting.
Another alternative is to sprout your own varieties using a micro-greens set-up, see our article about Microgreens HERE. Sprouting your seeds in shallow seedling trays and gently remove them when they are a few inches. Be sure to carefully clean all the roots of the soil before planting into your hydroponic system. This option does take a little longer and requires a little extra love and care when transferring to the hydro system, but you may still be able to enjoy your first harvest in as little as 4 weeks depending on the plant variety and your growing conditions.
Watering and Nutrients
A common misconception with hydroponic gardening is that plants are fed ‘steroids’ and chemicals to get them to grow more quickly, when in fact most nutrient solutions are simply a perfect balance of natural minerals that all plants need to grow. It is even possible to make your own solution using seaweeds and salts- but that is a whole science lesson in itself!
The store-bought hydroponic solution is often found in powder form and can be purchased from your local gardening store. There is also an increasing range of organic solutions on the market as well. Given the small size of your system, one packet of solutions may well last you for years- with the ability to create hundreds of liters. Follow packet instructions to mix your solution with water ensuring you calculate your ratios carefully.
When it comes time to harvest this can be a great time to train your plants. Clipping them from the center or high branches, to encourage lower wider growth patterns. Tall, top-heavy plants will likely fall and produce very little compared to their wider companions.
Recent times have highlighted the importance of self-sufficiency on a yacht, and this clean, lightweight and productive system has the potential to provide a significant food source for you and your crew with very little effort. Who doesn’t want a handful of fresh basil on their bolognese, a garnish of mint in their mojito, or a fistful of spinach with their poached eggs!
What is the best water source for your hydroponics system?
It is possible to use either desalinated water or water from a land source. Particularly in your greens infant stages, we recommend testing the pH of your water quality. You can pick up a simple pH test kit from your local hardware store. These kits are usually designed for swimming pools and are readily available, costing only a few dollars.
Ideally, most plants tend to thrive with a pH of around 5.5 to 6.5.
To raise the pH add only a sprinkle of baking soda and to lower add a few drops of regular household vinegar. This is a careful balancing act- a small amount of these pH-altering ingredients can vary your pH greatly.
Is hydroponics a way for the future for many landlubbers?
Maybe…. With increasing populations, climatic changes, lack of water, deteriorating soil quality, and reduced space there is a growing need for alternative methods for horticulture. Hydroponics allows many to have fresh foods when normally they may not have the opportunity. For some time now, hydroponic systems have been used aboard naval submarines and in Arctic research stations, supplying the crew with fresh fruit and veggies. There is now more research into producing similar systems in developing countries particularly where space, soil, and water are limited.
Do you have any more questions?
Add them to the comments below and we will do our best to answer them.
A liveaboard sailor and professional copywriter, creating content from the cabin of her floating home. Prior to life on the water, Hayley owned and operated a seaside cafe for over 7 years whilst starting a degree in marine biology. She now enjoys the space and time the liveaboard life has given her and enjoys preparing nutritious meals in the galley as well as utilising her qualifications as a yoga instructor to lead morning yoga sessions on the beach at each new anchorage.
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