Before we get into what are the best plants for aquaponics there are some preliminary decisions required. Firstly, what vegetables do you want to grow and are these suitable for growing in an aquaponics system? A large variety of vegetables can be grown so, assuming that they are, what space is available for the setup? What type of system will be the most appropriate?
I will be covering these aspects and more in this article and finish up by outlining some of the best vegetables to grow, using aquaponics.
First decide on the size of your aquaponics system
The best plants for your system depend on a number of different things. One of the main things to think about is the size of the setup that you will be using. A small aquaponics kit is going to have fewer fish and less waste, meaning lower nutrient concentrations. However, bigger systems will have more fish and hence more waste, with a higher concentration of nutrients. This decision is imperative so you can determine the sort of plants that would be right for you.
Suitable plants for a small aquaponics setup
Small greens and herbs are ideal for less nutrient-dense and smaller systems that require lower nutritional inputs. Some of the best plants for aquaponics systems that are on the more modest side, are radish sprouts, pak choi, watercress, basil, chives, mint, arugula, Swiss chard, spinach, kale, and lettuce.
A small system will enable you to grow leafy greens, for your salads and a selection of herbs. So, if you do not feel ready to go for a large system just yet, but you want to try it out, a small tank can be perfect. It is a great choice for beginners.
Plants to grow in larger aquaponics systems
However, if you are ready to go for a bigger aquaponic layout your choice of possible plants to grow will be greatly expanded. These systems are more nutrient-dense and they can grow plants that have both high-nutrient and low-nutrient requirements.
Large systems can grow the herbs and greens mentioned above, as well as tomatoes, peppers, cucumbers, beans, squash, peas and even broccoli, cauliflower, and cabbage.
In simple terms, larger, fruiting legumes and plants demand a lot of nutrients and energy. Due to their size, they need an increased growing area. It also takes a lot of potassium, phosphorus, and nitrogen to grow these larger varieties of vegetables.
To provide this increased demand for nutrients, more or larger fish are required. The increase in the number and size of the fish, and the added need for growing space, means that a larger setup is needed, to support the growth of the bigger plants.
Factors to think about when selecting the best plants for aquaponics systems?
Virtually any plant can be grown using aquaponic methods. Nevertheless, different plants have different requirements and they also thrive in different conditions. Before you begin selecting what plants are going to be right for your aquaponics system, it is vital to think about the following things:
What sort of growing system will you use?
Different plants have different root structures and this will determine the best growing method to use. There are three main types of aquaponics systems, which are as follows:
- Deep Water Culture (floating rafts)
- Media Bed
- Nutrient Film Technique
Plants with a shallow root system, such as lettuce and kale, will flourish well in a nutrient film system or floating rafts. Grow beds are ideal for root vegetables.
What are your plants’ needs?
As a rule of thumb, your plants will grow better if their nutritional needs are similar to the requirements of the fish in your setup.
Select fish and plants that have similar requirements as far as pH level and temperature are concerned, as the closer they match, the greater success you will have. A digital pH meter is a helpful instrument to determine the pH level of the water.
As I have already mentioned, some plants have higher nutrient requirements and are more suited to larger setups. Plants that require a lot of nutrients include cabbage, broccoli, beans and peppers.
You also need to consider your plant needs in terms of your own level of knowledge and experience. For beginners, lettuce is often a good choice to start, as it does not need a lot of maintenance.
What do you want to grow?
Aside from the considerations that have been discussed so far, you need to think about what you want to grow, when looking for the best plants for your system. After all, your aquaponics adventure is likely to go better if you are growing plants that you actually want to use or eat.
At the end of the day, if you are excited or passionate about something, you’re going to get extra enjoyment and be more dedicated, right?
This is why it is vital to think about what you want to achieve in your system. Doing so is going to enable you to make the right decisions on the varieties of plants you wish to grow.
How many fish are you going to be using in your system?
You also need to think about the number and type of fish in relation to the number of plants in your system.
Generally speaking, you should have one-inch of fish for every gallon of water. This then impacts on the number of plants you can grow.
Should you intend growing a large number of fish, more plants are going to be required. Balancing this means that all of the nutrients can be absorbed from the fish waste.
How much space is needed?
I have already discussed the size of the overall setup. A further matter to consider is the growing room, required by individual plants. Some plants will demand more space when compared to others.
Because of this, you need to carefully think about the width and height that is required for plants to grow, as well as the number of plants that your system will accommodate.
What is your local environment like?
Finally, you need to carefully consider the environment as well. The amount of rain, temperature range, and sunlight are all critical in the growth and development of a healthy plant. If you decide that you are going to grow outdoors, select a number of vegetables that will grow most effectively in your climate.
You could always opt to grow indoors or use a greenhouse, but you must look for plants that flourish with artificial sunlight or limited light. It is advisable to look for a plant that will thrive in your local climate, as this will reduce the power costs for maintaining your system.
To give you a better understanding of this, here is a summary of the plants that perform better in the warmth and those that perform better in the cold:
- Some of the best plants for warm environments include tomatoes, shallot, parsnip, parsley, garlic, chives, peppers, and cucumber.
- Plants that prefer a cooler setting include beets, winter squash, sweet potatoes, kale, potatoes, onions, strawberries, herbs, cauliflower, carrots, cabbage, and Brussel sprouts.
Choosing the best plants to grow with aquaponics
Let’s now take a look at some of the best plants for aquaponics growing systems.
Cucumber is an evident choice for this style of gardening, as it is a water-based plant. Growing them aquaponically will provide your cucumber plants with everything they need to flourish.
Media-based aquaponics systems are the best for cucumbers, and a water pH between 5.5 and 6.5 is optimum. They love sunlight and warmth and a lot of nutrients.
Cucumbers grow fast and do spread. Care should be taken to ensure that the root system does not block the flow of water.
Kale is a great option for a beginner to aquaponics or when starting up a new system. It is not too demanding of nutrients but the roots need to be kept moist, so a floating raft system is ideal.
Traditionally, kale is a cool weather crop and thrives in a water temperature range of between 55°F and 70°F with a pH scale of 6 to 7.5.
Growing kale, using aquaponics speeds up the growth cycle and the leaves will be ready to pick in about 6 weeks.
Lettuce is one of the most productive and easiest leafy greens to grow. It thrives in either a grow bed or floating raft system, in water that has a temperature between 70°F and 74°F. This range suits most varieties of fish.
You can either start your seedlings directly in your aquaponics system or use a seed germinating tray and transplant them. Plant them 7 inches apart and they will be ready to harvest in 4-5 weeks.
There are many different varieties of peppers, that can be grown using the aquaponic method; from hot chilli peppers to sweet bell peppers. In a controlled setting they can be grown all year around.
Peppers prefer full sun exposure and warm weather conditions. For optimal growth, a daytime air temperature of at least 70°F is required. The water should be maintained at no less than 60°F and have a pH range of 5.5 to 6.5.
If you choose to grow peppers, I recommend opting for a media bed system. The plants should be provided with a support structure to bear the weight of the foliage and the fruit.
Strawberries are an excellent choice for aquaponic cultivation but the water quality needs to be carefully monitored. It is necessary to balance the number of fish so that all the waste is converted to nitrates. Excess unconverted ammonia can kill your plants. The plants will also need extra potassium, to encourage the setting of the fruit.
Strawberries grow best in a soil-less growing medium, such as clay pellets, and a water pH of between 5.5 and 6.5 is ideal. They prefer cooler temperatures and thrive in an average daytime range of 65-70°F.
Using an aquaponics system you can provide a controlled environment that can be adjusted to create the ideal conditions, for growing tomato plants. Tomatoes enjoy warm weather, in the range 65-85°F, and a plentiful flow of nutrient rich water, of similar temperatures.
Extra potassium may be needed to encourage fruiting. A media bed system is best for tomato cultivation. The roots of the plants should be in contact with the water flow but not saturated. Planting should be 1 to 2 feet apart and a structure provided to support the plants as they grow upward.
Finally, if you’re looking for a herb to grow in your aquaponic setup, I would recommend basil. Basil grows at a rapid pace, and my personal favorite is Thai Sweet Basil. It has a light spicy flavor, which works well in plenty of different dishes.
Basil is a good choice for growing aquaponically or hydroponically because it is naturally tolerant to moisture and heat, as well as being very fast growing. Germination can take place within five days and the basil can be ready to harvest within just 25 days.
So, there you have it: matters to consider, when you are deciding what are the best plants for aquaponics. I hope that this article has been helpful and provided you with insights into some of the options that are available to you, to establish and run a thriving and productive aquaponics growing system.