Plants need a sufficient area to grow and to attain sufficient essentials such as light, air, and nutrients.
Fortunately, since nutrients and water are available at the root in aquaponic systems, the plant will not need to space out its roots in search for these elements.
Because aquaponics supply plant food so efficiently, aquaponics can generally support a plant density of approximately twice that of a garden in soil.
As a result, a compact garden will provide healthy plants without those plants having to compete for vital resources such as water and nutrients.
Why Is Plant Spacing Important?
Ideal plant spacing is beneficial because healthy plants do not have pests.
Spacing plants adequately will allow uniform air circulation and light availability for photosynthesis and deter mildew.
Research conducted by Johnson et al. (2020) on flowering plants grown for essential oil production demonstrated improvement with optimal spacing.
In this study, essential oil production increased from 18% to 37% with proper spacing and pruning interventions.
What Determines Plant Spacing In Aquaponics?
The Plants That Grow In Your System
Different types of plant varieties will have different space needs, depending on size and their respective growing habits.
Because every plant is distinct, there will be specific recommendations provided for spacing, which you should find on the seed packet.
The seed packet will also give you an indication of how much space is needed when the plant is at a full growth size.
Remember, the spacing instructions on the seed bank packet are usually for soil gardens. So you can safely place more plants, because the aquaponic system can hold more plants.
A table below shows the space needs for twelve popular aquaponic plants.
The list is built from other professional farmers’ experiences and also based on what research has shown.
The table gives you a few of the most popular vegetables that are grown with hydroponics. This link will give you more information.
| Aquaponics Vegetable | Recommended Space Requirements |
|---|---|
| Basil | 15–25 cm (8–40 plants/m2 ) |
| Cauliflower | 45–60 cm (3–5 plants/m2 ) |
| Lettuce (Mixed salad leaves) | 18–30 cm (20–25 heads/m2 ) |
| Cucumbers | 30–60 cm (depending on variety; 2–5 plants/m2 ) |
| Eggplant | 40–60 cm (3–5 plants/m2) |
| Peppers | 30–60 cm (3–4 plants/m2, or more for small-sized plant varieties) |
| Tomatoes | 40–60 cm (3–5 plants/m2) |
| Beans and peas | 10–30 cm dependent on variety (bush varieties 20–40 plants/m2 , climbing varieties 10–12 plants/m2 ) |
| Head cabbage | 60–80 cm (4–8 plants/m2) |
| Broccoli | 40–70 cm (3–5 plants/m2) |
| Parsley | 15–30 cm (10–15 plants/m2) |
| Swiss chard or Mangold | 30–30 cm (15–20 plants/m2 ) |
Recommended space requirements for plants
The Plant’s Stage of Growth
As plants mature, they grow in size, and you have to keep their growing space requirement in mind.
You can tightly plant younger crops in their early stages when you are nursing them, but you will need to thin and transplant as they mature.
You could do a geometric calculation to understand how you will space your plants.
Here is a short way to get an idea of the number of adult plants you can fit on a raft:
- Determine the area of the raft on which you are going to plant -(Length X Width)
- Determine the area needed for one individual plant – (3.14 X r^2 of the plant)
- Divide the area of the raft by the area needed for the plant
The Method of Aquaponics You Practice
There are different aquaponic systems:
- The media bed
- Deep water culture (DWC)
- Nutrient film technique (NFT)
- Wicking beds
Different systems are going to be best used with different situations and plants.
Similarly, each of these methods are suited to different spacing requirements.
Depending on which aquaponic techniques are being used, you will want to implement different types of strategies, including:
- To deter birds from bothering your grow bed, plant some onions, mint, or scallions between your plants. They’re not going to take up much room, and birds don’t like them, which means they help keep them away.
- You should introduce ladybugs into your garden. They will take care of almost all the bugs on plants, too. You can get ladybugs at Home Depot. No need to get any pesticides, keeping things natural.
- You can even feed eaten leaves or yellowing leaves to the fish. It will eat them up, and your system will flourish.
- You should have a variety of crops so that even if you have a severe infestation, it won’t affect the entire aquaponics system as it would in a soil system. You will have the ability to grow a wide range of each crop and the strength of the system will support that.
- You should stagger your plants to plant and harvest on an ongoing basis to maintain the adequate balance of what each nutrient and mineral is contributing to your aquaponics system. You will also have continuous harvesting to enjoy fresh fruits or vegetables each plant’s time frame.
- Cover as much surface area as possible in your grow bed. You can plant the fast maturing vegetables in between slower maturing vegetables, such as salad green planted in between eggplants are tomato plants. This will be beneficial, as the salad greens will grow and be ready to harvest in time for you to give space for the eggplants.
Whichever strategy you are using will also determine the spacing for your plants.
Conclusion
The spacing of plants in aquaponics is more than only one element.
Use the guidance and tips above to assist in proper spacing of your plants to produce maximum harvest.