Best Plants to Grow in Aquaponics: A Beginner's Guide
Some of the best plants to grow in aquaponics are the most commonly grown vegetables, leafy greens and herbs such as lettuce, Asian greens, rocket/arugula, basil and parsley. These plants have relatively low nutrient requirements, which makes them a great choice for beginners and newly established aquaponics systems.
As the fish grow, feeding rates increase and more nutrients become available, you can start growing larger plants such as broccoli, cabbage, tomatoes, cucumbers, capsicums/peppers and eggplants.
Some plants do better in media beds, others NFT or DWC while some, like potatoes and carrots, do well in flow through wicking style grow beds or pots.
Grow what you eat
Grow what you eat is probably the best piece of advice I can give you when deciding what to plant in your first aquaponics system, or any garden at all really. I think it's better to keep things simple by planting a few easy to grow varieties with low nutrient requirements that will provide you with a fast and tasty harvest when you first start off as mentioned above.
As the fish grow and you increase the amount of feed going into the system, the amount of nutrients available to the plants will also increase. This gives you the opportunity to gradually introduce larger and more nutrient-hungry plants as the system matures.
So there’s no need to try to grow everything at once. Start with plants that are easy to grow, harvest what you can and then experiment with other varieties as your system develops.
Choosing the Best Plants for a New Aquaponics System
The trick is knowing which plants to grow at different stages of nutrient build up in your system as it "matures".
Leafy greens and herbs are generally the easiest place to start because they don't require as much nutrient as large fruiting plants.
NFT
Nutrient Film Technique
DWC
Deep Water Culture
Media Beds
The type of root system a plant develops is also worth considering. Fast growing plants with relatively small root systems can work well in NFT and DWC systems, while larger plants can require considerably more space and support.
Although plants such as carrots and ginger can be grown in aquaponics, I prefer to use suitable wicking-style beds or pots rather than trying to grow them in a conventional media bed.
Let the Fish Help Guide Your Plant Selection
The amount of fish feed going into an aquaponics system is a useful way to estimate how much plant growing area the fish can support. The following is the rough fish-feed-to-plant ratio I like to recommend to beginner aquaponics growers. These feed ratios generally correspond to the 3 groups of plants, light, medium and heavy feeders, listed in this article.
The amount of feed going into the system is closely related to the number and size of fish you're raising. If you're unsure how many fish your system can safely support, have a look at my guide to Aquaponic Fish Stocking Rates, where I explain how grow bed and biofilter capacity influence the number of fish you can raise.
I think a good feed to grow bed ratio for plants with low nutrient requirements is 20-50g / 0.75 – 1.75oz of fish feed* per 1 M² / 9ft² of grow bed area. That means when you first start out you may have some vacant beds until the fish grow, feed rates increase and plant available nutrient increase over time.
Once you hit about 35g / 1.25oz of fish feed* per 1 M² / 9ft² of grow bed area you can start thinking about adding plants that require medium amount of nutrients.
Plants that require high feed rate are generally your fruiting plants. For these plants, I like to feed between 50-80g / 1.75-2.8oz of fish feed* per 1 M² / 9ft² of grow bed area.
*Fish feed with 30% or higher levels of protein
Fish Feed Rates Help Determine the Fish-to-Plant Ratio
A Note About Nutrient Requirements
It's worth remembering that a plant's nutrient requirement isn't a simple measure of how much nitrate (nitrogen) is in the water as some would suggest.
Aquaponics systems generally provide plenty of nitrate through the breakdown of fish waste (you can read more about this process in How Aquaponics Works) while other nutrients such as potassium, calcium, magnesium, iron and some trace elements may become limited depending on the type and amount of feed fed to the fish.
For this reason, when I talk about plants as having low, medium or high nutrient requirements, I'm talking about their overall nutrient requirements.
As the fish grow and their feed rate increases, the nutrient load of the aquaponics system also increases, allowing plants with different nutrient requirements to be grown.
Best Low-Nutrient Plants for Aquaponics
Leafy greens and herbs are a great place to start in a new aquaponics system as they are generally light feeders with lower nutrient requirements than larger and more nutrient hungry fruiting plants.
the smaller lettuce & Asian greens are a great choice for those utilising smaller set ups such at the Chop & Flip IBC Aquaponics System.
Once the fish feed amount and plant available nutrients increase you will be able to plant out larger fruit bearing plants if you have the space.
Lettuce
Lettuce is probably one of the easiest plants to start with that grows to harvest size quickly.
There are plenty of varieties available, including loose-leaf, butterhead and cos/romaine types. Loose-leaf varieties can be particularly handy because you can harvest a few leaves when you need them and allow the plant to continue growing.
Lettuce is also well suited to NFT and DWC systems with commercial farms preferring these methods above media beds.
Asian Greens
Asian greens like bok choy or pak choi, choy sum and mizuna are all light feeders which make them great fast-growing crops in a new aquaponics system. They also grow well in NFT & DWC.
Rocket / Arugula
Rocket, also known as arugula, is another relatively quick-growing compact crop that can be useful when starting an aquaponics system. You can harvest the outer leaves regularly in cut and come again fashion. They to grow well in NFT and DWC.
Radishes
Radishes are another option that provide a crunchy root as well as a peppery green leaf you can harvest as it grows.
They are also considerably quicker to mature than many other root crops.
Spinach
Spinach grows very well in aquaponics, however your local growing conditions can make a considerable difference to how well it performs if you live in warmer climates.
If it gets pretty hot where you live, try switching to heat-tolerant alternatives like perpetual spinach or silverbeet / chard.
Herbs
Herbs are another good choice for a beginner aquaponics system, and the selection is very broad.
Basil, coriander/cilantro, parsley, chives, thyme, sage and oregano are herbs that do well in beginner aquaponics systems.
One of the great things about herbs is that you don't need a huge plant before you start harvesting and reap the benefits from your hard work. They are all generally long-lived plants that will provide tasty harvests for months, if not years in some cases.
Peas and Beans
Peas and beans are also considered to be light feeders.
While they can be planted out from the get-go, I think it is better to start of with lettuce & other leafy greens as they will be ready to harvest in as little as 25 days, depending on variety and climate of course. You can also pack in more greens per M²/ ft² than you can these bushier plants.
Climbing peas and beans are a great choice if you have a way to support them at the edge of a grow bed. They won’t take up much space this way unlike bush bean varieties so would make them a better choice when planting out a new system.
Mint and Watercress – A WORD OF CAUTION!
A quick word on growing mint and water cress. These are recommended by some as great beginner’s herbs to use in aquaponics systems. I would suggest you leave these varieties until you have a bit more experience.
The reason being is that both can quickly overgrow a large media bed with greenery and roots if not harvested regularly.
I suggest they be grown in small dedicated beds where they can be kept in better check without the fear of them overgrowing other plants in the beds.
Best Medium-Feeding Plants for Aquaponics
Once your feed rates increase providing more nutrient rich waste you can start to look at planting out plants that are considered medium feeders.
Plants included in this group are the larger brassicas, namely broccoli, cabbage, kale, cauliflower etc.
Along with these you can pop in silverbeet / Swiss chard, onions, beetroot and carrots if you are game enough to grow them in beds with light media like clay or scoria/lava rock.
Broccoli, Cabbage and Cauliflower
These larger brassicas grow really well in aquaponics, but they do take a lot more space and time than lettuce and other leafy greens.
These plants can also become quite large, so it can be wise to plant them in their own dedicated beds. I recommend that they are grown in media beds due to their weight when fully grown and root ball size.
Kale
Kale is a brassica that can provide harvests over a longer period than many of its family members. Rather than harvesting the whole plant, you can pick individual leaves as required and allow the plant to continue producing.
Collards
Collards are a great brassica for those that live in warmer climate. Collards are relatively compact and, like their family member kale, are a great cut and come again plant you can continually harvest from through the growing season.
Silverbeet / Swiss Chard
Silverbeet, or Swiss chard, is particularly useful for home aquaponics because it is a fast grower than can produce leaves over an extended period. Rainbow chard is a great choice for those wanting to add some colour to their aquaponics.
It is also a good spinach substitute for Australian and other growers that live in warm-hot climates.
Celery
Celery likes plenty of moisture so is well suited to aquaponics. It’s a relatively compact plant that can take 3-4 months to reach a good harvestable size. You can also harvest the individual stalks as you need them or allow the plant to continue to form a single head you can harvest.
Celery is sensitive to extreme heat events and generally performs better during the cooler part of the year in hotter climates.
Beetroot
Beetroot grows well in aquaponics and, like radish, can provide you with a leafy harvest as well as the root. We like to pick a few leaves while waiting for the root to develop. Don’t take too many though as you could stunt the growth of the beet.
Carrots
Carrots are another plant that can be grown in aquaponics, but they aren't necessarily the easiest crop to grow in a conventional media bed. If you want to give them a go, I recommend using a shorter growing variety in a lighter growing medium like clay or scoria / lava rock. They will come out a bit “dimpled” and sometimes twisted so they might be one to grow in a soil or sand based wicking beds or pot.
Onions, Leeks and Garlic
Onions, leeks and garlic can also be grown in aquaponics but they aren't going to give you the rapid harvest that you get from leafy greens. They can take up to 8 months depending on variety and climate.
Best Fruiting Plants for Aquaponics
Plants that require high feed rate are generally your fruiting plants.
The most commonly grown heavy feeders in aquaponics are tomatoes, eggplant / aubergine, capsicums/sweet peppers, chillies, strawberries cucumbers, zucchini / courgette and other cucurbit family of plants.
These plants generally require considerably more nutrients than lettuce and other leafy greens due to their production of fruit. They also have much larger root systems which makes media beds the best option for most backyard growers.
Tomatoes
Tomatoes are one of the most popular fruiting plants grown in aquaponics and grow best when the system has sufficient nutrients. Keep in mind, the vining “indeterminant” varieties can grow very large so make sure you have adequate space to trellis them.
I have had better results from compact “determinant” varieties that tend to grow to a set size then fruit.
Cucumbers
Cucumbers, like all cucurbits, grow really well in aquaponics as they always have access to water.
They can grow rapidly and produce a large amount of foliage, so they need plenty of room and good support. They are another plant that would be best planted near the edge of a bed and allowed to grow over a trellis. There are a few compact cucumbers available that would suit those with limited growing space.
Zucchini / Courgette
Zucchini / courgettes also grow well but they do take up a fair amount of room. You can allow them to grow over the side of a bed or support them vertically with some twine which does help to conserve space. You can also remove older leaves without damaging the plant which will free up growing space under the plant as it matures.
Capsicums / Sweet Peppers and Chillies
Capsicums / sweet peppers and chillies are all members of the genus, Capsicum and grow very well in aquaponics. Different varieties vary in height from 300-900mm / 1-3ft in height and can take up a sizeable portion of grow beds.
A single plant can continue producing for months and in some climates will grow as a short-lived perennial.
Eggplant / Aubergine
Eggplant is another larger fruiting plant that grows well in aquaponics. There are also a fairly large variance in the height of different varieties with compact plants starting at about 300mm / 1ft tall the way up to 1200mm / 4ft.
Like tomatoes and capsicums, it is better suited to a system with a good supply of available nutrients rather than a brand-new system and can take over a grow bed if left unpruned.
Strawberries
Strawberries are a little different from many of the other plants in this section because they are relatively small plants and will grow well in NFT, DWC and media grow beds. Commercial and backyard growers will often make use of vertical growing spaces by planting strawberries in towers or grow pipes along walls.
Plants for More Experienced Aquaponics Growers
Potatoes, sweet potatoes, gingers and turmeric, as well as fruit trees, can also be grown in aquaponics.
These aren't necessarily plants I would recommend for someone setting up their first system, but they can be fun to experiment with once you have a good understanding of how your system works.
Potatoes and Sweet Potatoes
Potatoes and sweet potatoes do not grow well in conventional media beds, so I prefer to grow them in soil based wicking beds.
These beds are often set aside from the main system while still being irrigated by the aquaponics water.
This way they get the nutrients from the soil as well as a constant liquid feed from the aquaponics system.
Ginger and Turmeric
Gingers and turmeric are very heavy feeders and generally take a long time to grow. You can grow them in traditional aquaponics grow media and the plants will grow well. You will find that pieces of media will get caught up in the irregular growth pattern of turmeric and ginger rhizomes.
I prefer to grow them in wicking beds fed by aquaponics water alongside the other beds in the system.
This approach gives the plants access to soil nutrients as well as the nutrients being supplied by the aquaponics water.
The root sections also look better and are easier to clean come harvest time when grown in soil.
Fruit Trees in Aquaponics
It is possible to grow larger plants and even some fruit trees in aquaponics, although they obviously require considerably more space than lettuce or herbs.
The fruit trees I've seen do well in aquaponics are papaya and dwarf bananas.
Mind you, that's in the subtropics here in Australia but I can't see any reason why other varieties couldn't be grown in media or wicking-based grow bed systems provided there is enough space in the grow beds for their roots and nutrients available in their beds.
If you decide to experiment with fruit trees, make sure you consider the eventual size and weight of the plant. You will need to have them grow in grow beds that can handle their eventual weight.
Watch: Choosing the Best Plants for Your Aquaponics System
If you're still wondering what to plant in your aquaponics system, the video below walks through some of the things I consider when choosing plants to grow in a new aquaponics system.
The main thing to remember is that every aquaponics system is a little different. Your climate, growing method, fish stocking and feeding rates will all influence what grows best. Start with a few easy-to-grow plants you actually enjoy eating, then branch out and experiment as your fish grow and the system matures.
In the end, the idea isn't to grow every variety available. Just grow what plants you know you’ll consume, while maybe branching out to grow a few that you’d like to try.
Want to Learn More About Backyard Aquaponics?
If you're new to aquaponics and would like to learn more than I've covered in this article, I've put together an Online Aquaponics Beginner's Guide to help you understand how the whole system works.
The guide takes you through the important parts of backyard aquaponics, including how aquaponics nutrient cycle works, system design, fish stocking, cycling, water quality, filtration, plant selection and keeping everything running once your system is established.
It's based on the same practical backyard aquaponics methods I've used and shared through my videos over the years, but organised into one place so you can work through it at your own pace.