Aquaponics brings together fish farming and plant cultivation in a sustainable, circular system. But for this aquatic garden to become truly productive, you need to know which plants to choose.
Aquaponics rests on a delicate balance between fish, plants and bacteria. For the system to work properly, each element must play its part. Plants are not there simply to produce food: they purify the water, absorb nutrients from fish waste and play an active role in the stability of the whole setup. But not all plants adapt equally well to this growing method.
Here is some good news to start with: the list of species that thrive in aquaponics is far longer than most people expect. Salads and herbs lead the way, but tomatoes, strawberries, chillies and even some tropical crops find their place once the system is mature and sufficiently productive. The real criterion is not the species itself, but how well its requirements match the current state of your setup.
Choosing the right plants to grow in aquaponics leads to better yields, prevents imbalances and simplifies day-to-day system maintenance. In this article, you will discover which plants are easiest to grow, which to avoid, and the key criteria for building a productive, long-lasting aquaponic kitchen garden.
For beginners, it is advisable to start with easy-to-grow plants. The aim is to get the system up and running whilst ensuring an encouraging first harvest.
Leafy vegetables are particularly well suited to the early stages of an aquaponic system. They have relatively low nutritional requirements and a short growing cycle, which means you can quickly observe the positive effects of the fish-plant ecosystem.
Lettuces and salad leaves: these are the classics of aquaponics. They grow quickly — in around four to six weeks — tolerate temperature fluctuations well, and require only a moderate nutrient concentration. They are ideal for getting to grips with how the system works. One word of caution, however: once water temperatures exceed around 26 °C, they bolt and turn bitter.
Spinach and chard: these leafy crops are also extremely well suited. They cope well with variable conditions and can be harvested leaf by leaf over successive cuts, which extends the production period. Nutritious and valued in the kitchen, they offer an excellent effort-to-yield ratio.
Lamb's lettuce, rocket, watercress, and microgreens: even faster-growing, these crops are sown densely and cut as needed. They are perfectly suited to small grow beds and floating raft systems alike, and are very forgiving for those just starting out.
One final advantage is worth highlighting: these leafy vegetables do well in moderate light. Where a tomato plant demands a greenhouse or a south-facing position, a lettuce is perfectly happy on a well-positioned windowsill or under a supplementary LED grow light. That is what makes them the ideal starter crop, whether indoors or out.
Herbs are among the most popular plants in aquaponics. Their high culinary value, rapid growth, and modest nutritional requirements make them ideal candidates.
Like leafy vegetables, they can be grown with relatively few nutrients and adapt well to a young system that is still settling in. Another significant advantage: most of these plants can be harvested gradually, leaf by leaf, without compromising their development. This allows for continuous production over several weeks, or even several months.
Basil, mint, chives, and parsley: very easy to grow, they thrive in the constant moisture of the grow medium and offer a generous yield. They are the stars of aquaponic systems, often used in educational demonstrations.
Coriander, dill, celery, and shiso round out the selection nicely. Coriander bolts quickly in warm weather, which makes it worth sowing in small successive batches rather than all at once.
Thyme, rosemary, and oregano: although more Mediterranean in character, these plants can also be grown in aquaponics if placed in a drier area with a more free-draining grow medium. They require a little more attention but fit well into a diversified approach. In practice, the edge of the growing bed, or a pot filled with a coarser grow medium, suits them better than the centre of the trough.
From an economic standpoint, these are probably the most rewarding crops in a home system. A bunch of basil or mint is expensive per kilo, keeps poorly, and often travels long distances out of season. Having a ready supply at hand genuinely changes the way you cook.
Many fruiting vegetables — plants grown for their fruit — can also be produced in aquaponics, although they require a little more attention. Solanaceous crops make up the bulk of them: tomatoes, peppers, chillies, and aubergines.
The tomato is the most widely grown of all. Cherry varieties and smaller-fruited types are easier to manage than large beefsteak tomatoes, as they reach maturity faster and tolerate a slight nutrient deficit more readily. Plan for sturdy staking, a grow medium bed rather than a raft system, and plenty of space, as the root system is substantial.
Peppers and chillies need warmth and time. They are excellent candidates for a greenhouse or a well-lit indoor space, where they can even overwinter and grow again the following year. Chillies, being more compact, are well suited to smaller systems.
The aubergine is the most demanding of the lot, both in terms of heat and nutrients. It performs very well in a greenhouse, in a deep grow medium bed, but remains a gamble in a young system or one with a small fish population. You can also add cucumber and courgette to the mix — highly productive, but hungry and bulky plants.
What all these crops have in common is their nutritional requirements, which are considerably higher than those of salad leaves or herbs. Make sure your fish population is producing enough waste to feed them, and keep a close eye on classic deficiencies in potassium, calcium, and iron, which often appear at fruiting time.
Two practices make a significant difference. The first is pollination: indoors, without insects or wind, a simple daily shake of the flowering stems, or a brush with a soft paintbrush, noticeably improves fruit set. The second is pruning: removing side shoots and limiting the number of flower trusses concentrates the available nutrients on what truly matters.
The strawberry is arguably the most spectacular crop in aquaponics, and one of the most rewarding. Its root system is shallow, it appreciates consistent moisture without excess, and it lends itself remarkably well to vertical growing.
That last quality is precisely what makes it so interesting. On a growing tower, around thirty plants occupy less than a square metre of floor space. The fruits hang freely in the air, stay clean, do not rot against the grow medium, and can be harvested at a comfortable height without bending down.
Choose ever-bearing varieties, which crop in successive flushes from June through to the first frosts, rather than large-fruited varieties that produce everything within three weeks. Start from young plants rather than seed, as germination is slow and unreliable.
Two points to watch. Strawberries have a high potassium demand during fruiting, and it is often this deficiency that limits yield in a young system. As with tomatoes, indoor growing also requires a helping hand with pollination, otherwise the fruits remain small and misshapen.
Other soft fruits fare less well in domestic aquaponics. Raspberries, redcurrants and blackcurrants are perennial shrubs with substantial root systems that tolerate having their roots permanently in water very poorly. Blueberries require a highly acidic grow medium that is difficult to reconcile with the pH of an aquaponic system. It is therefore better to keep them in the ground and reserve the system for strawberries.
Aquaponics opens up some interesting possibilities for tropical species. Consistently warm water, high humidity, and a steady supply of nutrients replicate their native conditions fairly well. In a heated greenhouse or a bright conservatory, several crops become viable.
Ginger and turmeric are among the most accessible, provided they are planted in a deep grow medium bed where the water level drops back noticeably between cycles. These are rhizomes — they tolerate permanent immersion poorly, but respond very well to warmth and nutrient-rich water.
Thai basil, lemongrass, and kaffir lime behave much like conventional herbs, though they are a little more sensitive to the cold. Lemongrass, in particular, thrives with its roots in water and produces impressive clumps within a single season.
Passion fruit is a vigorous climbing plant capable of covering several metres of trellis in one season. It requires space, a sturdy support structure, and an already well-established system, but its growth in aquaponics is often remarkable.
Vanilla is, by its very nature, a genuine challenge. It is an epiphytic, climbing orchid that scales a support rather than rooting into a grow medium. It requires high atmospheric humidity, several years of patience before the first flowering, and hand-pollination flower by flower. None of this is impossible in a warm greenhouse, but it is very much a hobbyist's project rather than a commercial crop.
Finally, bear in mind the energy implications. At our latitudes, all of these crops require maintaining warm water for a good part of the year. They are most worthwhile if your pond is already heated for the fish.
Here is a rather niche avenue that is generating genuine interest in research circles: growing halophytic plants — that is, plants adapted to salt. Samphire is the best-known example, with its fleshy, crunchy stems that are highly prized in the kitchen. You can add sea aster, rock samphire and glasswort to that list.
One point needs to be made straight away, because it changes everything: these plants need saline or brackish water to perform at their best. They therefore have no place in a conventional freshwater aquaponic system, where the fish could not tolerate the salinity required.
Their natural environment is saline aquaponics, still largely experimental, which pairs species that tolerate brackish water — certain shrimps, notably prawns — with halophytic crops capable of making use of the effluents. The advantage is twofold: producing high-value vegetables, and treating water that would otherwise be difficult to manage.
For the home grower, this remains something interesting to know about rather than a crop to launch tomorrow. If you fancy experimenting, run it as a separate loop and never mix that water with the water in your freshwater pond.
You need to choose plant and fish combinations that share similar environmental preferences. For example, warm-water fish such as tilapia require water at around 24 to 28 °C, which is ideal for plants like basil or tomatoes, whereas cold-water fish like trout are better suited to crops that prefer cooler conditions, with lettuces and spinach at the top of the list. Make sure the temperature range, water pH and even hardness are suitable for both partners in the system.
A simple rule of thumb: start by identifying the temperature your water will actually reach throughout the year, then choose your fish, and finally the plants that thrive within that same range. Working backwards from the crops you dream of growing often leads to heating a pond all year round or stressing the fish.
pH is the second point of compromise. Plants prefer slightly acidic water, around 6, while nitrifying bacteria work best at around 7.5. The usual compromise sits between 6.5 and 7 — a range where everyone manages without being perfectly comfortable. It is one of the few values genuinely worth monitoring on a regular basis.
More fish means more nutrients in the water, which benefits the plants — up to a point. Too many fish, and therefore too much waste, can overwhelm the system and compromise water quality, while too low a density will not provide enough nutrition for your plants.
Finding the right balance for your system is all part of the process!
At the top of the list sit root and bulb vegetables — carrots, potatoes, onions, and beetroot. In a constantly irrigated grow bed, roots and tubers are prone to deforming, rotting, or remaining stunted. A radish or a young beetroot can, however, succeed in a deep bed where the water level drops back noticeably between cycles.
Other slow-growing plants or those with an overly large root system are also best avoided. Fruit trees and shrubs, for instance, are simply not feasible in a domestic aquaponic setup given their size and longevity.
Likewise, plants that prefer arid or very acidic soils — certain heathers or cacti — will not thrive in a continuously moist environment.
Be wary, too, of heavy-feeding crops planted into a young system. The species itself is not the problem — the timing is: a courgette or melon planted in the first few weeks will exhaust the available nutrients and stall, whereas it would perform perfectly well a year later.
Finally, one rule that admits no exceptions: never introduce a plant purchased from a garden centre into the system without thoroughly rinsing its roots, and certainly not one that has recently been treated with pesticides. The slightest insecticide residue goes straight into the fish water, where there is no soil to buffer it.
Aquaponics allows you to grow a wide variety of plants, from easy-to-grow leafy vegetables to more demanding fruiting plants, as well as aromatic herbs that adapt particularly well to this type of growing. The choice of plant species must be made in line with the maturity of the system, the nutrients available and your growing objectives.
One final piece of practical advice: progress in stages. Salads and herbs in the first season, tomatoes and strawberries once nitrates have stabilised, and exotic crops once running the system no longer requires you to think twice. Each step makes the next one considerably easier.
With a little observation and experimentation, it is possible to gradually fine-tune the balance between fish, plants and filtration to achieve a productive, stable system. Aquaponics is above all a learning process: every setup evolves over time, shaped by conditions, trials and accumulated experience.
Starting simply, respecting the needs of the ecosystem and observing how it functions on a regular basis are the keys to a productive and sustainable aquaponic kitchen garden.
Sources
University of Latvia et projet TransFarm, Plants in Aquaponics : Selection, Requirements and Limitations, Suitable species, temperature and pH ranges, and the special status of root vegetables.
Virginia Cooperative Extension, Calculating and Using Daily Light Integral (DLI), SPES-720NP, Quantified light requirements for lettuces, basil, tomatoes and seedlings.
Oklahoma State University Extension, Nitrification and Maintenance in Media Bed Aquaponics, Target pH and nitrate readings for a system considered stable.
New Mexico State University, Aquaponics, Circular 680, Effect of pH on nutrient availability and the usual nitrate range.
Eck, Körner et Jijakli, Nutrient Cycling in Aquaponics Systems, Springer, 2019, Sources of available nutrients and typical deficiencies in potassium, calcium and iron.
University of Florida IFAS, A Practical Guide for Aquaponics as an Alternative Enterprise, HS1252, The link between fish feed ration and the sustainable growing area it can support.
A system that has just been set up does not yet produce enough nitrate for hungry plants. The most reliable indicator is not the calendar but your test results: until nitrate stabilises within a range of around 60 to 70 ppm, with no ammonia or nitrite spikes, stick to lettuces and herbs. Depending on fish stocking levels and temperature, this stabilisation typically takes anywhere from a few weeks to a few months. Planting a tomato too early won't cause lasting damage, but the plant will stall and take up a useful space.
Almost, with one caveat: above approximately 26 °C in the water, it bolts and turns bitter. In summer, aim for partial shade or cooler water.
Light often determines the choice of species more reliably than nutrients do. It is measured as daily light integral, expressed in moles per square metre per day. The benchmarks published by the Virginia Tech extension place lettuces at around 12 to 17, basil at 15 to 25, tomatoes and cucumbers at 20 to 30, and young seedlings at just 5 to 10.
In practice, a north-facing windowsill, or a room lit without a horticultural lamp, peaks well below these figures. A grow bar delivering 200 µmol per square metre per second over sixteen hours provides roughly 11.5 moles per day, which suits leafy crops but is not enough for a tomato.
The conclusion is useful when making your choice: in a poorly lit space, do not try to compensate through fertilisation — grow leafy vegetables and herbs instead, and save fruiting crops for a greenhouse or a sunny outdoor spot in summer.
Confusion between the two is common and can cost weeks of progress. A few simple pointers:
When in doubt, remove the plant and inspect its roots before touching anything in the water.
Impossible, no; demanding, yes. The training materials from the TransFarm project place them among crops that require a specific grow medium and irrigation method, rather than among species to be ruled out altogether. A radish or a young beetroot can succeed in a deep clay pebble bed, provided the water level drops noticeably between cycles. A long-rooted carrot, however, remains a poor bet in a domestic system.
Yes, and it is often a good idea. Nasturtiums, French marigolds, and borage attract beneficial insects and act as early-warning indicators, as they react quickly to any imbalance. Two points to bear in mind: never introduce any plant that has been treated at a garden centre, as the residues will go straight into the fish water, and avoid ericaceous species, which will tolerate neither the pH nor the constant moisture.
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