Information

 

Plant species We are often asked which plants grow well in an aquaponics system and it seems that most herbs and vegetables adapt well to aquaponics. Of course some plants won’t do as well when using different methods, media filled beds seem to be the most successful for growing a large range of plants, and you can grow just about anything. We often hear people say “But isn’t aquaponics only good for leafy green plants?” This is a fallacy that has perpetuated for quite some time, but as you will see from the list at the bottom of this page, aquaponics will grow just about anything. This Habanero chilli plant on the right grew a fantastic crop of super hot chillies, and a single tomato plant in a nearby grow bed produced well over 30 kg of tomatoes. Some other fruiting varieties that perform well are; eggplant (aubergine), capsicum (bell peper), bean, peas and many more.

Root crops? What about root crops? No problem, although you are probably better off growing potatoes in the ground, they will still grow successfully in an aquaponic grow bed. Carrots are another great root crop in media beds, carrots harvested from grow beds have no sand on them and although you might wonder, how they grow in a bed filled with gravel they do a surprisingly good job. Beetroot are another winner, we grow a lot of fresh beetroot and they grow to a fantastic size if you let them go for long enough, the beetroot on the left was over 1kg.

What about deficiencies?

Just as with all gardening you may get some deficiencies in your plants, but generally this can be dealt with very simply. Seaweed extracts are a great way to supplement almost all minerals that might be lacking in an aquaponic system, seaweed extracts come in many different forms, and consideration towards harmful additives needs to be paramount as anything you add in the system will be passed on to both fish, bacteria, plants and you. You can also use powdered mineral substances. There are a number of different ones on the market, but once again, you must take care in their application if you haven’t used them before, remember, it’s not just the plants your caring for but also the fish and the bacteria population. The best way to stay on top of deficiencies, is to use a good quality aquaculture feed for your fish. Most good quality feeds have a percentage of ocean caught bi-product, this means that there’s a good range of minerals and trace elements within the fish feed. We have some systems that have not had any supplemental addition of minerals, for well over 12 months and plant growth is exceptional.

 

Can I plant seeds?

Definitely. In media filled beds we generally use a combination of seedlings and seeds. When first planting a grow bed in a new system, we recommend sprinkling a mixture of seeds over the grow bed, as well as planting seedlings in the bed. Planting seedlings is simple, we recommend that you use normal seedlings, but before you plant the seedlings, wash off the majority of the potting mix from the root ball in a small bucket of water, the potting mix should wash off fairly easily with just a gentle shake in the water.

While planting out the seedlings in the beds the media agitation causes the seeds that were sprinkled over the bed before, to fall down in between the media where it can absorb water and safely germinate. During planting trials I’ve found that this method has many benefits. As the seedlings grow and shelter the germinating seeds they tend to dominate the beds, and many of the germinating seeds can only grow very slowly, however, once the planted seedling matures and gets harvested, this opens up the canopy giving the small plants that germinated from seed a chance to take off. These plants now have a mature root system, and a great head start so they can grow very quickly. This mimics natural forest ecosystems, where young trees and other undergrowth grow quite slowly, until a large tree dies and the canopy opens up allowing light to get to the lower plants, which then stimulates their growth.

What are growth rates like?

Growth rates of plants in aquaponic systems can be quite phenomenal, in fact a trial by Dr Nick Savidov in Canada, found that aquaponic growth rates can exceed hydroponic plant growth by up to four times with some vegetables and herbs. The advantage of aquaponics over soil grown vegetables is that, during warm weather the plants get as much water as they need, due to the regular flooding of grow beds in an aquaponic system. Plants grown in the ground can use the water around their root system, very quickly in hot weather, leading to wilting from a lack of water very quickly, on a hot day. Plants in an aquaponic system get watered constantly, so they always have water, no matter how hot the weather is.

	Here are some young plants in a grow bed, Joel Malcolm photographed these everyday to keep a record of the growth rates of the plants. The bed was planted with different varieties of basil, mizuna, cucumber and broccoli
	13 days after the first photograph, all of the plants are growing quite well
	25 days from the first picture. Joel has already harvested a couple of cucumbers and there are many more to come, with plenty of fresh herbs and salad greens also available.

 

Joel has grown chives that were over one metre in length in the same system as you see above..

 

This is a list of plants that grew well for members of the BYAP online discussion forum, this is by no means an exhaustive list of all plants that will grow well, just a few of the great performers that forum members have grown.

 

Simpson’s Curled (Lettuce)
Oregon Sugar Pod (Peas)
Bloomsdale Savoy (Spinach)
White Bunching (Onion)
Tomato (Grosse Lisse)
Tomato (Beefsteak)
Cucumber (Lebanese)
Silver Beet (Giant Fordhook)
Lettuce (Cos)
Lettuce (All seasons)
Basil (Sweet green, purple, curly leaf and Thai)
Rainbow Chard
Parsley (Flat leaf and curly leaf)
Numerous tomato varieties (the only tomato variety that hasn’t grown well was pineapple)
Watercress
Yugoslavian watercress (also known as Lebanese watercress or Bulgarian watercress)
Chives (normal and garlic variety)
Chillies, many varieties, haven’t found a variety that hasn’t grown well yet
Celery
Kohl Rabi (Purple vienna)
Cicoria Variegata
Snow peas
Egg plant (Black beauty)
Capsicum (Californian wonder, Yolo wonder, Long sweet yellow)
Bok Choy
Broccoli
Cabbage
Cucumber (Burpless, Armenian)
Mizuna
Rocket
Coriander
Garlic
Dwarf beans (Butter beans)
Sage
Lemongrass
Yarrow
Comfrey
Rockmelon

 

Of course the plants you grow in your system may be limited by the type of aquaponics system you have, or more to the point, the type of plant growing system. If you have an NFT system you will not be growing carrots or large tomato plants because the small NFT pipes will not allow such growth. If designing your own aquaponic system you must put some thought into your plant growing method, and what you want to grow. This is one of the reason why we like deep media filled beds at Backyard Aquaponics, when you have deep media beds there are no limitations on growing different plants.