Cauliflower will grow well in aquaponics, but it is one of the more difficult plants to grow effectively.
Because it has very specific growing needs for each stage of its life and can only be grown in one type of aquaponic system, it’s probably not the best plant for beginners. However, if you’re an experienced aquaponics grower or simply want a challenge, it’s definitely worth the effort!
Here’s everything you need to know about cauliflower and aquaponics!
Growing Conditions
pH: 6 to 6.5
Temperature: 68 to 77 F (20 to 25 C) during the growing stage and 50 to 59 F (10 to 15 C) for head formation
Germination: 4 to 7 days with temperature between 47 and 68 F (8 to 20 C)
Light Exposure: Full sun
Harvest Time: 2 to 3 months (spring crops) and 3 to 4 months (autumn crops)
Plant Height Maturity: 40 to 60 cm
Plant Width Maturity: 60 to 70 cm
Recommended Aquaponic System: Media Beds
Aquaponic Cauliflower Facts
- Cauliflower is a winter crop
- Cauliflower works best in aquaponic media bed units
- Cauliflower needs adequate spacing due to its width at maturity
- Cauliflower has a higher than average nutrient demand (comparatively)
- Cauliflower reacts very well to higher concentrations of phosphorous and nitrogen
- Cauliflower needs potassium and calcium for the production of the heads
- Cauliflower is very susceptible to fungus
- Cauliflower is very sensitive to environmental changes
- Cauliflower heads will not develop correctly in hot, dry, or very cold temperatures
How to Grow Cauliflower in Aquaponics
Cauliflower can be grown in aquaponics, but it’s probably not the best plant for beginners. Because it has very specific needs — temperature, spacing, high nutrition, blanching — it’s a little harder to grow than other vegetables and it may not deliver what you want on your first try.
BUT, that doesn’t mean you should avoid growing it altogether. If you’ve got some experience under your belt and you can get the growing conditions right, aquaponics is a perfect fit for cauliflower.
1. Germination of Cauliflower
Cauliflower can be germinated in several ways so pick whichever way you’re most familiar with and stick to it. Under the right conditions, cauliflower should take 4 to 7 days to germinate in temperatures between 47 and 68 F (8 to 20 C). Additionally, in the early seedling days, you’ll want to provide direct sunlight to the plant to keep it from becoming too “leggy.”
2. Transplant Your Seedlings
When your cauliflower seedlings have 4 to 5 true leaves (roughly 3 to 5 weeks), transplant your seedlings into your aquaponic media bed. Handle them carefully and only transplant during optimal temperatures. Additionally, you’ll want to space each cauliflower plant about 50 cm apart so they’ll have plenty of room to grow.
3. Preserve the Cauliflower Heads
If you’re growing white cauliflower, you’re going to want to do something called “blanching” to preserve the heads and ensure that they maintain a white, creamy color. This involves wrapping the heads with the plant’s own leaves so that sunlight doesn’t penetrate the curds and turn them brown.
Step 1: Secure the Curd
Once transplanted to your aquaponic unit, it should take about 30 days to get a 6 – 10 cm diameter cauliflower curd that’s roughly the size of a golf ball.
Once this diameter has been reached, fold your cauliflower’s leaves over the head of the plant and use a set of rubber bands to secure it in place. You’ll also want to ensure that:
- The rubber bands aren’t too tight as you want to give the plant plenty of room to grow
- The rubber bands aren’t too loose as they’ll fall off
- There’s no moisture in the leaves when you fold them up (cauliflower is highly susceptible to fungus)
Step 2: Monitor Your Cauliflower’s Bands
When it comes to blanching maintenance, all you really need to do is make sure the rubber bands are secure and fitted correctly. Additionally, if you’re growing several cauliflower plants at once, try using different colored bands each day so that you know which plants are ready to harvest and which ones are freshly wrapped.
Harvesting Aquaponic Cauliflower
Harvesting cauliflower in aquaponics may be a little more complicated than other vegetables (such as basil or tomatoes) but you shouldn’t be intimated by it either. When the heads appear white, firm, and compacted, your cauliflower should be good to go. Here’s how to harvest:
- Use a large, sharp knife to cut the heads off. Try to leave a few of the outer leaves wrapped around the cauliflower as this will help preserve the quality of the plant until it comes time to eat.
- Remove the rest of the plant from the grow bed. Because cauliflower won’t grow another head, you need to remove the rest of the plant from your grow bed after harvesting.
- Dispose the rest of the plant in a compost bin (recommended of course). If you’re growing cauliflower or any other vegetables, you might as well start composting too.
Benefits of Aquaponic Cauliflower
- Cauliflower works great in media beds
- Cauliflower in aquaponics can be grown year-round under controlled conditions
- There are plenty of fish you can pair it with
- Growing cauliflower in aquaponics is quicker than traditional gardening
- Cauliflower is a high-demand and high-value crop
- Successfully growing cauliflower provides a feeling of accomplishment!
Disadvantages of Aquaponic Cauliflower
- Cauliflower is difficult to grow in DWC or NFT systems
- Cauliflower has very specific temperature needs
- Due to its width, cauliflower needs a lot of room
- Due to its weight, cauliflower needs a sturdier setup
- Cauliflower can bruise easily
- Cauliflower is susceptible to fungus
- Harvesting cauliflower can be more labor intensive than other vegetables
- Heads won’t develop in hot conditions
- Heads won’t develop in very cold conditions
- Heads won’t develop in very dry conditions
Why Cauliflower Works Best in a Media Bed
Because cauliflower is fairly heavy and needs a lot of space, you’re going to want to grow it in a media bed (as opposed to DWC systems or NFT systems). Growing cauliflower in a media bed will provide the plant with a firm, sturdy base and will give it plenty of room to spread out.
FAQs
Is Cauliflower susceptible to pests?
Yes, like all plants, cauliflower is susceptible to certain pests. Common cauliflower pests include:
- white maggots
- Cabbage aphids
- Cabbageworms
- Flea Beetles
Does Cauliflower Have to be Blanched?
No, cauliflower doesn’t have to be blanched, but it is recommended if you want to preserve a white, creamy color. There are also several varieties of cauliflower that have been specifically bred to self-blanch.
What Kind of Growing Medium Should You Use for Cauliflower?
Most reports indicate that Hydroton (aka clay pebbles) are the best growing medium to use for cauliflower. However, we recommend experimenting with different mediums to see which one works best for you.
What fish should you pair Cauliflower with in Aquaponics?
As cauliflower is a cool-weather crop, it makes sense to pair it with a cool-weather fish. However, just remember that you don’t want to pair it with a fish that’s challenging or just doesn’t make sense in aquaponics. Try reading our Best Fish for Aquaponics guide to see which one you should use.