Although aquaponics is an excellent alternative to traditional farming, some plant crops are challenging to grow. These are the tuber-like ones or those plants that grow underground. If you plan on cultivating the mentioned crops, wicking beds are an additional construction for your aquaponics setup. This post will help you understand more about the purpose of wicking beds and how they can benefit your garden.
What is a wicking bed?
A wicking bed is a method of growing root-bearing vegetables below ground that both gardeners and aquaponic farmers utilize. To grow crops like potatoes and carrots, wicking beds can be used with other growing methods such as deep water culture and the media bed approach.
Wicking beds are an enclosed water reservoir that allows you to water your plants below the root zone. It's an excellent method for growing root vegetables.
It is important to note that a wicking bed is an adjunct construction. The bed is a separate part of your aquaponics system, which you use to cultivate hard-to-grow crops. Experienced aquaponics producers typically utilize a fiberglass tub at least 400mm deep for the bed, but there is no clear guideline for how deep it should be. Some folks make do with a discarded refrigerator or bathtub. You could use any container you choose as long as it doesn't leak.
Why is a wicking bed used in aquaponics?
Here are some benefits wicking beds bring in your aquaponics setups:
- Growing space expansion: The wicking bed is a reasonable space solution when it comes to expanding your growing beds. In fact, the amount of water that you can spare, determines the size limit of the wicking bed.
- Simple construction: Wicking beds require inexpensive materials and straightforward design. You may either use an old plastic container or build a larger bed out of reclaimed wood with a plastic liner to serve as a water reservoir.
- Conserves water: Compared with traditional farming, the grower can save 50% of water usage in aquaponics wicking beds.
- Low maintenance: Because the wicking bed is autonomous, it can operate on its own once you have calibrated the essential factors.
- Weed control: In aquaponics wicking beds, the top layer of soil tends to stay dry since these plants are watered from below. Weeds have a more challenging time establishing themselves due to this setup.
How does a wicking bed work?
A wicking bed resembles an aquaponics media bed, but rather than flooding and draining, the water is gathered in a reservoir underneath. Wicking beds are usually filled with any soil, fertilizer, or media you like as long as they can "wick" moisture up from underneath. The water is then wicked up through the grow media and into the root zone, providing water to the plants. Your fish tanks' nutrient-rich water will be used to fill the water reservoir as needed.
Unlike other growing methods, this water cannot be returned to the fish tank, as you may have guessed. From here, I would advise combining this strategy with other growing techniques.
What materials do I need to construct wicking beds?
- Raised garden bed: You have the option to use prefabricated galvanized steel or build your DIY timber raised garden bed.
- Pond liner: Many gardeners use a less expensive PVC pond liner, which isn't technically classified as food-grade plastic. Butyl rubber pond liners are a bit pricey, but they come with an extended warranty and are meant to not leak for a long time.
- Coarse grade scoria: Because scoria is highly porous and light and loaded with air holes, it's utilized for wicking beds. It's similar to a sponge in that it can fill with water and drain through. Scoria has less rock and more area for water in any given volume compared to other materials.
- Geotextile fabric: The soil is separated from the scoria-filled water reservoir beneath it by a geotextile fabric layer, which prevents the soil from clogging up and filling the space where the water is held. Geotextile fabrics are non-degradable synthetic materials used in landscaping. They're commonly sold as a fine-grade weed mat, which looks like see-through cloth, is relatively inexpensive, and comes in grey, black, or white colors.
- Soil mix: Use high-quality soil with plenty of organic matter when filling wicking beds. Your crops and herbs will benefit from a blend of 50 percent premium soil, 25 percent organic compost, and 25 percent organic cow dung.
- Water overflow outlet fitting: Use a 20mm (3/4′′) threaded tank inlet (bulkhead fitting) for the water overflow outlet fitting, then drill a hole into the side of the raised bed with a drill and the suitable drill bit or hole cutter.
- Water inlet pipe: The water inlet pipe, which is made up of two sections of 50mm (2") PVC pipe linked by a 90-degree elbow junction, is used to fill the wicking bed reservoir.
To make a wicking bed, you have to prepare a few tools. These are all required, and their intended uses are listed below:
- A spirit level for leveling the scoria layer in the wicking bed reservoir and the garden bed on the ground
- An electric or cordless drill and the suitable drill bit or hole saw cutter for the bulkhead fitting size
- A set of miniature spring clamps or screw clamps for holding the wicking bed's pond liner in place while filling it with scoria and soil
- To cut the pond liner, you will need a pair of scissors
What vegetable crops are recommended for aquaponics wicking beds?
Growing root vegetables or tubers in wicking bed aquaponics systems is highly beneficial. Potatoes, beets, carrots, lettuces, and most other vegetables fall under this category. However, these wicking beds are unsuitable for trees and other perennials with deeper root structures.
How should you take care of plants in aquaponics wicking beds?
Caring for your plants in aquaponics wicking beds is not much that different from safekeeping other aquaponics crops. Nevertheless, here are some practical steps you can observe to ensure the well-being of your wicking bed plants.
- Inspect for any nutrient deficiencies. When critical nutrients are not readily available in the fish excrement used to feed the plants in aquaponics, the outcome would be nutrient deficiencies. Deficiencies can hinder plant growth and make them more vulnerable to illnesses and insects. To avoid or treat plant nutrient deficiencies in aquaponics, you should know their warning signs and be prompt in dealing with them.
- Avoid overcrowding your plants. Overcrowding has various effects on plant growth, including increasing disease development, hampered fruit and flower output, increased insect and pest problems, and altering overall growth and development. Allelopathy is a natural defense mechanism that plants use to prevent overcrowding and protect themselves from the effects.
- Scan for leaks. Always keep an eye on the flow of water to see any leaks. If the leaks are not adequately treated, they might pose problems for the fish and plants. Checking for leaks will also guarantee that your system is getting enough oxygen.