Grow more with less

By delivering essential nutrients directly to a plant's roots, hydroponics allows crops to grow without soil and, according to its advocates, often more efficiently than traditional cultivation methods. At its simplest, hydroponics is the process of growing plants with their roots suspended in nutrient-rich, oxygenated water. The term is derived from the Greek words hydro (water) and ponos (work), explains Justus Voigt, co-owner of Habitat Hydroponics.

"We often think plants need dirt to survive, but the fundamental realisation of hydroponics is that soil is largely a storage medium for water and nutrients, as well as a support structure for roots," he says. In conventional soil cultivation, plants expend energy developing root systems to search for water and nutrients. Hydroponic systems deliver those nutrients directly to the roots.

"By delivering balanced mineral nutrients directly to the root zone, the plant can direct more of its energy towards leaf, flower and fruit development," says Justus. Despite the science involved, he insists hydroponics is accessible to beginners. "You certainly don't need a PhD in aqueous chemistry," he says. "Most people can set up a simple system at home." For many urban Namibians, hydroponics has become more than a hobby. According to Justus, compact systems can make food production possible even in limited spaces. "Hydroponic systems are highly modular and ideal for small spaces. A vertical aeroponic tower, for example, can provide 36 planting sites within a footprint of just 35 centimetres in diameter." Whether on a sunny stoep in Windhoek or in a sandy yard in Walvis Bay, he says the systems provide an alternative for people with limited gardening space. Hydroponics also eliminates many common gardening challenges, including weeds, soil-borne pests and muddy work areas. For beginners, Justus recommends starting with a few essential components:

The essentials

A reliable light source, either natural sunlight or full-spectrum LED grow lights.

An inert growing medium such as clay pebbles or coco peat.

Hydroponic nutrients formulated specifically for water-based growing systems.

A pH testing tool to maintain water acidity between 5.5 and 6.5.

An air pump and aerator to keep the water oxygenated.

Getting started

Justus suggests a simple five-step process:

Choose easy crops such as lettuce, spinach or basil.

Fill a light-proof reservoir with clean water and add nutrients.

Adjust the pH to between 5.5 and 6.5.

Transfer seedlings into net pots filled with growing medium.

Monitor water levels daily and replace the nutrient solution every two weeks.

According to him, hydroponic crops often mature more quickly than those grown in soil. "Lettuce can be ready in 30 to 45 days, basil in about 28 days and spinach in roughly 35 days," he says. Many leafy greens can also be harvested repeatedly by removing the outer leaves while allowing the centre of the plant to continue growing. For those new to hydroponics, Justus recommends starting with lettuce, herbs, Swiss chard, kale and strawberries.

"Lettuce is the gold standard because it thrives in a water-based environment," he says. He advises beginners to avoid more demanding crops such as tomatoes, peppers and cucumbers until they gain experience.

"These plants require higher nutrient levels and more complex support systems," he explains. Hydroponics may also offer advantages in Namibia's arid climate. Justus says conventional irrigation can lose significant amounts of water through evaporation and seepage, while recirculating hydroponic systems use water more efficiently.

"In a recirculating system, the primary water loss comes from what the plant actually uses." Hydroponics can also overcome challenges associated with poor soils, salinity and rocky terrain. However, the technology is not without its challenges. Namibia's high temperatures can affect water quality and oxygen levels.

"Warm water holds less oxygen, which can increase the risk of root rot," says Justus. To counter this, growers often use shade nets, insulated reservoirs or cooling systems to maintain stable temperatures. He believes there is growing interest in home food production across Namibia. "We are witnessing a clear increase in demand for starter kits and home systems," he says. He attributes this trend to several factors, including rising food prices, increasing health awareness and concerns about climate resilience. For many people, he says, growing food has benefits beyond nutrition.

"Gardening provides structure, routine and a sense of achievement. I sometimes sit in my greenhouse after work and simply enjoy being surrounded by the plants and the sound of running water."

W: habitathydroponics.com E: [email protected] F: Habitat Hydroponics