This involves growing a plant without pot­ting soil, using an inert substance as the means of support, and supplying all the nutrients in the water. The plant needs watering less frequently (often only every 2—3 months), and there is less risk of overwatering or drying out.

The chosen plant must be suited to moist conditions, able to adapt to a new way of life, and tolerant of partial shade, since if the container is clear glass, algae will be a problem if it is placed in direct sun. Many containers are suitable for hydroculture, from the simple hyacinth glass to more complex double pots where the outer pot is the reservoir for an inner on? containing the plant and aggregate.

Supporting mediums

Many inert substances can be used as the support­ing medium, including Hydroleca, gel, and clay granules. Hydroleca is a lightweight, expanded clay aggregate, available as small pellets that are produced with a honeycomb center and a firm casing, which both holds and conducts water. Gel works on the same principle as the water-retaining geIs available for outdoor containers and hanging baskets, but here they are used without soil.

Dry crystals, which need to be soaked in water and liquid plant food for several hours before use, can be colored for instant effect. Clay granules are available as a whole kit, with a water indicator and fertilizer. The granules soak up moisture and release it back to the plant as needed.

Care of plants

The roots of the plant should never sit in water, because this will cause them to rot. All excess water not absorbed by the medium after watering should be drained off. For best results, use a cutting rooted in water, since it will already have succulent roots. The younger the plant, the higher the chance of successful conversion.

Fertilizing

Each medium has its own fertilizing regime, particularly if it has been purchased as a kit, so be guided by the advice on the pack. In general, fertilizer is applied when the water is refilled. However, ‘if the plant looks pale or yellow between waterings, the nutrient may not be sufficient, and a foliar feed should be applied once a week.

Gel hydroculture

This technique involves growing plants in water retaining crystals, rather than in soil.

• Measure dry crystals into a waterproof container and start adding the water., according to the instructions on the pack. As the gel begins to swell, add more water.
• Keep applying more water over several hours, leaving the gel to absorb as much as it can. Drain away any excess water. The gel is now ready to use.
• If clear gel is required it can be used immediately as it is. For colored gel, add food coloring to vary the shade or match the plant.
• Choose a cutting that has been rooted in water, since it will already have succulent roots to cope with the moist regime.
• Plant, gel, and container can all be chosen to complement their room setting, creating an unusual and low-maintenance focal point.