Can’t keep on top of houseplant watering? Hydro crystals could be the answer, says AG’s gardening editor Kris Collins

My kalanchoe, peace lily and spider plant will need little attention

Hydro crystals provide water and basic air and nutrients needed for plants to grow. I’ve used the crystals with a number of houseplants, all of which are doing fine after several weeks in these unusual growing conditions – and I haven’t needed to water them once!

Retailers say the crystals can last for 18 months, perhaps longer if kept out of direct sunlight. They may likely shrink after a few months as plants draw moisture from them, but resoaking them for a few hours, will return them to size for continued use.

Step by step: Potting on houseplants in soil-less hydro crystals

Hydrate the crystals as instructed on the packaging. The packs I’m using require one litre of water. For strong growth add liquid plant food to the water (at the recommended rate) before hydrating.

Leave to soak for at least 12 hours so crystals can reach their optimum size before straining away excess water. A kitchen colander or sieve can be used without worry of contamination.

Take your chosen plant from its pot and wash roots to remove as much compost as possible. If delaying planting, wrap exposed roots in a wet cloth or damp newspaper, and keep moist until ready for use

Part fill a clear glass or plastic vase with a thick layer of the crystals before placing plant roots inside. The bouncy crystals seem to have a mind of their own, so pour in a controlled manner!

Hold the plant in position and fill the remaining space in the vase with more crystals. Aim to have the plant set at the same depth as it was in the compost. Top heavy plants may need extra support.