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Water-retaining granules can be added to growing medium to increase its ability to retain water for longer periods of time. They may help reduce the demand of frequent watering during dry spells and are particularly handy in hanging baskets and containers, and where coarse-textured free-draining potting media is used.
Water-retaining granules swell to many times their size when wet and act as a helping hand with watering. Keeping lots of containers and hanging baskets wetted can be very time-consuming but by adding granules to the compost at the time of potting it may reduce the amount of times you would need to water.
However the addition of granules does not replace the need for regular checking of container plants for watering needs, especially when the plants are growing strongly and during dry weather.
Hanging baskets: The granules should be added to the growing medium as the baskets are being made up, at the manufactures recommended rate. Hanging baskets can be difficult to water, have little growing medium and dry out quickly as they are often high up and exposed to the wind. Adding water-retaining granules may help reduce the effects of water stress and produce a healthy, full basket. However, it is also important to use a fine-textured potting medium as well.
Containers: Pots that are crammed with plants or have fast-growing plants in them such as annual climbers are more likely to benefit from the addition of granules than those containing drought-tolerant or slow-growing plants such as succulents. Add the granules when you are re-potting a container or when you are planting up a new container.
For plants in the ground: Mixing in plenty of organic material such as composted garden waste is more effective than adding water-retaining granules to the soil.
Taking cuttings: Some water-retaining granules can be used neat and swollen with water as a rooting medium for cuttings in the same way that cuttings can be rooted in jars of water.
Cut flowers: Add water to the granules as instructed and then put them in your desired container and add flowers. Food dyes can also be added to give different effects. However, always follow individual product instructions as different quantities of the product are needed for different purposes.
Water-retaining granules do break down over time; one product claims it breaks down within five years. So when your growing media with the granules added is spent, it can be added to your garden compost pile. This can then be used either as mulch or dug into the soil as a soil conditioner.
Container maintenanceHanging basketsJohn Innes potting compostPeat-free growing mediaWater: collecting, storing and re-usingWater: using softenedWatering
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