Taking care of container plants
Plants thrive in warm well-drained potting mix, but to remain healthy they need a little more watering and feeding than the average garden plant. Top quality container mixes give a balanced blend of ingredients designed to combine optimum drainage with best possible water holding capacity. Most also contain controlled release fertiliser to get plants off to a healthy start.
Plants in pots need more frequent feeding than those growing in the ground. Feed little and often with liquid fertiliser or use controlled-release fertiliser. Concentrated powdered fertilisers are best avoided for plants in pots as they can burn roots. Quick growing annuals respond well to frequent feeding with liquid fertiliser, but make sure your potting mix is moist before applying.
In summer, daily watering is the necessary norm for plants in pots. In very hot dry weather you may need to water twice a day, especially when its windy. Windy weather accelerates water loss through leaf and pot surfaces.
SAVING SUMMER WATER
Choosing drought tolerant plants is a great place to start if you want to water less over the hot summer months. The next trick is to slow down water loss by evaporation. Hot summer temperatures and air movement conspire to strip moisture from plant and pot surfaces, so its best to avoid windy locations, especially for hanging baskets. Pots grouped together can shelter each other. The choice of pot will also make a big difference; big is generally better when there is a need to conserve water. It might be time to swap all those little pots for a few larger ones. Its worth setting up fixed irrigation drippers, especially if you have a lot of pots. If pots are grouped together, it’s easy to run a hidden length of irrigation tubing behind them. Wetting agents, such as Saturaid help water to spread throughout the potting mix rather than washing straight through. Top quality potting mixes often contain wetting agent. Otherwise you can mix it in yourself. Glazed and plastic pots hold water for longer than porous clay pots. For large pots a covering layer of pebbles helps slow evaporation from the surface of the potting mix. Sphagnum moss can hold up to 20 times its own weight in water and makes a very good liner for hanging baskets.