FEEDING
Once plants are established and well rooted into the compost a feeding programme can commence. For instance, with subjects planted in spring you can start feeding in summer. With autumn-planted subjects feeding can commence in the following spring.
Only apply feeds during the growing seasons – that is, spring, summer and early autumn. On average, plants in containers can be fed every two weeks, but if pot-bound weekly feeding would be better.
Use a compound general-purpose or flower-garden fertilizer containing the major plant foods nitrogen, phosphorus and potash. Liquid feeding is preferable for container-grown plants and certainly the most convenient means of applying foods. A fertilizer high in potash (for example, 10 per cent nitrogen, 10 per cent phosphorus and 27 per cent potash) is useful for flowering and fruiting plants.
Granular general-purpose or flower-garden fertilizer is best for raised beds, borders and large planters, applying an annual topdressing in spring and lightly forking it into the soil surface.
WATERING
Do not wait until the compost becomes bone-dry before watering as plants can suffer from this: flower buds and foliage can drop. Various plants, like camellias, rhododendrons, fuchsias and conifers soon react to dry compost by dropping leaves and/or flower buds. So regularly inspect containers, testing the compost surface for moisture content with your fingers. If it is drying out on the surface then apply water. Alternatively you could test the state of the compost with a soil-moisture meter.
Apply enough water so that it actually drains out of the bottom of the container; then you know that the compost has been moistened right the way through. Do not apply any more water until the surface is starting to dry out again (too much water can be harmful).
In warm weather containers should be checked once or twice a day for water requirements, and indeed may need watering once or twice, especially hanging baskets. Do check containers in winter, too, for although they dry out slowly the compost can still become dry.
If you have many containers to water you may find a watering lance useful, attached to the end of a hosepipe. With one of these it is an easy matter to water hanging baskets.
If you are away a lot in the spring and summer you may need to consider an automatic watering system. Ideal for containers is the drip system with many thin tubes ‘sprouting’ from a main hose. The thin tubes are positioned over the compost in the containers. Such a system can be fed either from an elevated water reservoir or from the mains water supply via a header tank with ballcock valve.
If you grow lime-hating plants beware of ‘hard’ or limy tap water. Occasional use of this does no harm but regular use can result in chlorosis of the leaves (the foliage turns yellow). Instead, try to collect and use rainwater.
