Planting and maintaining summer containers

Container displays have become an essential part of our summer gardens. Make sure your container plants last throughout the summer months by preparing the pot and growing media well, and choosing plants that will give reliable, long-lasting displays.

Containers offer gardeners the chance to experiment. The plantings are rarely permanent and, unlike in borders, it’s possible to change the soil to meet plants’ needs, and to control watering and feeding with ease. Although containers can restrict root development, they encourage vigorous plants to flower and fruit earlier, and limit otherwise over-large plants. With all this flexibility, it’s possible to grow most plants in pots - from large shrubs to succulents and annuals.

Setting up the container

To begin with, choose a suitable container. A single specimen plant will need a pot that’s large enough to contain the roots, whereas small plants are best grouped together in broader pots. To ensure adequate drainage, they must have at least one wide hole in the base, and a layer of crocks (right) or polystyrene blocks should be placed in the bottom. If possible, raise pots on small blocks or feet to guard against waterlogging.

For short-term summer displays use soil-less or multi-purpose compost. Longer-term plantings will benefit from soil-based composts such as John Innes No 3, while lime-haters prefer ericaceous (lime-free) compost. You can also add water-retaining granules and controlled-release fertilisers to the compost before planting up. Succulents will thrive best in open, free draining mixtures, such as John Innes No 2 with added grit or fine gravel.

Plant choice

Choosing plants that last the course of the summer takes some experimentation and research. For example, many seed-raised lobelia cultivars look tired by September, but Lobelia Laguna Series bought as plants will continue to flower until autumn. Nicotiana ‘Lime Green’ normally lasts longer than ‘Domino Lime’. Other stalwarts include Argyranthemum frutescens, Scaevola Whirlwind Blue and Fuchsia ‘Beacon Rosa’.

Foliage plants and succulents provide a dramatic and reliably showy element. Aeonium ‘Zwartkop’ heads make a striking statement on their own, or can be planted with other plants such as Pelargonium ‘Lord Bute’. Echeveria elegans with its blue rosettes of foliage is another useful succulent and can be grown in pans on its own, with other plants or will even tolerate being used as an underplanting for a standard Argyranthemum or heliotrope.

Caring for containers

More permanent plants should be transplanted in spring to encourage rapid establishment, while tender, summer plants can be planted up in late May. Check compost moisture levels daily from April to September and water thoroughly when dry. Feed plants weekly with a general-purpose liquid fertiliser four to six weeks after planting, unless the compost contains a controlled-release fertiliser.

Leigh Hunt

 

< Back to advice archive