Nasturtium

Name: Nasturtium (Tropaeolum Majus and varieties).

Height: Only 20cm, but if trailing up something the plant can get quite tall.

Foliage: Evergreen, although the plant will only last a year.

Climate: Cold temperate, warm temperate, arid/semi-arid, sub-tropical and tropical.

Soil: Not particularly fussy.

Position: Full sun, but will tolerate light shade.

Flowering: Summer and autumn.

Feeding: Best not to feed, as this can result in lots of leaves and few flowers.

Watering: Seeds and young plants require reliable watering as they establish. Older plants only need supplemental watering in very dry periods.

Characteristics of a Nasturtium

The nasturtium is a sprawling, rambling sort of a plant that will cover a lot of ground, or even cover a structure. The leaves are circular with radiating veins and are a sort of dull green. The leaves and stems are fleshy.

The nasturtium flowers come in the range of cream, yellow, orange and red, with the trumpet-shaped flowers sometimes featuring stripes and bi-colours. In most areas the flowers occur in summer, but autumn flowers can be produced by planting seed later in the season.

This plant is an annual, which means it grows, flowers and dies within about one year. Don’t worry though—it does tend to set a lot of viable seeds.

Uses for a nasturtium

Nasturtium is great for adding colour to a garden. Its rambling nature means it is suited to people who like a less formal garden. It can be grown up trellises and fences, or in a frame within a garden bed. Or, if you prefer, just let it wander along the ground to add colour.

Smaller forms are available that are ideal for growing in containers. These look especially nice when trailing down in a hanging basket. Both the nasturtium flowers and leaves are edible and are often seen in salads or as decorations on a plate. The leaves have a peppery taste and are great for adding a bit of zing to a meal, especially a salad.

How to plant and grow a nasturtium

Nasturtium can be grown very easily from seed sown straight into the garden. If you want a head start you can also buy seedlings in punnets.

Plant seeds or seedlings directly where you want them to grow

Water well until seed is up or the seedlings have settled in.

Reduce watering to about once a week.

Caring for your nasturtium

This easy-to-grow plant does not have too many requirements. It is probably best in a poorer soil, as soils that have a lot of nitrogen from manure and fertiliser tend to produce plants with lots of leaves and few flowers.

Grow your nasturtium in a sunny spot in an area that won’t get frost.

Diseases and pests affecting nasturtiums

Nasturtium flowers are sometimes attacked by caterpillars, especially those of the cabbage white butterfly. In fact, some people grow nasturtiums as a “decoy plant” to draw the caterpillars away from their cabbages and cauliflowers! If the caterpillar damage worries you then pull them off and squash them, or spray with a natural caterpillar killer.

Sometimes aphids and other sap suckers can attack nasturtiums, so spray with a garden insecticide to control these if their numbers build up to become a problem. Make sure you spray under the leaves, too.