Diascia

Class

Dicotyledonae

Division

Angiospermae

Family

Scrophulariaceae

Order

Lamiales

Genus

Diascia

Species

rigescens

Description

A herbaceous plant that is ideal for brightening up balconies and terraces thanks to its long flowering period, which lasts from March until the first frosts, with a profusion of flowers clustered in racemose inflorescences that rise above the dense foliage, also attracting insects that are beneficial forpollination and the preservation of biodiversity. Although it appears delicate, it is very hardy if kept adequately watered, bearing in mind that it does not tolerate periods of drought or waterlogging.

Curiosities and special features

The flowers of the species D. rigescens have a distinctive shape at the base of the upper lip of the corolla, which helps to attract bees; as they feed, these bees also carry pollen, thereby contributing to pollination and the preservation of biodiversity.

Origin and distribution

A botanical species native to the area stretching from the Eastern Cape Province to southern KwaZulu-Natal. Today, it is found in a range of varieties that differ mainly in the colour of their flowers and their growth habit.

Leaf

The leaves have a lanceolate blade with a slightly serrated margin.

Leaf colour

The foliage is a solid, bright green, which harmonises perfectly with the colour of the flowers.

Plant height

The plant grows to a height of 0.2 to 0.3 metres, making it ideal for planters and pots, but also for the front of mixed flowerbeds.

Lifespan

A perennial, semi-evergreen species, but mainly grown asan annual depending on climatic conditions.

Where to plant

Given its size and the shape it develops, it is well suited as a plant for balconies, hanging baskets and window boxes, where it will add a distinctive splash of colour whilst in bloom.

Stem

The stems are herbaceous; the plant has no thorns.

Flower

The flower is simple in form, small to medium in size, with a two-lipped or bilabiate corolla and petals bearing an eye. It is arranged in medium-sized racemes or clusters. It flowers from early spring to mid-autumn, with a flowering period of between 150 and 200 days. It attracts bees and bumblebees.

Growth

A plant with a rounded growth habit, perfect for creating a harmonious and well-proportioned look.

Plant habit

It grows in a semi-erect habit.

Branching

Branching is Medium.

PH

The ideal pH of the growing medium or soil for Diascia is between 5.0 and 6.0.

Sun exposure

Suitable for east/south-east-facing positions, partial shade, dappled shade and full sun, but at altitudes above 300 metres above sea level.

It is advisable to avoid direct sunlight during the hottest part of the day.

Ideal climate and temperature

The ideal temperature is between 12 and 18 °C. The biological temperature range is between 5 and 34 °C. It requires a temperate climate; in areas with cold winters, it is often grown as an annual.

If protected from the harshest cold – at temperatures below -5 °C – it withers in winter but can resume growth when the first warm spells of spring arrive and flower for a long period from spring to autumn.

Use

Due to its flowering period and the size it reaches, Diascia rigescens is widely appreciated in:
Ornamental use

Hardiness

A plant of moderate hardiness.

Soil

For use in baskets or planters, use a substrate specifically designed for spring-flowering ornamental plants, but with a slightly more acidic pH than conventional potting composts for flowering plants, containing peat and perlite to ensure proper drainage of excess water, as Diascia is sensitive to waterlogging.

If growing in a flowerbed, the soil must be well-drained and rich in organic matter.

Difficulty

Provided the right growing conditions are in place, it is fairly easy to grow.

Growing tips

A useful growing tip, specifically for Diascia, to prevent leaf and flower scorch:
Avoid direct sunlight during the hottest part of the day

Furthermore, to encourage more abundant flowering, prune the plant lightly after the first flush of blooms.

Combinations with other plants

Owing to its vigorous growth habit, Diascia is well suited to creating dense, monochromatic ground cover when planted on its own, as well as for mixed plantings with other ornamental species, arranged in carefully composed, uniform and restful schemes, determined by a range of factors such as personal taste, the season and the duration of flowering, as well as the final height reached by each individual species. We recommend combining it withAchillea millefolium, Calibrachoa, Lysimachiacongestiflora, Lobelia and Nemesia.

Propagation

Propagation is by seed and cuttings.

Watering

Avoid overwatering, to which Diascia is very sensitive, as this causes the foliage to turn yellow. At the same time, prevent water stress, which the plant also cannot tolerate. Water regularly without allowing the growing medium or soil to become waterlogged.

If grown in a basket, it is advisable to remove the saucer to prevent waterlogging.

Read more on the Joyflo blog

Fertilising

It is sensitive to over-fertilisation, particularly when combined with water stress. During the growing season, add a fertiliser specifically designed for ornamental plants to the potting mix or soil, diluting it in the watering can without exceeding the recommended dose or frequency.

Read more on the Joyflo blog

Edibility for humans

Non-edible.