See under Small Plants

See under Small Plants

See under Small Plants

Holcus mollis 'Jack Daws' Picture courtesy Green Acres Nursery CaliforniaDescription, History & Interesting Facts:

Holcus has 8 species of perennials which belong to the grass family (Gramineae/Poaceae). It originates from the woodland and grassland areas of Europe, North Africa and western Asia. These grasses do the majority of their growing in early spring and start again when temperatures start to cool down in late summer and autumn. During the warmer summer months, they stop growing and some will even go dormant. Most cool season grasses also grow best in a consistently moist soil.

Because these little grasses struggle through our hot and often dry summers, they have become less popular than they once were, and Holcus mollis 'Albovariegatus' is no longer freely available, but I have left it in my plant index for identification purposes, as you will still find them growing in many older gardens.

 Holcus mollis 'Albovariegatus' is the smallest, softest little creeping grass, with deep green leaves which are broadly margined in creamy-white. It will grow moderately to 15 to 20cm tall and spread 30 to 60cm wide. In summer it produces pale green or pinkish flowering panicles, which turn beige with age.

In many countries around the world the most damaging invasive plant species are grasses. However, the status of exotic grass invasions in South Africa has not been widely documented. As responsible gardeners I believe we should be extremely cautious when selecting exotic ornamental grasses for our gardens.

Although they are easily removed, Holcus can become invasive, especially in moist soils, and species like Holcus lanatus, a long-lived tufted perennial grass which grows up to 1 m tall, has widely naturalised itself in many countries, including southern Africa, tropical Asia, La Réunion, New Zealand, Hawaii, the USA, Canada, Central America and South America. In these regions it has become a weed of pastures, open woodlands, grasslands, watercourses, swamps, wetlands, crops, roadsides, disturbed sites, and waste areas.  Holcus mollis 'Albovariegatus' is not as invasive and is not classified as an invasive plant in SA but perhaps it is a good thing that this lovely little grass is no longer widely planted in South African gardens.

In the Garden:

Creeping velvet grass is a low-growing perennial which forms a creeping mat and enjoys growing in cool, slightly damp places in the garden. It can even be mown, and makes a pretty lawn or groundcover for shady areas. It is also a lovely edging plant for the shady border and great for rock gardens. It will even grow in little cracks in paving and walls etc. clinging on and slowly spreading, as long as there is sufficient moisture.

Cultivation/Propagation:

This little grass performs best in regions with cool summers and adequate rainfall, thriving both inland and at the coast. In hot regions the clumps will look untidy in summer and will need to be cut right back. It can also survive extremely cold winters; in temperate climates it is evergreen, and in cool to cold climates it is semi-evergreen or dormant in winter.

It prefers light, poor to moderately fertile soil which is moist, yet well-drained, but will adapt to most garden soils, including acidic and chalky alkaline ones. It can be planted in semi-shade to sun, but on poor soil it does best in semi-shade. Water regularly during hot, dry weather.

The best foliage is seen on young growth, so it benefits from the occasional hard trim; and the clumps are easily divided in spring or autumn. The foliage often deteriorates in colour once the flowers appear, so it is best to cut these off.

Problems, Pests & Diseases:

It does not suffer from any serious insect or disease problems, but has some susceptibility to rust.

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Armeria 'Ballerina' Lilac. Picture courtesy Ball StraathofDescription:

Thrifts can be found growing in the wild on maritime cliffs and meadows, salt marshes and mountain rocks all over Britain and Northern Europe. It is an evergreen perennial plant that produces compact tufts of grass-like leaves. The long stems are topped with papery pink or white flowers from spring to autumn and the plants grow about 15 to 30cm tall and spread 30 to 40cm wide. They over-winter as rounded, dense cushions of growth. 

(Armeria 'Ballerina') The Fleuroselect gold medal is a coveted award in the plant world, and for the first time it has been awarded to two Armeria varieties, A. pseudarmeria 'Ballerina Red' and A. pseudarmeria 'Ballerina White'.

These are first year flowering perennials that produce striking, ball-shaped flower heads on short, strong stems (20cm). They flower in summer, and are heat and drought tolerant. They can be used in mixed borders, as edgings and in containers. They grow to a height of + 20cm, and can spread +-15 cm, clump-shaped with mid green linear-shaped leaves.

 In the Garden:

 The flowers last long in a vase. It is a good ground-cover or border plant, forming a slowly spreading carpet. It does well in water wise gardens designed as xeriscape, rock or pebble gardens.

Cultivation/Propagation:

This tough little plant grows well throughout the country and is frost and drought resistant.

It is not suited to very humid regions but will tolerate salty winds at the coast and saline soils.

It will grow in nutritionally poor soil and prefers light sandy soils that drain well. Thrifts love full sun and cannot grow in the shade.

If you remove the dead blooms, the plants will continue to flower into autumn.

If the plants are overcrowded, they can be divided once they have finished flowering.

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Vinca major Image by For commercial use, some photos need attention. from PixabayDid you know that the large blue periwinkle, gewone-opklim (Vinca major) is a category 1B invasive plant in South Africa? However sterile cultivars or hybrids of Vinca minor are not listed. Read more below what this means for you and what the regulations are. 

 All the periwinkles come from Europe, central Asia and northern Africa; and the large periwinkle (Vinca major) is native to France and Italy, and eastward through the Balkans to northern Asia Minor and the western Caucasus. Vinca minor is often called the lesser, or common periwinkle because its leaves and flowers are smaller than the large periwinkle.

Because both are beautiful evergreen perennials that are extremely easy to grow, with attractive, glossy leaves and lovely violet-purple, pale purple or white flowers, they quickly became very popular with gardeners as a groundcover or trailing plant for semi-shade to sun.

In cultivation the plants generally do not bear fruit, and spread vigorously by rooted runners, and this is how they escaped garden cultivation. Both, but especially Vinca major, will often outgrow their original site, and when pruned or dug out by the roots and disposed of with the garden refuse, these remarkable plants will start rooting wherever they are discarded and will quickly colonize a whole new area.

Periwinkles grow throughout South Africa but the large periwinkle (Vinca major) is particularly problematic in KwaZulu-Natal, and both the Eastern and Western Cape. A variegated form is also available which has a similar, invasive habit. And, although sterile cultivars and Vinca minor are not listed, I believe we should exercise caution when growing these too, as they also spread via rooted runners, and in other areas of the world people are debating their invasiveness.  

Vinca major 'Variegata' Picture courtesy Leonora Ellie Enking from flickrSo what does this mean for you if you have Vinca major growing in your small garden or even on a large property or farm? Category 1b invasive species in South Africa require compulsory control as part of an invasive species control process. These plants are deemed to have such a high invasive potential that infestations can qualify to be placed under a government sponsored invasive species management programme. Wherever possible, the plants must be removed and destroyed responsibly, and no permits will be issued to keep these species.

You can spot the large periwinkle easily in the wild because it grows so rampantly, and especially in moist, shaded areas, along forest edges, streambanks and roadsides, and where moisture is sufficient it will also thrive in full sun. It can grow so rampantly that the trailing stems will form dense mats of vegetation - about half a metre high, completely covering the surrounding plants, blocking out the light and competing for nutrients.  This completely changes the habitat and ecosystem, and since infestations often occur in fragile environments like forests and alongside streams, this has serious implications for our biodiversity.

No herbicides are registered specifically for use on periwinkle, but a systemic herbicide sprayed on the leaves may kill the plants. Small infestations can be removed by hand-pulling, but ensure that all parts of the stems are carefully removed since any fragments will merely regrow. I never found any advice on how to safely dispose of the plants, but I would imagine that allowing them to dry out and then burning them would be good, or digging a very deep trench and burying them so deep that they cannot sprout and become compost is good?

The leaves contain toxins and are generally not browsed by animals. Gardeners and farmers are strongly urged to remove these plants, and to replace them with some of our most beautiful indigenous plants such as the Bush Violets (Barleria obtusa and Barleria repens), or for more sunny sites our gorgeous African Daisies (Dimorphotheca)