Thursday, 25 July 2013 00:28

Irish Moss - Sagina subulata

Sagina subulata 'Aurea' Picture courtesy Karen Maraj from flickrSagina subulata 'Aurea' Picture courtesy Karen Maraj from flickrCondensed Version:

Irish moss is renowned for planting between pavers but is very versatile in the garden. It forms a thick and dense mound of tiny yellow-green leaves, and although it only grows a couple of centimetres high, it can spread 30cm or more. The tiny translucent white flowers appear anytime from late spring to summer. What is commonly called "Irish Moss" (Sagina subulata) has rich emerald green leaves whilst the cultivar called "Scotch Moss" (Sagina subulata 'Aurea') is vibrant chartreuse.

Sagina does well in temperate gardens and thrives in cool, somewhat dry environments. It grows well in most parts of South Africa, and is cold and frost hardy. Although it likes a bit of humidity it can struggle in very humid regions, where the plants will 'melt-out' in the mid-summer heat, only reviving again in autumn. In dry and hot summer rainfall regions the plant will appreciate moderate watering and some shade during the heat of the day, and in the winter rainfall regions regular summer watering is required.

Athough Sagina thrives in gravelly well-drained soils it will adapt to most garden soils. It dislikes both drought and soggy, wet soils, so try to keep the plants evenly moist, watering before the soil dries out completely. Fertilise sparingly with liquid fertilisers, and weed carefully by hand.

Full Version:

Description, History & Interesting Facts:

Sagina subulata, commonly called “The Heath Pearlwort” “Irish Moss”, “Awl-leaf Pearlwort” or “Scottish Moss”, is a species of flowering plant in the pink and carnation family, Caryophyllaceae. It is an evergreen perennial groundcover which is native to Europe, from Iceland south to Spain, and east to southern Sweden and Romania.

In the wild it can be found growing on dry, sandy or gravelly soils, and although not a true moss, it forms a thick and dense mound of tiny yellow-green leaves, and although it only grows a couple of centimetres high, it can spread 30cm or more. The tiny translucent white flowers are slightly fragrant, and they make their appearance individually on erect stems that can measure up to 3cm in height, appearing anytime from late spring to summer.

What is commonly called "Irish Moss" (Sagina subulata) has rich emerald green leaves whilst the cultivar called "Scotch Moss" (Sagina subulata 'Aurea') is vibrant chartreuse.

In the Garden:

Don't worry about treadling lightly on Irish moss as it will bounce right back from occasional damage, and its soft and cushy texture makes it perfect to grow a meditation cushion with, perhaps at the end of a barefoot-friendly pathway. The delicate nature of this plant also makes it a favourite for fairy gardens and petite dish gardens.

Although delicate looking, Irish moss is tough and also great for blanketing the ground around flagstones or along the edges of gravel pathways where other plants sometimes struggle to grow, or to simply form a soft carpet amongst boulders in rock gardens or around water features.

It’s even wonderful for dry stone walls, and works well as a groundcover around potted garden and patio plants, or for a minimalist look, plant Irish moss on its own in a row of small pots – simply perfect!

Sagina subulata Picture courtesy Brigitte Rieser from FlickrSagina subulata Picture courtesy Brigitte Rieser from FlickrCultivation/Propagation:

Sagina does well in temperate gardens and thrives in cool, somewhat dry environments. It grows well in most parts of South Africa, and is cold and frost hardy, with minor winter browning in severely cold areas.

Although it likes a bit of humidity it can struggle in very humid regions, where the plants will 'melt-out' in the mid-summer heat, only reviving again in autumn. In these regions it’s vital that the soil has sharp drainage, and its best to keep the plants a bit on the dry side when humidity is high.

In dry and hot summer rainfall regions the plant will appreciate moderate watering and some shade during the heat of the day, and in the winter rainfall regions regular summer watering is required.

When we think 'moss' we think of plants that love moisture, but remember that Sagina in not a true moss and it dislikes both drought and soggy, wet soils, so the trick is to water moderately but regularly during long dry spells. Try to keep the plants evenly moist, watering before the soil dries out completely.

Athough Sagina thrives in gravelly well-drained soils it will adapt to most garden soils, even clay that drains. Adding some compost to very poor and sandy soils will be beneficial, as well as to amend clay soils for better drainage.

Fertilise sparingly with liquid fertilisers, and to keep the plants compact, avoid high nitrogen levels which can induce excessive foliar growth, so the plants become mounded rather than forming a flat carpet.

Weeds and grass can occasionally break through the tightly growing moss, threatening the health of the plant and disrupting the overall aesthetic. Pull them out by hand when they are still small, as pulling up established weeds will often damage the moss.

Weeding thoroughly and then covering the planting site with a black plastic sheet for up to three months before planting time will help to smother a lot of weed seeds before you plant or sow.

These plants can be propagated from seed or division, but for the average gardener it’s easiest to divide existing plants or those purchased at a garden centre. Division is best done in spring, by cutting narrow strips from established plantings, or digging out whole clumps to separate into pieces, ensuring that all pieces have roots for replanting.

Irish moss grows at a moderate rate and it may take several years to completely fill an area, so use many small, closely-spaced transplants to cover large areas more quickly. Ensure that the soil is kept moist until the plants are established.

Seeds can be started indoors several weeks before the average last frost date, or they can be sown directly into well-prepared beds in spring. Keep the soil evenly moist until germination, which can take 2 to 3 weeks.

Problems, Pests & Diseases:

Sagina is generally a trouble-free, durable plant, though like any plant, it is susceptible to a few pests and cultural problems. Fungal diseases are rare, but the plant is susceptible in very humid climates.

Poorly draining soil will contribute to root rot and other complications.

If over-watered, the plant may rot, but if it’s not watered enough, it may form dry, dead patches.

Fungus gnats or aphids may attack weakened specimens grown on overly moist soil.

Sagina may be attacked by slugs, which can be killed by placing a cup or bowl of beer, or other fermented liquid, next to the moss. Slugs find this irresistible, and land up inside the container, but are unable to get out.

Moles tunnelling under the moss may lift the plant, causing the roots to become dislodged. The moss must be carefully patted down back into the soil, or bare, dead patches will form.

Parts of the moss may die due to pet urine, excess fertiliser, or accidental herbicide exposure.

Warning:

Handling the plant may cause skin irritation or allergic reaction, and pollen may also cause allergic reactions.

Thursday, 25 July 2013 00:28

Snow-in-summer - Cerastium tomentosum

Cerastium tomentosum. Picture courtesy Green Acres Nursery CaliforniaCerastium tomentosum. Picture courtesy Green Acres Nursery CaliforniaJust like clothing fashions come and go, so do gardening trends, and this lovely groundcover is not as popular as it used to be, so its not readily available. However many older gardens and parks may still have it growing, so I have left it here for identification purposes.

This beautiful dense, creeping plant grows wild in Southern Europe; from Italy to western Asia, occurring on the rocky slopes of mountains, in full sun.

It is a vigorous groundcover for coastal gardens, reaching 15cm high and spreading by runners, up to 1m wide. Snow-in-summer is grown as much for its lovely silvery-grey foliage, as for its attractive flowers. Masses of pure white flowers completely cover the plants in spring and early summer.

This plant looks good all year round and will add interest and contrast to the landscape. Plant it as a groundcover, border plant or in rock and dry wall gardens. For a thick groundcover, plant it about 40cm apart.

Snow-in-summer is a perennial, evergreen plant that thrives in poor sandy soil, but will grow in any well-drained garden soil; in full sun. It is hardy to moderate frost and grows best in high rainfall areas, and must be watered regularly in summer, in the winter rainfall regions. It is hardy to moderate frost. Prune it when it has finished flowering, to keep it neat. It is perfect for a low maintenance garden and does not require feeding, but can be given a complete fertiliser in early spring.

Rumohra adiantiformis. Picture courtesy Forest and Kim Starr. Click on the picture to see their flickr pageRumohra adiantiformis. Picture courtesy Forest and Kim Starr. Click on the picture to see their flickr pagesaflag Condensed Version:

Gardeners love leatherleaf ferns for their beautiful leaves, their hardiness and ease of growth, as well as their versatility in the garden. Their large and leathery, deep green leaves blend effortlessly into so many garden themes, and make an excellent permanent ground cover for those moist and semi-shady areas.

These evergreen perennials spread by rhizomes and although they thrive in tropical and subtropical gardens, in South Africa they are also frost and cold hardy if planted in a protected part of the garden. In severely cold regions the plant will require some protection during the winter months.

The leatherleaf fern can take more sun in coastal gardens than it does inland, and although it tolerates salt spray, it looks much better if planted in a wind protected part of the garden. Once the plants are established they can be somewhat drought tolerant, especially in conditions with high humidity.

Ferns always look at their best when grown in indirect light like the cool shady areas underneath trees, where they will receive semi-shade to partial sun for short periods of the day.

To establish a deep, extensive root system, prepare the beds well by digging them over well to a depth of about 30cm and incorporate lots of organic matter like leaf mould and compost, palm peat, and even fine bark chips, together with a generous dusting of bone meal.  Ensure that the soil drains well, because although ferns love moist soils they do not like to be waterlogged. Ferns also generally prefer slightly acid soils, so the addition of acid compost or an acidic potting medium is recommended.

Potted plants do well in commercially sold orchid mix, or potting soil mixed with palm peat and the addition of extra perlite or grit for sharp drainage. 

Feed garden and potted specimens monthly in the growing period with a liquid fertiliser for leafy plants, mixed at half the recommended strength. A slow-release product may also be used. Remember to mulch your plants annually with bark chips, leaf mould, or any good organic material, as this helps to keep the soil cool and moist.

Follow a regular watering schedule until the plants are established, and thereafter they will only need moderate watering during dry spells. In seasonally dry regions the plants will die down if they are not watered, only to spring back to life again with the onset of the next rainy season. To look their best in the garden, never let your leatherleaf fern go completely dry, and try to keep it moist but not waterlogged.

Cut back old tatty-looking fronds regularly to keep your clump of leatherleaf looking good all year round. 

Rumohra adiantiformis growing in the shelter of rocks. Picture courtesy Clivid - Click on the picture to see the flickr pageRumohra adiantiformis growing in the shelter of rocks. Picture courtesy Clivid - Click on the picture to see the flickr pageFull Version:

Description, History & Interesting Facts:

Gardeners love leatherleaf ferns for their beautiful leaves, their hardiness and ease of growth, as well as their versatility in the garden. Their large and leathery, deep green leaves blend effortlessly into so many garden themes, and make an excellent permanent ground cover for those moist and semi-shady areas. Their fronds are sought-after by florists, and the common name "seven-week fern" refers to how long they can last when cut. Read more on planting and caring for these ferns below.

The leatherleaf fern belongs to the (Dryopteridaceae) or wood fern family which is very diverse, with approximately 570 species worldwide. They have a wide distribution in tropical and sub-tropical regions of both the old and the new world, including South Africa and diverse places like Colombia, The Galapagos Islands, Australia and New Zealand. The greatest numbers of species are found in southern, south-eastern, and eastern Asia.

In South Africa only a few species occur, from the Cape Peninsula eastwards along the southern side of the mountain ranges all the way to the Eastern Cape, and into KwaZulu-Natal, east of the Drakensberg, and into Mpumalanga and Limpopo, to the Soutpansberg mountains. Species occur from sea level, up to approximately 3,000m in the Drakensberg.

The wood fern family are mostly forest dwellers, forming colonies of plants which thrive in the dappled shade and leaf litter of the moist forest floor. They can also be found growing on rocks, but rarely in trees as epiphytes, and at higher altitudes they are often found colonising sheltered rock crevices.

They also favour permanently moist, or seasonally moist habitats, with some species being restricted to the summer rainfall regions of South Africa, and others occurring in both the summer and winter rainfall regions. Other species can be found in sheltered positions in open grasslands, for example, in  sinkholes and along drainage lines, or at the base of boulders, which all offer some protection and shade. They spread by underground rhizomes, and these protect the plants from fires, and once a fire has swept through the area, they quickly regenerate after rain.

The leatherleaf (Rumohra adiantiformis) is native to South America, the Caribbean, southern Africa, the Western Indian Ocean islands, Papua New Guinea, and Australasia. Countries it is native to include such diverse places as Brazil and Colombia, the Galápagos Islands, the Greater Antilles in the Caribbean, Zimbabwe and South Africa, Australia, and New Zealand.

The leather leaf fern is widely grown in South African gardens and can vary significantly in size, depending on climate and rainfall, for example, in moist tropical and sub-tropical regions it can attain heights of 75cm to 1.5m with a 1m spread, but in cold and dry inland gardens, or on exposed coastal sites, the plants will remain a lot smaller. The plant can take 2 to 5 years to reach its ultimate height and spread, so generally leather leaf ferns are sold as growing 50 to 60cm tall, with a 40 to 50cm spread.

Other South African members of the Dryopteridaceae which are recommended as garden subjects include Cyrtomium micropterum, and Polystichum luctuosum, P. macleae, P. monticola, P. pungens, P. transvaalense and P. wilsonii.

Find more information on these indigenous beauties – click on the names to read more at PlantZAfrica and Fernkloof.org.za

In the Garden & Home:

Gardeners love leatherleaf ferns for their beautiful evergreen leaves, ease of growth, and versatility in the garden, and in the UK the leatherleaf has gained the Royal Horticultural Society’s Award of Garden Merit.

Their glossy and coarsely toothed deep-green fronds make an excellent permanent ground cover for shady beds, underneath evergreen trees and palms, or shrubs like camellias, coprosma, hydrangeas and gardenias.

Leather leaf ferns will add texture and contrast to formal or informal gardens and are attractive filler plants. For a modern look, try combining them with ornamental grasses like carex, complimented by nandina, black bamboo and New Zealand flax.

Because leatherleaf ferns thrive near water, they are ideal for accentuating water features which are sited where there is semi-shade. They also work well as a cover-up for slab foundations or underneath low windows and overhead shade structures.

This plant spreads slowly, which works nicely for small spaces or in a hanging basket. This also makes them perfect to grow in atriums and low, broad pots with a wide diameter which allows them space to spread.

Leatherleaf ferns also make great indoor pot plants if they can be placed in a cool, yet brightly lit spot indoors, and if the leaves and topsoil are mist sprayed regularly with water. Pot and feed as for those growing outdoors. 

The fronds are sought after by florists around the world because they will last for weeks in a vase, making the leather leaf essential for all cutting and cottage gardens.

Cultivation/Propagation:

These evergreen perennials spread by rhizomes and although they thrive in tropical and subtropical gardens, in South Africa they are also frost and cold hardy if planted in a protected part of the garden. In severely cold regions the plant will require some protection during the winter months.

The leatherleaf fern can take more sun in coastal gardens than it does inland, and although it tolerates salt spray, it looks much better if planted in a wind protected part of the garden. Once the plants are established they can be somewhat drought tolerant, especially in conditions with high humidity.

Ferns always look at their best when grown in indirect light like the cool shady areas underneath trees, where they will receive semi-shade to partial sun for short periods of the day. Leatherleaf ferns will even grow in complete shade, but growth may be less vigorous. Avoid positions where they will receive really deep, dark shade, as well as those which get too much sun, or harsh afternoon sun.  

To establish a deep, extensive root system, prepare the beds well by digging them over well to a depth of about 30cm and incorporate lots of organic matter like leaf mould and compost, palm peat, and even fine bark chips, together with a generous dusting of bone meal.  Ensure that the soil drains well, because although ferns love moist soils they do not like to be waterlogged. Ferns also generally prefer slightly acid soils, so the addition of acid compost or an acidic potting medium is recommended.

Potted plants do well in commercially sold orchid mix, or potting soil mixed with palm peat and the addition of extra perlite or grit for sharp drainage.  

Feed garden and potted specimens monthly in the growing period with a liquid fertiliser for leafy plants, mixed at half the recommended strength. A slow-release product may also be used. Remember to mulch your plants annually with bark chips, leaf mould, or any good organic material, as this helps to keep the soil cool and moist.

Follow a regular watering schedule until the plants are established, and thereafter they will only need moderate watering during dry spells, as the leatherleaf is not as thirsty as many other ferns. In seasonally dry regions the plants will die down if they are not watered, only to spring back to life again with the onset of the next rainy season. To look their best in the garden, never let your leatherleaf fern go completely dry, and try to keep it moist but not waterlogged.

Cut back old tatty-looking fronds regularly to keep your clump of leatherleaf looking good all year round. 

Some species have rhizomes which are close to the ground and multiply readily by branching, and these are best propagated by division. Other species have sub-erect or erect rhizomes and are propagated by spores, as offshoots are not readily produced.

Problems, Pests & Diseases:

If grown correctly the leatherleaf is not prone to many pests or diseases. Watch out for common garden pests like caterpillars and the occasional snail or slug. Scale and mealy bugs can become a problem on plants grown indoors or in a covered area like a patio, but are easily treated.

Ferns are sensitive to some pesticides, so consult with your garden centre on the best product to use and how strong to make the mixture.

Warning:

We did not find this fern listed as toxic to pets, but it is always wise to discourage pets from chewing on plants, and to supervise babies and small children around plants.

Thursday, 25 July 2013 00:28

Mazus, Creeping Mazus - Mazus reptans

Mazus reptansMazus reptansDescription, History & Interesting Facts:

Mazus is a self-rooting, low-growing perennial groundcover which is native to the Himalaya Mountains and to Australia. It has attractive bright green leaves, and produces masses of small lavender-blue or white flowers with yellow and white centres; from late spring to mid-summer, with sporadic blooms throughout summer and autumn if conditions are right. There's also a white variety called 'Alba'.

In the Garden:

Mazus has long been prized as a groundcover because it forms a dense ground-hugging carpet, and grows very quickly without being aggressive. It is sometimes used as a lawn substitute in small areas with limited foot traffic; and will tolerate the occasional mowing. Mazus is ideal planted between stepping stones and alongside steps, and thrives in rock and woodland gardens. It is a pretty border plant and is an attractive filler plant between larger summer flowering perennials. It grows well in slightly moist soil, making it an excellent choice for waterside gardens and next to water features. If planted over liliums, daffodils and other bulbs it will serve as a 'living mulch'; shading their roots and keeping them cool without interfering with their growth. It is also wonderful to stabilise the soil on slopes and has proven to be a great green roof plant in regions with good summer rainfall. It will trail down beautifully if planted into hanging baskets and containers.

Cultivation/Propagation:

Mazus will grow very quickly in semi-shade or full sun and does best in a sheltered spot in the garden. It is hardy to cold and frost; in warm regions the plants are evergreen, but are semi-evergreen or totally dormant in cold winter regions. Mulch the roots in very cold regions to keep the roots from freezing. The plant will tolerate hot, humid summers if the soil is kept moist. In very hot, dry regions it will appreciate some shade during the hottest part of the day. It thrives in a moderately fertile, moist but well-drained soil; but will adapt to any well-drained garden soil, including clay. If the plants receive adequate sunshine they will remain short, +-3 to 5cm, with a spread of +-25 to 30cm. Water regularly in summer; especially during dry spells. Divide overcrowded clumps every 2 to 3 years in spring or autumn.

Propagation is by division and root cuttings in spring; or from seed sown in spring or autumn.

Problems, Pests & Diseases:

Mazus is not plagued by any serious pests or diseases but watch out for snails and slugs.

Thursday, 25 July 2013 00:28

Dead Nettle - Lamium maculatum cultivars

Lamium maculata 'Beacon Silver' Picture courtesy www.steyns-nursery.co.zaLamium maculata 'Beacon Silver' Picture courtesy www.steyns-nursery.co.zaDescription, History & Interesting Facts:

This genus of about 50 species consists of annual and perennial flowering plants, belongs to the mint family, and is native to Europe, Asia, and North Africa. The common name "dead nettle" refers to their resemblance to "stinging nettles", but the two are unrelated; and unlike stinging nettles, Lamium do not have stinging hairs.

Many exciting named selections are available to local gardeners; and of all the shade-loving groundcovers dead nettle is probably one of the quickest and easiest to grow. Their gorgeous variegated leaves make them worthy garden subjects for adding texture and as contrast plants in garden beds and borders. Cultivars can have mottled green, silver white or gold foliage; and in late spring and summer they bear showy spikes of shell pink, pink, dark lavender, or white flowers, depending upon the cultivar.

(Lamium maculatum 'Beacon Silver') has silver leaves with a very narrow green margin, and dark lavender-pink flowers.

(Lamium maculatum 'roseum') has silver-grey leaves and pink flowers.

(Lamium maculatum 'Chequers') has green leaves with a prominent silver stripe down the midrib and dark violet-pink flowers.

(Lamium maculatum 'Cannons Gold') has striking golden chartreuse leaves with soft mauve-pink flowers.

(Lamium maculatum 'White Nancy') has silver leaves with very narrow green margins, and white flowers.

(Lamium maculatum 'Pink Pewter') has silver-grey leaves, and soft-pink flowers.

Lamium maculata 'White Nancy' Picture courtesy www.steyns-nursery.co.zaLamium maculata 'White Nancy' Picture courtesy www.steyns-nursery.co.zaIn the Garden:

Their gorgeous variegated leaves make dead nettle a worthy garden subject for adding texture and contrast in garden beds and borders. Lamium species are used as food plants by the larvae of some butterfly and moth (Lepidoptera) species and are loved by bees. They are also beautiful planted in hanging baskets and pots, mixed with other suitable plants.

Cultivation/Propagation:

Dead Nettle is a vigorous, easy-to-grow, semi-evergreen perennial. Most varieties will grow +-10 to 15cm tall; reproduction is vegetative growth, and any stems touching the soil will root readily, and under optimal conditions the plants can become invasive, but are easy to control.

Lamium thrives in fertile, moist but well-drained soil, but is adaptable to most garden soils; neutral, alkaline and acid, and will grow in sandy soils if they are well prepared with added compost, and in clay beds if the drainage is good.

Although dead nettle enjoys moist soils, once established it will even flourish in difficult areas of dry shade.

Lamium grow throughout the country and enjoy a cool shady spot in the garden; even growing in full shade. They are very hardy to frost, but Lamium maculatum 'Pink Peuter' Picture courtesy www.steyns-nursery.co.zaLamium maculatum 'Pink Peuter' Picture courtesy www.steyns-nursery.co.zaduring severe winters the foliage will partially or completely die down; if the roots are mulched the plants will recover in spring as they enter their new growth cycle. Plants will tolerate fairly dry conditions, but are not really well suited to very hot and dry inland areas; excessive sun and drought will scorch the foliage and lead to dieback. If grown in hot, humid regions ensure that the soil drains very well.

Although semi-evergreen in temperate climates, the plants are inclined to look a little untidy in winter; but grow with a vengeance again in spring. It is best to cut this plant back after the first bloom to promote compact growth. All cultivars are silver-variegated, but green shoots may occasionally develop, these need to be cut out or the plants will revert back to their original green form.

Propagation is usually by division of the rooted runners in spring.

Problems, Pests & Diseases:

Lamium do not suffer from many pests or diseases but keep an eye out for snails and slugs.

Thursday, 25 July 2013 00:28

Ivy - Hedera

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