The Protea Family (Proteaceae)
The protea family (Proteaceae) includes a wide range of ground covers, trees and shrubs that often make superb garden plants. While some of the species are frost-tender, they are in all other respects remarkably resilient plants that often thrive in situations where others would rapidly succumb. Poor soils and hot dry positions that scarcely seem capable of supporting life are often ideal for Proteaceae. If any plants could be said to thrive on neglect the proteas can.
Proteas (the term is often used collectively as well as for the genus itself) are a variable group. Indeed, the family was named after Proteus, a Greek god capable of changing his shape at will. It includes some 60 genera and 1400 species of Southern Hemisphere plants, the bulk of which are native to southern Africa and Australia with the remainder coming from South America and many of the Pacific islands, including two species (Knightia excelsa and Toronia toru) from New Zealand.
There is an enormous variety of foliage among the proteas. It is almost always evergreen, but may be needle-like, as with many grevilleas; long, narrow and serrated like that of Dryandra formosa; or rounded and leathery like the leaves of Protea cynaroides. Some genera, particularly Leucadendron, include species with brightly colored foliage, the intensity of which varies with the season. Leucadendron stems retain their color for weeks when cut and are an important part of the cut flower industry.
Protea flowers are composed of clusters of narrow tubes that are often curved. These 'spider' flowers are seen at their simplest in the two native species and some of the grevilleas. In many cases what appears to be the flower is actually a bract of brightly colored leaves surrounding the true flowers. The most impressive example of this is the dinner plate-sized flower head of Protea cynaroides. The flowering season also varies; many proteas and grevilleas flower in winter, while leucospermums tend to flower in summer. With careful selection it is possible to plants in flower all year round.
The flowers often contain large quantities of nectar that many birds relish. Some species have very sticky flowers that will trap visiting insects, especially bees an this slightly sinister side of the flower appears to serve no particular purpose.
The South African and Australian Proteaceae tend to be at their best in warm, dry conditions and often thrive in coastal areas. Inland, unseasonable early and late frosts often kill all but the hardiest specimens. The South American genera tends to be hardier and prefer somewhat damper conditions. Embothrium in particular, can withstand hard frosts and is grown over most of the country. But where winter temperatures regularly drop to -6°C or lower, most proteas require frost protection.
Cultivation
Other than a suitable climate, the key to success with proteas is establishing the right soil conditions. The protea family is mainly adapted to mineral based soils that drain very quickly and which often have low nutrient levels. These soils tend to be moderately acid and are often especially low in phosphates.
Good drainage is absolutely essential. Rich loams and heavy clays do not make good protea soils. If you have a heavy soil do not try to improve it by adding sand or shingle as this will often make the problem worse; the soil binds with the sand and shingle and sets like concrete. Instead add more humus. Proteas would not appreciate the rapid burst of nutrients from a rich compost so the humus used should be fairly low in nutrients. Natural leaf mold and rotted pine needles work well. To avoid these materials compacting down into a poor draining thatch, incorporate about 50% fine shingle grit by volume and combine the mix with the existing soil.
Most proteaceous plants come from areas with low rainfall or where the rains are strictly seasonal. Many are coastal plants although most of the South African genera include alpine or sub-alpine species. Knightia from New Zealand and Embothrium from Chile are exceptions; they usually occur away from the coast, in areas where rainfall is quite high and not seasonal. Nevertheless, they still demand excellent drainage.
Although proteas are remarkably resilient and not difficult to grow there seems to be some common myths regarding their cultivation. Like most myths these have some basis in fact, but they can be misleading.
Myth 1: feeding proteas will kill them.
That's not strictly true. Proteas need nutrients just like any other plant, but their are a little more exacting than some. It's not fertiliser that does the damage but high phosphate levels and intense bursts of nutrients that lead to overly rapid growth. Avoid most general garden fertilizers, fresh animal manures and anything with added superphosphate. Because proteas will tolerate poor soils, it is often easier not to feed them rather than risk damage, but you'll certainly get better results if you apply a slow release, low iron phosphate.to -15°C with some protection. However, in very cold winters it may lose up to two thirds of its foliage. Overall Embothrium requires more moisture than most Proteaceae but good drainage is still important. It may be grown from seed but is usually propagated by semi-ripe cuttings.
Grevillea
With some 250 species, this is the largest of the Australian proteaceous genera. Most of the common garden species and cultivars are ground covers to medium-sized shrubs (up to 3m) with needle-like foliage. However, some species are far larger. The silky oak (Grevillea robusta), which is often seen in mild area, can grow to 20m and in common with most of the larger species it has large pinnate leaves. Grevillea banksii has similar foliage but only grows to about 3.5m × 3m.
The more densely foliaged plants, especially Grevillea juniperina and Grevillea rosmarinifolia, are often used as hedging plants. These plants grow to at least 1.5m high.
Grevillea flowers are often described as 'spider flowers'. This refers to the styles of some species, which tends to radiate from the center like a spider's legs. Some species have 'toothbrush' flowers; the styles are all on one side like the bristles of a toothbrush. The best known example of this type of flower is the common red-flowered cultivar 'Robin Hood'.
Many Grevillea cultivars are cultivated and they generally adapt well to garden conditions. Among the most popular are 'Jenkinsii' (a heavy flowering form of the red-flowered Grevillea rosmarinifolia), 'Robyn Gordon' (orange-red to red toothbrush flowers) ×gaudichaudii (deep red), 'Austraflora Canterbury Gold' (light golden yellow) and many of the Poorinda cultivars. Grevilleas are among the most widely available proteaceous plants and most nursery stock a good selection.
The species and hybrids vary enormously in hardiness. Some will stand little or no frost but others, such as Grevillea rosmarinifolia, will tolerate frosts of -10°C or lower; all prefer full sun with good drainage. The species are easily raised from seed and most hybrids strike quite freely from semi-ripe cuttings taken in late summer or autumn.
hakea
This Australian genus includes about 130 species, few of which are widely cultivated. The most common is probably Hakea laurina, the Pincushion Hakea. When not in flower, this species could easily be mistaken for a small eucalyptus. It has bluish-green narrow, oblong to sickle-shaped leaves and reddish-brown bark. It grows to about 6m × 4m and mature trees have a slightly weeping habit. The name pincushion refers to the flowers, which are spherical, with numerous radiating styles. They appear in late autumn and early winter, opening cream and turning to orange and red as they age. This shrub is hardy to about -5°C once well established and is easily grown in most well-drained soils.
Of the other species, the most common are Hakea salicifolia, Hakea prostrata and Hakea sericea. They are hardy to about -8°C or slightly lower and are easily grown in most soils. Hakea salicifolia has narrow, willow-like leaves, spidery, white flowers that are produced in spring. It grows up to 5m high and will tolerate poor drainage. Hakea prostrata and Hakea sericea have fine needle-like leaves and white or pale pink flowers in winter and early spring. It grows to about 3m × 2m. All member of this genus are usually raised from seed but some can be grown from cuttings. A few, such as H. franciscana, are weak growers that often perform better when grafted onto more vigorous stocks, such as Hakea salicifolia.
Isopogon
Drumsticks, which refers to the shape of the flower stems and unopened buds, is a name often used for Isopogon anemonifolius but it can also be applied to the genus as a whole. It is an Australian genus of 34 species of small to medium sized shrubs, most of which grow from 1-2m high and about as wide. They have a preference for poor but well-drained soil and will quickly collapse if over-watered or overfed. Most species have narrow lanceolate leaves about 75mm long and some, such as the common Isopogon anemonifolius, have finely cut foliage reminiscent of Marguerite daisy or Anemone leaves.
The flower heads, which open in spring and early summer, are composed of a central cone from which radiate numerous styles. Some species have short stiff styles but in others they are long and filamentous. The flower colors are mainly white, yellow or pink. The two most widely grown species, Isopogon anemonifolius and Isopogon anethifolius are hardy to about -5°C, but many species, such as Isopogon cuneatus and the temptingly beautiful pink and yellow-flowered Isopogon latifolius, are damaged at temperatures below -2°C . Isopogon species are usually raised from seed.
Knightia
The Rewa Rewa or New Zealand Honeysuckle (Knightia excelsa) is the best known of the two New Zealand proteaceous species. In the wild it can grow to be a tall narrow tree up to 25m high and it is one of the few proteaceous plants to have been harvested.
https://certsgoal-sample-exam-questions.blogspot.com/2022/02/100-updated-cisco-300-215-exam.html
https://certsgoal-sample-exam-questions.blogspot.com/2022/02/100-updated-cisco-300-410-exam.html
https://certsgoal-sample-exam-questions.blogspot.com/2022/02/100-updated-cisco-300-435-exam.html
https://certsgoal-sample-exam-questions.blogspot.com/2022/02/100-updated-cisco-300-510-exam.html
https://certsgoal-sample-exam-questions.blogspot.com/2022/02/100-updated-cisco-300-535-exam.html
https://certsgoal-sample-exam-questions.blogspot.com/2022/02/100-updated-cisco-300-625-exam.html
https://certsgoal-sample-exam-questions.blogspot.com/2022/02/100-updated-cisco-300-820-exam.html
Comments
Post a Comment