Growing proteas: step-by-step guide

Also known as the sugarbush, this fynbos species is cultivated for the cut-flower market.

The protea bush can be harvested many times. This is another pincushion variety.
Photo: FW Archive

Proteas, part of the fynbos floral kingdom, are a group of indigenous plants cultivated as cut flowers.

Species include Brunia, Berzelia and the Ericas. Proteas are named after the Greek god Proteus, who was able to change into many forms, and the Proteaceae family encompasses a wide variety of flowers and leaves.

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There are 1 600 species, including pincushions and conebush, which are also cultivated in South Africa.

Proteas can be propagated from seed or cuttings. Only healthy plants not subject to stress may be used for cuttings, and no cuttings may be harvested from plants that display any symptoms of disease.

Cuttings

Cuttings are usually harvested from December to the end of April. To see if the cutting is ready, take one of 20cm and bend it. If the ends can touch each other, it is still too young to cut; if the cutting breaks, it is past its best.

Guidelines

  • Protea cuttings can be harvested from December to April.
  • The ends of shoots are used for the production of cuttings.
  • Cuttings must be harvested in the morning. At no stage should the plants be subjected to heat or drought stress. After harvesting, the cuttings should be kept cool.
  • The leaves on the lower half (50%) of each cutting are removed and the end dipped into a growth hormone. The cuttings are then placed in growing bags – preferably transparent – that have holes and are filled with a mixture of coarse sand and peat, in order to develop roots.

The cuttings must receive a mist spray every hour of the day, and a spray programme against disease must be applied.

After six weeks, they will begin to form roots; those that have not can be destroyed after five months.

Cuttings are ready to be planted when the new roots are well-developed and discoloured brown roots are visible on both sides of the bag. The cuttings must then be planted in well-drained, unfertilised acidic soil.

Enviro-friendly control

Because proteas and other fynbos species are cultivated in their natural environment, the crops are attacked by many pests and diseases. If only toxic agents are used for control, the natural enemies of the pests will also be killed, leading to bigger problems.

Therefore, chemical control methods must always be environmentally-friendly.

Deadly disease-causing fungi cannot be seen by the naked eye, but the symptoms can. A plant whose roots are attacked will wilt and die.

Diseased leaves and stems have brown patches or red spots. In time, the whole leaf or stem may die.

Plants subjected to drought or an excess of water are more susceptible to disease. The growth period, when new leaves and shoots are being formed, is usually the time when fungi attack the plant.

General control measures

  • Cuttings must be taken from disease-free mother plants.
  • Dead or diseased parts of plants must be carefully removed and burned.
  • Plants must be planted in deep and well-drained soil in a position where they receive sunlight and good air circulation.
  • The weeds must be controlled.

Propagation by seed

When proteas are propagated by means of seed, the following procedures should be practised:

  • Harvest the seedbuds nine to 12 months after the plants have flowered – that is when the plants flower again.
  • After the seed has been harvested and sorted, it must be stored in a cool, dry place until it is sown in autumn. The sowing time for proteas is from March to May.
  • Seedbeds must be prepared in an open, sunny position. A bed should not be wider than 1m, the depth not more than 30cm and it must have good drainage.
  • Seed can also be sown directly on the land if plentiful and cheap. Broadcast the seed and rake it lightly. An alternative method is to make planting holes in rows on the land and sow three seeds a hole, preferably during rain. Cover the seed lightly.

From an infopak compiled by E Reinten, Elsenburg/ARC fynbos unit, for the Western Cape department of agriculture.