No. 86/95

Waxflower for cut flower production By Digby Growns, Geraldton, and officers of the Floriculture Section, South Perth

Waxflowers (Chamelaucium uncinatum and other Other species of Chamelaucium are sometimes used as Chamelaucium species and hybrids) have become a cutflowers: central part of the native cutflower industry in Western • Chamelaucium megalopetalum (large waxflower) - Australia, because of their ease of cultivation and high Flowers white, large, aging to pink, red or purple. productivity. The flowering stems are sought after as Newer selections may improve the commercial backing fillers for single-stemmed flowers such as roses, viability of this species. The flowering season is carnations and chrysanthemums. They are also September to October. becoming sought after as a flower in their own right. Colours range from white through pale pink, dark pink to • Chamelaucium ciliatum (Stirling wax) - Flowers white purple. to pink. Native to a wide range of soil types, including gravel and clay soils. Periodically popular. The Varieties flowering season is September to November. Chamelaucium uncinatum is the most widely cultivated • Chamelaucium floriferum (Walpole wax) - Flowers of the waxflowers. Varieties are available to give a pinkish-white with purple centre. The flowering flowering season from June to November in traditional season is August to November. waxflower growing areas. The precise time of flowering There are many other waxflower varieties available, and depends on the variety grown and the season. Day length growers should contact Agriculture Western Australia, and temperature both affect flower initiation and time to exporters, nurserymen and grower associations for flowering. Growing waxflower further north and further advice on the best selections to grow. Future develop- south to where it is now grown could extend the seasonal ments will see a wider range of colours available all availability of waxflower. season, and the increased planting of improved, hybrid varieties.

Table 1. Some commercially available varieties of waxflower

Variety Flowering time Characteristics

Purple Pride early to mid season Purple flowers. May include a number of different selections. The most widely grown wax variety. CWA Pink early season Pink flowers. Some other pink selections may go under the same name. Usually a vigorous, untidy plant. Sells well because it is early flowering. Mullering Brook mid to late season Small, mauve flowers. More upright and long-stemmed than other selections. There are several different selections grown under this name. Alba mid season White flowers. Very vigorous. May include some different selections. Grown widely. Has problems with leaf yellowing and tip growth. Becoming less widely grown. Lady Stephanie mid to late season A hybrid between C. uncinatum and C. floriferum with small pink flowers. Upright in form, with flowers up the stem. Has remained reasonably popular over time. Eric John mid season A compact hybrid wax with small mauve terminal flowers. It has sold very well in Japan. Only recently available commercially. Jubilee mid to late season Deep pink flowers. Has problems with extension growth. It has sold very well in Japan because of the limited availability of this colour at this time of the year. Only recently available commercially. Grandiflora mid season Large mid-pink flowers. A vigorous, untidy plant. A more recent release than some other varieties.

Important Disclaimer The Chief Executive Officer of the Department of Agriculture and Food and the State of Western Australia accept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it. For more information visit our web site www.agric.wa.gov.au Soils The following spacings are typical: Well-drained soils are essential. Sand or sandy loam C. uncinatum - 2 m between plants, 3 m between rows soils with a slightly acid to neutral pH are preferred. (1667 plants/ha). C. ciliatum, C. megalopetalum - 0.8 m between plants, Climate 2 m between rows (6250 plants/ha). Waxflower tolerates a wide range of conditions. Frosts Irrigation from mid winter to spring will affect flower quality and may render the crop unmarketable. Even if the crop has no Waxflower needs a significant amount of water for visible damage, repeated frosts may damage the maximum production. The best place to plant is on a site cambium of the trunk, effectively ringbarking the tree. where the water is between one and three metres below Under these circumstances there is a slow decline, the surface. If this is not possible, trickle or microjet eventually ending in death. irrigation is needed during the summer months to In high rainfall areas Botrytis flower blight may be an maximise production. Several outlets per plant may be ongoing problem. needed. The limited research suggests that irrigating to at least Field planting 75 per cent of evaporation may be necessary. A mature C. uncinatum can use as much as 20 L per plant per day Waxflower plantlets are usually supplied in small tubes in the heat of summer. However, for plants pruned and for planting. These plantlets can quickly become cultivated for cut flowers, the amount of water required rootbound if they are left in the tubes for too long - will be less than this. rootbinding can occur in a couple of weeks. Once you have received the plants, do not delay planting. Start irrigating as the soil water level decreases. In early summer give each plant at least 4 to 6 L of water per day If plants are rootbound, prune the roots with a pair of to maximise production. Increase this rate to at least 8 to clean, sharp secateurs before planting to ensure the 10 L per day by late summer. roots grow vertically. It may then be necessary to prune the top part of the plant to reduce transpiration until the Monitor soil moisture levels to help to minimise water and root mass has increased. nutrient wastage, by ensuring water is applied most efficiently. New instruments for soil moisture monitoring When your plants arrive, inspect them carefully for any are being continually developed and evaluations by signs of poor health. If you have any concerns, do not Agriculture Western Australia have shown many of them plant any of them until a pathologist has tested a sample to be unreliable. See Farmnote 79/94 ‘Soil moisture for possible diseases. Many nurseries now belong to the sensors for sandy soils’ (Agdex 560), or for the latest Nursery Accreditation Scheme, which ensures that information on any aspect of irrigation, consult your certain minimum hygiene standards are being followed adviser. and that the risk of jarrah dieback (Phytophthora cinnamomi) and other soil diseases is minimal. Levels of total soluble salts less than 270 millisiemens per metre (about 1500 ppm) are desirable, but there may The best time to plant is autumn, since it allows plants to be some varieties that will tolerate higher levels than this. establish over winter. If good irrigation facilities are available, also consider a spring planting. Fertilisers Many different planting arrangements have been used in Western Australia, including double rows and close- Waxflower responds well to balanced fertilisers applied planted hedges. Ensure that plants are in straight lines - at moderate rates. Do not consider producing waxflower this makes harvesting and spraying easier. without fertiliser. Table 2 shows the current minimum recommended rate of each element. Apply fertiliser throughout the year. As summer is the main period of growth, it is important that nutrients are available to the plant at this time of year. Reduce rates, especially nitrogen, after budding to minimise ongrowth. Fertilisers can be applied in solution through the irrigation system, in solid form, or as a combination of the two methods. If you are applying solid fertilisers, you should be aware of how long one application lasts and that if you apply the fertiliser when conditions are dry, plants cannot take up the nutrients until it rains. Nitrogen from some solid fertilisers such as urea can also be lost to the atmosphere if the rain does not wet the fertiliser sufficiently. The most efficient way of applying fertilisers is through the irrigation system on a daily or weekly basis. This allows plants ready access to the nutrients at all times of the year.

Figure 1. Waxflower planting in single rows. Table 2. Recommended fertiliser rates (kg/ha/y) for waxflower planted at 1667 plants per hectare

Nitrogen 80 Phosphorus 10 Potassium 80 Other macro elements Calcium 15 Magnesium 5 Trace elements Fetrilon Combi® or Librel BMX® at recommended rate

Insect pests Insects are not a major problem in waxflower, but flowers will be rejected if insects are found in shipments on entry to countries such as Japan and USA with strict quarantine requirements. Rutherglen bug, wingless grasshoppers and the ring- barking weevil can cause damage at planting. Farmnote No. 1/96 ‘Pests of export wildflowers and proteas’ (Agdex 280/620) gives details on these pests. Figure 2. Gall caused by a small wasp. The gall wasp, a serious pest in Queensland, has little impact in Western Australia. The wasp causes tiny galls disease. It is spread from plant to plant underground by on the young leaves (see Figure 2), decreasing the value means of water movement, so that infections tend to of the product and creating quarantine difficulties. Ensure move downhill. Isolate infections if possible, burn the that cuttings are free of gall wasp. infected plants and apply preventative treatments of Fos-Ject® (mono di-potassium phosphite) to surrounding Waxflower can be attacked by a ringbarking weevil native plants. to Western Australia, although waxflower is not a preferred host. The larvae of this weevil, which ringbarks Botrytis flower blight the stem below the soil surface, severely damages some Chamelaucium species. In particular, plantations of Botrytis flower blight is the main above-ground disease. C. ciliatum and C. axillare have been heavily attacked by It can cause significant losses both in the field and during this pest and an insecticide drench once a year is shipment to export markets. The symptoms are brownish recommended. lesions on the petals and in severe cases, shedding of the buds and flowers. Post-harvest, it develops on Leaf tip larvae can damage shoot tips. Spray plants flowers in export cartons as a hairy mould, mostly on ® monthly with a synthetic pyrethroid such as Ambush . buds and flowers. Many insects, including thrips, bugs, beetles and weevils, Wet, humid conditions favour the development of live on waxflowers and although they do not cause a Botrytis. In export cartons, moisture loss from the flowers great deal of damage to the crop, they can cause provides ideal conditions for the growth of the fungus. rejection of shipments through quarantine restrictions. Field control of insects during the season is essential, Control must start in the field. Spray plants fortnightly with since disinfestation after harvest does not provide a high a fungicide from the time they bud until the end of enough level of kill. harvest. Rovral® is one suitable chemical. During wet weather, more frequent sprays will be needed. Use ® For thrips and bugs, use Mavrik , for beetles and weevils fungicides in rotation to prevent the build-up of resistant ® ® use Ambush . Mavrik is not needed if you are using strains of pathogens. Flowers infected with Botrytis may ® Ambush . For further information, consult your adviser. not be visible at the time of harvest but will cause Diseases problems later. Pruning Root rots Prune waxflower immediately after harvest, to keep the Species of Pythium and Phytophthora can cause root bushes to a manageable size and ensure maximum stem rots and eventual death of plants. Pythium is a problem length for the next season. Leave some green shoots on in winter, or in poorly drained areas. the plants; 45 cm is an average pruning height. Young Phytophthora can be imported on planting material, bushes can be shaped after their first flowering, even shoes, vehicles or animals. Good hygiene practices are though the flowers are not being harvested. necessary to prevent the importation and spread of this Yields Further reading Many factors influence the productivity of Chamelaucium • Farmnote No. 86/88 ‘Preparation of liquid fertiliser species, including fertilisers, pests, diseases and stock solutions’ (Agdex 545). irrigation. Grower experience in Western Australia • Farmnote No. 46/04 ‘Cooling cut flowers and foliage’. suggests that the yields in Table 3 can be expected from healthy, well-managed bushes. • Farmnote No. 89/88 ‘Post harvest insect disinfestation treatments for cut flowers and foliage’ (Agdex 280/56). Table 3. Yields of Chamelaucium species: Number • Farmnote No. 1/96 ‘Pests of export wildflowers and of 500 g bunches produced* proteas’ (Agdex 280/620). Species Year 2 Year 3 Years 4-10 • Farmnote No. 98/88 ‘Pests of young trees’ (Agdex 620). C. uncinatum • Farmnote No. 35/92 ‘Wildflower production - getting Alba 4 7 15 started’ (Agdex 280/10). Purple Pride 3 5 12 CWA Pink 4 6 14 • Farmnote No. 79/94 ‘Soil moisture sensors for sandy Mullering Brook 3 5 9 soils’ (Agdex 560). C. ciliatum 14 5 • Farmnote No. 108/94 ‘Disinfestation of wildflowers C. floriferum 13 3 using insecticide dips’ (Agdex 280/56). C. megalopetalum 13 3 Lady Stephanie 3 5 18 * Nil production in Year 1. Note: The number of stems/bunch ranges from 5 to 15, averaging about 8. The price per bunch will depend on flower quality, stem length and stem thickness.

Post-harvest handling Bud and flower drop is often a problem in export shipments. Cool fresh flowers as soon as possible after harvest. Try to pick in the cool of the day when the bushes are turgid and immediately place the flowers in water in a shaded place. Many flower farms use a covered trailer. Where it is likely that flowers have a high incidence of Botrytis, or are likely to encounter ethylene in transit, place the flowers in a 4 mM STS pulse for 20 minutes as soon as possible. Flowers that are already stressed will not respond to STS - the damage is already done. Also dip flowers for export in Rovral® (1 g/L) and Cislin® (2.5 mL/L). After dipping, air-dry the flowers while they are standing in water, before packing them - see Farmnote No. 108/94 ‘Disinfestation of wildflowers using insecticide dips’ (Agdex 280/56) and Farmnote No. 89/88 ‘Post- harvest insect disinfestation treatments for cut flowers and foliage’ (Agdex 280/56) for further details. Finally, grade the flowers and place them in accurately labelled boxes for forced air cooling to 2°C. Efforts should be made to maintain this temperature during transport to export destinations.

ISSN 0726-934X

© State of Western Australia, 2007