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Christmas Bush : Cutflower Cultivationcultivation fertiliser frost harvest market packing pests planting postharvest product propagation pruning site soil varieties water weeds yields Ceratopetalum gummiferum is a tall shrub or small bushy tree growing from 3 - 12 m high and 2 - 6 m wide in its habitat. Flowers are about 6 mm across, white, and numerous; sepals enlarge in fruit and become bright red, rarely white. Sepals (modified leaves) make up the calyx, which encloses and protects the floral parts during development NSW Christmas Bush grows along the coast and near ranges from the Blue Mountains to the Richmond River. Soils vary from coastal forest light sands to rocky shale hillsides to moister more organic sites in sheltered gullies.
Harvested product is stems carrying the partly mature fruits surrounded by sepals coloured to bright red. This is an important difference to other crops, e.g. Riceflower and Wax, which are harvested at an early stage of flowering (near anthesis). Bush must go through the flowering stage, set fruit without excessive flower drop, and carry the developing fruit for about 8 weeks after flowering has finished, until full colouring of the sepals has occurred. If unharvested, sepals fade after maximum colouring and the propeller-shaped seeds spin off the plant in February. Our best plants at five years have so far been able to regrow to a larger size and increased yield each year. Plants in cooler districts may lose vigour after 7 - 8 years of heavy cutting, and may need replanting. Plants will have provided an good economic return by this time, so replanting would be feasible. Annual stem growth will also be shorter in cooler districts. Root system development must be strong enough to feed regrowth of more than 50% of the plant mass annually, so thorough ground preparation and quality planting material are vital. Plants can be expected to live for many years (if they don’t encounter any diseases or accidents), as Ceratopetalum is a hard-wooded tree; Ceratopetalum apetalum, Coachwood, is a close relative. Cultivation : grown in single rows. Space between rows is 4m as plants will grow out 1m each side and 2m is allowed for access for harvesting and spraying. Spacing in rows varies from 1 - 2 m. We use the closer 1 m spacing to maximise area return in the first 5 - 6 years. Maintenance and overhead costs remain the same, with increased yield. Plant cost is recovered in the first harvest (15 – 18 months). If plants grow too close and shade each other (reducing flower production) after 7 - 8 years, every second plant would be removed, or possibly transplanted. Bush must have very good drainage both in the soil and on the surface. Otherwise, it can be susceptible to the root fungus, Phytophthora cinnamomi, which is the most important disease of Australian cutflowers. Deep ripping and mounding or hilling of rows to 20 - 70cm high is recommended (except perhaps in very light soils) to maximise soil aeration for root growth. Raised rows also provide some relief from extended periods of heavy rain or high water table. Channel or slotted underground drains may be needed in heavier soils. True contour rows tend to catch water and organic matter on the high side, so rows should run lower than contour, but not so steep as to cause erosion. The exact layout will be determined by the degree of slope, aspect and boundaries of the block and access considerations. Rows are best broken, for speedier access, by cross roads at around 50m length. This allows around 2,250 plants per hectare (900 plants per acre).
Planting : Bush is planted with minimum root disturbance from tubes; we have had higher survival rates and better performance after 12 months from deeper 125mm tubes with a plant around 20cm high, than from smaller plants. Plants should be bushy and actively growing, and sun-hardened. We plant out through most of the year, avoiding the hottest and coldest months. Young plants need daily watering in summer, and new plants must be thoroughly watered at planting. Spring planting is recommended for frosty sites.
Soils : Bush has succeeded on our property in shallow rocky podsolic loam and nearby on deep fertile alluvial silts. Very sandy soils may be difficult. Bush generally seems to be quite adaptable to soil type; its suitability for alkaline soils has not been determined. Location influences growth habit; on deep alluvial soils, Bush is thriving, growing with more compact internodes, which yield high quality stems.
Site : Best colouring is obtained by planting in a sunny situation, and plants are ready to harvest earlier at a site with more sun. Hot and drying winds can cause fruit drop before harvest. This may limit the areas in which Bush can be grown successfully. Windbreaks would be advisable for exposed sites, as for other flower crops.
Frost : tolerance is not yet fully known as data on minimum temperatures and their duration is scarce; our feeling is that to -2°C will be ok, with -2°C to -4°C a danger area and below -4°C out of range, but these will need to be confirmed over the next few years as reports come in from different locations. There have been plant deaths and also successes in frosty areas. Spring and early summer plantings will allow more time for growth than autumn plantings. Bigger plants are less susceptible. Mounding increases above ground height and temperature, tree guards may also raise temperatures. Some growers have prevented frost damage at -4°C with two or more sprays of Envy, a polymer frost protectant; others, with -6°C, failed. Most sites are quite variable in temperature, even over a few metres; try measuring next winter with some minimum-maximum thermometers.
Propagation : selected forms are grown by cuttings, which can be difficult and take a long time to root. Seed germinates readily when fresh. Seedling plants are very variable in growth, often late flowering, and light coloured with low flower count; not recommended for cutflower production. Grafting onto clonal rootstock selected for vigour may offer faster plantation establishment and greater productivity. Grafted plants are not yet commercially available.
Weeds & mulch : moisture retention is important, particularly from flowering to harvest. Weeds compete with the crop and host pests. We use weedmat, two strips 90cm wide, one each side of the row, with a 20cm gap between mat strips. Strips are fastened with wire pegs. The gap is to allow application of solid fertilisers to the soil, and to maximise aeration around the base of the plant. This gap is mulched with hardwood chip. Weedmat has a high initial cost but is cheap to install and does a thorough job of weed suppression for at least five years. Other mulchs may be used, e.g. woodchip, hay; these tend to be cheap to buy but expensive in application labour. We also control weeds by hand, brushcutter and by cautious use of herbicides. We use glyphosate between plants and along the weedmat edges. Bush is not particularly sensitive to glyphosate; however we aim to mulch rather than spray for long-term soil health. Caution : we killed some plants with a grass-selective herbicide, Sertin, which had been successfully sprayed over other crops. Inter-row roadways are kept grassed and mown.
Fertiliser : Bush is a heavy feeder and responds well; we use Osmocote Plus 8/9 month, applied once after harvest (January), and pelleted chicken manure (Dynamic Lifter or TerraFirma LongLife), applied in January and April. The plant makes most of its stem regrowth from January to June. Bush is not phosphorous sensitive. We also use a complete high potassium liquid fertiliser, alternated with calcium nitrate through the drippers about every four weeks from January to September. No fertiliser is used from then to harvest. We are aiming for a fairly low fertiliser status by harvest in November to prevent soft new shoots growing through the flowers, and to achieve a slightly hardened product for shipping. Bush needs high iron levels, particularly the white varieties.
Water : Bush uses relatively large amounts of water, especially in summer. We apply around 4L / day on 2 - 3 year old plants, with about half or less in winter; this would be given in two or three applications per day. Our soil type is reasonably heavy, and water use on lighter soils or windier sites may be much more. It grows through most of the year here and so is also regularly irrigated in winter. We use Drip-In dripper lines, at 4L/hour. Limited information suggests lack of much tolerance to saline water, far less than Riceflower.
Pest & disease control : Leaf-curling psyllids often appear on new growth, and are the main pest. Scale can be a persistent problem, particularly if plants are not growing strongly. Aphids, caterpillars and thrips can attack new shoots and flowers, although they have not been a major problem to date. Elephant beetles chew holes in the bark. We use regular oil-soap sprays at 4 - 10 week intervals (Synertrol and NatraSoap), backed up by an insecticide as necessary. The oil-soap spray is environment-friendly and very useful if used regularly, before insects get well established. We also use phosphonate (AgriFos) as a preventative for Phytophthora cinnamomi. It is sprayed on the foliage as it acts by strengthening the plant’s immune response rather than against the fungus itself. We use it with oil at 2 - 8 week intervals, depending on likely disease pressure (high temperature and rainfall). It can be used in combination with many other sprays, but always test a new combination on a small scale first.
Pruning : mostly occurs at and after harvest. Unharvested branches are cut back ¼ to ½ their length. The main trunks are cut to around 2 - 2.5m. We leave the short lower side branches on the plant after harvest to feed it until the top regrows. These low branches are cut back (thicker) or off (thinner) later in autumn. These "nurse branches" have been found critical for survival in some other crops. Bush will regrow from a bare trunk but much more slowly than if about 25% of the foliage remains. New shoots are tipped in March - April if they are going to be too long by the following summer. Young plants are pruned in the nursery to form a multi-trunk structure rather than the natural Christmas tree shape, and can be tipped several times in the first year. Flowers are cut off small plants at the white flower stage to direct energy to new shoots. Older plants, around year 8 - 10, may need a heavy rejuvenation pruning, removing some trunks at the base.
Harvest is early November – mid December on the NSW north coast and SE Qld. with bud initiation after short days around late June, bud development through July and August, flowering in September and fruit development through October. This timing will be later in colder districts. Product from NSW south coast and central Victoria flowers in January and is harvested in March. Plants harvested for the first time are earlier by about one week than older plants.
Harvest stage : Sepal colour gradually darkens to a maximum then lightens again; this can be confusing until you are accustomed to it. Pick when colour has deepened and nearly all calyxes have coloured. Stems harvested with around 3 % of white flowers left (the youngest flowers right at the top of the stem), i.e. the rest coloured have the best vaselife. Earlier harvest does not have enough colour and later harvest shortens vaselife. Stems mature progressively over the plant, starting on the sunny side about two-thirds of the way up. Stems are selectively cut near their bases over about 3 - 5 weeks for any one block. Spread of flowering on the plant is extended by cooler, moist weather and shortened by hotter, drier weather. Bush likes rain at harvest and can be picked wet. We pick at least every 2nd day. Avoid picking in the heat of the day. Some blocks on our property are ready 1 - 2 weeks earlier because they receive more (morning) sun. We place cut stems into water with preservative within 3 minutes of picking, and into the coolroom within 45 minutes. Our harvest period is around 6 - 7 weeks.
Postharvest : stems are held in water in a coolroom at 8 - 10°C overnight or for at least 2 – 4 hours before grading and bunching. The water contains bleach (0.5ml/L) and citric acid (0.25g/L). Lower temperatures (2 - 4°C) may be used without any problem, but are not necessary.
Packing : Bush is sold by the stem in 40, 50, 60, 70 and 90cm lengths for export markets. Stems are cut to length and leaves stripped from the lower 10 - 20 cm, depending on their length. Bunches of 3, 5 and 10 stems are made, depending on their length and volume. Young plants usually have bulkier stems (shorter internodes) than older plants and so pack at fewer stems per box. Bunches are dipped in an insecticide / fungicide solution (Cislin & Rovral) and sleeved when nearly dry. The domestic market prices by the bunch and will accept a bunch of mixed stem lengths, from 5 - 25 stems, depending on their size and fullness.
Market timing : The product has been named "Festival Bush" ( to de-emphasise the Christmas seasonality ) by the Flower Exporters Council of Australia in a new catalogue for the Japanese market. However, the Japanese may ignore this and continue to refer to Christmas Bush; they seem to be happy to have the product anytime from early November to March. New Year is a major event in Japan and Christmas is increasingly important. In the North American and European markets, demand could be expected to peak in November – December. Poinsettia, a well known floral decoration in the same traditional red - green Christmas colour combination, sold 55 million pots last year in USA, mostly in November. Thanksgiving is a major opportunity for early product in the US market, as are Chinese New Year and Valentine’s Day for late product in Asia and USA. The Sydney market is oversupplied with late, mediocre bush-picked product but demand is strong for high quality product from late November to Christmas. Demand in other Australian markets is growing strongly as florists discover good product.
Yields : plants may have 3 - 4 saleable stems 12 months after planting. This can double each year, at least to year 5, and increase more slowly in later years. Japanese market returns have been as high as $1.50 - $2 / 50cm stem, but a more realistic price to work on for the longer term may be in the range of 50c. Christmas Bush has generated a large amount of interest and excitement in that market since we first trialed it there in 1992 and seems likely to be a major Eastern Australian cutflower crop. Quality product was sold in 1996 in the top end of the US market at Japanese price levels.
Varieties : High quality product has a high sepal to leaf area ratio with shorter internodes, i.e. more colour per stem. Reds : Albery's Red : compact, dark red colour, early, floriferous, moderately vigorous; the most important commercial variety so far. Well accepted in the Japanese market and brings best prices in the Australian market. Selected by Neil Kirby from seedlings grown by Peter Albery, a well-known Sydney nurseryman, and sold in the nursery industry for about 15 years. Produces strong, straight upright stems. Grows 3 - 5 m tall if not pruned. Shiraz : : a new form with larger leaves and sepals than Albery’s, and a most attractive deeper colour. Sepals are slightly bell-shaped. Later by 2 – 3 weeks than Albery’s, with a slightly more pendulous growth habit. High sepal to leaf ratio; excellent market response to trial shipment. An exceptional variety to extend the season for early growers. Wildfire : a form with narrower leaves, red stems, slightly longer internodes, narrower sepals of a lighter colour and a more vigorous grower than Albery’s. Leaves and sepals are often slightly whorled. Shipments in 1995 and 1996 returned the same prices as "Albery’s Red", but its overall quality is not as good.
Whites : white sepals look great contrasted with red, for the traditional Christmas look. Good response from Japanese market to trial shipments, although there were some problems with brown spots on white sepals. The fungal spotting can result from rain, overhead irrigation or condensation. Silent Night : a new PBR variety selected by Jeremy Smith, a Central Coast NSW grower. Large sepals, lime green foliage and a vigorous grower. Best white to date. White Christmas : It is not as vigorous or compact as "Albery’s Red". Sepals are smaller than "Silent Night" Some pink forms are being trialed and will be released this year. There are several other coloured foliage varieties; they flower poorly. There has not yet been any systematic investigation of different forms over the large distribution range of the species. © Mountain Nursery 1997 |
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