Site selection
Choose a weed-free and disease-free site, preferably not old pasture with a previous phosphorus fertiliser history. Verticordias appear to absorb phosphorus if available in the soil solution and it may reach toxic levels in leaves and affect yield.
They prefer deep sand or sand over gravel. Some Verticordia species tolerate sites where there is coarse sand over a watertable within, say 1 metre, of the surface and respond to the greater availability of water by producing high yields.
If a weed risk site is chosen, apply pre-emergent (such as simazine) and knockdown herbicides (glyphosate and Spray.Seed®) to clean up the site before planting.
Planting and establishment
Weed control needs to be maintained during establishment to ensure plant survival. In cooler climates use of plastic mulch or in warmer climates Weedmat or laying a 75-100mm thick layer of bark mulch can be used to give effective weed control during establishment. Mulch is particularly effective in promoting growth as it not only controls weeds but conserves soil moisture and moderates soil temperature, being cooler in summer and warmer in winter. The more even temperature aids plant growth.
Planting is best done in spring to early summer, the exact time will depend on the location with later planting in cooler locations. For the first 3-4 months during establishment plants should be protected with covers such as ‘grow cones’ or tree guards. Covers also aid in preventing damage from native animals.
Tube stock should be freshly propagated in tree tubes with straight roots just appearing out of the planting tube. Planting old stock where the root system has become curled around in the planting tube can result in poor establishment in the field and development of a 'knotted root system' where the root system eventually cuts off the tap root, killing the plant.
Propagation of tube stock needs to be timed to produce fresh tube stock at planting time.
Planting patterns and densities can vary from 6,600 to 22,200 per hectare depending on species. For example, plant V. fragrans and V. grandis in double rows with 1m between plants, use a staggered grid pattern in beds 3m apart.
For V. plumosa and V. pennigera plant in double rows, 0.6m apart with 0.7m between plants.
For V. serrata plant in double rows with 0.3m between plants. In cultivation trials by DAFWA, yields per metre of planting bed ranged from 240 stems of V. cooloomia to 40 stems of V. serrata with stem lengths of 50 to 110cm.
Fertilisers
Verticordias have a low requirement for fertilisers at establishment. At planting, 10 grams of low phosphorus (2.6%) slow release fertiliser such as Osmocote® or Nutricote® should be spread on the soil surface within a 15cm radius of the plant. Once established, after two to three months, plants require 60-90kg/ha/annum of nitrogen, 60-90kg/ha/annum of potassium, 8-12kg/ha/annum of phosphorus and 7-10kg/ha/annum of calcium together with a balance of trace elements.
If symptoms of yellowing and leaf drop occur it may be necessary to reduce or eliminate phosphorus from the fertiliser mix. Fertilisers are best injected during irrigation using fertigation.