Growing Zinnias

Latest Update 5th March 2020.
 
Zinnias

• I grow zinnias as a bee attractant and for its bold colourful flowers which grow for most of the warmer months.
• They are drought tolerant once established, but are frost tender.
• Its a very tall plant, and I usually grow them behind ground cover plants in herbaceous borders.
• They are annuals and I grow them from seed in an Ecopropagator.
• I allow some of the flowers to go to seed so I can save them for future years.

Details

• Binomial Name:                                         Chrysogonum peruvianum.
• Family:                                                      Asteraceae.
• Garden bed type:                                       Drip line irrigated.
• Plant Spacings (centres):                           250mm.
• Climate:                                                    Warm Temperate.
• Geography:                                               Southern Hemisphere.

Growing Conditions:

• They need full sun, and die back in winter.
• They are happy in hot weather and are drought tolerant.
• Minimise soil disturbances to maintain a natural soil structure.
• They are propagated from seed in a propagator and planted out when ready into prepared beds.

Feed the Soil.

• A light covering of homemade compost before planting, followed by straw mulch once the seedlings are established is all they need.

Growing Instructions

• They are propagated by sowing seed in a propagator in early spring and planting out in prepared beds when ready.
• They are a tall plant and need plenty of space leave at least 250mm between plants.
• Don't remove or dead head the flowers unless you are harvesting them, they will set seed which can be collected when dry and used to grow new plants in the future.
• Spray the foliage with aerated compost tea as scheduled in the propagation plan.

Organic Pest Control.

• Caterpillars.
• I use aerated compost tea as a foliar spray on all my ornamental plants. It strengthens foliage and provides a biological barrier to plant pathogens.
• As a last resort use bacillus thuringiensis (Dipel in Australia) as a foliar spray it becomes a potent (organically certified) killer of caterpillars. When ingested by leaf eating caterpillars it kills them by releasing toxins into their gut. They stop feeding and die within a few days.
• General:
• Regular foliar sprays of aerated compost tea boosts the natural defenses of plants by colonising the leaf surfaces with beneficial microbes. These microbes defend the plant against airborne pests and diseases.
• Similarly, proper soil preparation including annual applications of home made compost boosts the community of beneficial microbes, which defend the plant's roots against pathogens.