Lynette Morgan’s growing tips
• Large-flowered chrysanthemums are typically planted outside from mid-August onwards in the North Island and September onwards in the South. As they don’t flower until autumn, they have a reasonably long planting season and can still be planted out through summer in most areas. Plant in full sun or partial shade.
• These hardy perennials survive winter in a dormant state after being cut back hard after flowering finishes in late autumn or early winter. While most varieties tolerate frost, heavy wet soils through winter, and slug and snail damage in spring can be a problem. Raised beds are useful in particularly wet areas.
• Established plants develop underground “stool” systems from which shoots will arise in late winter or early spring to restart growth when conditions become warm enough.
• Chrysanthemums can also be grown in pots, as container plants, if kept well trimmed to maintain a compact shape. Regular watering and application of liquid fertiliser every week is recommended for potted plants.
• In the garden, chrysanthemums are heavy feeders once spring growth starts to pick up pace. A specific chrysanthemum fertiliser is recommended before planting and as a side dressing through the growing season. High levels of potassium assists with strong flower development and should be applied in midsummer before floral initiation begins.
• Once flowers begin to develop, keeping up with staking: supporting heavy flower stems and disbudding are the main tasks.
• Chrysanthemums take several weeks from flower bud initiation to full bloom. They should be harvested promptly if being used as cut flowers – holding blooms on the plants can lead to a loss in colour intensity and risks petal damage from pests and weather. Once cut, a standard floral preservative solution can be used. However, most blooms will last three or more weeks in a vase.
• General garden sprays can be used for insect pests such as aphids which may appear in spring. Avoid spraying the tops of the plants once the flower buds have formed.