Dusty Miller Growing Guide

Dusty Miller New Look photo courtesy of Liz Krieg, Maple Flower Farm

Common Name Dusty Miller, Silver Ragwort, Senecio
Genus  Jacobaea
Species J. maritima (aka Centaurea Cineraria) 
Family Asteraceae
Life Cycle  Tender perennial, often grown as an annual 
Tray Size  210
Plug Care Harden off and plant or bump up soon after receiving plugs to avoid them becoming rootbound. Water plugs in well as they get established but mature plants are quite drought tolerant and do not need frequent irrigation. 
Netting / Staking Not necessary. 
Temperature Range Happy growing in temperatures as low as 40F when young, but protect from frost. Will overwinter reliably in zones 8 and warmer, but have been known to overwinter up to zone 6 if it is a mild winter. 
Spacing 6-10" might seem like tight spacing but it encourages long stems. 
Soil Preference Loose, well draining soil that is moderately fertile. They appreciate some compost soil amendments and light fertilizer, but are generally not heavy feeders. Good drainage is essential. 
Day Length Day-neutral, will grow more rapidly with longer days. Plant in full sun, unless in areas with extreme summers where afternoon shade is appreciated. 
Pinching Pinch a couple weeks after the plugs are planted to encourage basal side branching. 
When to Plant Plant in spring after all danger of frost has passed. They may be planted earlier than last frost if protected under a tunnel. 
Harvesting Expect to harvest your first stems approximately 90-110 days after transplanting. This varies from temperature and weather conditions - the warmer it is, the faster the plants will grow. Cut the entire stem, as long as you need it (usually close to the ground) with multiple leaves along the stem. 
Post Harvest Care Place cut stems immediately into cool water. The use of a floral preservative will help increase vase life. Expect a vase life of up to a week. Sometime hydration can be tricky and the leaves wilt - the use of Quick Dip or a similar product help with more reliable hydration. 
Diseases / Insects Dusty miller is affected by few pests or diseases. Root rot from over-irrigation an leaf blemishes from overhead watering are some of the main issues. 
Bailey's Notes Dusty miller has been known to overwinter even in zones as cold as 6A, but it's unreliable in these areas with cold winters. They typically flower in the second year. Flowers should be cut off as they sap energy from the plant and you want that energy going into more foliage. 
Resources NA