Photo Credit: Amanda Keene of Flowers on Phoenix grew these tremendous Bells of Ireland from Farmer Bailey plugs. 

Common Name Bells of Ireland 
Genus  Moluccella 
Species M. laevis
Family Lamiaceae
Life Cycle  Hardy annual 
Tray Size  210, 285
Plug Care Harden off and plant immediately after arrival, do not  allow plugs to become rootbound or experience any  stressful conditions prior to planting or they may flower  prematurely. Be gentle with the root ball while  transplanting as this species does not like root disturbances. 
Netting / Staking 1-2 layers of netting is recommended. 
Temperature Range These are cold loving plants - plugs should be planted a  couple weeks before the last frost date in your area. They can handle a light frost but should be protected   during a heavy frost event. A long cool period while establishing will give the tallest, best quality stems. The plants will stop producing and decline in quality as the heat of summer starts to kick in mid-July.  
Spacing 10-14"
Soil Preference Neutral to slightly acidic pH, well drained and nutrient  rich. Amend bed with compost and granular fertilizer before planting.  
Day Length Day Neutral. Plant in full sun. 
Pinching Do not pinch. 
When to Plant Plant in early spring, before the last frost. They can handle a light frost but should be protected from a deep freeze event. 
Harvesting Expect flowers to appear only 5-6 weeks after transplanting (temperature depending). For fresh cuts,  wait until you see the small white flowers starting to develop within the bells. If harvesting to dry, wait until the small white flowers are completely open. 
Post Harvest Care Expect up to one week vase life. For a cleaner look, try  stripping or snipping all the leaves from between the bells. Cut stems should be placed into cool water immediately. Hang upside down in warm, dry, well ventilated area for drying. 
Diseases / Insects Moluccella plants are very robust plants are rarely suffer from disease or insect pressure. 
Bailey's Notes

Bells of Ireland do have thorns hidden between the bells so be aware of these during harvest. 

If the seeds are allowed to mature and fall from the plant they will readily germinate the following spring.

Resources

Three Acre Farm Guide to Growing Bells of Ireland