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Ministry of Agriculture, Food and Rural Affairs


Other Common Names Include: Vernonia, ironweed

Latin Name: Centrapalus pauciflorus var. pauciflorus (formerly Vernonia galamensis, var. galamensis)

Plant Family: Asteraceae

Close Relatives: Sunflowers, daisies

Uses and Markets: Industrial; oil contains vernolic acid, a unique epoxidized fatty acid ester used primarily as a plasticizer and in the manufacture of paints and coatings.

Vernonia plants growing in research test plots in Arizona, October, 2008.  (photo credit: David Dierig)
Production Life Cycle in Ontario


Hardiness Zone


Special Notes

Vernonia is subject to seed pod shattering (dehiscent), which can reduce harvest yields.  Day-neutral hybrids should be used to ensure flowering occurs in Ontario.  Plants are slow to establish.

Propagation method


Greenhouse Seeding/Propagation Dates


Field Seeding Date:

Late spring after danger of frost has passed.  Seed to a plant density of 30,000 to 60,000 plants/ha.

Field Transplanting Dates


In-row spacing

15-30 cm

Between row spacing

75-100 cm

Optimal Soil temperature at planting



No current Ontario fertility recommendations exist. Research and recommendations from outside Ontario do not necessarily apply to Ontario growing conditions.  Research from the U.S. indicates 100 kg N/ha, and 50 kg P and K/ha are sufficient for vernonia seed production. Click here for phosphorus and potassium application guidelines and for more information on specialty crop fertility.

Soil type

Well-drained soils.  Sandy, loam soils.

Soil pH

pH 6-8

Special requirements for growth habit

Generally drought tolerant.  Excessive moisture, particularly after first flowering should be avoided. 

Optimal Temperature Range

Temperate climate.

Temperature sensitivity

Frost sensitive.

Irrigation requirements

Irrigation usually not required.  Moisture is required for good seed germination.

Days to harvest

Crop requires ~150 frost free days to mature (variety specific).

Specialized equipment


Harvest Scheduling

Single harvest.

Hand harvest or machine harvest

Machine harvest.

Quality parameters/grades

No established grades in Canada.

Additional Harvest Notes

Significant seed loss can occur from capsule shattering.  Standard canola harvesting practices can be followed (see OMAFRA Agronomy Guide for Field Crops Publication 811).

Post harvest
Special handling/curing

Harvested seed is dried to 8% moisture prior to final cleaning.

Storage Conditions

Relative humidity (RH): N/A

Temperature: N/A

Air Exchange: N/A

Duration: N/A

Specific pests observed on this crop in Ontario (observations based on limited experience with this crop)

Unknown – limited to no production of this crop in Ontario to date.

Other Potential Pests: The following pests have not been observed on this crop in Ontario. However, they are either significant concerns for closely related plants in Ontario, or are reported on this crop in other production areas. This is not a comprehensive list of all potential pests. Not all of these pests will necessarily survive Ontario’s climate, but could potentially survive in a protected environment (e.g. greenhouse, storage facility).

Insects and Invertebrates: Helmet bug (Captosoma spp.)*, Vernonia worm (Indent spp.), aphids, blister beetles, lygus bugs, blister beetles , various stink bugs (Cluster bugs, harlequin bug, others)

Diseases: Damping off (Rhizoctonia, Fusarium), bacterial leaf blight, fungal leaf spots (Alternaria, Phoma), powdery mildew (Erysiphe sp.), rust, Fusarium wilt

*Indicates pests commonly mentioned as causing significant damage or economic loss to this crop in other regions. 


To date the following pests have been the most significant in Ontario: n/a – limited production of this crop in Ontario to date. North American research trials have seen relatively few insect and disease problems, however there have been a number of reports of a `sudden death syndrome` in vernonia, characterised by the sudden wilting and death of entire plants.  The cause is thought to be a disease, however the species has not yet been identified.  

This crop is in the new (revised 2007) Crop Group 20: Oilseeds group, when grown as an oilseed. For more information on Crop Groups, refer to the Pest section.  Always refer to product labels, and follow all directions specified on the label, before applying any pest control product.  For more information, consult an OMAF and MRA specialist.
Additional Notes


Ontario Research Projects Used to Create This Profile


  1. Angelini, L.G., E. Moscheni, G. Colonna, P. Belloni and E. Bonari.  1997.  Variation in agronomic characteristics and seed oil compostion of new oilseed crops in central Italy.  Industrial Crops and Products, 6:313-323.
  2. Baye, T. and S. Gudeta.  2002. Pest survey of Vernonia galamensis in Ethiopia.  In J. Janick and A. Whipkey (eds), Trends in new crops and new uses.  ASHS Press, Alexandria, VA.
  3. Bhardwaj, H.L., A.A. Hamama, M. Rangappa and D.A. Dierig. 2000.  Vernonia oilseed production in the mid-Atlantic region of the United States.  Industrial Crops and Products, 12:119-124.
  4. Teynor, T.M., Putnam, D.H., E.S. Opllinger, E.A. Oelke, K.A. Kelling and J.D. Doll.  1992.  Vernonia.  In: Alternative Field Crops Manual.  University of Wisconsin-Extension, Cooperative Extension Service.  Department of Agronomy, Madison, Wisconsin.
  5. Roseberg, R.J.  1996.  Underexploited temperate industrial and fibre crops.  P 60-84. In J. Janick (ed.), Progress in new crops.  ASHS Press, Alexandria, VA
  6. Dierig, D.A., T.A. Coffelt, F.S. Nakayama and A.E. Thompson. 1996.  Lesquerella and Vernonia: Oilseeds for arid lands.  P 347-354. In: J.Janick (ed.), Progress in New Crops.  ASHS Press, Alexandria, VA.