Background

Sweet basil (Ocimum basilicum L.) is one of the most popular culinary herbs. It is used as a fresh or dried whole herb and may be steam-distilled to produce an essential oil. Basil oil has perfume and pharmaceutical use as well as use as a flavoring ingredient. Many types of sweet basil, with a diversity of flavors and aromas, are available for cultivation.

The annual plant is grown from seed or transplants. Basil is very sensitive to frost, so the length of the growing season restricts production in Montana. Basil grows rapidly, and several cuttings may be obtained. Plants should be cut 4-6" from the ground to permit regrowth. Harvest for fresh or dried leaves is done before bloom, while harvest for oil is done at full bloom. For commercial oil production, basil is cut and allowed to wilt before steam distillation.

Sweet basil will not be a highly productive crop in many locations in Montana, but the many types of basil may provide an opportunity for specialized markets.

Research Summary

1998

'Italian Large Leaf' basil was sown in the greenhouse on May 5, 1998, and transplanted to the field on June 17. Six-row plots were 8 ft long with rows 18" apart and 8.7" between plants, with four replications. Plants were harvested three times during the season: on July 22 the stalk was clipped above the first branch and on August 4 the top 2/3 of the plant was clipped, both at the early bloom stage. The final harvest was on September 18. Border rows were not included. Plant material was air-dried before distillation on October 7.

Table 1. Yield of 'Italian Large Leaf' sweet basil at the Western Agricultural Research Center, 1998
 
Oil (lb/a)
Dry weight (lb/a) *
Harvest 1
0.8
581
Harvest 2
2.8
855
Harvest 3
5.5
1,850
Total
9.1
3,253

* Weight includes stems

1999

Three cultivars of basil were grown in 1999. Sweet Dani and Cinnamon basil were from Johnny's Selected Seeds, Albion, ME, and Italian Large Leaf was from Garden City Seeds, Victor, MT. Plants were sown in the greenhouse on April 16 and transplanted to the field June 11. Plot size was as in 1998. Sweet Dani and Cinnamon basil were harvested on July 20 and August 10 at 6" from the ground, and the entire plants cut on September 9, while Italian Large Leaf was harvested only on the last two dates. Plant material was air-dried before distillation on September 18.

Table 2. Yield of three cultivars of sweet basil at the Western Agricultural Research Center, 1999
Cultivar
Oil (lb/a)
Dry weight (lb/a) *
Dried leaf (lb/a)
Sweet Dani
 
 
 
Harvest 1
0.8
213
147
Harvest 2
3.6
1,099
758
Harvest 3
5.8
1,287
862
Total
10.2
2,599
1,767
Cinnamon
 
 
 
Harvest 1
1.5
144
99
Harvest 2
5.2
1,112
767
Harvest 3
4.6
1,020
627
Total
11.3
2,276
1,493
Italian Large Leaf
 
 
 
Harvest 1
5.2
1,180
887
Harvest 2
2.9
1,221
859
Total
8.1
2,401
1,746

* Weight includes stems

Acknowledgments

Seed of Sweet Dani and Cinnamon basil was provided by Johnny's Selected Seeds, Albion, ME.