The inventory data from 2015 show that Cinnamomum cassia plantation area in Thanh Hoa province was 1,229.48ha, of which 93.37ha was of pure Cinnamomum cassia plantations and 1,206,11ha was of mixed species forests. In plantations, most of the Cinnamomum varieties were bought from elsewhere. A review of the existing models in the area showed that Cinnamomum cassia were mainly grown extensively under the projects 661, 327, planted at will by household and planted in sexual seed orchards. On average, the yield of dry bark at age 5 reaches 1kg/tree, but at the age of 15, the dry bark production can be 10 times greater and at the age of 18, 20 times. Since the early 2010s, due to the low price of cinnamon, farmers have cut down many of this species and the planted areas were left uncared. Moreover, the original variant has not been preserved, leading to a low amount of essential oil. In general, Cinnamomum cassia has been seriously degraded in both quantity and quality.

Plus trees were selected in two steps: observing morphology and comparing growth and quality indicators of potential plus trees. The indicators used for comparison consisted of diameter, height, bark thickness, essential oil content and cinnamaldehyde ratio. The selected plus trees were those that were free of pests and diseases, with the diameter, height and bark area of ​​at least 10% greater than the population’s average. 40 plus trees, with the essential oil content 10% greater than the population’s average, were selected out of 109 trees. Clones XL01, XL16 and XCM01 showed prospects of high essential oil productivity and content. In addition to plus tree selection, the research also established an asexual seed orchard in Thanh Hoa with 1,400 transplants meeting the standard 04 TCN 147-2006.

From the seed source of 40 plus tree families, the project produced 30,000 seedlings to test on a 10-hectare intensive cinnamon model at Xuan Lien Nature Reserve. Standards for seedlings grown in the model were: at least 12 months of age, height > 25cm, diameter of root collar of 4 - 5mm and with at least 14-16 leaves. After 12 months, the average survival rate of seedlings in the model reached 94%. The project also conducted experiments on the effect of different canopy covers on the growth of Cinnamomum cassia. Results of monitoring and evaluating the growth of these trees showed that the canopy cover of 0.3 - 0.4 yielded the best growth. The above research results were the basis for drafting a technical regulation for intensive cultivation of Cinnamomum cassia for Thanh Hoa area.