Controlling ginseng diseases in your commercial ginseng planting

People frequently ask me how to control disease in ginseng, particularly damping off disease (caused by Rhizoctonia solani ), foliar leaf disease (caused by Phytophthora cactorum ) and black root rot (caused by Cylindrocarpon destructans). Because this is an FAQ, here is an answer. Start by checking out this paper for the background. As you can see, the first two diseases don’t effect goldenseal or black cohosh, the last disease only effects seeds/seedlings of these herbs. So for people who want to prevent these diseases from impacting yields on their ginseng forest farm, I suggest spacing out your ginseng beyond what the “rake and scatter” method sometimes results in. Using the extra vacant space, you now have room for interplanted goldenseal, which can grow into a barrier around your ginseng. While goldenseal seed is perhaps an under-utilized forest farming resource (I have been saying this for years), in our scenario where damping off disease may actually already be present, in lethal quantity, in the exact spaces where ginseng seed was planted but failed to establish… deploying a goldenseal rhizome seems advisable. This topic is pretty well covered by Adrianne Sinclair and Paul M. Catling in an obscure publication that has been reproduced with permission by the NRCS. One forest farmer they interviewed called ginseng and goldenseal “‘the king and the queen,’ the ‘queen’ (goldenseal) being more robust and reliable.” At some point you will harvest the ginseng, and then the goldenseal can be left to fill in those spaces.

Details:

1. For planting the ginseng seed, I use a Dr. Ming’s ginseng seed planter. The picture below shows a friend of mine planting ginseng seed with this planter. This tool allows you to achieve good seed singulation, which saves money, as you can plant plant just 25% the weight of seed you would using the rake and scatter method. Think about it- 3 or 4 lb seed/acre vs 15 or 16 lb seed/acre. $105/lb for ginseng seed that’s a big difference!
2. Because you have precise control over seed spacing, plant the ginseng seed on a 1.5′ to 2′ grid in the late autumn.
3. The following summer, observe where the ginseng has and has not germinated. Mark spots for replanting with one color of surveyor flag, and spots equally spaced between the rhizome seedlings as well.
4. After the ginseng leaf senescence in the autumn, and once the soil moisture is adequate, replace each flag with a goldenseal rhizome. Rhizome should be 2-3″ inches in length and have multiple buds and rootlets. Take care not to damage buds.