There are some reports of minor frost damage from the frost on May 13/14. The damage is not always immediately obvious, but does leave plants more susceptible to foliar diseases. Damage is mostly confined to minor splitting of the stems. Growers should closely monitor low areas of gardens for both damage and disease.
Conditions in most of the ginseng growing area have not been conducive to the development of foliar Phytophthora. Root Phytophthora is present in many older gardens and a single wet period could result in foliar infection, especially at this time of year when tops are still unfolding and plants are more succulent. Despite the dry conditions, growers should closely monitor gardens for foliar infection if any rainfall occurs.
Some areas are becoming very dry since Norfolk County and surrounding areas were bypassed by most of the rain over the past week. Since ginseng has only recently emerged, soil moisture levels under the straw in ginseng gardens may still be adequate. However, growers should closely monitor soil moisture levels this year and irrigate on a regular basis to avoid moisture stress. Growers should retain more area for seed production this year in case of another hot and dry year.
Many growers are preparing for fumigation over the next few weeks. With the dry conditions, irrigation will likely be required to ensure good soil moisture before fumigation unless we get substantial rain before that time. Soil moisture is important for both activating the fumigants and for a better seal of the soil surface for untarped fumigants.