The length of field growing season in the temperate and subtropical regions of the United States including Virginia, does not allow ginger (Zingiber officinale) rhizomes to mature naturally. As a result, saving rhizomes as seeds is often impossible and the supply of seed ginger rhizomes (seeds) has been mostly from Hawaii. To mitigate this challenge, Cooperative Extension at Virginia State University attempted to produce ginger seeds hydroponically in a greenhouse for two years. In 2022/23, cultivar Chinese Ginger (4-6 buds/rhizome) was presprouted in the greenhouse using 1-gallon pots filled with soilless media in January and transplanted into 20-gallon fabric containers filled with soilless media or pine bark on May 6 or 17, 2023. Plants were fertigated on weekdays with a nutrient stock solution containing 6 oz 4-18-38 plus micros, 3 oz magnesium sulfate and 8 oz calcium nitrate per gallon. Seed harvests took place from January 15 to March 18, 2024. The yield was significantly higher with soilless media (12.7 lb./plant) than with pine bark (11.1 lb./plant) although the marketable yield was not statistically different. Plants in soilless media were difficult to harvest (heavy and wet soil, tangled roots). Marketable yield was the highest for plants harvested from 240-269 days after transplanting (DAT), followed by 270-289 DAT. Harvests after 290 DAT had 37-53% culls. The overall yield was not different in terms of transplanting dates, but May 6 transplanting had significantly less marketable rhizomes compared to May 14 transplanting. The first-year results favored using pine bark and harvesting 260-290 DAT. In 2023/24, ‘Blue Ring’ and ‘Yellow Ginger’ were added. Pre-sprouting started in March and transplanting occurred in late May 2023 with only pine bark as the media type. Fertigation and irrigation were discontinued in mid-December to allow media to dry. The yield of ‘Chinese Ginger’ raged from 11.3 lb./plant in early November 2023 to 13.7 lb./plant in late February 2024, indicating possible early harvests and curing if storage space is available, which would avoid heating greenhouse in deep winter. ‘Chinese Ginger’ had the highest yield (13.8 lb./plant), followed by ‘Yellow Ginger’ (12.5 lb./plant) and ‘Blue Ring’ (9.7 lb./plant). All three cultivars had 10-20% culls due to rotting (disease) and scarring. Our results proved the feasibility of ginger seed production in local greenhouses and the great yield with a hydroponic system. We will refine the system and test the quality of seeds in field and high tunnels in 2024.
