We have experimented extensively with summer digging systems over the past several years. In 2002 we successfully dug almost every plant in production, even during the hot droughty weather. Our system is not rocket science, just several key steps that ensure success. First, we inject a solution of water and Bio Plex into the root zone of each plant prior to digging. The amount of fluid is significant; we apply at the rate of 50 gallons per two inches of caliper. It is critical that ample water and Bio Plex reach all growing parts of the plant.
In the second phase, we apply a thorough application of 2% Vapor Guard to the plant. We tried many different foliar materials and concluded that Vapor Guard is the key to summer digging success. Unfortunately, Vapor Guard cannot be applied to blue plants such a Picea pungens ‘Hoopsii’ because it will turn the foliage green.
After a 24–48 hour wait we dig a somewhat larger ball than typical of dormant harvest. The ball will be from 10 to 15% larger depending on the specific plant. We then immediately transport the plant to our fully enclosed holding building and water the root ball heavily for the next 2–3 days while the soft tissue is “hardening” off. The plant is then ready to ship protected by a side board kit or cooled reefer.
Another advantage we have over some growers is our farm’s 100% coverage with drip irrigation. Our plants are never allowed to enter a period of drought stress, enhancing our ability to summer dig. Starting with a plant’s third through fifth year in the field, we may limit the irrigation to insure that the plant becomes accustomed to the typical growing conditions that it will encounter after leaving the farm.
During the infamous drought of the summer of 2002, we dug every week during season while being selective during peak flush cycles. However, summer digging of Prunus and Hibiscus cultivars is very risky even with the above steps and we therefore discourage their summer sale.
Summer digging incurs a surcharge of 15% of the invoice value to cover the added labor and material inputs. However, we wave the summer digging charge on orders exceeding $5000 or approximately half a truckload when the invoice is paid within terms. The savings on your larger order will make the freight charge more then free.