Historically, the establishment of deciduous orchards was typified by planting bare-rooted trees during dormancy. With the advent of technology and the demand for rapid turn-around times, more growers are turning to the use of container-propagated potted trees. Bare-rooted trees still account for the majority of new plantings, but the use of potted trees, which are planted during all 12 months of the year, have some singular demands.
Most of the time when a potted tree is planted, it is leafed-out and actively growing. This presents a special demand for keeping the trees hydrated since their water use is ongoing from the moment they arrive for planting. This is especially critical for hybrid rootstocks, which can be more sensitive to dehydration. While keeping the trees watered before and at planting is important, the days after are the most critical, especially until the roots develop outside of the peat/vermiculite square they were propagated in.
Due to the poor hydraulic conductivity between the root square and the soil interface, oftentimes the soil around the new planting may be moist, while the root mass is dry. It is important to monitor the status of the root square. Some growers will lightly break up the rooting mass at planting to allow the roots a more intimate contact with the native soil. Even with this method, ensuring adequate moisture post-planting is critical.
Other factors commonly encountered when potted trees are planted late into the growing season are developmental. These may include factors such as the number of buds that break into branches, the orientation of the breaks, the caliper of the trunks, and insect pests.
When large caliper (greater than ¾-inch) trees are planted during dormancy, they can be treated similarly to bare-rooted trees. Small caliper trees that sometimes are thinner than ¼-inch, or trees planted in the heat of summer, present the greater challenges.