An extremely wet late summer has raised an age-old issue with new citrus nursery plantings. What is the ideal time to plant young trees, and are new tools and horticultural techniques impacting these decisions? Are there viable alternatives to the old conventional wisdom?
Many growers aim for late winter or early spring planting as it allows sufficient time to establish trees for winter. Traditional growers would await the February full moon as evidence they were past the most significant risk of cold weather and then take advantage of the full optimum growing period from March to October. Others would eliminate the risk of cold weather and plant late March into May. Even without the challenges of HLB, Florida winters present a myriad of stresses to young trees. The achievement of a robust root system and moderate increase in trunk girth can improve young tree survival. This takes time and supports the conventional approach of planting in the spring.
However, spring 2013 brought heavy and regular rainfall to the citrus production areas that carried into summer. Growers hoping to plant were faced with the choice of planting late or trying to find a way to postpone planting altogether. For some, delayed planting was not an option. They planted anyway and hoped for the best, but with diminished optimism.
Discussions with nursery growers revealed some are finding that new young tree care programs are expanding the window of acceptable planting dates. Improved nutritional programs with slow-release fertilizers tailored for use on young trees has improved young tree performance and improved their ability to weather natural stresses. However, there are a couple significant challenges with summer planting that must be managed. First, high disease and Asian citrus psyllid pressure intensifies with trees planted in the summer and it is imperative specific young tree management practices be employed. The alternation of systemic soil applied and foliar pesticides provides the protection young trees need through this heavy growth stage and minimizes the risk of pesticide resistance. Second, mature tree production caretaking is at its peak during the summer. Young tree care can be compromised if a specific caretaking regimen for new plantings is not in place.
Figuring Fall Factors
Summer planting is one thing, but fall and winter planting? Young trees will be going in the ground as this article goes to press and continuing into early winter in some areas. Some growers prefer to minimize the transition shock caused by high summer temperatures. Shorter days and reduced photosynthesis promotes root growth and helps prepare young trees for a strong spring flush. Growers with adequate supply of water are more confident about their ability to protect young trees from freezes. Small trees can be effectively iced over with elevated microjets, and some believe may actually be better protected than three- to five-year-old trees with inadequate canopy to retain heat and too much size to ice over.
Sometimes choices and differing philosophies and options can lead to frustration and confusion. Despite the obvious limitations that may be presented by a grove’s geographic and physical limitations, there do appear to be some viable alternatives to traditional planting schedules that are meeting with success. Consideration of “alternative” planting times also may improve efficiency in nursery operations. Growers are encouraged to communicate with their nursery and inquire whether a revision of the planting schedule would enhance the nursery’s ability to complete an order.
Finally, nurseries should encourage even the smallest growers to implement specific programs for new plantings. Caretaking and nutritional needs of young trees are distinctly different in today’s world — and some planning and forethought can improve their success.