Winter returned over the weekend covering area pecan groves with a blanket of new snow (photo above). The temperature dropped down to 2 F this morning in the Neosho River flood plain outside of Chetopa, KS. At this time of year, pecan growers are supposed to be thinking about making their Spring fertilizer application, not shoveling snow and hauling firewood.
In timing the spring fertilizer application, it is important to remember that soil nutrients are most readily adsorbed by actively growing pecan roots. With all the cold weather we've had this winter, pecan roots are still laying dormant it the cold ground. New root growth will not start until soil temperature begin to rise with the coming of spring.
Because roots are buried in the soil, it is not easy to see when their growth begins in the Spring. However, watching for the earliest sign of bud swell is a good indicator that a pecan tree is coming out of dormancy and spring root growth has begun. I carefully watch lateral buds on one-year-old shoots. The first sign of bud swell will be the splitting of the outer bud scale (photo at left). When this happens, I know that root growth has started and it is a good time to spread fertilizer under my trees.
