A few questions come up every year in regards to fertilizing first, second, and third leaf trees. Since these trees are rapid growing, and in some cases, producing crop, adequate fertilization is crucial for growth. First leaf trees: As a guideline, I generally recommend no more than one ounce of elemental nitrogen per tree per application. Three to four (or more) applications using a general blend (i.e. 12-12-12 NPK) fertilizer per year will produce a nice result. Using a triple 12, this totals about 8 ounces of actual fertilizer applied per tree. Applications should begin upon leaf out and continue about every 4-6 weeks. To prevent any nitrogen burn, the first applications of the year should be less than one ounce while later applications should not be greater than one ounce. Although I know some growers are successful, I have observed enough tree damage to caution against using liquid based fertigation products for first leaf trees. It is easy to overdose the trees with nitrogen, especially in hot weather, causing tree die-back. I agree that using granular fertilizers is a conservative approach, but one that has been tested and used extensively over the years. Second leaf trees: The rootzone of 2nd leaf trees can be quite extensive, but is still limited in comparison to mature trees. Even if the grower is able to fertigate, I usually still like to see the first application to be granular. Why? In many cases adequate potassium and phosphate have not been applied in the previous dormant season, thus applying a 12-12-12 fertilizer will ensure at least some level of these nutrients as the tree begins the rapid growth period of April and May. Later applications can be made through the fertigation system. Again, follow the rule of one ounce per tree per year of growth. So,
Recent Comments