The Extreme Heat and CRF Longevity

As growers, all of you know that the longevity of a CRF (Control Release Fertilizer) is listed on every fertilizer bag. Usually, this is listed in the form of months and with some manufacturers, in days. You also know that these published lengths of release are based on 70-degree temperatures. With the extreme temperatures that we continue to deal with, your CRF (no matter who the manufacturer is) is running out much quicker than you planned or expected. When we finally get relief from this scorching heat, many shrubs and trees will be putting on a fall flush and it will be beneficial to have some nutrients available to support a good, healthy spirit of growth. By using a potable EC (electrical conductivity) meter now, you’ll be able to tell if you’re fertilizer is still releasing or if it’s all used up. If it’s all used up, using a very short-term granular product can assure you that your flush looks good and healthy.

- Danny Dudoich, Grower Specialist