Root Injection rates for Arbor Care 15-8-4 are as follows:
Arbor Care should be injected into the top 4 in. to 8 in. inches of soil where feeder roots extend. Start application of fertilizer approximately 2-3 feet from tree trunk and extend the same distance beyond the drip line. A grid pattern should be laid out, and spacing should be every 2 1/2 ft to a depth of 4 in. to 8 in. A minimum of 5 gal. of tank mix (solution) should be applied per inch of tree diameter. Inject approximately 1/2 gal. of fertilizer solution at each point. Please see the label for complete application instructions.
You will use 89 oz to 2 gallons of Arbor Care per 100 gallons of solution. So if you need to make 55 gallons of finished solution, then you are using 49 oz of Arbor at the low rate and 140 oz of Arbor care at the highest rate.
Arbor Care 15 - 8 - 4 can be applied as a foliar spray or as a soil injection. We do not recommend applying this as a drench in the soil since that likely would not be able to reach the roots. Please refer to the product label here for complete application directions and rates.
No, Arbor Care 15 - 8 - 4 is only labeled for use on Trees, Shrubs, Ornamentals, or Evergreens, it is not labeled to be used on lawns. We do have Lawn Fertilizers that are better options.
We apologize but we do not see how often the Arbor Care 15 - 8 - 4 should be applied on the product label. It will vary depending on the amount you are applying and the amount of nitrogen needed. Please contact the manufacturer for more detailed information. You may reach Growth Products at 800-648-7626.