When should I fertilize my Red Tip Photinia and my Nellie R Stevens holly and what do I use?
Red Tip Photinia are not a recommend shrub for our area because of the endosporium fungal leaf spot due to the higher humidity in our county, and the Nellie R Stevens holly is a top quality plant for Parker County.
You can use the same ratio fertilizer for most of your shrubs that you use for your general lawn fertilizing (4-1-2 or 3-1-2) and fertilize at the same time.
That is the quick answer. A better answer is submit a soil sample to Texas A&M (soil test kits available from the Parker County Extension Service at 604 N. Main, Weatherford. After the soil test returns the county agent will be happy to review it with you. The soil test can save you lots of time and money. Your soil might not need as much Nitrogen or no Phosphorus, or Potassium. So, a 10-0-0 or 20-0-0- fertilizer could do the trick. OR your soil could need a 3-1-2 ratio. Some home owner have found the soils calls for Iron and Nitrogen and nothing more.
The time fertilize your shrubs would be late fall with a slow release (SR) granulated fertilizer. Mulch and put your shrubs to bed for the winter.