Question
I planted a wall of Leyland Cypress last fall.  What is the best fertilizer program for me to apply this fall and when?

Answer
A slow, gentle Time Release fertilizer that amounts to a Soil Amendment would provide optimal nutrition for your new Cypress collection.

Cheap, common fertilizers sold in large bags with megadoses of minerals are not going to work in your favor.

You want to tilt the Soil in your favor, and direct microorganisms to generate the nutrition at the perfect pace, adjusted by temperature and moisture, just like they wood in Nature.  This is especially important when you are talking about large shrubs or Trees like yours.  

Organic fertilizers are the ideal, original slow release fertilizer.  The nutrients are derived from Manure, Fish Emulsion, Bloodmeal, Kelp or Seaweed, Alfalfa or Cottonmeal, Greensand and a long list of others.  Compost and Humus are packed with Organic Matter that builds great Soil.

The best organic fertilizers raise populations of soil microbes.  Instead of dousing the roots for a few seconds in quick-evaporating Urea Nitrogen fertilizer, say, the microbes generate a constant supply of minerals, over a very long period of time, converting the fertilizer into the perfect form of Nitrogen for the plants while adjusting the pH and supporting other complex biochemical activities that we are still trying to understand.

A top dressing of Compost and leaf mould in autumn will break down through the Winter.  Come Spring, it will work with your Fertilizer to build leaf growth.  A high Nitrogen Fish Emulsion or Bloodmeal application would be a well timed Spring feeding.  For now, IF your soil is low in Phosphorous, a high-Phosphorous amendment is called for, the best known being Bone Meal.  Note that some parts of the country are known for Soil that is already HIGH in Phosphorous -- parts of the West plus a strip along the Northern U.S.   Deficiencies show up in Soil down South.  If you have a largely Clay soil, or if the pH is too low or too high, or if you have too much Iron or Aluminum in your Soil (either naturally or because you used too much Ironite etc), Phosphorous will be locked up and unusable.  This is why a Soil Test is a critical part of EVERY gardening project, whether you are planting a Tree or growing a Lawn or tending your Roses.  Everything begins with the Soil.

If you would like to give me your Zipcode or nearest City, I will be happy to zero in on the local Cooperative Extension and see where they are sending Soil Tests these days.  Thanks for writing.  rsvp