Originally Posted by agjack
How long should miracle gro liquid feed be used for shrubs and plants in the Northwest-Wa state?
Borrowed from this site, end of fourth, and all of fifth paragraph: 07-30-00 gardening.wsu.edu At this time of year, stop fertilizing landscape plants so that they can start "hardening off" for winter. (Doesn't it seem weird to consider winter now?)
Keep fertilizing plants in containers, annuals in flower gardens, and vegetables in active growth. But when trees and shrubs stop growing vigorously, don't fertilize. Most landscape plants have completed their growth for the year by the end of July. You may even be noticing some leaves beginning to show tints of red as they mature.
As you can see by the link this was the end of July, actually the whole page is a good read
As is EB1744 - Your Yard and Water Quality
, talks 'bout water usage and having your soil tested before fertilizing.
And EB1034 fertilizer usage
, which talks of fertilizer usage. It says mid-July.
As a general rule of thumb.....Shrubs slowdown, and stop growing after the hot months. I usually stop when the average mean temp drops below 60F/15.6C. You have to give the shrubs time to prepare for winter hardening, and dormancy. If you fert too late, their still alert, when its time to go to sleep.
For anyone in the Oklahoma climate here's a good schedule put out by the Sooner's: http://pods.dasnr.okstate.edu/docush...LA-6408web.pdf