Fertilization
Plant fertilization can influence healthy flower production and foliage growth, but an excess of plant fertilization can decrease them. A moderate rate of growth and good coloring is what is desired for most woody plants.
A lot of times, a gardener will assume that because their plant is not doing well, they need to apply fertilizer but this is not the case. The problem needs to be fixed before adding fertilizer, or the problem will only increase.
When to fertilize new plantings:
Wait until Fall to fertilize plants planted from the Spring, and wait until Spring to Fertilize Fall planted plants. Everything should have a general rule of waiting 6 weeks before applying fertilizer. Any newly planted plant is under stress due to the transplant and it can very easy to over-do the fertilization.
When to fertilize established plants:
Fertilizing encourages “water-demanding” new-growth. This should always be done based on the circumstances of nature. Rainfall, soil type, plant age & size should all play a factor in the amount and timing of fertilization.
Timing of Fertilization:
A fertilizer will generally take an average of 3 weeks to completely absorb into the root system of a plant. Woody plants can absorb fertilizer as long as the ground is above 40 degrees. Root growth occurs during cold weather even when the foliage is dormant.
Fertilizing trees should occur in the spring before new growth begins, or in the fall about one month after the first killing frost.
Fertilizing in late summer (August) should be avoided because this encourages new growth which might not have time to harden over before frost.