Trees and shrubs that should not be fertilized include newly planted specimens and those with severe root damage from recent trenching or construction.
Now a majority of arborists consider late September or October a great time to consider a fall fertilizer for trees and shrubs. They say to apply it then, or about a month after the first killing frost. Why? Because plants (including trees) will use the nutrients they need in different ways throughout the year.
Trees and shrubs should be fertilized in early spring, and a light fertilizer application can be made in early summer if conditions are conducive to plant growth (that is, reasonable temperatures and soil moisture). Avoid fertilizing trees and shrubs stressed by drought during the summer months.
Young, rapidly growing trees should be fertilized annually to promote rapid establishment. Mature trees may need fertilization every two or three years to maintain good foliage color and vigor.
Damage due to excessive fertilizer or rock salt applications generally appears as marginal leaf browning (brown edges or leaf tips) or leaf scorch on deciduous plants (they drop their leaves at the end of the season). On evergreen trees and shrubs needle tips will turn brown and become brittle.
Plants that are fertilized in the fall have an earlier green up, and regular fertilizing throughout the year makes for healthier plants in general. The same logic applies to your shrubs, trees and perennials: give them a nutritional boost before winter to help them bounce back vigorously in the spring.
Fertilizing trees in the fall is important timing, particularly for deciduous trees, as many key nutrients are used up earlier in the year, producing leaves and fruit. To replenish those lost nutrients and prepare your trees for the next growing season, tree fertilization is key.
Late summer and early fall are the best times to fertilize shrubs and trees. At this point in the year, woody plants make the most efficient use of the fertilizer's nutrients, which are absorbed when the roots are actively growing and shoot growth has ceased.
Water helps "activate" your fertilizer. It helps move the granules deep into the thatch where it starts to break down so that it can be soaked into the root system. So rain after a fertilizer is a GOOD thing. The issues is when we get too much rain over a short period of time.
Timing: Apply early spring lawn fertilizer once between February and April, when your grass is starting to green up and begin to actively grow (around the time your lawn first needs to be mowed).
Most importantly, tree fertilizer spikes inserted around a tree base leave your tree much more vulnerable to infestation from insects or tree diseases. These fertilizer spikes provide the perfect opportunity for insects to infest and damage the root system, which can lead to severe tree damage or even tree death.
If you are fertilizing in mid to late summer, avoid formulations high in nitrogen as this will just promote weak, new growth that may be easily damaged in the winter. We recommend fertilizing in Spring (before summer heat kicks in), then again in September.
When To Fertilizer Your Lawn in the Fall. The best time to apply your last fertilizer application is between August 15 and October 1. Ideally, your last lawn feeding should take place six to eight weeks before the average first frost in your area.
The exact timing for when you should fertilize your lawn in the fall varies based on weather conditions and climate zone. In most regions, October is not too late for fall fertilizer, and you can even put fall fertilizer down in November in many places.
We recommend waiting 24 hours after fertilizing to water your lawn, which will give the fertilizer time to settle. After the 24 hours are up, it's important to give it a good soak—not just a quick spritz with your hose—to activate the fertilizer and help the critical nutrients absorb into the soil.
Watering after fertilizing washes the fertilizer off of the grass blades and into the soil, where it can get to work nourishing your lawn. It's also important because if fertilizer sits too long without being watered in, it can burn the grass.
It is a smart idea to fertilize your trees in the late fall, around November. Fertilizing your trees in the late fall will ensure that they have the nutrients they need to make it through the winter and thrive when spring comes around again.
If necessary, spring and fall are the best times to fertilize trees and shrubs. Fall applications should be made after leaf drop (mid-October through November). Spring applications should be made in late March or early April before the trees and shrubs begin to leaf out.
While the best method for determining exactly how much fertilizer is needed is a soil analysis conducted by a laboratory, most cool-season grasses require 2 to 4 pounds of nitrogen per 1,000 square feet each year, and a majority of this nitrogen should be applied in two fall applications; one in September and the other ...
Keep watering trees on a regular schedule through the fall and until the ground begins to freeze (usually late October or November). Once the ground freezes, continue to monitor weather conditions throughout the winter months.
This can cause droopy leaves, leaf die back, or discoloration. Sometimes you will see evidence of over-fertilization if you see a white crust of fertilizer on the soil. Over-fertilizing a plant can cause an imbalance in the soil resulting in chlorosis, or the yellowing of plant leaves.
In general, with good plant health care, it takes around four to six weeks for fertilizer to work on trees. That is because it takes a while for the fertilizer to be absorbed by the tree's roots and for the nutrients to spread throughout the rest of the tree.
Organic granular fertilizer can last for 1 to 5 years or more. Although some cooperative extensions warn that organic granular fertilizers' shelf life is only 5 years, that depends on the ingredients included in a given formula. As mentioned above, fertilizers containing microbes tend to be shorter-lived products.