I know it sounds like the wrong time to fertilize your garden, with everything going into senescence…and for those who already think I am wacky, this will enhance that perception. However, there is method to the madness! Let me explain.
Sometime cooler weather will make plants seem dead or dormant when they are not, their roots are only growing. That is a good time to fertilize with a high phosphorus fertilizer to help ensure that your plants will have a strong root system next spring.
When there is an early frost in the fall this helps plants to produce higher levels of amino acids which will help them to resist freezing and making them hardier when the winter temperatures drop. As you start your fall fertilization remember that different plants have different needs such as perennials, your spring bulbs and your roses.
Perennial love a high phosphate fertilizer with low nitrogen content and fertilizing with this type will give you a lovely array of blossoms at blooming time. In September or October plant your spring bulbs such as tulips and daffodils and feed them with a phosphorus fertilizer at the root level to help get them established before the winter sets in.
As I plant I like to add a little compost as food being sure to plant with the tips up and in a manner that the hole is at least 4 times the height of the bulb. Now is not a good time to fertilize roses, they should be fertilized and cut back after they have gone dormant for the winter.
For the vegetable garden the same holds true. Adding compost to the garden the season before growing is essential. Micronutrients from the compost take time to break down and become available for root absorption (approximately 8-12 weeks). Since most people plant in April and May, that leaves February and March as the latest time you can fertilize so nutrients are available in the soil at the time of planting. Successful gardeners know that waiting longer is preferable and fertilizing in the fall give ample time for the soil to rest and regenerate with its augmentations! Get out and fertilize today!