In most cases, plants appreciate being fed in early spring, before the growth spurt begins. In general, fertilization of in ground plants with a slow release product after mid-July isn't recommended. After midsummer, plants need time to completely harden off before fall and winter.
Perennial flowers are a bit different than annuals. They generally require less fertilization and since they often slow down growth in autumn to prepare for dormancy, fertilization should be avoided after late summer.
Fertilizing in the fall helps plants be hardier when the temperatures drop. We also recommend applying fertilizer in the late fall, toward the end of October or early November. This application will catalyze one last frenzy of root growth and really give your plants some staying power through the cold months.
Perennials appreciate having a high phosphate fertilizer with low nitrogen content. Applied in the fall, you will be assured of stronger plants in the spring producing more flowers than you ever thought they could. Fall fertilizing of garden perennials will really pay off during the blooming period.
Beginning late summer and through September and into early October is a great time to fertilize many plants. This includes lawns, young trees, shrubs that need to grow more leaves and groundcovers that need to spread and cover.
Fall Fertilizer Timing
For the majority of cool-season lawn owners, apply fertilizer anywhere from September through early November.
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.
Applying fertilizer in the wrong season can cause increased tender new growth that can be damaged, especially if applied in cold weather in late fall or in winter. So it is best to stop fertilizing during dormant seasons. Additionally, in zones that can be in danger of a late freeze, it's best to wait until mid-spring.
Some perennials, like hostas, peonies and daylilies, need to be pruned in fall to avoid winter damage. Plants like these should be pruned after the first few frosts in late fall or early winter. Other perennials like mums and coneflowers are better off being pruned in spring just before new growth comes in.
Broadcasting a slow release fertilizer is the best choice to meet season-long plant nutrient requirements, but you can also use a balanced fertilizer such as 20-5-10. If your soil test indicates that you do not need phosphorous, choose a product such as 20-0-10.
Water and Feed Your Perennials
You can easily water and feed at the same time with Miracle-Gro® Liquafeed®. When watering, avoid perennials' leaves to prevent disease, and aim for a soil consistency that is neither too wet nor too dry.
Late fall fertilization will provide better winter color of the stand, quicker green-up in the early spring, and an increase in root growth. Late fall applications of fertilizer are more important to the health of lawn grasses than spring applications more commonly practiced by most gardeners.
It does not need much fertilizer; however, if your soil is not in good shape or the plant is not thriving you may need to feed the plant. Rich soil and a lot of water is just as important for hosta health as is fertilizer. New hostas planted in the spring will need a good starter fertilizer to help establish the roots.
No matter which fall gardening project you choose, be sure to make plant roots super-happy by using Miracle-Gro® Potting Mix (for containers) or Miracle-Gro® Garden Soil for Vegetables & Herbs (for in-ground).
Perennials that require minimal fertilizer include ornamental grasses, false indigo, asters, sea holly, bee balm, and butterfly weed. On the flip side, some do better with extra nutrients. Heavy feeders include mums, lilies, lupines, tall phlox, peonies, delphiniums, and astilbes.
Prune foliage down to just a few inches from the ground and make sure to clear away any debris from the garden to help prevent disease and rot in the early spring. If perennials (like Bee Balm or Phlox) were diseased this past season, cut the foliage all the way down to the ground and don't compost it.
Over fertilization can actually decrease growth and leave plants weak and vulnerable to pests and diseases. It can also lead to the ultimate demise of the plant. Signs of over fertilization include stunted growth, burned or dried leaf margins, wilting, and collapse or death of plants.
You should fertilize your lawn a day or so after a light rain or using a sprinkler. This prevents the application from being washed away. The moisture gets your soil damp and ready to receive nutrients. Do not apply fertilizer before or after heavy rains.
It is important to water plants thoroughly with plain water before applying the liquid fertilizer to avoid burning the roots if the soil is dry. Also, take care that the fertilizer is indeed diluted based on instructions, or you could burn the leaves.
While this fall lawn fertilizer dose is important, an application at the end of October or early November is essential. At that time, apply a fertilizer with a formula of 13-25-12. The push of phosphorus will stimulate root growth through November and even into early December.
The November fertilizer application is the second most important time for cultivating a cool season bluegrass or tall fescue lawn, with September being the most important application. The November application helps the lawn flourish in several ways.
August is an ideal time for gardeners to give their plants a boost into the later stages of growth. Many people who are just learning how to garden at home overlook the benefits of fertilizing their plants.