Fall is actually better than spring to plant trees and shrubs—for both you and your plants! Cool air temperatures make planting more enjoyable for you, and plants establish quicker as they are less apt to suffer drought stress. In addition, ideal soil conditions exist for root growth, because the soil is still warm from the summer’s heat, yet moist and easy to work from fall’s gentle rains. Therefore newly planted trees, shrubs, and perennials are well rooted before the ground freezes. Next spring, instead of concentrating on both roots and shoots, new energy funnels directly to new top growth. Not only that, your new plants have two cool seasons, fall then spring, to become established before the heat and drought of summer. You spend less time working in your garden, and more time enjoying it.
Fall is absolutely the best time to start a new lawn, or rejuvenate an existing one. August 15 through September 25 is ideal for getting grass seed established. Grass plants are at their peak in terms of being able to use fertilizer in the fall as well.
There are a few tradeoffs. There are a handful of plants that do not like to be late fall transplanted. This is probably more of an issue when they are dug out of the field than when they are grown in containers, but a few limits do exist. Selection may be a little more limited in the fall. We have many more of the plants that are colorful at this time of the year, but we may have a few less of the spring blooming ones.
Autumn is also the only time to plant spring flowering bulbs such as Crocus, Tulips, and Daffodils.