Why Fall Is An Ideal Time to Plant
September and October is an excellent time to transplant perennials, shrubs, and trees and trees across the country. But in the Southwestern US, where winters are mild and the summers are extremely hot, fall is the best time to plant! Cooling air temperatures and warm soil temperatures are ideal for establishing new transplants. Although you won't see a lot of stem and leaf growth in the fall, the plants are busy growing new roots. With the arrival of spring, the fall-planted garden is ready to burst forth with vigorous new growth and a profusion of flowers.
Fall Planting: Growing Strong Roots
80% of a plant's root growth occurs in the late summer and fall months. Root growth continues slowly through the late fall and winter, as long as the soil is not frozen. Better root growth increases the number of nutrients stored in the plant over the winter.
Compared to spring-planted perennials, which suffer a period of transplant shock and take time to establish their roots and begin to grow, plants installed in the fall grow rapidly in the spring—with more vigorous top growth and flowering because their roots were established over the fall and winter.
With a more established root system, fall-planted trees, shrubs, and perennials are much better able to handle the harsh, drying winds of spring and the withering heat of summer.
Fall Planting For Waterwise Gardening
Fall planting is better from a water-use perspective:
- As plants begin to go dormant in the fall, they use less water.
- The soil is cooler in the fall, so it stores moisture better.
- You'll need less water, and watering chores are much easier, because you have to water less frequently.
- Fall is less windy than spring. Wind dries out the soil quicker and dehydrates plants.
For best results, be sure to use Superthrive root stimulator is used at the time of planting to encourage healthy roots, and apply the mixture several times after planting. Also, be sure to inoculate the roots with the water soluble Plant Success mycorrhizal inoculants—root inoculation only needs to be done once at planting time.
Mulching is also essential to successful fall planting. It keeps the plants from drying out in the dry fall and winter weather, and will keep the soil frozen over the spring months to prevent frost heaving of the roots.
Fall Watering For Waterwise Gardening
Water is crucial during the fall and winter. Water regularly through the fall months, decreasing frequency as the daytime temperatures cool in late October and November. From 4-6 weeks after planting, the plant should have pushed new roots out into the planting hole.
Once a plant is established, watering frequency can be reduced. When the soil begins to freeze, soak it once every 2-3 weeks through the winter months, except when it is very cold and the ground is frozen solid. In zone 5 and colder regions, the soil begins to freeze up in early to mid-November and stays frozen through January. By early to mid-February the day temperatures will begin to rise above 45-50° F providing an opportunity to water.