August Begins the Season For Garden Makeovers
The time period from late August through early November is the ideal time for garden do-overs. Flaws that revealed themselves during spring and summer can be corrected, out of control perennials tamed with digging, dividing and pruning, and new trees, shrubs, perennial plants and bulbs can be established before the soil turns too cold for any growth. Best of all, inclement weather is less likely to cause planting delays. With a little planning and some savvy shopping, the fall garden makeover can be both easy and economical.
Wage War on Weeds
Summer is the time for every weed that has taken root in the garden to come to maturity, so it is also an excellent time to eliminate all of them. In order to prepare a new planting bed or revive and old one, weeds and errant grass should be tackled with a combination of pre- and post-emergent herbicides. The most common post-emergents are the glyphosphate-based liquids. These are nonselective, and quickly kill all vegetation that is treated. Pre-emergents are another matter. Dry pre-emergents, such as Preen® or corn gluten meal, need to be broadcast after plants or bulbs are installed. Liquid pre-emergents, such as Gallery®, can be mixed with the liquid post-emergent and applied simultaneously. The purpose of applying pre-emergents is to keep the seeds of pesky grasses and weeds from sprouting in your newly-tilled soil. One of the most pernicious weeds, henbit, germinates in late September and by April it will take over any bed. Most pre-emergents are viable for three to four months, so your bed should stay weed free until the ground freezes.
For Plants On
During late summer, garden centers and mail order houses want to unload excess inventory, so this is the time to pick up good plants at great prices. Potted plants may be overgrown and perennial flowers scraggly, but judicious deadheading and pruning prior to planting will cure a host of aesthetic problems. Avoid those plants that appear to have insect damage or are diseased. If the plant's roots are tightly bound in the pot, be sure to tease the roots apart and spread them out in the planting hole. This keeps the roots from girdling the plant and ensures a solid anchor.
Another source of bargain plant material is the farmer's market. Many growers sell divisions or seedling perennial plants from their ornamental gardens. These probably won't be the newest red-hot varieties, but farmers markets can be an excellent source for bulk lots of generic perennials such as hostas, daylilies, iris, rudbeckia and common herbs such as sage or thyme.
Finally, plant societies often have fundraising sales during this time of year. Shoppers can find named varieties and interesting and exotic hybrids at these sales, prices are always well below retail, the plants for sale have been grown locally so are already acclimated to area soil and climate, and society members are happy to answer questions regarding care and maintenance.
Watch the Water
The biggest challenge involved in fall makeovers is to maintain adequate moisture levels. Spring plantings have the advantages of cooler temperatures and more frequent rains; late summer and early fall tend to be hot and dry. Water in the plants at the time they are installed, mulch the bed well, and provide one inch of water weekly until the first heavy frost. This will allow the plants to establish a healthy root system before the ground freezes.
Change The Diet
Finally, fall plantings have different fertilization demands than do spring installations. Avoid using fertilizers with high nitrogen levels; "winterizers" or "root booster" fertilizers are a better choice. High nitrogen fertilizers stimulate soft tissue growth in plants, and this tissue is easily killed by frost. Perennial trees and shrubs that flower on old wood can be treated with a high phosphorus fertilizer so that flower buds will form and be ready to bloom next spring and summer.
With a few exceptions, plants that are installed in the spring can be installed successfully in the fall. Take advantage of this time for a second chance to create a first-class garden.