THE ADVANTAGES OF FALL PLANTING
by Bill Harlow
One of the most often asked questions is: Is there a BEST time to plant trees and shrubs? The answer is “yes.” Although in Tucson we are able to plant most trees, shrubs, vines, etc., for twelve months out of the year, the one BEST time to plant is in the fall. Fall, in this situation, covers the period from the last week in September until about Thanksgiving. The only plants not recommended for fall planting would be frost-sensitive plants such as bougainvillea and hibiscus. Citrus, both dwarf and standard, can benefit from fall planting if you give them protection on cold nights.
The two biggest advantages of fall planting are: (1) your new plantings require less water because temperatures are cooling down instead of heating up; and (2) fall plantings take full advantage of the spring growing surge while spring plantings are still getting established. An additional benefit of fall planting is that you can plant some plants in the full sun that would burn if planted in late spring or summer. Star Jasmine is a good example. Normally recommended for shade, semi-shade, or morning sun only, it will do well in full sun locations if planted in the fall. Then as the weather warms in the spring, the new leaves on the plant acclimate to the increased heat and sunlight.
Fall planting works because our soils hold the heat from summer through fall and into winter. This warm soil allows new roots to begin to grow. Even as the soil gets colder, roots continue to grow using the plant’s stored food.When the warmth of spring arrives, fall plantings, with their larger root systems supplying maximum water and nutrient needs, undergo a dramatic growth surge. Spring plantings, with their skimpier roots, are not ready for a full surge of new growth. Another advantage of fall planting is selection. Especially with desert plants, spring selection, both from a size and variety standpoint, is often poor. As the summer goes on, the selection increases. And in the fall, selection is often at its peak. Plus, with the cooling temperatures, fall is one of the most pleasant times to be outside in your garden. So, if you are thinking about planting trees and shrubs, this is a great time to do it.
Fall also offers the widest and best selection of winter/spring bedding plants and spring-flowering bulbs. The very best selection of bulbs is probably during the last ten days of September – right after stores receive their fall shipments. Bulbs are graded by size. The largest grades are usually sold singly, and the smaller grades are sold in packages of six or more. The largest bulbs will give the best results.
Most fall bedding plants begin showing up around October 1. Ideally, you will plant when daytime temperatures drop to the low 90s, and nights are down around 65 degrees.
Bill Harlow is co-owner of Harlow Gardens and has lived in Tucson for over fifty years.
5620 E. Pima St., Tucson, AZ 85712