First, Fall is the best time to plant herbaceous plants and woody ornamentals. At the fall time of year, the top of the plant has less demand for nutrients and water and the plant can work on root establishment. This is a less stress time for the plants so energy can be put into a good root system.
Deep-tilling the soil to a depth of 8-12 inches is also beneficial. Large planting holes in good deep tilled soils can help roots spread out and get established. Tilled soils can also provide good drainage and break up hard matter in the ground. Before planting, you need to do a simple drainage test. Dig a hole 15 inches by 15 inches in diameter and fill with water. If water is still in the hole after an hour then that spot may not drainage well. If the water stays for several hours you are going to have to improve drainage for sure.
Another BMP is to add amendments to the soils when necessary to improve the overall quality. Most of our soils are low in organic matter. It is suggested to apply four inches of compost to the soil surface and then till in to a depth of 12 inches in the planting area. According to Westerfield and Wade, research has shown that amendments to the individual planting holes can actually be harmful. They can act like a sponge and hold too much water in the hole, but encourage the roots to stay right in that small area and not branch out. Also, do not put general purpose fertilizers such as 10-10-10 in the planting hole of ornamentals. Fertilizers such as 10-10-10, 8-8-8 or 16-4-8 are chemical salts and can dehydrate the roots and make the plant have even higher water demands. Use these fertilizers on the soil surface by spreading away from the plant base out to the drip line. The exception to the rule is seasonal color plantings. It is common to place slow release fertilizers in the planting hole beneath annuals or perennials to make sure they have enough nutrients. Another BMP for the seasonal color beds is to plant them on raised beds about 10-15 inches above the regular surface level. Remember these are short-lived plantings that need good water supply and nutrients. The raised beds help them with drainage and also make them easier to see.
Mulching can be critical to ornamentals. Keeping a 3-5 inch layer of mulch on the soil surface can help combat weeds, conserve moisture plus reduce rapid changes in soil temperatures. Do not put mulch against the base of the plant, but do mulch out to the drip line. Also, investigate for moisture stress with landscape items. Wilting plants or ones with an unnatural gray-green color may be suffering from moisture stress. These items may need irrigation. Fewer, deeper waterings are better than frequent, light irrigations. Light irrigations will result in shallow rooted plants that will suffer in times of watering bans or drought. Remember that irrigation is better if done between 9 pm and 9 am.
Plus, irrigation with a goal of getting water to the ground such as with soaker hoses will reduce evaporation and wasting moisture. Keeping the foliage dry can reduce chances of disease establishment. Finally, do not over-fertilize. This can cause excessive foliage growth that will result in greater water demands for the plant. For more information on landscape best management practices contact Gordon County Extension at 706-629-8685 or email@example.com.