Jasper County

Fall Color and Fall Chores (Bringing in the patio plants)
By: Carol Kay, Master Gardener

So, how do all those leaves turn such brilliant colors in the fall? The color changes result from the decomposition of chlorophyll, the substance that gives leaves their green color.

Chlorophyll pigments are just one of the pigments in leaves. Two other important ones include the red, blue, and purple anthocyanins and the yellow to orange carotenoids.

In autumn, decreasing day lengths, colder temperatures and a decrease in nutrients available to plants cause chlorophyll to break down first, then decrease in carotenoids. In some types of leaves, levels of anthocyanins increase because photosynthesis is still occurring resulting in high leaf sugar levels. This excess sugar is converted into anthocyanins.

This is why bright sunny days result in a good display of red hues and trees and leaves in the sun take on a better color than those shaded.

Plant responses to changes in day length, temperature and available nutrients are very genetically variable. Within one species some cultivars change color in fall better than others. This can best be seen in the genus Liquidambar or Sweetgum. Some cultivars around the city are now beginning their displays of red orange and yellow. Other cultivars never change color and sometimes keep their leaves well into winter making those trees a hazard in winter snowstorms. So October is the time of year to shop for trees with fall color to make sure you get the show you want for your yard.

Fall is for planting (no kidding). Some folks look at this slogan as just a way for nurseries to sell more plants when business is slow in the fall, but the truth of the matter is that fall is an excellent time to plant in all but the very coldest high altitude areas of the country. Fall is the only time of year when you can plant dormant spring blooming bulbs like tulips and daffodils. During the fall perennials, shrubs and trees have very active roots. In fact these plants do about 80% of their yearly root growth in the fall triggered by the short daylight hours and cooler night temperatures. It is a fact that a plant with an established root system resulting from fall planting is ready and able to grow vigorously and flower heavily the following spring and summer. It also saves water. Newly transplanted in September, a perennial or shrub’s watering schedule actually decreases in frequency as the season progresses into October and November.

The shorter days and cooler night temperatures also signal us that it is time to prepare our patio plants for indoors (before frost can do damage to them).

Completely wash leaves and containers using a strong spray from the garden hose. Remove any sunburned or damaged leaves, stems etc., and be sure no varmints (garter and ribbon snakes, spiders, tree frogs – you see what I mean) are looking for a free ride inside. Use a general household pest/insect spray and take care to spray all surfaces. Leave outside overnight (to get rid of smell). Now is also a good time to repot (while you can do it outside) or add new potting soil to cover exposed roots. Light fertilizer additions may be made. If leaves appear to be yellowed due to over watering or leaching, apply a solution of 1 teaspoon Epsom Salts per quart of water to leaves, or sprinkle 1 – 2 teaspoons dry over soil and water in. Calcium deficiency can also occur and supposedly a solution of eggshells "marinated" in water in a tightly sealed fruit jar may be added (1 teaspoon per quart of water). This solution is good for ferns. It smells, so best to do outside and let odor leave before returning indoors.

Chrysanthemums should be showing color now and if bushes were "pinched" back at least 2 – 3 times before July 1, beautiful, full clumps should be ready to give their riot of color before frost. New mums planted this fall should be watered until frost to establish good root systems to carry through the winter. Many expensive plantings do not survive until spring because potted mums were just lifted out of the pot and stuck in the ground in the fall, never watered.

		University of Missouri Extension Jasper County jasperco@missouri.edu Web site maintained by: Virginia Bryan bryanv@missouri.edu Last updated: 09/02/2009