Released September 18, 2009
URBANA, Ill. -- Fall is often a better time to prepare flower beds for new crops than the spring, said a University of Illinois Extension horticulture educator.
"The weather is better, organic material is available in the form of tree leaves, and the soil is not frozen or too wet to till like it will be in the spring," said Jeff Rugg.
"For many people, the weekends of the fall season are taken up with football, kid's soccer games, or other activities that don't allow you to even think of your landscape, but this is a great time of year to work outside. If you can't get out much, try to take some photos or video of your landscape in the fall to see how you like it and what to change when the garden catalogs arrive in the winter. Many great landscape ideas can be found in Botanic Gardens during the fall."
The first thing to do is to analyze the success of this year's annuals, perennials and vegetables, Rugg recommended.
"Why did they do well or why did they do poorly? Was there a problem with the weather, soil, sun light or watering? Was the plant adapted for that kind of growing condition? For this year, did you find the time to do normal maintenance chores like pruning, fertilizing, dead heading or watering? Did you take pictures of the bed when it was doing well and when it was looking its worst?
Now decide how many of the problems you can fix this fall," he said. "Can you change the drainage or soil texture by adding organic matter? Can you add some top soil to change the angle of the bed so water flows better? Can you add some timbers around the bed to raise the whole thing by adding more soil?"
As you can see, there is a lot to think about. It may be time to start the whole bed over again, or it may just need a few plants moved to better locations that fit their requirements better.
"It is useful to know which plants are just going dormant and which ones are dying, before you start yanking out the plants," he noted. "Many good plants have disappeared from landscapes because someone mistakenly pulled out plants that were going dormant, not dying."
Once you have an area of bed cleared of plants, you can begin preparations for the next crop.
"Using your analysis, you may decide to add organic matter to the soil," he said. "Mix it into the bed at least six inches deep for annuals and a foot deep for perennials. Deeper beds allow the plants to grow more roots, which means they will have more access to water and therefore need less watering. In the north, you can leave the soil roughly tilled, so frost action can break it down and kill any insects.
"Cover the bed with mulch. Add two or three inches of mulch over the tops of perennials after they are completely dormant."
If there are annuals in the bed, they are going to die as winter weather and less sunlight comes. As they start to look bad, it is best to remove as much of the plant as possible.
"If a bunch of roots come up with the soil, toss the whole thing," said Rugg. "Don't spend a lot of time trying to get the roots unless the plant died of root rot. Then, you should remove the roots and some extra soil too. It the plant was not diseased, throw the whole thing in the compost pile. If it was diseased, send it to the professional compost site if your city has one as part of your trash pick-up program."
In warm southern climates, you can replace summer annuals with winter annuals that like cooler weather. Pansies, mums and kale are all good cool season crops that can last for many weeks in the fall and may even bloom again in the spring, even in the northern states. Be careful to keep them watered. Many people forget to water plants in the fall, because it is not warm enough to make it seem like they need it.
Whether or not you replant annual flower beds, you may also want to apply a pre-emergent weed killer to stop weed seeds from germinating during the winter or early spring.
"If you have perennials in the bed, they too are going to die back this fall," he said. "Some will die completely to the ground, leaving only a few dead leaves and withered flower stalks. Others will only die partially, leaving green leaves and maybe even green flowering stalks with a few left over flowers.
"Perennials can be cut back piece by piece as they die back (even in May or June for early bloomers) or they can be cut back all at once, even if they are still somewhat alive late in the fall. Perennials that have seeds growing on the top of the old flower stalks can be left until spring, so that birds can eat the seeds over the winter."
After the first frost, northern gardeners will need to dig up summer flowering bulbs like cannas, dahlias and gladiolus. Wash off the soil, sprinkle on a little fungicide and let them dry. Store them in a loose bag in a dry, cool, dark place until spring. If the location is too warm, they will shrivel up and if it is too moist, they will rot.
Northern gardeners will plant spring flowering bulbs in the garden after the first frost. Create well-loosened beds with lots of organic matter. If you have problems with rodents, try planting the bulbs in a loose pillow shaped "bag" made from chicken wire.
"For all gardeners, many perennials can be divided and replanted as they go dormant," Rugg noted. "Re-work the bed and add some organic matter if the bed needs it. Don't be afraid to dig them up, cut them apart and move them to new locations. It is easier to see where they should go now than in the spring before everything starts growing."
If the plants have been blooming well for several years, but did not do so this year, they are good candidates for dividing. Use a shovel, trowel and knife to decide where to dig and cut the plant in half or quarters. If possible, leave half of the plant in the ground undisturbed. Fill in the left over hole with good soil and organic matter so the remaining plant can expand.
"Move the cut out portion to a new location that is also fixed up with good soil," Rugg said. "Or, it can be potted up and given away. If it is potted, it can be buried in the ground and mulched over for winter protection and then pulled up and sold or given away in the spring."
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http://www.aces.uiuc.edu/news/stories/news4895.html
Source: Jeff Rugg, (630) 553-5823, jrugg@illinois.edu
Editor: Gary Beaumont, 217-333-9440, beaumont@uiuc.edu
