Dig Dahlia Tubers
Dahlias should be finished blooming by now. Cut remaining flowers from plants, and then wait for frost to kill the foliage. Cut dead foliage down to the soil line, dig the tubers, and store them for the winter in a cool, dry area in bags of slightly moist peat moss. Tubers can be separated now or left in clusters. I divide mine in spring after new buds begin to swell.
Avoid Red Thread Disease
Help your lawn avoid red thread fungal disease by providing its nutritional needs this fall and winter. Feed the lawn with a 3-1-2 ratio of nitrogen, phosphorus, and potassium fertilizer, applying it now before fall rains begin. If you haven't applied lime in the past two to three years, wait a week after fertilizing and apply lime at the rate of about 80 pounds per 1,000 square feet of turf grass area to maintain the pH between 6 and 7.
Store leftover dry fertilizers in a dry, frost-free area over the winter months. Place fertilizer packages in plastic bags and label them well before storing. Liquid materials can degrade, and glass bottles can shatter if left out in a tool shed. Wrap liquid containers in newspaper, place them in a cardboard box, and store them in a safe area of the garage.
Plant Tulip Bulbs
Tulips need to be planted in cold soils or they will send up shoots before roots are established. Plant them deeply to encourage large, uniform flowers. Deep planting also makes the bulbs less susceptible to mouse and squirrel damage. Dig holes 2-1/2 to 3 times as deep as the bulb is wide. Generally, you'll need a hole 4 to 6 inches deep. In mild-winter climates, you can plant up to 8 to 12 inches deep, leaving 4 to 6 inches between bulbs.
Clean Up Now to Reduce Plant Diseases
Reduce common perennial flower diseases, such as hollyhock rust and botrytis blight of peony, in next year's garden by removing and disposing of all old stems this fall. This will reduce the number of overwintering sites of the disease-causing organisms, and you'll have less trouble with your plants next year.