Gardeners have plenty of tasks to complete by winter

Plants that prefer acidic soil conditions, such as rhododendrons and azaleas, can benefit from an application of granular sulfur to the soil in fall. If your blue hydrangeas have turned pink, sulfur applications may return the flower's color to blue.

Avoid contact with the sulfur by wearing latex gloves and keeping dust out of your eyes. Apply to the soil at a rate of 4 pounds of sulfur per 100 square feet and gently scratch in. Sulfur works slowly in the soil and repeated applications in spring and fall may be necessary from year to year to get results.

• Fall is a great time to plant and transplant trees and shrubs. In general, trees and shrubs do not need to be pruned when transplanted to compensate for loss of roots during transplanting.

Fall conditions, which include warm soil, moderate air temperatures and rain, help plants re-establish their root systems.

Evergreens benefit from planting early in the fall to minimize the chances of winter burn. Try to get them planted before the middle of October and continue watering them weekly or as needed until the ground is frozen. They should not go into winter under stress from being too dry.

Mulch is also important to install for fall plantings; use 2 to 3 inches of mulch for trees and shrubs and 1 to 2 inches for perennials and ground covers.

It is best to keep the mulch away from the crown (base) of the plants.

Good soil preparation is important for successful planting. It is best to amend the entire planting area or bed instead of individual planting holes. Evenly incorporate 2 to 3 inches of compost into existing garden soil.

• Weeds can still be sprayed with herbicide in the fall. Herbicides are most effective when temperatures are consistently above 55 degrees Fahrenheit and weeds are actively growing. Spot spray the weeds to minimize the amount of herbicide you use.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.