Soil testing will bring you better gardening results

  • Fall is a good time to test your soil as you divide, transplant or add new plants to borders and flower gardens.

    Fall is a good time to test your soil as you divide, transplant or add new plants to borders and flower gardens. Courtesy of Chicago Botanic Garden

By Tim Johnson
Chicago Botanic Garden
Posted10/6/2019 7:00 AM

Have your garden soil tested to determine how best to manage it and what fertilizers to use. Make a composite sample from a few areas in the bed and send it in for testing. If your garden is large, break it into test zones.

Soils in the Chicago area tend to have adequate phosphorus levels, so choose fertilizers that have little to no phosphorus. A soil test will confirm the status of your garden soil and will help you craft a management plan for your garden soil.


• Be sure to document any changes you have considered for your garden. It is easy to forget these observations over winter. Good garden notes will make you more efficient and your garden better looking.

• 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 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. Keep the mulch away from the crown (base) of the plants.

by signing up you agree to our terms of service

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

• Fertilize your lawn if you did not do so in September. Fall is a good time to fertilize if you are doing one application a year. As a general rule, never apply more than 1 pound of nitrogen fertilizer per 1,000 square feet of lawn during any single application.

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

Article Comments ()
Guidelines: Keep it civil and on topic; no profanity, vulgarity, slurs or personal attacks. People who harass others or joke about tragedies will be blocked. If a comment violates these standards or our terms of service, click the X in the upper right corner of the comment box. To find our more, read our FAQ.