Question: How good are weed-and-feed fertilizers?
Answer: Fertilizing and weed control are two separate processes and should be dealt with accordingly. It isn't that much more work, and the time savings of applying the combination materials certainly do not justify the risks you take in the process. You may need to fertilize your plants at times that would be inappropriate for herbicides and vice versa. For example, early spring applications of weedkillers are often made around or just before the average date of the last killing freeze. Warm-season lawn grasses should not be fertilized that early. However, the bigger concern is that many weed-and-feed fertilizers contain herbicides that can damage desirable landscape plants. Valuable trees and shrubs can be lost in the process.