The answer to 'frequency of weed control' is that most experts recommend controlling weeds on a regular, consistent basis throughout the growing season. This typically means treating for weeds every 4-6 weeks during the spring, summer, and fall months. Consistent weed control is important to prevent weeds from going to seed and spreading further across your lawn and garden.
The exact frequency may vary depending on your local climate, the types of weeds present, and the methods you use for control. In some cases, more frequent treatment may be necessary, especially during peak growing seasons or if you have a severe weed problem. It's also important to time your weed control applications properly, such as applying pre-emergent herbicides in early spring before weeds germinate.