The best time to fight crabgrass with pre-emergent herbicide is when forsythias tend to bloom. In the mid-Atlantic region, this is usually between April and May. Even if you're late to apply the herbicide, it’s effective as long as the crabgrass plant has fewer than five leaves.

Ultimately, pulling weeds vs. spraying them depends on what’s happening in your yard and your personal preferences. Manual weed removal doesn’t introduce any chemicals into your landscape, targets specific problematic plants, produces immediate results, can be free if you go the DIY route, and is inexpensive with a weed service if you only have a handful of weeds. On the other hand, spraying is often preferable for severe weed infestations and situations involving difficult-to-pull weeds because it treats multiple weeds at once, is usually more effective long-term, is less time-consuming, and costs less when done by a pro.

Pulling weeds can spread weed seeds and disturb the soil, leading to seed germination. Pulling weeds can also trigger growth in weeds that reproduce through their root systems—disturbing the roots without fully removing them may cause more weeds to grow from the roots.

Professionals employ protective measures such as covering or temporarily relocating plants, minimizing chemical usage, and carefully planning construction routes to avoid damage. These precautions preserve the integrity and appearance of the landscaping during projects.