• BROOKINGS, S.D. - When the lilacs bloom, it's time to apply crabgrass control, said Paul O. Johnson, SDSU Extension Agronomy Field Specialist.
• "The products should not be put out too early as they only have a certain period of effectiveness and may not last the full season, and then you will have late season crabgrass in the lawn," he said.
• The best time to apply these products each year, Johnson said is when the lilacs start to bloom.
• "In a normal year this is about the middle of May, but this year with the cool spring it will be delayed a week or two," he said. "If you get your crabgrass treatment out too early and get some late season emergence there are some post-emergence treatments that can take out a flush of plants, but be aware that any seeds that germinate after the spraying will need another treatment as there is no residual with post-emergent treatments."
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• Crabgrass control recommendations
• Johnson explained that crabgrass is a warm season annual grass that is capable of producing 150,000 seeds per plant. Crabgrass Seedlings appear pale green and have a coarser leaf. The plant can push out its branched, purple seed heads in 45 to 50 days. It is the number one grassy weed problem around home lawns.
• Pre-emergent crabgrass preventer killer is the best control option that Johnson recommends. These mostly come in a granular form but also can be in a spray form. Most of the granulated products are available with fertilizer as the carrier.
• He added that when you mow, catching the clippings can help to reduce the amount of seed released back into the lawn.