Different veggies germinate at different temperatures. Whether you’re planting seeds or targeting weeds, it’s important to check your soil temperature before beginning. Even the best-planned garden project can fall flat if temperatures are not appropriate for the occasion! For example, did you know that you should: Plant spring bulbs when the soil temperature drops below 60° F. Apply crabgrass control in spring, when soil temperatures reach 55° F for 4-5 days in a row. Plant cool-season grass seed once soil temperatures are in the 50s F. Give your new shrubs time to grow roots before soil temperatures fall below 40° F.