Spring fever is here, thanks in large part to unseasonably warm temperatures that have swept most the nation this month for good and for bad.

Yes, green stuff is growing—but unfortunately, not everything coming out of the ground is good for your lawn.

What are the signs to be looking for? If your tulips, crocuses, and forsythia are blooming, beware. What follows them is crabgrass.

Dreaded crabgrass

Dreaded crabgrass

When nighttime soil temperatures reach over 50 degrees for three consecutive days, this serves as an alarm clock to “wake up” crabgrass seeds, alerting them that it’s time to germinate. Now is the time to lay crabgrass preventer, or a pre-emergent herbicide, that can be found at any local garden center or hardware store. Taking this pre-emptive measure will save you heartache in the long run and keep your lawn healthy. Unfortunately, if temperatures drop again—which they likely will in much of the country—you will need to perform this drill once more after temperatures start to creep up and stay up.

On a more positive note, also out of hibernation are your favorite shrubs. Rhododendrons, azaleas, and hydrangeas are emerging from dormancy, and like bears that have awakened from a long slumber, they’re hungry. To keep them flourishing, pick up some 4-3-4 mix for less established plants or 10-10-10 garden food for more mature shrubs, and work it into the soil around them now.

And finally, be kind to your bulbs. Unseasonable temperatures have tricked them into coming out before their time. Help them survive the stress of another temperature fluctuation by putting down some 3-5-3 mix to give them the strength to weather this spring longer and better—despite any snow that might still fall.