WASHINGTON — This week’s cold snap might shock some plants after such a warm March.

“It may blast the blossoms on some summer bloomers,” says WTOP Garden Editor Mike McGrath. “It could kill the flowers on my peach tree and rob me of any peaches for this entire season.”

If you have azaleas or rhododendrons you think might be vulnerable to the cold, McGrath suggests watering them: “Plants that are well-watered can resist frost better.”

A plant’s ability to fend off frosty temperatures can also be affected by clouds and wind. McGrath says cloud cover is good for relative humidity, which helps plants resist frost.

“If there’s wind, frost doesn’t form as easily on plants,” McGrath adds.

Overall, freezing temperatures in April are not unusual.

The average date for a last frost in D.C. is about May 1. McGrath says in cooler D.C. suburbs, it’s May 15.