Mild winter temperatures are causing many plants and trees to bloom early across the region. Virginia Cooperative Extension agriculture expert Kirsten Ann Conrad says that unpredictable weather patterns in March, may require special care and attention from spring gardeners.

“The return of colder temperatures could abruptly halt the early warming cycle and normal seasonal progression of temperature-induced blooming. Trees with flowers, opening flower buds, and even young tender leaf buds are at risk from damage if temperatures fall below 32 degrees,” says Conrad.

“With the early progression of the spring blooms, comes the early release of pollen,” says Conrad. “If flowers are open and mature, they are releasing pollen. A late winter freeze however could kill flower buds and reduce the amount of pollen in the air. A very wet spring with frequent rains may also reduce aerial pollen count as well.” 

Spring flowering trees can sustain some damage to the flower and leaf buds. “Cherry trees and most flowering ornamentals will avoid extensive damage as long as the temperature stays above 26-27 degrees. Less than that, the damage increases proportionately. Up to 90 percent of cherry blossoms in late bud or flowering stage will be damaged at temperatures that go down to 24 degrees Fahrenheit.” Conrad offers the following tips for protecting trees and plants from the late winter cold temperatures. 

  • In a home garden situation, a late winter freeze will damage flowers, but will not usually injure the tree itself. Cover small tender plants, and budding/blooming plants to protect them from freezing temperatures. Throwing a sheet or a blanket of fabric or plastic over them will provide 4-6 degrees of frost protection. 

  • Not all early spring flowering plants will need this protection. Many of the spring flowering bulbs are quite cold hardy. Daffodil flowers for instance can withstand freezing temperatures down to 20 degrees without showing much damage. 

  • Planting warm season plants in cold soil will stunt plant growth and may result in root death. A little patience will pay off in the long run. Spend the extra time in the garden working soil and adding compost to improve its water holding and disease fighting capacity. 

About Conrad

Kirsten Ann Conrad is an agriculture natural resource agent with the Virginia Cooperative Extension, which is an educational outreach program of Virginia's land-grant universities: Virginia Tech and Virginia State University, and a part of the National Institute for Food and Agriculture, an agency of the United States Department of Agriculture. The program strives to improve the well-being of Virginians and increase producers' profitability through programs that help put research-based knowledge to work in people's lives.


To secure an interview with Conrad, contact Shannon Andrea in the media relations office at [email protected] or 703-399-9494.