Warm days followed by chilly nights have become a common pattern across south-central Pennsylvania this month, leaving many eager gardeners unsure about when to begin their seasonal planting.
Inside the greenhouses at Whitecomb’s Farm Market in Conewago Township, York County, plants are continuing to grow despite the unpredictable weather outside.
Owner Greg Whitecomb says the greenhouse environment allows them to control nearly every factor affecting plant growth.
“We control everything in the greenhouse, the climate, the water, everything we control,” Whitecomb said.
While outdoor temperatures may swing from the 70s one day to the 30s the next, Whitecomb says cold weather isn’t always the biggest challenge for plants.
“When you have cloudy days, that’s not good for the plants, so we like sunny days, but we’re about where we should be with growth and everything for this time of the year,” Whitecomb said.
For gardeners hoping to plant outdoors early, those temperature swings can slow things down. Without warm soil, plants may struggle to grow even if they survive the colder temperatures.
“You need warm soil temperatures to really make plants grow, and we don’t have warm soil temperatures right now,” Whitecomb said. “If you plant things outside right now and protect them, they’re just going to stay sort of stunted and not be grown until you get your warm days and warm nights.”
Some flowers, such as pansies, can tolerate colder conditions and are often among the first plants seen outside in early spring. However, many popular spring plants remain sensitive to cold temperatures and frost.
“Just avoid the cold sensitive plants, which is the majority of plants right now,” Whitecomb said. “Again, have patience. It’s coming. The warm weather is coming.”
Whitecomb says last week’s stretch of warmer weather did bring some visitors out to browse and start thinking about their gardens.
Still, many customers appear to be waiting for more consistent spring temperatures before making purchases or beginning their planting season.
Until then, Whitecomb advises gardeners to be patient and wait for warmer days and nights before getting too far ahead of the season.