Phenology – Nature’s gardening time table

Phenology can be more reliable than historical gardening data. Climate change has distorted traditional regional gardening data. Some areas of the country are hotter, colder, drier, or wetter than ever before. Phenology refers to ‘key seasonal changes in plants and animals from year to year—such as flowering, emergence of insects and migration of birds—especially their timing and relationship with weather and climate’ (USA National Phenology Network). Nature is a more reliable source to tell us when to plant seeds, apply insect and weed controls, and begin other seasonal gardening projects.

Examples of phenological correlations include (from the University of Wisconsin’s Extension Office and Dr. Leonard Perry, University of Vermont’s Extension Office):
• Plant peas when forsythia blooms
• Plant potatoes when the first dandelion blooms
• Plant beets, carrots, lettuce and spinach when lilac is in first leaf
• Plant corn when oak leaves are the size of a squirrel’s ear
• Plant bean, cucumber, and squash seeds when lilac is in full bloom
• Plant tomatoes when lily-of-the-valley plants are in full bloom
• Transplant eggplant, melons, and peppers when irises bloom
*Eastern tent caterpillars hatch when red maples first bloom
*Bronze birch borer adults emerge when black locust full bloom
To learn more visit National Phenology Network