Have you heard of phenology? It's a Greek term meaning "science of appearances".
Phenology is the art of observing natural occurences and using them to plan your garden planting schedule. Most species in nature use the basics of phenology - sunlight, rainfall and temperature - as catalysts for events in their life cycle. Phenology triggers when frogs emerge, birds migrate, seeds emerge, fruit trees flower, insects breed, etc.
For example, if an apple tree blooms while insects are still in a larval stage then the flowers aren't pollinated and fruit never develops.
I am trying to unlearn planting dates and learning to do things based on how the old time farmers did it. While I've always heard I should plant potatoes on St. Patrick's day, some years it's just too cold and rainy here to do that. Waiting a week or 2 won't hurt anything as poor weather will delay the plant any way.
Here are some common phenology planting guides:
- When daffodils and forsythias bloom, plant peas. Also, prune your roses & fertilize your lawn now.
- When dandelions bloom, plant potatoes, beets, carrots, brassicas (cabbace, broccoli, brussel sprouts), collards, lettuce & spinach
- When lilacs bloom, plant beans, cucumber and squash seeds. This is also when crabgrass will begin to emerge.
- When apple blossoms fall, plant corn
- When irises bloom, transplant cucumbers, squash, eggplant, melons and peppers
- Plant tomatoes when daylilies are in full bloom (if you're a fisherman, then herring are usually running up river to spawn when dogwoods are blooming so it's a good time to go fishing!)