When to Plant What

Phenology and the Study of Letting Nature Tell You When to Plant

How do you know when to plant? Well, there are no guarantees, but if you let nature tell you when it's safe to plant seeds or put your plants out, you're probably on the right track. Nature sends certain signals that will let gardeners know how the weather and climate are progressing. There's a science devoted to this, called phenology.

Phenology is the study of the timing of recurring biological phenomena and their relationship to the weather.

It is useful to gardeners, as a guide for when to plant. Weather can vary from year to year, but you can let the plants and animals tell you when it's time to start seeds. For instance, plant your peas when the forsythia blooms. It's no guarantee that you won't lose a few plants to a late frost, but phenology is a good guideline to keep you in the ballpark. You can even use it to be pro-active against pests.

Here's some phenological gardening advice I've collected over the years. For the most part, I/ve found it reliable. If you have any to share with us, please drop me an email.

Read more about gardening with nature in Organic Gardening Essentials.

Phenology Clues

Plant peasWhen forsythia & daffodils blooms
Plant potatoesWhen 1st dandelion blooms
When the shadbush flowers
Plant beets, carrots, cole crops, lettuce and spinachWhen lilac is in first leaf
Plant beans, cucs and squashWhen lilac is in full bloom
Plant tomatoesWhen lily-of-the-valley are in full bloom
Transplant eggplant, melon and peppersWhen irises bloom
Plant cornWhen apple blossoms start to fall
Seed fall cabbage and broccoliWhen catalpas and mockoranges bloom
Seed morning gloriesWhen maple leaves reach full size
Plant cool season flowers (pansies, snapdragons...)When aspen and chokecherry trees leaf out
Watch for:
Eastern tent caterpillars to hatchWhen crab apples start to bloom
Gypsy moths hatchWhen the shadbush flowers
Squash vine borer eggs are laidWhen chicory flowers
Mexican bean beetle larvae hatchWhen foxglove flowers open.
Japanese beetles arriveWhen morning glory vines start to climb