Digging Out the Phenology Notes

Another sign of spring: Blossoms on star magnolia in St. Paul.

Yesterday, I wrote about how some experts suggest gardeners handle the extremely unusual warm spring we are experiencing. The usual advice for spring in Minnesota would be to back off and stay out of your yard and garden until at least mid- to late April. But I think this year we may need to shift away from the usual advice. That’s why I dug out some notes I had on phenology, the study of nature signs and how they can be used to guide garden activities.

In the days before Doppler radar, USDA Hardiness zone maps and even university extension, gardeners relied on birds, bugs and flowers for advice on when to plant what. I’m not sure how reliable this advice is, but here are some typical spring activities and what to look for to guide when to do what:

• When crocus bloom, remove the mulch on your strawberries. (It’s happening here.)
• When yellow forsythia bloom, prune roses and fertilize the lawn. (Happening here.)
• When leaves first emerge on lilacs, plant lettuce, beets, spinach and other cool-weather crops.
• When the aspens have leafed out, plant pansies and other hardy annuals.
• When lilacs are in full bloom and the barn swallows return, set out your tomato plants and basil.
• When irises bloom, set out your squash and melon transplants.
• When dandelions go to seed, it’s time to plant petunias.

What guides are you turning to this topsy turvy spring? What are you doing differently this year?