When you hear mourning doves singing before dawn, then organize all your buckets for tapping maple syrup.
When you hear the titmouse making its early mating calls, then test cattle for anaplasmosis.
When you hear red-winged blackbirds along the 40th Parallel, then the maple sap should already be running. In Arizona, the hay harvest will be underway, and farmers in California will be planting the spring oats and barley.
When the temperature reaches 55 degrees, then open up your beehives and check to see that the bees are alive and well. If you find eggs in the cells, you know the queen has not died.
When the first snowdrops emerge from their foliage (but are still not open, then be sure your cabbages, kale, Brussels sprouts and collards are sprouting under lights.
When aconites bloom, then spread fertilizer in the field and garden so that it can work its way into the ground before planting.
When maple sap runs, then prune house plants to encourage spring growth.
When the Groundhog Day thaw arrives, then go to the wetlands to find skunk cabbage in bloom.
When the first daffodil foliage is two inches tall in Midwestern gardens, then monarch butterflies are beginning to migrate north from Mexico.
When you see sparrows courting, then cut branches of forsythia and pussy willows for forcing indoors.
When trees bloom early but the flowers are killed in the cold, then feed your bees to take up the slack.
When pussy willows begin to emerge, then it is time to spray fruit trees with dormant oil. Include ash, bittersweet, fir, elm, flowering fruit trees, hawthorn, juniper, lilac, linden, maple, oak, pine, poplar, spruce, sweet gum, tulip tree, and willow for scales and mites.
When the first knuckles of rhubarb emerge from the ground, then it’s time to plant your onion sets and seed your cold frames with spinach, radishes and lettuce.
When you smell skunks at night, then plant impatiens and coleus for May and June.
When the red tips of peonies push out just a little from the ground, then listen for blue jays courting and watch for wild turkeys to be gathering in flocks.
When strawberry plants have new foliage, then the steelhead salmon run, which started in the fall, finally comes to a close in Lake Erie.
When wild multiflora roses sprout their first leaves in the Ohio Valley, then wildflower season has begun in the Southwest and bald eagles are laying their eggs in Yellowstone.
When you see tulip foliage emerging from the ground, then horned owlets hatch in the woods and sweet corn is coming up along the Gulf coast. Redbuds and azaleas are in full bloom in Georgia, rhododendrons just starting to come in. In the lowlands of Mississippi, swamp buttercups are open, violets and black medic, too.
When you see the first chipmunks, then look for your mare to start cycling.
When you see small brown moths on warmer afternoons, then you know that ducks are looking for nesting sites and that ambystoma salamanders will be mating at night in the slime.

When pussy willows emerge all the way, that is a sign that maple syrup time is just about over for the year and that red-winged blackbirds have started to stake out their territories.
When maples flower and woodchucks dig up the hillsides, then ducks are scouting for nesting sites and onion sets can be tucked into the garden soil.
When coltsfoot buds in the hills of Pennsylvania and West Virginia, azaleas are past their prime in Georgia.
When you see aspens in bloom in the Rocky Mountains, watch out for grizzly bears emerging from hibernation.
When bleeding hearts are an inch tall, then look for purple cress blooming in the bottomlands.
When you see bumblebees and carpenter bees working in the flowers, then you know it’s time for termites to swarm.
Cabbage butterflies in your back yard announce that bass and sunfish are moving to spawn in shallow waters.
When you see golden forsythia flowering, then you know that middle spring has come to your township, and that the first major wave of wildflowers – the trilliums and bloodroots and Dutchman’s britches and more – will be in bloom throughout the woods.
When the rhubarb is up a few inches, then you know the daffodils are blooming and maples are coming in.
When raspberry and rose bushes are developing fresh leaves and wild onions are getting lanky, then bald eagle chicks are hatching and peregrine falcons lay their eggs.
When box elders bloom and pussy willow catkins get their pollen, watch out for the first mosquitoes to bite.
When magnolias are blooming in the Ohio valley, then Sandhill cranes are migrating in the Rocky Mountains.
When the mourning cloaks, the question marks, the tortoise shells and the cabbage butterflies come out, catfish are feeding and goldfinches are turning gold.
When you see the first monarch butterflies in your garden, and the iris start to bud, that’s the time to go out to the fields looking for armyworms, slugs, corn borers, flea beetles and leafhoppers.
When you hear the robin chorus an hour or so before dawn, then, when the sun comes out, look for green-bottle flies and garter snakes.

MARKERS FOR THE PROGRESS OF SPRING
Driving South from the Ohio Valley at the end of March, a traveler has the opportunity to observe the signs of middle and late spring several weeks early. Even from the window of a car on the expressway, one can see the season change mile by mile, about one day, in fact, for every ten to fifteen miles. Some of the more obvious markers of that change offer gauges of progress in time as well as in space.

Marker Ohio Valley Location in late March

Forsythia bloom April 1 Central Kentucky
Daffodil bloom April 1 Central Kentucky
Plum &pear bloom April 7 Southern Kentucky
Tulip bloom April 10 Southern Kentucky
Full dandelion bloom April 15 Northern Tennessee
Wisteria bloom April 15 Central Tennessee
Apple bloom April 15 Central Tennessee
Redbud full bloom April 15 Southern Tennessee
End pear bloom April 20 Southern Tennessee
Azalea bloom April 20 South Carolina
Honeysuckles in bloom April 25 Northern Alabama
High canopy leafing April 30 Central Georgia
Poison Hemlock May 23 Southern Louisiana
Full Canopy May 30 Northern Florida

Markers such as the above not only create a calendar of moveable feasts, they also tell a phenological story, a story of all the other pieces of spring that are connected to the markers themselves. Daffodils, for instance, tell of all the early woodland wildflowers of middle spring. Redbuds announce the delights of morel mushrooms. The full canopy simply says it’s summer.