If you’re like me you’ve caught a case of pre-spring fever. How can we help it when the flowering plums almost overnight are cloaked in bright pink blossoms and clumps of bright yellow daffodils turning their faces to the sun? If you have allergies, it’s no secret that every acacia in the county is blooming. It’s fascinating to mark time with events in the botanic world. There’s even a word for it- Phenology. Websites like USA National Phenology Network at http://www.usanpn.org/ offer lots of information on the subject.
When do they occur each year? Phenology is a real science that has many applications. In farming and gardening, phenology is used chiefly for planting times and pest control. Certain plants give a cue, by blooming or leafing out, that it’s time for certain activities, such as sowing particular crops or insect emergence and pest control. Often the common denominator is the temperature.
Indicator plants are often used to look for a particular pest and manage it in its most vulnerable stages. They can also be used to time the planting of vegetables, apply fertilizer, prune and so on. Here are some common garden plants and what they indicate:
When daffodils begin to bloom, sow peas.
When dandelions bloom, plant spinach, beets and carrots.
When lilac leaves are the size of a mouse’s ear, sow peas, lettuce and other cool-weather crops.
When lilacs are in full bloom, plant beans.
Once lilacs have faded, plants squash and cucumbers.
When apple trees shed their petals, sow corn.
When dogwoods are in full bloom, plant tomatoes, peppers and early corn.
When bearded iris are in bloom, plant peppers and eggplants.
When locust and spirea bloom, plant zinnia and marigolds.
When forsythia and crocus bloom, crabgrass is germinating. When this happens the soil temperature at a depth of 4" is 55 degrees. Treat with a pre-emergent.
When crocus bloom, prune roses and feed your lawn.
Mexican bean beetle larvae appear when foxglove flowers open.
Record your own observations at Project BudBurst at http://neoninc.org/budburst/index.php to start a data base for our area. Another great site is National Sustainable Agriculture Information Service at http://attra.ncat.org/index.php. Sites like these can also help you design orchards for pollination and ripening sequence, design for bee forage plantings, design perennial flower beds and wildflower plantings as well as plantings to attract beneficial insects and enhance natural biological control. How cool is that?