Do you have any lilacs on your property? If not, you might consider planting one. These shrubs are the very best weather indicators. They help gardeners decide when to start spring planting. We all know how unreliable the weatherman can be. Thermometers and barometers can't predict weather conditions half as well as a lilac, which is affected not only by temperatures, but rainfall, humidity, wind and sunshine.
Volunteers from the University of Vermont have been observing lilacs each spring since the mid 1960s, recording the exact dates when leaves appear, buds open, flowers bloom and die. These observations show much more accurately what's going on with the weather than planting guides and hardiness zone maps.
The study of the relationship between climate and biological events, such as when a lilac blooms, is called phenology. It's not a new science. Phenological calendars have been used for centuries. American Indians taught our ancestors to plant corn only when oak leaves grew to the size of a mouse's ear!
By studying the phenology of a lilac, observers have discovered that cool weather crops such as lettuce, root crops and peas can be planted when lilacs are in the first-leaf stage, when the widest part of the earliest emerging leaves have grown beyond the ends of the bud scales. Beans, cucumbers and other tender crops must wait until the lilac is in full bloom.
Farmers have learned that the alfalfa weevil appears exactly ten days after the first lilac blooms. Therefore they make their first cutting before the ten days are up, avoiding lots of damage. Orchardists can predict when their apple trees will bloom by studying the development of lilac leaves, allowing them to put out their beehives for pollination at the right time.
Of course lilacs aren't infallible. I remember the blizzard in May of 1977 that dumped so much snow on the blooming lilacs that they bent right over to the ground. But generally speaking, they're far more reliable than the weatherman.
My family's property was bordered by a hedge of lilacs my mother planted when I was a kid, and I grew up with a house filled with their perfume each May. I was so enamored of their blossoms that I planned to have them at my wedding - a white bouquet for me and lavender ones for my bridesmaids. When I ended up getting married in March, Hank somehow managed to get lilacs from a florist in Holland who had them shipped to a florist in Hartford.
A lilac doesn't have the prettiest shape when compared with other small trees such as a dogwood or a hydrangea or a graceful beautybush. These shrubs constantly produce suckers and their leaves are often plagued with mildew. but you can't beat them when it comes to their sweet-smelling blossoms.
When we moved to Locust Hill there were lots of lilacs on the property. The best one was a large Persian lilac with deep purple blossoms. Unfortunately we had to remove it when we landscaped that area of the yard. The lilacs that grew on the west side of the house were so mildewed and ugly that we finally dug them up and got rid of them. The single lilac in the front yard was so old and gnarled and twisted that it looked like a giant bonsai. It finally died of old age.
We now have only one lilac on Locust Hill, a very fancy white one I bought and planted in a very difficult spot on the north side of the house where it gets almost no sun. It took that poor shrub five years to produce its first blossom. It has had blooms each spring ever since, but because of its position it's not a very good weatherman.
Of course there are plenty of other perennial plants that make good weather indicators. If you look around your yard and pick a tree growing in the same sort of environment as your vegetable garden you can make your own observations. Keep a record, and in a few years you'll know just when it's safe enough to set out your tomatoes.
