Phenology is the science of appearances, or knowing which plants can tell you when to start weeding, planting, fighting insects or tackling any other gardening priority.
Once the forsythia begins to bloom, for instance, it's time to renew your war against crabgrass.
When to fertilize the lawn? Think apple blossoms falling. Time to set out tomatoes? Yes, if dogwood trees are in flower.
"Phenology makes us more aware of our environment," said Robert Polomski, a horticulturist and arborist at Clemson University in Clemson, S.C. "Associating gardening tasks with flowering times is a neat way to look at how nature really functions."
Forsythia grows most everywhere in Zones 5-8. Its yellow blossoms are among the most recognizable signs of early spring, making this member of the olive family one of the best seasonal indicators for gardeners. Turf grass specialists often use the bloom time of forsythia as a bellwether for scattering pre-emergent herbicides on crabgrass-prone lawns.
"A garden weed preventer or pre-emergent kills the seeds before they can grow into seedlings," Polomski said.
Phenology blends science with legend. It charts plant and animal development, and how those are influenced by climate change over long periods of time. It also includes the observations of people who have worked the ground for generations.
Scientists know, for instance, that soil temperatures must reach at least 35 degrees before onion and lettuce seeds will germinate. But Felder Rushing, a former extension horticulturist, 10th generation American gardener and folklorist from Jackson, Miss., puts it in a more homespun and equally correct way: "When fishermen are sitting on the riverbank instead of on their bait buckets, the soil is warm enough to plant."
Some other reliable natural markers compiled by University of Wisconsin-Extension:
— Plant potatoes as the first dandelions bloom, and peas when the daffodils flower.
— Transplant eggplant, melons and peppers when the irises bloom.
— Start looking for trouble from squash vine borers when chicory flowers open.
— Put seed corn in the ground when oak leaves are about the size of a squirrel's ear.
— The time is right for planting tomatoes when lily-of-the-valley is in full bloom.
— Seed morning glories as soon as the maple trees leaf out.
— Grasshopper eggs hatch roughly at the same time that lilacs bloom.
— Prune roses when crocuses begin to flower.
Gardeners aren't the only ones who read signs of the seasons for practical reasons. Bird watchers use them for timing migrations, fly fishermen for signalling the insect hatch and farmers as clues in weather forecasting.
Phenologists monitor one species as a reliable way to track changes in another. Birds head north, for instance, just as the insects begin to appear in their summer breeding grounds. Insect populations build when their host plants produce leaves.
Native tribes in British Columbia used the arrival of buds and blooms from certain berry-producing shrubs to signal when it was time to fish for halibut or spawning salmon. That gave them a competitive leg up over other animals consuming the same, often limited resource.
"People good at observing things can often predict when the purple martins start arriving," Rushing said. "It becomes part of the local lore."
Don’t have a compost pile yet? Well get started, it's easy! Composting is a great way to give fallen leaves, grass clippings, kitchen veggie scraps and garden trimmings a productive use. Compost is excellent when mixed in with soil before planting, and makes great mulch when your garden has already been started. Make sure your compost gets to at least 160° F, essential for destroying weed seeds, which is important when using the compost as mulch.
Mulch is a layer of material spread over the surface of your garden’s soil that helps it to retain moisture, keep temperatures cool, and inhibit weeds. Organic mulch also breaks down over time, making the soil more fertile. Compost, straw, bark, newspaper, grass clippings, and shredded leaves are all great organics to use for a blanket of mulch.
Want to attract some lovely butterflies to enhance your garden’s aesthetic? There are many different flowers that produce the nectar they love. Lilacs, marigolds, and sunflowers are just some of the options you can plant to color your garden with elegant butterflies. Place them in areas with abundant sunlight for the best result.
Rabbits love vegetables gardens, especially your leafy greens. The best defense is to build a chicken wire fence around your garden, at least 2 feet high. Make sure to bury it as well, at least a foot if you can though less will work, as rabbits are more likely to go under the fence than over. Interestingly enough, human hair scattered around the garden is an effective rabbit repellent, and eventually becomes a nice fertilizer. This can easily be obtained from local salons.
Birds should be welcomed into your garden. They love to eat plenty of pests like aphids, caterpillars, slugs and even mice, all of which can be detrimental to your garden. Invite birds to stay with bird feeders, houses and baths. Too many birds can become an issue if you are growing a lot of fruits and berries, so you may have to experiment to find the right balance.
Herbs make great companions planted alongside your vegetables. In general, the strong scent of most herbs will deter many different insects. Specifically, basil will help control flies and mosquitoes, spearmint keeps away ants and aphids, and rosemary will repel certain beetles and moths. In addition, these herbs will be a tasty addition to your edible garden!
If birds and herbs aren’t enough to solve your insect problem, there are many organic pesticides available. One of the safest options is insecticidal soap, which must be used directly on the insects. It is non-toxic to animals and can be used until you harvest your veggies. Just be cautious of using it in direct sunlight when hot out, as it may burn your plants.