Gardening by Nature’s Clues

Forsythia!  Don’t you welcome its cheery yellow blooms when winter seems to strangle us?  Love it or not, forsythia tells us Spring is on the way.  

Did you know you can plan your early garden tasks using the bloom time of forsythia and other indicator plants?  The vernal equinox may fall around March 21 every year, but nature doesn’t follow the calendar.  A cold winter can last well into April.  A warm winter teases out an early spring.  

Rather than following a strict calendar, use nature’s clues.  In my area, yellow forsythia begins blooming sometime between mid-February and the end of March, depending on yearly conditions.  Your local area may warm up faster or slower from year to year. Using the forsythia bloom time in your area gives you a reliable indicator of your local conditions.

The practice of noting the “key seasonal changes in plants and animals from year to year” is called phenology, according to the USA National Phenology Network.  Using indicator plants is not just for the home gardener.  The National Phenology Network uses thousands of volunteers to record their local indicator plants and animals, adding their observations to the national data base. This data base can show trends for better planning by farmers, government leaders, and gardeners.  If you’re interested in helping the Phenology Network, check out the website at

Let’s return to our cheerful forsythia, one of nature’s earliest indicator plants for our area. But don’t mistake the even earlier blooming yellow winter jasmine for forsythia! They’re easy to tell apart: winter jasmine has five petals, while forsythia has only four petals.

Here’s what forsythia tells you when it starts blooming: the conditions are right to plant cold-hardy vegetable seeds such as peas, spinach, lettuce, carrots, chard, beets, radishes, and parsnips.  You can also plant cold-hardy flower seeds such as sweetpeas, poppies, calendula, alyssum, cornflower, and baby's breath.  

When the forsythia petals are dropping, it’s safe to prune your roses, buddleia (butterfly bush), caryopteris, liriope (monkey grass), nandina, hollies, and other evergreen shrubs. These plants are no longer likely to be damages by a hard freeze.  Some other appropriate garden tasks include applying pre-emergent herbicide to your lawn (if needed), weeding the early weeds as they sprout, and removing some of the winter covering from your beds, if you used any.

Daffodils are typically the next to bloom, although the early bloomers may be alongside the forsythia.  But when you see masses of daffodils, you can now plant your pea seeds, which need a little more warmth to germinate.  You may also plant out your cold-hardy transplants such as cabbage, broccoli, onion, snapdragon, salvia, pansy, and larkspur.  Some sources advise waiting a little later to plant these, such as when the serviceberries (juneberries, shadbush), ornamental quinces, and cherry trees are blooming.  When these plants bloom, you can also safely plant your potatoes.  

Leaves of certain trees can also be used as indicators.  When the maple leaves are the “size of a squirrel’s ear,” you can plant your bean seeds. When the oak leaves are also the same size, corn seeds can be planted.  I really don’t know the size of a squirrel’s ear, but I enjoy the idea.

When you see the blooms of the wild cherries and spirea shrubs (“bridal veil” is a common variety), plant your cold-tender transplants.  If there’s a late frost, place a light covering over them for protection.  And when the lovely clumps of lily-of-the-valley are blooming, plant your tomatoes.  If planted too early, they will sulk and not grow until the weather warms up.

Our region has a long growing season, and many tasks have a multi-week window in which to do them. These are all suggestions, not rules. Sometimes the best time to do a task is when you can get to it!

Sharon Burnham

Forsythia Bush

Winter Jasmine Bush

Forsythia Flower

Winter Jasmine Flower

Gardens are not created or made, they unfold, spiraling open like the silk petals of an evening primrose flower to reveal the ground plot of the mind and heart of the gardener and the good earth.

Wendy Johnson

Using Format