Finally it’s the time of year when we can plant some things in the ground. Some seeds can go in now, most other seeds & plants need to wait for warmer days. How do we know what to plant when? In April and early May most soil is still too wet to dig unless you have raised beds. Let’s look at several ways to determine when it’s OK to plant seeds or put out transplants. Also, a few words about the benefits of not mowing lawns in May and what good are wasps?

Frost Free Dates. Climate change has affected our growing season, so an earlier spring  might help us to plant sooner.. Most plants can’t take a real “frost” (when the air is still) or “freeze” (when there is a breeze) so they need to go in after danger has passed. That is tricky since we can’t be sure what the weather might bring this month (or next week!) but we do know the average dates based on years of historical weather records. At higher elevations in Mount Holly (1,600 to 1,800 ft.) the safe planting date is usually May 30 and at lower elevations of Wallingford, Shrewsbury, or Ludlow that is about May 24. These are averages and best guesses, not absolute rules! Remember that it’s not important that your plants go in on the earliest dates possible. If you would like recommendations for specific plants, then you can use one of the below online guides or printed tables for our area.

The University of Vermont Extension/Master Gardeners program has an excellent website that includes planting schedules based on agricultural zones plus details about spacing, depth, and number of seeds. This website has many links to good resources for all kinds of useful gardening information. This should be your basic Go To place for reliable information. Note that depending on your exact location, we are in either zone 4 (higher elevation) or 5 (lower elevation). Johnny’s Seeds also has a calculator online that uses your zip code/hardiness zone and to tell you when to start seeds indoors and the earliest dates to transplant outside by plant.

The Old Farmers’ Almanac has a similar table plus they include planting by the moon information. An added feature of the Almanac is that clicking on the name of the plant opens a growing guide for that specific plant. Very handy.

I like the old fashioned “natural” way to determine earliest local planting dates based on observing nature’s signals (“You can see a lot by observing”, Yogi Berra) We can determine time to plant by using our own local natural events  Scientists refer to these chronological events as Phenology. Here is a list of suggestions that you can use in your garden, wherever you are located:

Earliest times to plant…

Peas & onion sets … when forsythia or daffodils begin blossoming

Lettuce, beets, carrots, spinach… when first lilac leaves open, dandelions in bloom

Transplant broccoli, cauliflower, kohlrabi, cabbage… when dandelions are in full bloom

Potatoes… when dandelions are in full bloom

Beans, cukes, squash… when lilacs are in peak bloom

Transplant tomatoes… when lily of the valley are blooming or apple blossoms open

Corn… when oak leaves are dime size (young)

Peppers, melons, eggplants… when irises are in full bloom

Using these planning tools can take the guesswork out of planting and make gardening more productive and enjoyable. I tend to be conservative and plant a little later than the earliest dates. Delayed planting of squash and cucumbers, for example, can also avoid the main hatching of cucumber beetles and thereby reduces pest damage.

If you are an eager gardener, there are a couple simple “season extending” tricks to get an earlier start.  Most effective are raised beds that drain better and warm quicker than flat ground.  Also covering your planting areas with black plastic or ground cover a couple weeks ahead of planting will warm the soil and activate the soil beneficial soil life.  Finally, covering young transplants like broccoli, cauliflower, lettuces, etc. with row cover (Agribon) helps retain daytime warmth overnight.

A great conservation idea is called “No Mow May, let the pollinators play”. This is very simple and makes sense. Avoid mowing your lawn in the month of May so that those early wildflowers (dandelions, clover, violets, etc.) can blossom and provide early nectar for pollinators. At least don’t mow areas with abundant dandelions and clover blossoming. These flowers are the first available major food for many wild pollinators, and honeybees and bumblebees, and gives them a spring boost. It also gives you a good excuse to delay mowing! If you like this idea, you can extend the benefits by mowing less lawn all summer and converting some areas to pollinator gardens. After May when I find a patch of wildflowers in the lawn I avoid mowing there until they have finished blossoming. At the very least, raise your mower blades to 4-5 inches to mow higher. That results in healthier grass with deeper roots too. More information is available on the Vermont Agency of Agriculture website.

In support of wasps. Again, I want to remind everyone that wasps are one of our best allies in garden pest control. Wasps are beneficial predators and play a vital role in keeping leaf eating bugs under control. The really good news is that fewer than 2% of wasps are the stinging “social wasps” that we avoid (yellow jackets, paper wasps, bald-faced hornets). These stingers are the familiar wasps that build (and protect!) their nests in the ground or hanging above ground and will sting if threatened. Unless they are located near human activity, wasps should not be harmed and be appreciated for their benefits of keeping nature in balance.

How can you tell the difference between bees and wasps? Bees are hairy, wasps are not. You can easily encourage early wild pollinators like the small nonstinging mason bees with nesting houses of reed tubes made from the invasive Phragmites stems!  Cut them into 6-inch-long pieces, then bundled together and hung out for pollinator housing.

Early spring is the time to watch for wasp nest building near your home. If you quickly remove new small nests and they will move elsewhere. There is no need to kill them with poisons! Most importantly, 98% of all wasp species will not sting you but will provide great insect control around your home and garden. They are even believed to attack Emerald Ash Borer, a new serious tree pest in Vermont. Encourage their presence with small flowering plants such as fleabane, Queen Ann’s Lace, asters, mints, milkweeds, tickseed (Coreopsis), goldenrod, white clover, and boneset. If you see a swarm of honeybees hanging somewhere in your yard, call me and I will remove them for free.

Compost happens. Keep improving your soil with homemade compost.