We’re finally in the time of year when we can plant some things into the ground.  Some seeds can go in early, 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 or till unless you have raised beds.  Let’s look at several ways to help determine when it’s best 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.  Most plants can’t take a real “frost” (happens when the air is still) or “freeze” (happens 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 but we do know the average dates based on years of historical weather records.  At higher elevations like Mount Holly that safe date is about 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 unless you are a competitive gardener 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 several online guides or printed tables for our area.

The University of Vermont Extension/Master Gardeners program has a excellent website that includes planting schedules based on agricultural zones plus details about spacing, depth, number of seeds.  This website is very extensive and has many links to good resources for all kinds of 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) or 5 (lower elevation).

Johnny’s Seeds has a calculator 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. They also have a great calculator for repeating or succession plantings so you can plan for harvests throughout the growing season.  Enjoy salad greens, beans, etc. all summer long instead of getting overwhelmed in July and then having none.  Yes, we can grow salad greens all summer long! 

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 convenient.

An old fashioned “natural” way to determine local planting dates is based on observing nature’s signals yourself.  (“You can see a lot by observing”, Yogi Berra)  I first encountered this practice among the Mayan farmers in Central America where they use natural events as signals to determine when to clear land, when to burn, when to plant, and when to expect pests.  We can do something similar by using our own local natural events for an indication of when to plant.  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…                           Is when…

Peas & onion sets                                        forsythia or daffodils begin blossoming

Lettuce, beets, carrots, spinach                first lilac leaves, dandelions in bloom

Transplant broccoli, cauliflower,

    kohlrabi, cabbage                                    dandelions in full bloom

Potatoes                                                        dandelions in full bloom

Beans, cukes, squash                                lilacs in peak bloom

Tomatoes                                                       lily of the valley blooming or apple blossoms

Corn                                                               oak leaves are dime size (young)

Peppers, melons, eggplants                      irises 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. 

A great new conservation idea is called “No Mow May” let the pollinators play. The idea is very simple and makes sense.  Avoid mowing your lawn in the month of May so that those early wildflowers (dandelions, clover, etc.) can blossom and provide vital nectar for pollinators.  These flowers are the first available major food for many wild pollinators, including honeybees and bumblebees, and gives them a spring boost.  It also gives you a valid 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 later flowering plants 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 at the Vermont Agency of Agriculture website.

A word in support of wasps.  Did you know that wasps are one of your best allies in garden pest prevention?  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 are the 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 be appreciated for their benefits at keeping nature in balance. 

Of course, honeybees and bumble bees are also critical for plants as pollinators but are not predators of other insects.  Bees are not aggressive and rarely will sting unless directly threatened. How can you tell the difference?  Bees are hairy, wasps are not.

Early spring is the time to watch for 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.

Compost happens. Remember to keep improving your soil with homemade compost.