May: To Do in the Garden

by Gary Crispell EMGV

Is this a great country or what?! We get to stay home and play in our yards and the government sends us a check. Of course, on the down side if we don’t stay home, we could die. Meh.

The 350,000 wildflower and pollinator seeds I sowed last November ALL came up (except where I backed off the driveway and smushed some). My family and I were initially rewarded with a blue blanket of campanula (Campanula persicifolia).undefinedThey are still there, but the red clover (Trifolium pratense, pictured above) is beginning to draw more attention. There are some poppies (Papaver orientale) waving their red heads in the seemingly constant breeze and the cornflower (Centaurea montana) plants are showing signs of bloom buds. We eagerly await their azure wonders. Here and there are some unidentified (by me, anyway) delightful small flowers in various hues. Each like a small surprise. The bearded iris (Iris germanica) I moved from our last home and which hadn’t bloomed in several years have been spectacular (proving the benefit of dividing perennials every now and then). But, enough about my yard. It is May. I am frustrated in not being able to do an effective Maypole weave all by myself. If you figure that one out, let me know. I do think your time would be better spent in the garden working on the following list of things to do.

Lawn Care

So, after 40 years of preaching the no-fertilizer-after-mid-May mantra for cool season grasses, I read that the erudite scientists at that esteemed university on and around Western Boulevard in Raleigh have determined that it is actually okay to feed your fescue (and bluegrass) into the late spring and possibly beyond.  However, “moderation in all things” should be the goal using a balanced (e.g. 10-10-10 or equivalent) fertilizer. 

Warm season grasses (Bermuda, zoysia, centipede) will benefit from an application of a slow release fertilizer if you didn’t get that done in April.

Mow cool season grasses at the 3-inch to 4-inch setting on your lawn mower to help shade out weeds and keep the root zone cool.

Other Fertilizing

Long-season crops (those that produce over an extended period or take a season to produce) would enjoy a balanced fertilizer snack about now.

Summer flowers will be ecstatic if you would give them a bit of balanced sustenance.

Non-native rhododendrons and azaleas (sort of redundant there) can be fed with an acid fertilizer if a lower pH is needed. Have your soil tested to be sure.


NCSU has an excellent planting chart for annual vegetables named Central North Carolina Planting Calendar for Annual Vegetables. The chart has a wide variety of vegetables, herbs and flowers listed with guides for planting as seeds, transplants, crowns or tubers. There are also instructions concerning plant spacing. Learn more


Sharpen up those shears and loppers. A farmer once told me the best time to prune is when the shears are sharp, but I like to think we are more sophisticated than that. Non-native rhododendrons (and azaleas) may be pruned as soon as they are through blooming. Pruning needs to be completed before the Fourth of July as any done after that will run the risk of cutting off next year’s buds.

Check camellias and azaleas for leaf galls and remove any that you find. They are not pretty, but will not harm the overall health of the plant.

Keep garden mums pinched back until mid-July if fall blooms and full plants are the goals.

Resist the urge to cut back foliage of spring bulbs. The plants need the foliage to produce energy to store in the bulbs so they may bloom vigorously again next year.  Let them turn yellow before the annual haircut.

Spraying (if you must)

Insecticide for borers on iris, rhododendron, blueberries and squash.

Fungicide on fruit trees and bunch grapes, tomatoes with signs of blight.

Continue a regular program for roses.

Check for bagworms on trees and shrubbery. They will be “out of the bag” soon and vulnerable to pesticide application. Learn more

This is a good time to spray invasive vining weeds like poison ivy/oak, honeysuckle, English ivy, etc.

Other Things with Which to Occupy Yourself in the Garden in May

Check cruciferous plants (cabbage, broccoli, cauliflower, etc.) for worms. Spray as needed.

Entomological adventures – Look for insects and arachnids on azaleas (lace bugs, spider mites), euonymus & camellias (tea scale), boxwoods (leaf miners—check for adult flies on outside of leaves). If the weather becomes hot and dry, check all your houseplants (inside and out) for spider mites and aphids.

Mulch, mulch, mulch!! Shredded hardwood, pine bark, shredded cypress and pine needles (pinestraw) are horticulturally sound and aesthetically pleasing choices.  Consider using decorative gravel (river stones) next to structures as the ubiquitous termites find them difficult to digest.

If you must spray pesticides please be gentle with the environment. Use the least amount and the least toxic product that will do the job. There are a growing number of organic products on the market that work well in a variety of situations. 

Enjoy May in the garden. It is the kindliest month in North Carolina.

Run the flag up the pole on Memorial Day and thank a veteran.

If you have questions ask an Extension Master Gardener Volunteer. It’s our job to help. Call 919-560-0528 — Monday through Friday, 9 a.m. – 4 p.m. or email your questions to

Also, there are numerous publications from the NCSU extension service online. Learn more

Photo credit: Sanja565658 CC BY-SA 3.0