Gardeners Calendar: To Do in May

by Gary Crispell, EMGV

Hopefully by the time you read this it will have ceased to snow and perhaps even warmed up enough to make this calendar relevant. Regardless, May is a busy time in the Piedmont garden so break out those shorts, tee shirts and knee pads and let’s garden!

Lawn Care
Warm season grasses (Bermuda, zoysia, centipede) should begin to show signs of life this month. When they do (usually around Mother’s Day) feed them with a quality slow-release fertilizer.

Cool season grasses (tall fescue, perennial rye and bluegrass—the kind without banjos) should have had their last nitrogen fertilization in late March/early April. Fertilizing after mid-April is inviting fungal disease problems (e.g. brown patch) in July and August. Mow cool season grasses at the 3- 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 could give them a bit of balanced sustenance, also.

Non-native rhododendrons and azaleas can be fed with an acid fertilizer if a lower pH is needed. Send in a soil sample (they are free this time of the year) to make sure.

NCSU has an excellent planting chart for annual vegetables at 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.

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 pruning 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.

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 and camellias (tea scale), boxwoods (leaf miners—check for adult flies on outside of leaves). If the weather becomes hot and dry check all your house plants (inside and out) for spider mites and aphids.

Mulch, mulch, mulch!! Shredded hardwood, pine bark, shredded cypress and pine needles (pine straw) 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.  If you have questions Ask an Extension Master Gardener Volunteer. It’s our job to help. Also, there are numerous publications from the NCSU extension service on line.

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