May: To Do in the Garden

By Gary Crispell, EMGV

So, here we are in the first week of May still waiting for those April showers to fully materialize.  Apparently, that wasn’t a thing this year (or last for that matter).  Perhaps we are witnessing a new normal?  Climate change anyone?  Early May forecasts predict more of the same.  Better break out the hose and sprinkler (although at least we’re good for this week!).  Did any of y’all have to cover up tomato plants so they didn’t freeze in late April?  Yeah, me too, however mine were still in pots on the deck.  Sure, didn’t see that coming.  So, maybe it’s safe now?  It is May, right?  Let’s go get in the garden.


If you are among the OCD types when it comes to your cool season (fescue/bluegrass) lawn, you may fertilize it with a balanced fertilizer (E.g., 10-10-10).

If your affections lean toward warm season grasses (Bermuda, zoysia, centipede), an application of a slow-release fertilizer is in order.

Keep mowing height at 3”-4” for your cool season lawn.  That will help protect the root from summer’s heat.


Long season crops (those that produce over a long period or take an entire season to produce) would benefit from balanced fertilizer feeding.

Fertilizing summer flowering plants now will reward you with more numbers and prettier blooms this summer.

If a SOIL SAMPLE (free right now) indicates, give your non-native rhododendron and azaleas (Yes, that’s redundant.) a dose of acidic fertilizer.


Check out the NC State web site for the Central North Carolina Planting Calendar for Annual Vegetables.  It is a great guide when and how to plant flowers, herbs and vegetables and includes spacing guides.


Grab your shears and loppers and make sure they are sharp.  Prune non-native rhododendrons (and azaleas) after they finish blooming and before the 4th of July.  They start setting next year’s blooms after that.

Check camellias and azaleas for leaf gall.  They ain’t purty, but they are harmless.  Just prune them out as necessary.

Keep garden mums (Chrysanthemum sps.) pinched back until mid-July if it’s Fall blooms you desire.

Fight the temptation to cut back the foliage on spring bulbs.  They need that to photosynthesize sugar to store in the bulbs so they can regal you again next spring.  Let the leaves turn yellow before cutting.


Spray an appropriate insecticide to treat for borers on iris, rhododendrons, blueberries (Vaccinium sps.) and squashes.

Spray fungicide on fruit trees, bunch grapes, tomatoes showing signs of blight.

Keep on (like forever) with your rose program.

Check for bagworms on trees and shrubbery.  They will be out and about this month (It’s real hard to mate inside the bag.  It’s a space thing.)  and much more vulnerable to a pesticide application.

 Many invasive vining plants are susceptible to herbicide control this month.  Think poison ivy/oak (Toxicodendron radicans/T. toxicarium), honeysuckle (Lonicera japonica), English ivy (Hedera helix), etc.


Keep a look out for worms on cruciferous veggies (broccoli, cauliflower, cabbages).  Only spray as necessary and read the label for the right spray/harvest interval. Stay away from Seven Dust as it can hurt other beneficial insects.

Other exciting entomological endeavors include checking for insects and arachnids on azaleas (lace bugs & spider mites), euonymus & camellias (tea scale), boxwoods (leaf miner adults who will be flying around on the leaves).  When the weather gets really warm (ok, hot) check houseplants for spider mites.

Spread some mulch—save some water.  Mulch will mitigate soil moisture evaporation and help keep roots cool.

Always use the smallest amount of and least toxic chemical when applying pesticides.  There is no planet “B”.

If you have questions ask an Extension Master Gardener Volunteer.  We’re here to help.  You can also check the NCSU Extension Service website for more information on a vast array of horticultural subjects.

May in the garden.  It doesn’t get any better than that.

*Resources and Further Reading

All About Soil Sampling and How to Get Supplies from Durham County Cooperative Extension

Organic Lawn Care Guide

Central North Carolina Planting Calendar for Annual Fruits, Vegetables, and Herbs

General Pruning Tips,died%20due%20to%20water%20stress.

Guide to Roses for North Carolina

Learn more about insects and how to control them from the North Carolina Extension Gardener Handbook

NC Extension Gardener Plant Toolbox (find your perfect plant or figure out what that unknown weed is!)