Uncategorized – Extension Master Gardener Volunteers of Durham County

Gary Crispell NC State Extension Master Gardener^SM volunteer of Durham County

IT’S MAY!! A most delicious month in North Carolina. A Goldilocks month, if you will. Not too hot. Not too cool. Just right (mostly).

(From left to right) Dianthus barbatus flower detail DncnH CC BY 2.0, Coreopsis flowers and leaves Andrey Zharkikh CC BY 2.0, Bellis leaves and flowers Morgaine CC-BY-SA 2.0 Image credit: NCSU Plant Tool box

The Accidental Cottage Garden (ACG) is pleased and showing great promise. Already there are multi-hued sweet Williams (Dianthus barbatus) and dainty mock vervain (Glandularia bipinnatifida) (such a remarkably long name for such a fragile looking little flower). Standing much taller are lance leaf coreopsis (C. lanceolata), English daisies (Bellis perennis), fire pinks (Dianthus x Firewitch), bearded iris (Iris germanica), an iris that has teased (frustrated?) me for five years, blue flag (I. versicolor), and crimson clover (Trifolium incarnatum). The peonies (Peaonia suffruticosa x Hybrid) made a brief yet spectacular showing the week it was in the mid to upper 80s. Perhaps they would have lasted longer had the weather been more to their liking. Interestingly absent were the five spots (Nemophilia maculate). Interesting because we seeded part of THE BANK (on Washington St.) with seed left over from the ACG and there are a lot of five spots there. Hmmmmm.

Enough about me (well, actually about the ACG). LET’S GARDEN!!

*Single and double flowering peonies blooming in May.* Image credit: Marcia Kirinus

LAWN CARE:

Warm season grass folks, it’s your turn. If you didn’t fertilize your lawn in April, what are you waiting for? Put out an appropriate amount (Data taken from the SOIL TEST you submitted last fall) of slow release fertilizer on your Bermuda or zoysia and hope that nature graces us with adequate moisture to get it into the soil. Cool season folks, you may put a moderate amount of a balanced (10-10-10 or equivalent) fertilizer on your fescue, bluegrass or perennial rye lawn with the same caveats as applied to the warm season people. Sharpen those mower blades. A clean cut is less stressful on the grass. (It’ll cut down on lawn therapy bills). Keep cool season lawns at 3”-4”in height. It helps shade the roots when it gets hot.

FERTILIZING:

Speaking of such, long season vegetables like tomatoes, beans, squash, and other similar kinds will benefit from a side dressing of a balanced fertilizer 6-8 weeks post germination. What?! You didn’t start your vegetable plants from seed? You bought them from a Big Box?? Sigh. Give them a week or two in the ground and then do likewise. While you have the bag open throw a handful at your summer annuals and perennials, too. Rhododendrons including azaleas and other ericaceous (acid loving) plants would appreciate a light fertilizing now.

PLANTING:

May is the second best time in the veggie garden. (Everybody knows that harvest is really the best time). It is time to plant beans (snap, pole, bush lima, etc.), cantaloupe, cucumbers, eggplant, okra, southern peas, peppers (sweet and hot), pumpkins, squash, watermelons, and for those of you who don’t compete in the, “first tomato on the block”, contest; tomatoes. Gladioli bulbs and dahlia tubers may be planted now as well as begonias, geraniums, and any annuals you didn’t plant in April (and didn’t have to cover last week).

PRUNING:

Spring flowering shrubs (e.g. azaleas, gardenias, etc.) may be pruned as soon as the blooms fade. Azaleas, in particular, can be pruned up to the fourth of July without cutting off next year’s buds. Overgrown hedges and shrubs can be pruned still. Keep pinching back garden mums until mid-July if fall flowers are the goal. Hand prune out azalea and camellia leaf galls. They are generally benign to the plant, but are not the least bit attractive. I know your grandmother always cut the foliage off her daffodils and iris as soon as the blooms were gone. Please resist the urge to continue that tradition. The bulbs (tubers) need the foliage to produce the sugars that provide the energy they need to be able to recreate the show next year. Wait for the foliage to yellow before amputating it and relegating it to the compost heap. The bulbs will thank you.

SPRAYING:

Monitor rhododendron species including azaleas for borers. Spray as necessary. Spray iris beds for borers which you most likely will not see. They attack the tubers. BOLO (be on the lookout) for bag worms. They doff their bags this month looking for…well you know. It is the only time spraying them is effective. May is a good time to attempt to eliminate poison ivy/oak (Rhus radicans). Also, Japanese honeysuckle (Lonicera japonica). If you have a lot of it, the late Bill Smith, former owner of Crooks Corner, has a great recipe for honeysuckle sorbet. It is featured in this month’s Our State magazine. Begin spraying squash vines for borers. This will be a weekly thing until the end of June. Monitor blueberry plants (Vaccinium sps.) for borers. Spray as necessary. Continue the never ending chore of spraying roses for a wide variety of things. Ditto for fruit trees and bunch grapes. And them there are all the ubiquitous and voracious summer insects and arachnids including lace bugs on azaleas and pyracantha, boxwood leaf miners who should be out of the leaves doing the same thing the bag worms are doing by the end of the month, euonymus and tea scales, aphids on anything at any time, and the bane of my existence, white flies. They are pernicious. Keep an eye on your tomatoes for any signs of blight and spray as soon as any appear. Always, always only spray when necessary and READ & FOLLOW label directions.

OTHER THINGS TO DO OUTSIDE IN MAY THAT ARE POSSIBLY GARDEN RELATED (or not):

Celebrate May Day. You don’t have to do a maypole weave. (Does anyone even know how to do that anymore)?
Celebrate Cinco de Mayo obviously with Mexican cuisine and tequila. OK, the tequila could be optional, maybe.
Mulch stuff.
Put out an American flag on Memorial Day before you head for the beach and thank a veteran.

IT’S MAY, Y’ALL. ‘Nuff said.

Resources and Additional Information

Bagworms: NCSU Bagworms in Ornamental Landscapes
How invasive plants affect NC: NC-IPC Plant Invasives
List of invasive plants in NC to consider removing: NC IPC list of invasive plants.
Tomato Late Blight: Fact sheet from NCSU extention
NCSU planting guide for veggies, fruits. A garden calendar/timeline

Article Shortlink: https://wp.me/p2nIr1-4ud

By Deborah Pilkington, NC State Extension Master Gardener^SM volunteer of Durham County

Container gardeners, me included, give a lot of thought to choosing which plants will go into the containers. But not a lot of thought is given to the containers themselves. Yet, to have a successful container garden in full sun, shade, or anywhere in between, the choice of pot is as important as the choice of plant. So, for the next few minutes, we’re going to look at factors that should be considered for container choices, especially in our newly-designated hardiness zone 8.

Porosity

*Examples of porous pots*. (Image credit: Deborah Pilkington)

Some containers, such as the familiar terra cotta (“baked earth” in Italian) are very porous, meaning the pot draws water from the potting media through its walls. Other porous materials include hypertufa, unglazed ceramic, and clay. Because of this, these porous pots may require more frequent watering, something to think about if they are going to be in full sun. Less porous choices would be wood or concrete, and the least porous pots are made of metal, fiberglass, plastic, or glazed ceramic. That means they are going to help the potting mix conserve water.

Size

The smaller the pot size, the more frequently it will need to be watered, sometimes more than once a day. A larger container is going to be heavier and less likely to tip over. Larger containers will require less frequent watering but can be a bear to move from location to location…unless you own one of these (see the photo below). And the cost of filling the container with potting mix is also a consideration.

*The difficulty of moving very large pots!* (Image credit: Deborah Pilkington)

Fragility

If a container is fragile and susceptible to cracking in cold temperatures, it will need to be moved to a sheltered area for winter. Terra cotta, clay, unglazed ceramic, and hypertufa are all fragile materials. The sturdiest are metal, plastic, concrete and wood.

Heat Holders

Metal containers, and dark-colored containers are heat holders in full sun. They can even be hot to the touch! Potting mix in these containers can rise to well over 100°F. Keeping roots well-watered, unless you are growing cactus, is a must.

Shape

If you are going to grow a shrub or tree in a container, at some point the plant will need to be lifted from the container to be root pruned—an onerous but necessary task. So, for shrubs or trees you want to choose a container that is wider at the top (below on the right) rather than narrower (below on the left) to make lifting easier.

(Left) This container is more narrow at the top and would make it difficult to remove a shrub that had grown in the pot. (Right) In contrast, this pot is wider at the top than the bottom and it would be easier to remove a shrub that had been grown in the pot. (Image credit: Deborah Pilkington)

Drainage

Good drainage is a must in container gardening. If the container doesn’t have drainage holes, you can add them using a drill and the appropriate drill bit. And to ensure correct drainage, don’t put anything in the bottom of your container but soil mix. Adding gravel or covering the hole with broken terra cotta not only defeats the purpose of ensuring drainage, but it also raises the level of the perched water table, moving the level of saturated soil even higher in the container and closer to the roots.

*Drilling holes in metal containers at Cocoa Cinnamon Demo Garden on Geer Street.* (Image credit: Deborah Pilkington)

For gardeners with limited space, especially the newcomers to Durham’s condominiums and apartments with balconies, container gardening can bring some beauty and food to your home. For urban container gardening inspiration, visit the International Award-Winning Master Gardener^SM Container Demonstration Garden at Cocoa Cinnamon at Foster and Geer streets in Durham.

*Get more ideas on container gardening by visiting the Cocoa Cinnamon Demonstration Garden at 420 West Geer Street in Durham, NC.* (Image credit: Deborah Pilkington)

Resources and Additional Information

Check out the links below to learn more about plant hardiness zones including the history and factors used to determine the hardiness zone of an area. What does this really mean for North Carolina gardeners?

2023 USDA Plant Hardiness Zone Map | USDA Plant Hardiness Zone Map

Gardening Association of North Carolina – 2023 USDA Plant Zone Update (gaonc.org)

AN ILLUSTRATED HISTORY OF AMERICA’S PLANT HARDINESS ZONES (With a Closing Look at North Carolina) | by Tom Packer

For more information on perched water tables and soilless media check out the below online guide about drainage for containers.

How to Improve Drainage in Plant Pots, The Proper Way to Do It! – Deep Green Permaculture

If you want to take a deep dive into the physics of water movement in soilless media and media components, visit the following links.

Growing Media (Potting Soil) for Containers | University of Maryland Extension (umd.edu)

Homemade Potting Media (psu.edu) — How to make your own potting media

Learn more about choosing pots with the in-depth article below.

Containers, Pots, and Planters: What Material Is Best? (gardenerspath.com)–

Article Short Link: https://wp.me/p2nIr1-4sZ