Welcome to Garden Zone, a monthly newsletter for anyone interested in gardening. ​​It's produced by Extension Master Gardener volunteers in Mecklenburg County.

The University of Florida estimates there are close to 5.5 million species of insects worldwide. Of those, less than one percent are considered agricultural pests.  Most insects are harmless to your crops, or even beneficial like pollinators and predatory beetles. However, insects that are pests can do a lot of damage. For us gardeners, farmers, and even consumers, it is critical to discuss the potential impacts a changing climate will have on pest populations.

Insects are ectothermic just like reptiles and amphibians. Their body temperature is controlled by the surrounding environment rather than by internal mechanisms like in mammals. Insects want to avoid freezing temperatures if possible. They do this by migrating or by entering a state of winter dormancy. At its most rudimentary understanding, warmer temperatures improve an insect’s ability to multiply and reproduce more rapidly on the orders of generations. Warmer temperatures allow insects to expand their range and disperse more readily. While temperatures are becoming more favorable for insects with climate change, other conditions like the availability of food are far less certain.

Plants migrate north in a warming climate. What might have grown well in a region traditionally like corn, cotton, or soy, may no longer produce favorably. Increased carbon dioxide concentrations in the atmosphere change the chemistry of plants affecting their nutritional value. Plants stressed from heat and drought are more susceptible to damage and pathogens from pests.  At the same time, the emergence of new plants impacts the availability of food for herbivorous insects. This may be good for some insects and bad for others. New crops favor different insects, and new pests emerge.  

In summary, climate change has created both favorable and unfavorable conditions for pests that are hard to predict. Unfortunately, these impacts are not limited to pests. Beneficial insects will be equally impacted. To mitigate these impacts in your garden, grow a diversity of plants from flowers to food. This will provide forage for beneficial insects while reducing the browse available for emerging pests. Use integrated pest management when dealing with insect issues and most of all, be willing to grow alternative plants, even if they are nonnative. After all climate change has transformed the definition of what is native.

Photo courtesy of Intern Charlotte Ramirez

Like Nancy Andretti and Lisa Livingston, who were profiled in the March “Meet a Master Gardener” column, Jennifer Joiner is a newly-certified EMG from North Mecklenburg.  Spending time playing and picking vegetables in her grandparents’ huge garden as a child inspired Jennifer’s lifelong love of gardening. She fondly remembers her grandfather climbing pecan trees and shaking them so that she could gather the nuts.  She learned about the Extension Master Gardener program from her stepmother, who also completed the Master Gardener program in North Carolina, and was inspired to help the community and share her gardening knowledge.  Her favorite thing about being a Master Gardener is the bond that she has formed with the North Mecklenburg EMG volunteers and answering questions from the community. Her favorite thing to grow is perennials because of their many varieties and colors, and because of the beneficial insects that they attract to her yard.

Nancy, Jennifer and Lisa are especially thankful for fellow EMGVs Sylvia Hindman and Keith Jones for spearheading efforts to reopen the Davidson Farmer’s Market booth, bringing horticultural outreach to the North Mecklenburg community!  They enjoy the diverse questions that they are asked each week and have become quite the experts on insects, tomato plants and fig trees!  They have found it particularly gratifying to be able to help the new area residents that seem to arrive at the Farmer’s Market each week, all with questions about how to best improve their garden practices and fix their new yard issues.

Photo courtesy of EMG Amelia Russell

There is wonderful simplicity in the clean visual of a naturally edged garden. Hardscapes of bricks, pavers and commercially produced edging material offer aesthetics as well. When searching for alternatives, we are limited only by our imagination.

Edging with stone, a striking contrast of earth’s permanence against the fragility of flora, brings to mind rocks, flagstones, and pebbles. Expand this vision to create stacked stone terracing or large rocks on either side of smooth river stones in contrasting colors or vertically cut “gravestone” squares and rectangles in differing heights of Granite or Quartz. Other choices from your stone supplier may include Fieldstone, Limestone, Sandstone, Travertine, Marble, or Onyx.

Logs of Bamboo, River Birch, Tulip Poplar, Persimmon, Oak, Elm or Cherry, placed vertically or horizontally, provide interesting textures to a garden. Similar-sized branches, soaked for pliability, can be woven for a more rustic look.

Wine bottles in a single color, hues within a selected palette or a variety, create a garden edge with added shimmer from the sun. Bury the throat of the bottles to a pleasing depth for the edging design selected. An alternative, with only the bottoms exposed, creates level garden edging and pathways.

Seashells, including large clam shells, can be nestled together. Tire rims and hubcaps reveal the passion of a car enthusiast. Art inspired molded edging, cast iron, metal and woven resin fencing are always possibilities.

And, of course, colorful, favorite flowers or fragrant herbs create the ultimate living garden edge.

Photos courtesy of Pinterest, and Foter Magazine

Have you ever had any nursery grown shrubs or trees grow slowly, require too much water or slowly die after you planted them? When you pull the dead plant out of the ground you may find that girdling, circling roots have been the problem. When plants are not put into larger size pots quickly enough, the roots circle around the inside of the pot and stay that way even after being put into a larger pot. When you plant, knock off or wash off as much of the potting media as you can and spread out the main roots so they reach out to the sides in all directions. If the roots are already girdling and will not reach out, cut off the roots that won’t straighten. The plant can usually recover from this, but not from circling roots that are shaped like a previous pot size. If you can’t spread out and save enough roots, consider returning the plant. And when you are ready to plant, don’t plant too deeply, the root flare should show, and don’t let your mulch touch the trunk! This photo is of an azalea purchased in a 3 gallon pot that had no visible circling roots. When it died, it was clear that the cause of death were circling roots from when it had been a baby in a 4” pot!

Photo courtesy of EMG Jean Wilson

Back in 1997, when I first moved to the Charlotte area from Western Pennsylvania, my precious cargo included family pass-along plants.  Even though I was a Master Gardener, little did I know that most of what I lovingly transplanted would not survive in Zone 7b-8a.  Perhaps the most heart-breaking of all was the loss of Grandmother’s white and purple lilac plants (Syringa vulgaris) which required a cold winter chill. 

Fast-forward about 10 years.  While browsing through the annual influx of garden catalogs, I stumbled upon a miracle - the Miss Kim Korean Lilac!  Trembling as I placed my order, I began the weeks-long wait until my three very tiny pots of Miss Kim were delivered.  Two were planted close to my front door and the third was planted along a walkway. As the saying goes, first year they sleep, second year they creep, and third year they leap!  The unmistakable scent of lilacs finally filled the air and transported me back to my Pennsylvania home. 

Many Southern gardeners are still not aware that low-chill lilacs are available.  The most reliable cultivars include: Angel White Lilac - Lavender Lady Lilac - Blue Skies Lilac - Old Glory Lilac - Chinese Lilac - and Miss Kim Korean Lilac.  Bred for up through zone 8, they bloom anywhere from March through May depending on the variety.  

Easy to care for, lilacs need full sun, do not overwater, fertilize with 10-10-10 in late winter, and prune (if needed) right after blooming.  Miss Kim reliably makes April one of the loveliest months of the year for me. 

Photo (Miss Kim Korean Lilac) courtesy of Planting Tree

The humble marigold is a great companion in the garden, particularly to tomato plants.

Planted near the tomato, marigolds don’t hang about just looking attractive.

Marigold flowers emit a volatile plant compound, limonene which deters whiteflies.  French marigolds emit the highest concentration of limonene. Studies show that planting marigolds before or at the same time as planting tomato plants significantly minimizes the number of white flies.

Not only do marigolds repel them, they can also help the tomato grow stronger and more productive by helping prevent root-knot nematodes. A study published by the University of Hawaii at Manoa shows that planting tomatoes where marigolds had been planted within the same year resulted in higher yields.  Healthy roots, happy plant!

Marigolds are attractive to beneficial insects like bees, butterflies, and ladybugs.  The pollinators help the flowers, and the lady bugs kill aphids, spider mites, and mealybugs among other pests.

It is important to keep the marigolds blooming by dead heading in mid-summer. 

Current studies question whether an aqueous solution of marigold flowers sprayed on the tomato plant could be beneficial.  Studies suggest that the flower extract may increase the tomatoes’ height, number of branches, leaves, flowers and fruit.  Experiments also seek to learn whether the extract can be a natural pesticide as well as controlling early blight, wilt, fruit spots, blossom end rot and sun scald. 

Ooh, La, La, you modest marigold.  Thank you for being such a wonderful companion. 

Photo courtesy of NCSU Plant Toolbox

Growing Blueberries in Nort Carolina By EMG Marcia Ammons

So why should you add them to your garden?  They are easy to grow, fast-growing, and perennial!  They are highly productive, taste great, and there are so many ways to eat and prepare them! And my personal favorite - No Squash Borer Issues.

Growing chayote squash is easy.

1. Get a few chayote from a grocery store. Plan on planting 3 to increase your odds (2 out of 3 I planted made it).
2. Leave the fruits out on your counter for a few weeks. They will grow shoots out of the blossom end within a few weeks.
3. Once they sprout and the vines are about 5-6 inches long, place sprouted plants with the large end down - so the spout is facing down - at a 45° angle. The top of the chayote must be exposed - covering the whole fruit will cause it to rot.
4. Make sure you have something sturdy for them to climb where you plant the sprouted fruit. They climb on whatever is available (fence, trees, trellis).
5. Full sun but will take half shade.
6. Chayote like well-draining compost, nitrogen, and mulch (ph of 6-6.8).

My plants produced in the fall after growing vigorously all through the spring and summer. They typically flower 110-120 days after planting. There will be hundreds of male flowers and only a few females. Once fertilized, the female flower will mature into a harvestable fruit within 30 days.

https://www.mirliton.org/growing-guide-2/ 

Photos courtesy of Intern Charlotte Ramirez

With an unseasonably warm February, we see Iris blooms in abundance. Iris is one of the most popular perennials and is available in a variety of colors with varying blooming times. The family Iridaceae is a very large one of perennial herbaceous herbs growing from a rhizome, corm, or bulb. Some varieties require rhizomes to be at soil level, while others tolerate planting corms and bulbs deeper in the soil. Most iris require periodic division of the rhizomes. 

 A common mistake is to plant iris too deeply. Iris are generally planted 12 to 24 inches apart. Close planting gives an immediate effect but closely planted iris will need to be thinned often. Plants spaced further apart will need less frequent thinning.

Irises should be planted in late summer or early fall, as this will give the rhizomes time to establish roots before winter. If you are planting bearded iris, make sure to plant them with the top of the rhizome exposed to the sun, as this will help prevent rot. Other types of iris, such as Siberian and Japanese iris, should be planted with the top of the rhizome just below the soil surface. Choose an area in your garden that receives at least six hours of direct sunlight each day to encourage flowering. 

After blooming is complete, allow the foliage to deteriorate and then remove the spent foliage. With a minimum of care they will reward you with beautiful blooms year after year.

Photos courtesy of EMG Parul Srivastava

“A weed is but an unloved flower.”

― Ella Wheeler Wilcox

If your yard is like mine, it has been taken over by chickweed, henbit and its close cousin, dead-nettle.  All of these are annuals.  Chickweed is a low level ground cover with tiny white flowers and small lobed leaves.  Henbit and dead-nettle have small, purple flowers and square stems.  Dead-nettle differs with its reddish-purple tinted leaves.  The bees love all of these and they provide an early nectar source so if you can tolerate them in certain areas, let them be.  

As a cool season annual, they have one growing season and then die back with the onset of warm weather.  However, if they are able to flower, they will reseed, lay dormant over the summer and germinate with a vengeance in your lawn and beds when the weather begins to warm the following spring.  

So, what can you use to control these prolific weeds? The best way to control the weeds in your lawn at this time is to spray the yard with a 2,4-D or dicamba herbicide post-emergent.  Please follow the directions on the product label exactly.  If you have them in your garden beds, they can easily be weeded by hand. To limit the germination of seed, a pre-emergent will need to be applied in late summer and then again in late winter.  By following these measures, the amount emerging next spring will be greatly diminished.  Best of luck!

Photo 1: Henbit (Lamium amplexicaule), Photo 2: Dead-Nettle (Lamium purpureum), Photo 3: Chickweed (Stellaria media)

Photos Courtesy of Pixabay