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

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April Garden Tasks

Hello to warm, sunny days! Do you think we're frost-free? The 10-day forecast looks really good! Based on historic averages for the last frost date for Mecklenburg County, we should be OK. More info: Anchorhttps://products.climate.ncsu.edu/freeze/map.php

Consider these gardening tasks for April:

✳️ Prune back ornamental plants such as holly, nandina and pyracantha. Prune spring flowering trees after they bloom (e.g., flowering cherry, Bradford pear, serviceberry), only if needed.
✳️ Plant carrots, celery, collards, lettuce, parsley, radishes and turnips.
✳️ Set out warm season vegetables, such as corn, cucumbers, squash and tomatoes.
✳️ Plant seeds or seedlings of annual vines, such as morning glory, moonflower and passion flower.
✳️ Fertilize spring flowering shrubs and vines after they bloom. Lightly fertilize blueberries a second time when they bloom.
✳️ Mow cool-season lawns (tall fescue) weekly, if needed, to a height of 3 inches.
✳️ Check your lawn for white grubs by using a spade to turn back a square foot of sod 2 or 3 inches deep. If you see more than 5 in a square-foot area, consider treatment.

Planning Ahead - Blossom End Rot

Have you ever noticed a soft, dark, bruise like spot on the bottom of your tomatoes?  This is blossom end rot and it’s not a disease however it is a physiological disorder caused by a calcium imbalance.  Blossom end rot often appears after rapid growth followed by dry conditions or because of inconsistent soil moisture.  The disorder can also be aggravated when adding too much nitrogen fertilizer to the tomato plants. 

Calcium only moves into the tomato plant when there is an ample water supply therefore irregular watering can lead to periods of drought or over watering. The fruit will continue to grow when the soil is dry however it will suffer a calcium deficiency. Over watering or periods of heavy rain can cause the calcium to leach from the soil.

This disorder is more common when growing tomatoes in containers and in raised beds; however, it can occur when the plants are grown in the ground as well. Be sure to have your soil tested, look for a soil pH between 6.5 and 7.5, use fertilizers low in nitrogen and high in superphosphate and be sure to maintain a consistent soil moister. 

Keep an eye on your peppers, squash, cucumbers, and melons because this disorder can occur in them as well.

Images courtesy of Pixbay

Solitary Bees

Of the over 500 species of bees in North Carolina, about 90% are considered solitary bees.  They do not live in hives but nest in the ground, former dwellings, clumps of ornamental grasses, attics, etc.  You may have recently seen these holes; they are not ant hills but solitary ground bees emerging from their winter work.

Need help identifying what you see?  NCSU Bee Identification Guide 

Nests are usually made up of chewed up leaves, pith and mud.  The leaf of choice will depend on the species of bee. Each female builds her own chamber and starts at the back to build a barrier made up of deposits of the leaf/mud solution.  She then adds a mixture of pollen and nectar called ‘bee bread,’ lays an egg and repeats the process until she reaches the front opening.  These chambers will sustain the laid egg through its emergence months later.  Interestingly, after mating, the female bee will store male sperm in a sac on her body.  Then, she will decide if the egg will be male or female.  She will place female eggs (fertilized) in the back and males (unfertilized) in the front.  The males will emerge first and offer protection from predators; they will be eaten first! Most female bees will produce two or more generations per year. The female will provide little or no further care after their eggs are laid. 

Solitary bees come in many different sizes, colors and shapes (some even resemble wasps).  All are incredible pollinators.  A single mason bee may pollinate 50,000 flowers in a season!  However, like honey bees, all solitary bees are under attack from the use of toxic chemicals, parasites, diseases and loss of habitat.  What can you do?  Check out this article from Union County Extension.

Solitary bees are not aggressive and do not actively defend their nest like social bees.  So, it is perfectly fine to observe their activity without fear of being stung.

Photos 1 courtesy of NCSU, Solitary Ground Bee holes

Photo 2, 3, 4 courtesy of Pixabay, Mason Bee, Leaf Cutter Bee, Carpenter Bee

Photo 5 courtesy of iStock, Sweat Bee

Shady Ladies of the Garden


Just as there are certain plants that thrive best in the sun, there are those that prefer dappled sun, part shade, and even full shade.  Most of us immediately think of azaleas, camellias, hostas, and ferns as the obvious choices.  Our gardening friends a little further north of Mecklenburg County would also include rhododendrons and mountain laurel.  But, depending upon whether we are looking for groundcovers, colorful leaves and flowers, shrubs, or trees, there is a wide selection of plants available to us.  It is always better to select plants native to our region but, to get more variety, we can mix it up with non-natives.  In addition to the plants mentioned above, let’s explore a small sampling of the wide world of shade plants starting at ground level and working our way up to the treetops.  It’s quite a trip!

Groundcovers - Creeping Jenny, Pachysandra, Liriope, Sweet Woodruff, Lamium Maculatum (Dead Nettle), Vinca Minor (Periwinkle), Ajuga (Bugleweed)

Flowering plants Impatiens, Dicentra (Bleeding Heart), Hellebores (Christmas Rose), Primula (Primrose), Heuchera (Coral Bells), Tiarella cordifolia (Foamflower), Digitalis (Foxglove), Pulmonaria (Lungwort), Astilbe, Spiderwort, Begonia, Lily-of-the-valley

Foliage Plants - Hakonechloa (Japanese forest grass), Caladiums, Coleus, Heuchera (Coral Bells), Ferns, Brunnera, Solomon’s Seal

Shrubs - Oak Leaf Hydrangea, Sweetspire, Daphne, Pieris japonica, Aucuba (Spotted Laurel), Loropetalum, Viburnum

Trees - Japanese Maples, Birch Trees, Dogwood, Witch Hazel, Cercis (Redbud), Amelanchier (Serviceberry), Sourwood

Oak leaf Hydrangeas in bloom in the JCRA shade garden courtesy of NC State Extension Gardener Plant Toolbox, Glenn Wagstaff 

Hat Racking Trees

In the Old Days, before air conditioning, summers were very hot in North Carolina. To cool their houses people planted deciduous trees, strategically placed to shade their houses and yards. Did you know that the air under an oak tree can be 10 degrees cooler than the air around it? This is not only from the shade it makes but from the cooling effect of transpiration, or evaporative cooling. These days, with rising summer temperatures and rising electric costs, trees can still help out a lot! A big oak will not only help with cooling but is a keystone plant providing food and shelter for our native birds and beneficial insects, a win-win! See picture number 1 for a healthy tree shading this house and yard.

Something that has become popular in the countryside, but is fortunately rare in Charlotte, is ‘hat-racking’ trees. Branches are cut off where there is no branch collar and no join to another larger branch. This is called a ‘heading cut’. The heartwood is exposed and no healing can take place. If the tree lives, there is an eruption of small branches at the cut that turns each of the stubs of branches into a bush. The wind resistance of the tree goes up and there is increased risk of wind damage and of blowing over in a storm. Each of these new branches is also weakly connected and more likely to break. Equally distressing is that it makes a beautiful and magnificent tree ugly and misshapen. The tree will never be the same or be able to serve its purpose as well as it had. (See picture number2)

Please, if you have a tree in your yard, don’t cut off its top. If you are worried about the health of the tree or its ability to stay strong in a storm, use a certified arborist to give you advice and to thin and shape it if necessary. Hopefully it can continue to shade your house and yard and provide a home for all creatures great and small! (See picture number 3)

Picture number 5 shows a healthy oak shading a house that has probably been thinned by a profession arborist.

Pictures curtesy of EMG Jean Wilson


Time for Hummingbirds


It’s time to hang your feeders and plan ways to attract the hummers throughout the summer. The Ruby-throated hummingbird has already been sighted in Mecklenburg County.  Arriving from their long journey from Central America and Mexico, they are ready to eat.  

Choose your favorite red feeders easily found in the marketplace. Glass is easiest to clean. An ant moat on the top and bee guards can keep other insects away. There are some new styles which are easier to fill.

Fill the feeder with a homemade solution of four parts hot water to one part white sugar, which best replicates natural nectar.  Do not add anything else including red dye which can be harmful to the birds. Be sure the solution is room temperature to prevent shock.  

Keep the solution clean. In spring, there will be fewer hummers, so fill the feeder half full and refrigerate the rest of the solution.  Replace the solution every week or when it becomes cloudy.  With warmer weather, more will come to feed. Then, in fall, as they are preparing for their long journey, you will see so many attracted to your feeder and flowers. 

Hummingbirds eat insects and spiders, enjoy a drink from shallow water, nectar rich flowers.  Consider planting colorful or tubular flowers like Lantana, Zinnias, Firebush, Flowering Quince, Salvia, Milkweed. You can find a comprehensive list at Find a Plant by Common Name | North Carolina Extension Gardener Plant Toolbox (ncsu.edu).

Good News! Hummingbirds will remember your garden and return year after year. 

Images courtesy of Pixbay

Plants that like Wet Feet

If you are lucky enough to have a rain garden or a place in your yard that is frequently moist, or if you have a stream bank, you are very lucky, because there are so many lovely native plants that thrive with wet feet! It is especially helpful to the land if you have a place like a rain garden to hold water safely for a short time so it can soak into the ground. If water runs off quickly into the storm drains, it fills the creeks to overflowing and further erodes their banks.

 It’s good to have a shrub layer, especially along a stream bank, to prevent erosion. Elderberry, Ninebark and Silky Dogwood (#2) are all so easy to root that they are used as ‘Live stakes’ to plant on bare stream banks. Just stick a branch stem 2-3’ long in the ground near the water in the late winter and it should root by the end of spring. They all have pretty white flowers as well. Other great choices are Buttonbush, Swamp Azalea, and Winterberry Holly.

 Shorter flowering plants that prefer wet feet include Blue Flag Iris, Cardinal Flower, New England Aster (#6), Golden Ragwort (#1), Jewel weed (#5) and Swamp Milkweed (#3).

 If you have a place for taller flowering plants, it’s hard to go wrong with Joe Pye Weed, that the Tiger Swallowtails love, New York Iron weed (#4), Swamp Sunflower and Boneset. The flowers of all these plants are very popular with butterflies and other pollinators.

Photos courtesy of EMG Jean Wilson

Soil Testing


An Important Element in Successful Gardening

What type of soil do your plants, trees, and grasses need to be successful? Take the guesswork out and ensure more success and happier flora by sending in a soil sample from your yard. This practice, done every 3-4 years, can offer a perfect remedy for problem areas in your yard, both known and unknown.

The N.C. Cooperative Extension Office, located at 1418 Armory Drive in Charlotte, has soil sample boxes available. Instructions on the boxes outline detailed information on how to properly take the soil samples from your yard. Test multiple areas within your yard and send in the boxes for testing at no charge (except for postage) from April through November to the address on the form for the North Carolina Department of Agriculture and Consumer Services (NCDACS).  

In several weeks, you will receive the results of the soil test, which will outline specific ways that your soil can be amended to obtain a healthy, viable soil. The report will have a handy section titled, “Understanding the Soil Test Report,” so don’t worry if the report looks very technical. If you have questions about the sampling or the results, you can contact the Extension Master Gardener (EMG) Horticulture information line by emailing https://www.mastergardenersmecklenburg.org/question.html.  An experienced EMG will reply with helpful information and/or resources within 24 hours.

North Carolina notoriously has acidic, clay soil. The appropriate amount of fertilizer and/or lime can rejuvenate your soil, allowing for better plant nutrition. You can adjust the quality and acidity of your soil based on the soil report from the NC DAGS (https://www.ncagr.gov/agronomi/uyrst.htm).

In the Extension Master Gardener handbook, found online at https://content.ces.ncsu.edu/extension-gardener-handbook, information in Chapter 1 covers soil and soil tests. 

Another informational piece from North Caroline State University is, “A Gardener’s Guide to Soil Testing,” found at https://content.ces.ncsu.edu/a-gardeners-guide-to-soil-testing

Happy Planting!

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The Mecklenburg Extension Master Gardener Volunteer (EMGV) program operates under the Mecklenburg Center of the NC Cooperative Extension Service (NCCES), a part of NC State University and NC A&T State University. 

NCCES is a part of Mecklenburg County Park and Recreation.

NC State University and N.C. A&T State University commit themselves to positive action to secure equal opportunity and prohibit discrimination and harassment regardless of age, color, disability, family and marital status, gender identify, genetic information, national origin, political beliefs, race, religion, sex (including pregnancy), sexual orientation and veteran status. NC State, N.C. A&T, U.S. Department of Agriculture, and local governments cooperating.