Learn With Us, April 2023

The Plant Sale is here! Due to the weather forecast, the sale will be part indoors and part outside under tents, so grab your raincoats and come on out!

Container Gardening: Planting and Design
Tue, April 18, 10am – 11am
Cocoa Cinnamon, 420 W Geer St, Durham, NC 27701

For city dwellers, growing plants outdoors often means gardening in containers. Whether you live in an apartment, condo, townhome or house, our Urban Container Gardening series will get you prepared to grow ornamental plants or edibles in containers at your city home. For this two-part talk, you can attend either one or both seminars, as they’ll cover complementary information.

For our second class, you’ll learn from Extension Master Gardeners Cathy Halloran and Jackie MacLeod about selecting the right plants for the right place, differences between types of plants, design tips to make your containers look great, and then get your hands dirty designing and planting in containers.

Join the Extension Master Gardener℠ Volunteers of Durham County to learn gardening tricks and tips at the Cocoa Cinnamon Container Gardeners.

REGISTRATION REQUIRED https://www.eventbrite.com/e/container-gardening-planting-and-design-418-tickets-513365117887

$5 fee

Parking is available along the street and in the Cooperative Extension Parking lot (721 Foster St). There is a limit of 15 people per class.

This class is part of the Bull City Gardener Learning Series and is open to everyone.

This class is made possible by an Inspire-Connect-Empower Grant from the Master Gardener Association of North Carolina.


Durham Garden Forum

Tue, April 18, 7:00pm – 8:30pm

Anne Spafford, Professor of Landscape Design at
NC State University
High performing landscapes refer to garden elements
that serve multiple functions. A rain garden, for
example, can also be a pollinator garden, and can be
composed in a way that brings humans joy. A privacy
screen can also support wildlife. In this engaging
presentation, Anne will share her top ten design,
implementation and management strategies for
achieving sustainable and attractive landscapes.

The Durham Garden Forum is an informal
group that meets once a month to enrich
our gardening knowledge and skill.
3rd Tuesdays, 7:00- 8:30 pm via Zoom link sent to
registrants.
Memberships: $25 per year
Members have access to video library of presentations
CONTACT US: durhamgardenforum@gmail.com


Container Gardening: Planting and Design
Sun, April 23, 2pm – 3pm

Cocoa Cinnamon, 420 W Geer St, Durham, NC 27701)
Description
For city dwellers, growing plants outdoors often means gardening in containers. Whether you live in an apartment, condo, townhome or house, our Urban Container Gardening series will get you prepared to grow ornamental plants or edibles in containers at your city home. For this two-part talk, you can attend either one or both seminars, as they’ll cover complementary information.

For our second class, you’ll learn from Extension Master Gardeners Cathy Halloran and Jackie MacLeod about selecting the right plants for the right place, differences between types of plants, design tips to make your containers look great, and then get your hands dirty designing and planting in containers.

Join the Extension Master Gardener℠ Volunteers of Durham County to learn gardening tricks and tips at the Cocoa Cinnamon Container Gardeners.

REGISTRATION REQUIRED https://www.eventbrite.com/e/container-gardening-planting-and-design-423-tickets-517763884717

$5 fee

Parking is available along the street and in the Cooperative Extension Parking lot (721 Foster St). There is a limit of 15 people per class.

This class is part of the Bull City Gardener Learning Series and is open to everyone.

This class is made possible by an Inspire-Connect-Empower Grant from the Master Gardener Association of North Carolina.


For more classes and events, see: Triangle Gardener

Garden To-Do List for April

by Gary Crispell, Master GardenerSM Volunteer

APRIL GARDENING CALENDAR 2023

What a roller coaster ride!!  Let’s call it Maruaryune because it came right after Februril.  Pity the plants.  They are sooo confused.  We have a pair of azaleas (Rhododendron x poukensis) in the backyard.  The blooms on one were totally annihilated by the last hard freeze.  The other one is doing just fine even though they aren’t four feet apart.  The fig (Ficus x Brown Turkey) may have received a terminal shot this year.  It is the second year in a row that the leaves have been frozen just as they were emerging.  The apple tree (Malus x Yellow Delicious) is unfazed by it all, thank you very much.

The Accidental Cottage Garden is surprising me yet again.  I had planned to remove the mulch and till the entire bed with the tractor, but there are too many perennials returning for me to justify that.  So, looks like a job for the mini-tiller and way more work for the gardener.  Life can be sooo hard sometimes.

One of the returning perennials is the Siberian wallflower (named for a junior high boy at his first dance).  (Cheiranthus allionii).  It is already in full bloom.  Let us hope April is pleasant (i.e., warm) so that the 250,000 seeds I bought will all germinate and give me something to write about all summer.  Now I have shared part of my “to do” list.  Here is a more complete list of things we can do together apart.

Cheiranthus allionii (Siberian wallflower) – photo credit: Gary Crispell

LAWN CARE:  Statistically this is the first month to fertilize warm season grasses (Bermuda & zoysia—not centipede) because they should be just breaking dormancy.  My zoysia broke dormancy three weeks ago.  Go ahead and fertilize like everything is normal (Might not be any such thing.)

Centipede gets its only feeding in late May.

Just like last year, the window for applying preemergent crabgrass control may well have slammed shut two weeks ago.  The rule of thumb is to make the application sometime between when forsythia blooms and when the dogwoods (Cornus florida) bloom.  The C. florida in my yard are wide open in bloom now.

Cool season grasses may also be fertilized now using a balanced (10-10-10 or equivalent) fertilizer in moderation.

FERTILIZING:  Besides lawns (see above), all the stuff you didn’t get to last month because you couldn’t bring yourself to do it in 45 degree weather or when it was raining (which was most of the time it wasn’t 45) can be fertilized now.

PLANTING:  It is soooo tempting.  Like the weather is mostly warm(ish).  And the sun feels so good.  And we’ve been cooped up since I don’t know when.  And…  It’s a crap shoot, y’all.  I’m gonna list ‘em with the caveat  that you might have to protect them before the month is over.  Or you can be conservative and wait until mid April.  This blog assumes no responsibility for frosted plants that we didn’t plant ourselves.  That said, here’s what can be planted ‘cause the soil temp is already all ready.

Squash, cucumber, melons and corn can be planted from seed.  Go ahead and bring out the flats of tomatoes and peppers that you started in January and stick ‘em in the dirt.  Please plant enough to share.  Some folks have thumbs that are other colors than green and some folks carry all their possessions on their backs and don’t have anywhere to plant stuff.  All of them like fresh veggies.

Warm season grasses (Bermuda, zoysia, centipede) can be planted now.  Bermuda can be planted from seed, but the requirements are stringent.  Zoysia, centipede and hybrid Bermudas need to be sodded or plugged (sprigged).  NCSU Turffiles website is a great resource for any North Carolina grass information.

PRUNING:  Remove winter damage from trees and shrubs.

Suppress any urges to prune spring-flowering shrubs {lilac (Syringa sps.), azaleas (Rhododendron x hybrids), mock orange (Philadelphus), etc.} until after the blooms fade.

Prune berry-bearing plants [hollies (Ilex sps.), pyracantha, etc.] while in flower to know how much fruit is being pruned away.

Prune flowering cherry (Prunus sps.) and redbud (Cersis sps.) only as needed.

SPRAYING:  The bugs are not confused.  They are opportunistic and the weather has been warm enough often enough to provide lots of opportunities.  So, they are out there feeding on anything they can get their little mouth parts on.  The usual suspects this time of the year are lace bugs on azaleas and pyracantha, boxwood leaf miners (self-explanatory), euonymus and tea scales on euonymus and camellias (and other stuff in the vicinity—opportunity) and spider mites on lots of varieties, but most likely on coniferous (cone bearing) evergreens.  Aphids will be on literally everything as soon as it is consistently warm.

A light horticultural oil will usually result in positive outcomes (the critters will die) as the oil smothers all phases of the insect life cycle.  Insecticidal soap is effective on larval and adult phases.  Other more toxic products are available, but are less ecologically friendly.  Always read the label and follow all the instructions contained thereon.

Spray iris beds for borers.

Treat cruciferous vegetables (broccoli, cabbage, brussels sprouts) for worms (caterpillars).

Spray squash plants weekly from now until June for squash vine borers.

Spray apple and pear trees with streptomycin to control fire blight.  Apply once at bud opening and again at full bloom.  In rainy weather a third application may be necessary.

Begin weekly fruit tree spray program after the blossoms drop their petals.

Pots of pansies brighten up the deck – photo credit: Gary Crispell

OTHER STUFF TO KEEP YOU OFF THE STREETS WHEN YOU HAVE COMPLETED THE “TO DO” LIST (or not):

By mid-month it’ll be time to hit the local garden shop (not big box) for those delightful bunches of color we call annuals.  By the end of the month the selection should be awesome and who doesn’t love the cheerfulness of a pot full of Evovulus, or petunias, or celosia, or a thousand other species.  We keep pots of pansies on the deck all winter and whatever catches our eye at the garden shop for the summer.  I’m always open to trying new varieties.

Mulch is a many splendored thing.  It is the finishing touch to a landscape planting.  Not only is it aesthetically pleasing, but it is functional by helping to mitigate soil moisture loss, keeping roots cool and assisting in the suppression of weeds.

April being what it is in North Carolina, requires a bit of spontaneity on our part if we want to sit outside and partake of nature’s goodness.  I mean, the weather has been known to change hourly.  One has to be always ready and flexible.  It’s worth the effort when you hit it right.  Only May and October are better and October is equally unpredictable.  (It just has the multi-hued leaves as a redeeming value.)

So, IT’S SPRING!!!  Enjoy.  

Happy new beginnings, y’all.

Further reading:

From NCSU:

NCSU Turffiles

General Pruning Techniques

From the Blog:

More about horticultural oils

Mulch and more mulch

Leaping into Spring: Revisiting ‘Dividing Perennials’

If you’ve noticed a plethora of perennials in your garden this spring, take advantage of this beautiful spring weather. It’s not too early to divide your plants – just follow the steps Andrea Laine described in this post from 2020. Go ahead, expand your garden, or maybe share your perennials with your neighbors so that you can make room for new Backyard Treasures from the Master Gardeners’ plant sale on April 8th!

by Andrea Laine EMGV

There’s a saying among gardeners: Sleep, creep, leap.

The first year that an ornamental plant is in the ground, it sleeps. Above ground it looks like nothing is happening. All the action is underground where it is creating strong roots. A quality root system is essential for absorbing water and nutrients to deliver to the rest of the plant.

The following year, the plant creeps. We may notice new leaf buds, an elongated stem, and we are content (or relieved) that the plant is still living.

Then, finally, in its third or fourth year, the plant really starts to get showy. It leaps! There are new leaves and bold flowers. The plant is noticeably taller and/or wider and we gardeners are filled with pride and joy and our enthusiasm for gardening probably leaps, too.  

Stokesia ‘Blue Danube.’ Photo by A. Laine.

This is so true of herbaceous perennials! Before you know it, it is time to divide the perennial into smaller plants. Division can control a plant’s size and invigorate the original plant, assuring that it continues to flower abundantly. (If your perennial no longer flowers very well, that is a sure sign that it is crowded and needs to be divided.) Another benefit is that you will have new plants to place in another part of the garden or share with a friend or neighbor.

Time of year
The best time to divide herbaceous perennials is early spring, however bearded iris and Asiatic lilies prefer later summer to early fall and some plants like black-eyed Susan are so resilient they’ll accept division in spring or fall. Choose a cool or cloudy spring day or an early fall day. Dividing or planting most perennials during a hot and/or humid day, such as we tend to have during a Durham summer, is generally not advised. Also, do not divide or dig around plants the same day they have been watered.

Step-by-step guide

Step 1.  Prepare by putting in place everything you may need to complete the task: a long-handled spade or digging pitchfork, a sharp knife (I use an old steak knife from the kitchen), a full watering can or hose, and newly dug holes in the ground. If you intend to gift your divisions to other gardeners, then also have containers, a small spade and potting soil by your side.

Step 2.  Survey your plant(s). From afar, it looked like I had two giant clumps of Stokes Aster (Stokesia ‘Peachies Pink’). See photos below. They had  been in the ground four years. But upon closer inspection, notice that there are actually multiple small clumps growing close together.

Step 3. Dig and separate the plant. Use the spade or fork to dig deep on all four sides of the plant. In the case of these asters, I need not dig up the whole planting, just the smaller clumps that I wish to relocate. If the plant’s divisions are growing closely together, as may be the case with a Daylily or a Bearded Iris, you may need to dig up more, or all, of the plant. When that is the case, gently pull the division away from the original plant. Tease it with your fingers. If this is difficult, as it may be with plants that are overdue for dividing, it’s okay to cut through the clump using the knife. Just be sure that each smaller clump gets three to five shoots and part of the root system.  

Digging to divide a perennial into multiple plants. photo by A. Laine

Step 4. Replant the divisions, with proper spacing and depth (the crown at soil level), as soon as possible into your previously dug holes or at-the-ready containers. The goal is to minimize the amount of time that the roots are exposed to the drying effects of air. Water the new planting well.

As you can see in the photos above, the new divisions look a bit forlorn 10 days later. They will need nurturing equivalent to any new planting; that means vigilant watering through their first year. It is also helpful to snip new flower buds off the first year or two, if any even develop, so the plant’s energy can be concentrated on developing its root system. Remember: sleep, creep, leap!

Step 5. Pay attention to the original plant. Rebury its roots if any were exposed during the division. Enrich the soil with compost or soil conditioner. Even just loosening it will help; Plants dislike growing in compacted soil. Having some garden soil or compost on hand is helpful but not necessary. It’s okay to add the compost later in the growing year when social-distancing may not be as critical as it is this spring.

Exposed roots of Stokes aster following separation and division. photo by A. Laine.

Follow similar five steps if you wish to relocate a plant: Prepare, survey, dig, replant, nurture. I divided the asters last spring and the new plants are doing very well. I will divide and move some hostas to shadier places this year. My landscape has changed (we took down some larger trees) and the hostas are no longer planted in the right place for their needs.  

Early spring days are excellent for separating, dividing or relocating perennials. And, these are tasks you can accomplish with equipment and material already on hand. Perfect for gardeners sheltering-in-place.

1Perennials not recommended for division

  • Baby’s Breath (Gypsophila)
  • False Indigo (Baptisia)
  • Balloon Flower (Platydocon)
  • Flax (Linum)
  • Bugbane (Cimicifuga)
  • Lupine (Lupinus)
  • Butterfly Weed (Asclepias)
  • Monkshood (Aconitum)
  • Clematis
  • Russian Sage (Perovskia)
  • Poppy

Divide Only to Propagate

  • Bugbane (Cimicifuga)
  • Tall Sedum (Sedum “Autumn Joy“)
  • Garden Peony (Paeonia)
  • Yucca
  • Red-Hot Poker (Kniphofia)

Resources  

1. Some plants need dividing more often than others. Scroll to the bottom of this link for a list of perennials and their division requirements.
https://extension.psu.edu/dividing-perennials

http://chemung.cce.cornell.edu/resources/dividing-perennials

Further Reading

A glossary of gardening terms
https://content.ces.ncsu.edu/extension-gardener-handbook/glossary

The many ways to propagate plants are described in the Extension Master Gardener Handbook: https://content.ces.ncsu.edu/extension-gardener-handbook/13-propagation#section_heading_5641

The Budding Orchardist: There is No Off-Season

The Third Installment in the Series “The Budding Orchardist”

By Jeff Kanters, Master GardenerSM Volunteer

“The only true wisdom is knowing you know nothing.” –Socrates

(Image credit: Jeff Kanters)

After the long, hot, and drought-ridden summer of 2022, mid-October and November ushered in cooler weather along with shortening days. With these seasonal changes, the orchard trees, having stopped their robust vegetative growth, began to harden off and dropped their leaves through December. During this time, sugars once built and maintained in the trees’ leaf canopies via photosynthesis were transported down to the roots to be stored over the cold months ahead.

Preparations began in November to ready the trees for cold dormant-season management. Fruit tree care during the fall and winter seasons is as vital as it is in the spring and summer. Our team undertook the following to ensure future successes in the orchard.

• Painting the Trunks of Young Fruit Trees Before Winter

Trunk of fruit trees painted with white latex paint which helps prevent unwanted damage and subsequent problems. (Image credit: Jeff Kanters)

In early November all fruit trees were painted with a 1:1 dilution (one part water, one part paint) of white water-based (latex) paint along their trunks from the ground up to the first scaffold limbs. Important Note: Do NOT use OIL-based paint, as OIL-based paint is TOXIC to the trees! We did this for one main reason, and we get many questions about this.

The white latex paint reflects the sun’s rays and discourages large temperature swings to the bark’s surface. An extreme rise in heat of bark along the south-facing lower trunk can cause expansion and cracking when the daytime and nighttime ambient or air temperatures are at or below freezing. The cracking and damage to the trunk from temperature extremes opens the tree up to diseases and insects.

• Winter Pruning of Young Fruit Trees

After painting the trees, we scheduled winter pruning. Research has shown that the most optimal time to winter prune trees in the piedmont of North Carolina is between late December and early March, with February being the optimum month. There are fewer insects and diseases present, and the trees are dormant.

Winter pruning allows better visualization of the branching structure and the identification of diseased or damaged limbs. Also, by this time all the trees’ excess food (i.e. carbohydrates) is now stored in the roots, so pruning during dormancy does not decrease the available food stores of the trees when spring arrives.

While some root stocks may have a dwarfing influence on the top above-ground growth of some trees such as apples, this is not true of other types of fruit trees like peaches and plums. If you want to keep your fruit tree at a reasonable size for managing and harvesting fruit most easily, annual winter pruning is essential.

Neglecting annual training and pruning of fruit trees results in poor shape development, less quality fruit, greater disease susceptibility, and shortened life span of the tree.

Key fruit tree pruning priorities to maintain health and productivity of the tree are

  1. Remove all dead, dying, and diseased limbs.
  2. Remove limbs that crossover which can rub together causing damage to limbs and harboring disease.
  3. Remove limbs that grow downward or straight up.
  4. Increase sunlight penetration into canopy.
  5. Increase air flow in canopy and reduce fungal disease.
  6. Increase fruit production.
  7. Develop strong 45-degree angles on limbs to support fruit load.
  8. Maintain tree size (5 to 10 feet is the ideal size for the home orchard in terms of accessibility).

Important Note: Structurally, pome fruits (apples and pears) are pruned as a central-leader, Christmas- tree-like shape; stone fruits (plums and peaches) are pruned as an open-vase, bowl-shaped, multiple trunk form.

Key Pruning Equipment For Small Fruit Trees

A line-up of some of the fruit grower’s most important tools. (Image credit: J. Kanters)
  1. Lysol® disinfectant spray – Critical to ensure that the pruning tools are kept disinfected between pruning cuts to avoid the spread of disease. You can also spray tools with a 70-90% concentration of rubbing alcohol or 10:1 diluted bleach. The rule we apply is that if a tree appears healthy, then spray tool once before starting to prune and then spray again after completing the pruning of the entire tree. If, on the other hand, you have a tree with damage and potential disease on a particular branch you select to prune out, sterilize the pruning tool before and immediately after the pruning cut to avoid spreading disease to other healthy branches or limbs on the same tree you plan to prune next.
  2. Handheld bypass pruning shears – for pruning small branches up to ½ inch in diameter. Attempts to cut larger branches with pruning shears often results in torn, jagged pruning cuts and may damage the shears.1 (See note below for more information on bypass vs. anvil-action tools).
  3. Compact pruning tool blade sharpener – Very handy in keeping the blades of shears and loppers sharpened for clean prune cuts.
  4. Bypass pruning lopper – for pruning larger branches between ½ inch up to 1 ¾ inches in diameter.
  5. Pruning saw – for pruning large branches and limbs greater than 1¾ inches in diameter. Pruning saws are unique in that the blade teeth are oriented in alternating fashion forward and backward along the saw blade, thus allowing you to cut both on the forward push and the backward pull of the saw. Many shapes and sizes are available, from compact folding saws to straight fixed blades.

• Dormant Spraying of Young Fruit Trees

As soon as possible after the trees are winter pruned, we dormant spray the entire tree with horticultural oil and fungicide. This treatment focus is preventative spraying before symptoms are observed. After pruning, the tree structure is smaller and less spray is needed to cover the tree. Also, the spray application covers pruning wounds adding further protection from diseases.

The horticultural oil typically kills overwintering aphids, spider mites, scale, and eggs as they are hatching and before populations take off in warmer weather. The fungicide kills overwintering fungal spores to suppress development of rusts, fire blight, and peach leaf curl diseases. We opted to use Neem horticultural oil as the base oil.

We are testing the use of a liquid copper-based fungicide that can be mixed with the Neem oil and applied at the same time to the trees. We follow the manufacturer label directions on mixing and dilution in the spray pump spray tank. We wear rubber gloves, face masks, and safety goggles when spraying the trees, along with long sleeve shirts and pants.

Important Note: Keep sprayers dedicated to the sprays applied. Do NOT use one sprayer for different types of spraying. For instance, commercial growers have a specific sprayer for herbicide control and another sprayer for disease and insect control. We label our sprayers with waterproof markers designating their specific use. Be careful not to use more spray solution than needed.

The timing of spraying is the tricky part. By late February temperatures are starting to moderate more in the Piedmont. To maximize the effectiveness of the spraying, ambient air temperatures should be above 40 degrees Fahrenheit. Second, rainfall is not good within a 24 to 48-hour period after spraying as the effectiveness of spraying is considerably lessoned. As you can imagine, this task is easier said than done, given the fluctuating late-winter to early-spring temperatures and sporadic rains. We keep a close eye on both temperature and precipitation forecasts to optimize the effectiveness of the winter spray program. We strive to spray before too much bud swelling and break on the trees.

Important Note: To protect our beneficial insects, we strive to conduct dormant spraying before blooming and pollinators are visiting. Any subsequent spraying during the growing season is timed after blooming and when pollinators are not active. More on growing season spraying pros and cons the next installment.

The saga continues as the young trees awaken from dormancy and their growth resumes in March through the summer months. Join me looking ahead as we face summer disease and insect pest challenges on the orchard trees. Stay tuned.

______________________________________________________________________________

Notes

1–A few notes on bypass vs. anvil pruning shears and loppers. We strongly encourage the use of bypass shears and loppers rather than anvil types. The bypass types are essentially two blades that make a clean cut. The anvil shears and loppers crush the branch stem and cause more jagged, less clean cut that may open the tree up for disease.

Bypass pruners (left) work much like scissors and make cleaner cuts while anvil pruners (right) tend to crush plant material. (Image credit: Barbara H. Smith, HGIC Clemson Extension)

Resources and Additional Information

Fruit Trees General:

Fruit Tree Pruning Basics:

Winter/Early Fruit Tree Spraying:

Article Short Link https://wp.me/p2nIr1-3eX

Plant-Palooza: Inaugural Plant Festival and Annual Plant Sale Coming in April

By Melinda Heigel, Master GardenerSM Volunteer

You don’t want to miss these two exciting events! For more information on both events, visit the website https://www.backyardtreasuresplantsale.org/.

The inaugural Plant Festival on Saturday, April 1 will feature over 20 exhibitors and Master GardenerSM Volunteer plant experts to answer questions about native plants, non-native plants, trees, and shrubs, vegetables, herbs, annuals, and houseplants. You can also tour our on-site demonstration garden. To learn more about the festival, check out https://www.backyardtreasuresplantsale.org/plant-festival.

For the annual Plant Sale on Saturday, April 8, please note that the line forms early and plants go quick! Please be green and bring your own box to the plant sale to carry your plants home. Find a list of plants available at the sale along with photos, descriptions, and a searchable database at https://www.backyardtreasuresplantsale.org/perennials.

______________________________________________________________________________

Article Short Link https://wp.me/p2nIr1-3j7