Silky dogwood shows its colors

Each month, UT Gardens at the University of Tennessee suggests a Plant of the Month to garden writers and gardeners in the state. The January, 2020 featured plant is Silky Dogwood (Cornus amonum), a deciduous shrub native to the eastern U.S. that has small white flowers in late spring and clusters of blue berries in late summer and fall.

The silky dogwood that’s featured this month, though – a variety called ‘Cayenne’ — shows its best feature in winter, when the stems can stand out in bright, beautiful red against an otherwise brown landscape, or (if we’re lucky) with a background of fresh snow.

“Red twig dogwoods are hard to beat for their dramatic colorful show of stems in the winter,” says Jason Reeves, a research horticulturist at UT Gardens in Jackson, TN. Common cultivars include ‘Baileyi,’ ‘Cardinal,’ ‘Isanti,’ ‘Winter Flame’ and others.

Grow food with your flowers

From The Foodscape Revolution by Brie Arthur: ‘Limelight’ hydrangeas makes a good backdrop for a basil edge.

A few weeks ago I talked by phone with Brie Arthur, the author of The Foodscape Revolution, to include her voice in a story for The Tennessean in advance of the

Photo courtesy Brie Arthur

Nashville Lawn and Garden Show, which was the first weekend in March. Her book, and her gardening passion, is about making space in your landscape for food, growing it alongside the trees, shrubs and ornamental plantings that can make up a tidy landscape, even if you live in a neighborhood under the rules of a persnickety homeowners’ association.

The story in the paper turned out to be more about the show than about how to beautifully flout the HOA’s rules, but Brie and I had talked for much longer, as gardeners are inclined to do, about the benefits and the joy of growing food and flowers. Since many of her ideas weren’t included in the story about last weekend’s garden show, I’m happy I can share them here.

Longer life for poinsettias

Question: How long do poinsettias last? The plant I brought home early in December still looks nice, and I hate to throw it out. Will it keep growing?

The length of a poinsettia’s life generally depends on how much care you’re willing to give it. Some people bring it home to display for a few days, and without any attention at all it dries out and begins to drop its leaves within a couple of weeks.

If yours is still doing well, you’ve given it at least the minimum amount of TLC: indirect light in a room that’s not too warm, enough water to keep the soil moist but not soggy. If you continue to care for it, the plant should last well beyond the holidays.

Spend summer in the shade

We’d like to have a perennial garden, but we’ve moved into a place that has a lot of trees in the yard. We get some sun a couple of times during the day, but there is no place that gets full sun all day. What are some perennials that grow and bloom in part sun or shade?

Hosta and spiderwort are two shade-loving perennials to add to a shady landscape.

In mid-summer, many gardeners might say you’re lucky to have those shady spots, where you can be outdoors but can stay out of the blazing July sun. Landscape designers know the benefits:

“A shade garden in the summer is a wonderful place to relax,” says landscape designer Mary Higgins, who owns Lavender Blue Garden Design in Middle Tennessee.

“I take care of a lot of gardens in the sun. When I get home, I find I get a lot of pleasure out of my shade garden. The sunny garden takes work. The shade garden is a place I can actually sit and read, relax and slow down, even on a hot day.”

There are plenty of plants that can thrive in areas that don’t get full sun.

The heat’s on: August garden tips & tasks

Gardeners in Middle Tennessee (where The Garden Bench calls home) know that August can be brutal, and some days it’s best to stay inside. Here’s a tip: Get out early – before 7 a.m. if you can – and get those necessary tasks done. Then enjoy the rest of the day indoors, and remember that cooler days will be here soon.

Early in the month

Keep deadheading daisies, coneflowers, black-eyed Susans and other summer-flowering perennials.

Many things stop blooming when it’s 90 degrees and above. As things cool down slightly, flowers in the beds and vegetables in the kitchen garden should be blooming again. Provide ample water if it doesn’t rain.

Continue to watch for Japanese beetles. Pick off any you find on your roses or other prized plants, and plunk them into a bowl of soapy water.

Save your prized tomatoes from the birds. Pick them before they are fully red and let them ripen indoors.

If petunias are looking scrappy, cut them back and provide a light dose of fertilizer. They should soon re-bloom.

Continue to harvest and use basil frequently to keep the plant from setting seed too early.

Mid-August

Begin cleaning up vegetable beds. Remove dead or dying foliage and any rotting vegetables. A tidy garden bed means fewer places for destructive insects to overwinter.

Watch for spider mites on roses, which thrive in hot, dry weather and can quickly defoliate a rosebush. A strong spray of water on the undersides of the leaves every two or three days for a week should help keep them under control.

If you saved your potted amaryllis bulb from last winter and it has spent the summer outdoors, move it to a cool, dark place and let it dry out. Amaryllis needs a dormant period before it blooms again next winter.

There’s no need to water your lawn every day. Experts advise deep watering every few days rather than a shallow sprinkling every day.

Try to keep ahead of the weeds. But if you can’t, at least snip or pinch off the tops to keep them from flowering and setting seed.

Later in the month

Late summer is a good time to thin iris beds. Cut back the foliage, dig up the rhizomes and brush off as much dirt as you can. Discard any roots that are rotting or soft, then replant the rhizomes.

Avoid planting new trees and shrubs in the hottest part of summer. Be sure that trees, shrubs and perennials planted this spring are receiving enough water during long hot spells.

Some summer herbs can be frozen to use later. Try freezing fresh sprigs of parsley, oregano, sage, tarragon and dill. Rinse the herbs and pat them dry, then place them in separate freezer bags or containers with tight-fitting lids. Use them within four months.

Begin gathering seeds of annuals or vegetables to plant next year. Dry seeds thoroughly and store them in a place that’s cool and dry. Be sure to label them before you put them away.

Plant a cool season kitchen garden late this month — spinach, greens, kale, lettuces and other favorites. Keep beds or containers watered as seeds sprout, and watch for late-summer insect pests.

Herbs, garden color, and a Book Giveaway!

I’m planning to grow an herb garden for the first time. When is the best time to set out transplants?

Wait until warm weather to plant any type of basil.

Now that spring is definitely on the way, of course we’re anxious to get things planted, and the herb garden is a good place to start. Some herbs can withstand chilly temperatures, and may already be available at nurseries or garden centers. Herbs that are more hardy – sage, thyme, oregano, parsley, cilantro, rosemary – can be set out very early, but to be safe (and depending on the climate in your area) you may want to wait until closer to the last frost date. (That’s around mid-April in USDA Hardiness Zone 7a, where The Garden Bench calls home).

Tender herbs such as basil absolutely will not tolerate cold weather, and you should

Parsley can withstand a chill, and can be planted now.

wait until after the last frost date – or even a few days longer, just in case — to set out transplants.

In general, herbs grow best in well-drained soil in a spot that gets full sun, but there are a few herbs that do well in partial sun or partial shade. Garden author Judy Lowe lists chives, cilantro, lavender, lemon balm, parsley and sweet bay as plants that tolerate a little shade.

And for aspiring gardeners without a place to dig, herbs do well in containers — alone or planted with other herbs in a garden arrangement. At the appropriate time, set transplants in containers in good potting soil. Place them in a sunny spot on the deck, porch or patio, and keep the containers well-watered.

Color all year long – And a book giveaway!

Nellie Neal photo by Dave Ingram

Nellie Neal’s appreciation for color in the landscape began while she was college.

“I became aware of this garden that was on my route every day. I noticed that it didn’t matter what day of the year it was, there was something going on that was worth a look.” She watched throughout the cycle of the year: where the azaleas bloomed, where the gardenias flowered. In winter, where the shrubs held gorgeous berries.

“It’s really when I became enamored with how the colors and the form go together to create this effect.”

Today, Nellie is a garden writer and radio host living in Jackson, Miss. and the author of The Nonstop Color Garden, a guide to designing flowering landscapes for year-round enjoyment.

Nellie offers some of her garden color tips in a story in today’s Style section in The Tennessean. Here at The Garden Bench, I’m giving away a copy of the book.

Leave a comment at the end of this post about your favorite season for color — or just name a color you like. Respond by 6 p.m. Friday, March 20, 2015 and your name will go into a drawing to win a copy of Nellie Neal’s The Nonstop Color Garden.

What’s blooming indoors? African violets

My African violets have flowers for just a few weeks, then go for months without blooming at all. How can I get them to bloom longer?

You might think African violets are finicky houseplants, but they’re quite easy to grow. And when they bloom in winter, their flowers can bring cheer to an otherwise gloomy day.

African violet expert Julie Mavity-Hudson of the Nashville African Violet Club passes along these tips: African violets thrive in bright, indirect light and average room temperatures. The soil should be slightly moist, but not soggy (“The thing that kills more African violets than anything is overwatering,” she says).

A plant that otherwise looks robust may not bloom because it’s not getting enough light. Move it to a south- or west-facing window in winter, where the light is brighter. Watch for too much sun, though; direct sun will burn the leaves of African violets. They also do well under plant lights.

These plants also bloom better when they are slightly root-bound, so don’t rush to re-pot. They may also benefit from a light feeding of a bloom-boosting plant food every few weeks. With the right conditions, they may bloom nearly non-stop.

 

 

Special care for holiday cactus

Our Christmas Cactus usually blooms around Thanksgiving. Sometimes the buds drop off before they’re open. Can you tell me what’s wrong? What kind of care do they need?

Thanksgiving cactus

It’s common to call all of those exotic looking winter-blooming houseplants Christmas cactus, but there is more than one type. (Schlumbergera bridgesii) is the botanical name for Christmas cactus, and it usually does flower around Christmas. But there is also S. truncata, or Thanksgiving cactus, which normally blooms about a month earlier.

In general, any of those “holiday” cacti need bright light and a moderate amount of water. Barbara Pleasant, in her book The Complete Houseplant Survival Manual, suggests letting the soil dry out a little between waterings, and providing a dose of a balanced fertilizer about once a month in winter.

Christmas cacti are photoperiodic plants – that is, they respond to the change in proportions of light and dark, and begin to form buds at the onset of longer nights and shorter days in fall. Blooms open a few weeks later.

They can also be finicky about a change in conditions once they begin to bud – if you move them around, for instance. “Once plants begin blooming, they may drop their blossoms if exposed to any kind of stress,” says Barbara Pleasant in her book about houseplants.

More information and care tips from the Clemson University Cooperative Extension Home & Garden Information Center: the Schlumbergera is native to Brazil, and they grow as epiphytes in tree branches in shady rain forests. They enjoy being outdoors in summer, but bring them indoors when nighttime temperatures get down to 40 to 50 degrees – and certainly before frost. Place them in a cool, dark room, and bring them out into bright light when buds begin to develop.

Here’s how to tell the difference between Thanksgiving and Christmas cactus: Look at the stem segments. Thanksgiving cactus each have 2 to 4 sharp serrations along the margins. The margins of Christmas cactus are more rounded. One other distinguishing factor: When the flowers open, look at the pollen-bearing anthers. The anthers of Thanksgiving cactus are yellow; those on Christmas cactus are purplish-brown, according to the plant experts.

 

Why lilacs don’t bloom

Question: Our lilac bush receives sunlight for about half the day and bloomed in the past, but not much. Now it does not bloom at all, though the foliage is healthy. It is planted in well-drained soil, and other lilacs in the neighborhood are doing well.

Lilac (Syringa vulgaris) ‘Albert F. Holden’

Lilacs are deciduous shrubs that produce clusters of flowers in mid-spring. There are several factors that could keep the plant from flowering, but the most common is the lack of sufficient sunlight. Garden experts who favor lilacs insist that they really need full sun – six or more hours of direct sunlight – to bloom.

As gardens grow and change over the years, the nature of the sunlight the garden receives may also change – trees grow taller and wider and filter more of the sunlight that gets to your garden. Could that be a factor in your landscape?

Lilacs also need adequate water in summer – not just a sprinkling around the roots, but the entire ground, says gardener Anne Owen, who has several years’ experience with growing lilacs in Middle Tennessee.

One other thing to consider is whether the plant needs pruning, which could encourage the setting of new buds and flowers next year (lilacs bloom on the previous year’s growth).

And as always, consider testing the soil. If a soil sample from your garden bed test low in phosphorous, the lilac may respond to an application of fertilizer.

In general, here is what lilacs need to grow well and bloom each spring: Full sun, well-drained soil that is lightly alkaline or neutral pH, regular water. Be aware that they are prone to developing powdery mildew. Also note that lilacs bloom best where winters are consistently cold, and they suffer in long, hot summer nights. If you live in the Southern U.S., garden expert Felder Rushing suggests planting lilacs in well-drained soil on the north side of a building, where it might be colder in winter, and hope for cool August nights.

Callas’ beauty can be fleeting

QUESTION: My calla lilies, which are supposed to be white, are blooming, but the blooms are green! Otherwise, the plants look healthy. In fact, I’ve noticed in the past that they form seed pods. Is something wrong with them?

Calla lilies are lovely flowers, and easy to grow in containers or in the ground. The most common varieties produce white, yellow or pink flowers. That flower is technically the spathe, which wraps around the spadix, where the actual flowers grow. When the spathe turns green, it’s going through its natural life cycle on the way to making seeds.

Susan Bryant at Lakeside Callas in Dandridge, Tenn., explained that the spathe turns darker as it matures, and the outside of the spathe begins to turn green and to close up, with seeds forming inside.

“It starts turning green and closing up after a few days,” she said. Heat and lack of moisture might cause it to close up sooner. If you don’t watch them every day, it’s possible to miss the blooms.

You can cut the flower stalk off after it blooms, which will help the bulb grow larger. The foliage stays green and adds texture and interest to perennial beds. If you allow the seed pods to remain, let the seeds ripen and plant them in a pot indoors to grow over the winter, then put the new bulbs in the garden next summer.  It will take two years for the new plants to bloom, Bryant said. The offpspring may be a different color from the parent.

Callas prefer moist, well-drained soil and grow well in full sun, but they tolerate a bit of shade. In colder climates, the bulbs may need to be dug up and stored over the winter and replanted in spring. Gardeners in Middle Tennessee generally find that bulbs survive the winter in the ground.