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    Save the Date: Perennial Plant Society’s 30th Plant Sale is April 4, 2020, 9 a.m. – 1 p.m. at the new Expo 3 Building at The Fairgrounds Nashville. Here’s where you can find the newest varieties of perennials, shrubs, vines and annuals from local growers, along with long-time, never-fail favorites, ready for spring planting. Learn more at the PPS website.

     

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Dreaming of warmer weather: a to-do list

Here’s a ray of sunshine to warm up a winter day…

Sunflower Teddy Bear for Garden Bench

It’s hard to think about a garden when the ground is frozen solid. But for gardeners, January is not a total loss. I looked around the world of garden calendars to find to-do lists to back up that claim, and came across these nice little bits from The Garden Girls — Dr. Sue Hamilton and Beth Babbitt – at the University of Tennessee Plant Sciences Department. Here’s some of what they suggest for January, when it’s too cold to get out and dig:

  • Use the time to design and plan. Now that the garden in bare, take a look at  the “bones” and determine where you may need to move plants, add new plants, add hardscape, or make new beds.  If it looks a little dull out there right now, consider adding plants that can provide winter color and interest. Take notes so you can remember these ideas when the time comes for action.
  • Gather your seed-starting supplies if you want to get a head start on spring by starting seeds indoors. The early-season plants should be started indoors by the end of the month. Go ahead and place your orders from mail-order services to get the best selection of plants and seeds.
  • Give your houseplants a little love. Trim, groom, clean, divide and re-pot as      African violetneeded. Still hanging on to that Christmas poinsettia? Take the pot out of the foil wrap and place them in another container to catch overflow water. Keep it in bright sunlight and the soil evenly moist. When the color starts to fade, cut it back to about half and continue to treat it like a houseplant. After the danger of frost, move it outdoors where its lovely green foliage will grow all summer.

The Garden Girls also have advice on how to protect landscape plants during a deep freeze:

  • When the temperatures are below freezing, avoid contact with trees and shrubs because frozen plants can break easily. Ice-laden plants are especially prone to breakage. Lightly cover plants that are subject to winter damage, but avoid using plastic, which can heat up too much when the sun is out. Don’t walk on frozen grass.
  • If you do find winter damage, don’t be in a rush to prune. Remove broken limbs, but if it’s simply burned foliage you see, wait to see if the damage is superficial; it may bounce back.

Think of January as a time of anticipation. Spring will be here before you know it.

Tropical hibiscus adjusts to winter indoors

Question: I had two hibiscus trees in pots outdoors last summer and brought them in for the winter. I placed them in front of a sunny window, but now most of the leaves have turned yellow and fallen off. It does appear that new leaves are trying to grow. What should we do to keep these beautiful plants alive?

Hibiscus c Rojypala wikimedia commonsWhen you bring tropical hibiscus plants (Hibiscus rosa-sinensis) indoors, they respond to the lower level of light by dropping their leaves, so your plants are doing what is normal. You can see that the plant is healthy, because new leaves are already sprouting.

To keep it healthy while it’s indoors this winter, provide water when the soil dries out to within 1 inch of the surface and feed it lightly every few weeks with a high-nitrogen fertilizer. Watch for spider mites, and use insecticidal soap to keep them under control.

A hibiscus growing outdoors can grow to unmanageable size, so now might be a good time to prune it, and if the plant needs repotting, it’s a good time to take care of that chore, as well.

Return the hibiscus to its outdoor home when the weather warms up again in the spring.

 

Leave gladiolus in the ground?

We planted gladiolus in the ground and in containers this summer. I’ve heard they need to be dug up and stored over the winter. Really?

glads orange garden benchGladiolus are tender summer-flowering plants that grow from corms, and where you live will probably determine whether to dig them up or not. Here in Middle Tennessee (Zone 7a), the recommendation from the University of Tennessee Extension is to dig up and dry the corms after the foliage dies back and before a heavy frost, but the truth is, most gardeners I talk to here leave the corms in the ground and they usually survive.

In colder areas, they should be dug and stored. The Web site of the Purdue University Cooperative Extension Service (in Indiana) for example, says that gladiolus corms should be dug after frost. Dig the corms by loosening the soil so that you can pull the plant out of the ground. Shake off the loose soil and allow the corms to dry in the sun for a day or two. Cut the foliage off 1 – 2 inches above the corms and store them in a cool, dry place.

Plant the corms again after the soil has warmed up, in late April or May. By planting in two-week intervals between May and July, you can have a succession of blooms for several weeks beginning about mid-summer.

Protect banana trees from the cold

'Texas Star' banana. Photo by Dave G.

‘Texas Star’ banana. Photo by Dave G.

We planted a new ‘Texas Star’ banana tree this spring. It’s growing and looks great, but how do we protect it this winter? We live in Middle Tennessee, and it is planted in an open area near a pool.

The ‘Texas Star’ banana is said to be a cold-hardy variety, but it still needs coddling over the winter here in Zone 7a, where temperatures regularly fall below freezing. Once they’re exposed to a couple of frosty nights, the leaves will be reduced to a wilted mush. The important thing is to protect the underground rhizomes. The University of Tennessee Institute of Agriculture grows an impressive Hardy Banana in the UT Gardens in Knoxville, and provides this information for overwintering a banana plant:

Just before frost is expected, use a clean, sharp saw to cut the stems and leaves down to about 8 – 10 inches above the ground, then pile a thick layer of mulch over the crown. They say it’s best to use a heavy mulch (pine bark or hardwood), which won’t blow away easily. Others suggest you cover the stump with the leaves you cut from the plant, or wrap the stump with a blanket, and cover it with an overturned plastic garbage can.

In the spring, remove the mulch after the danger of frost is past, and the rhizome will send up new shoots and grow rapidly when the weather has warmed.

By the way, in this area banana trees are grown for their exotic foliage; it takes a long time to grow bananas, and summer here just isn’t long enough (though if you’ve grown bananas here in Zone 7a, I’d love to hear from you!).

Give mums a trim now … or later

Question: In your opinion should chrysanthemums be cut back in the late fall or spring?

Different sources say different things about what to do with mums after they are browned by frost. One source advises to cut them back in the spring; another says to cut them back to about 8 inches after they finish blooming in the fall.

In my experience, either way seems to work. I usually leave them until spring in my garden beds, which tend to be informal (some might call them “messy”), and often the new leaves start to come up from the roots very early — as early as February, if we have a mild winter. At that time, I cut back all the dead stems and divide and move clumps where necessary, and they grow happily and vigorously through the spring and summer. I cut them back a couple of times during the summer to delay flowering, and they start to bloom in the fall.

If you prefer a tidier look throughout the winter, cut off the blooms after they turn brown. They will rest during winter and be ready to pop up again early next spring.

 

Give porch ferns a place indoors

QUESTION: Is there a way to save Boston ferns over the winter without bringing them into the house? The ferns I had on my porch this year were large and beautiful. Indoors, they drop leaves and make a mess. Can I keep them in the garage?

Most experts suggest the best way to keep Boston ferns over the winter is to bring them in and treat them like house plants. Unless your garage has a window that allows bright light to enter, it’s probably not the best option.

Southern Living Garden Book provides a method that may minimize leaf drop: “In fall, use sharp scissors to cut back all side fronds to the rim of the pot, leaving the top growth about 10 inches high. Place the pot indoors next to your brightest window and keep the soil fairly moist. By spring, your plant should be bushy again and ready for its return to the porch.”

Houseplant expert Barbara Pleasant (The Complete Houseplant Survival Manual) adds that Boston ferns need high humidity in addition to bright, filtered light, so daily misting is helpful. A light dose of balanced houseplant fertilizer every couple of weeks keeps them healthy.

It’s normal for them to shed leaves, she says, so keep scissors handy for clipping broken or brown fronds.

*

 

Bring bay indoors

I bought a bay laurel seedling this past spring that was about six inches tall and set it out in a pot in the herb garden because I heard you may have to bring it indoors in the winter. It’s now about a foot tall. Could it survive outdoors? How do you harvest and use the leaves?

Bay laurel, or sweet bay (Laurus nobilis) is generally considered hardy to Zone 8 (well to the south of us here in Middle Tennessee), so it will need to come indoors before it gets too cold.

Place the plant where it gets as much sun as you can give it, in a south or west-facing window, if possible, and don’t let it get too dry (keep the soil evenly moist but not overly wet, the experts at the Herb Society of America suggest). It may also appreciate occasional misting if the air in your house is very dry. Take it back outdoors when the weather is consistently above freezing in the spring.

Bay leaves can be used dried or fresh; they’re usually added to long-cooking soups and stews. Snip them from the plant and use them as needed, or dry them to save for later. Use them whole (crumbled leaves have very sharp edges, which could be an unpleasant surprise to diners), and be sure to remove them before you serve. A bay leaf is a key ingredient in a bouquet garni (tied in a bundle along with thyme, parsley and other herbs), which would be added to a dish while it’s cooking and removed before serving.

By the way, there have been reports of bay laurel surviving the winter in colder climates, provided it is in a protected area. But to be on the safe side, find a sunny spot for it indoors.

 

Don’t worry about the daffodils

It’s only January, and the daffodils in my yard are already coming up! How do I keep them from freezing?

Early risers: daffodils can survive winter.

It may seem too early for this unmistakable sign of spring, but it’s not unusual for the shoots of early daffodils to begin pushing up through the ground. In some places, they started coming up before Christmas. The best thing to do is: Nothing. In fact, there is nothing you can do. Spread some pine straw over the daffodil bed if it makes you feel better, but really, even that is an unnecessary step, says Anne Owen of the Middle Tennessee Daffodil Society.

We’re at the mercy of the weather fluctuations, but generally, a blast of cold weather won’t hurt the daffodils, Owen says. The worst that could happen is that the weather turns warm and stays warm enough for long enough that the daffodils bloom; then the flowers might succumb to a snap of extreme cold. If we get a freeze while only the leaves are up, they should survive without a problem.

Good reading

It’s a good time to sit down with a stack of seed catalogs (or a list of seed company URLs) and plan this year’s kitchen garden. Here are some of my favorites (where I indulge in a little wishful thinking):

Seed Savers’ Exchange (Unusual varieties not found at the big box store seed kiosks)

Seeds of Change (Seeds, supplies, and live plants, too)

Territorial Seed Company (Try out the online garden planner)

Southern Exposure Seed Exchange (“Particularly suited to the Mid-Atlantic and similar regions”)

Renee’s Garden (Pretty as a cottage garden)

Baker Creek Heirloom Seeds (Recipes included!)

John Scheepers Kitchen Garden Seeds (Straightforward, with tidy line drawings; more tips and entertaining reading at the website)

Brent & Becky’s Bulbs (One of the best sources for bulbs, say those in the know)

Burpee (for sheer volume, and all those luscious pictures!)

No-fly zone

QUESTION: Some of the plants I brought in from outdoors seem to have tiny white flying bugs all around them, and are a nuisance. What are they? And what can I do about them?

 

Schefflera can play host to whiteflies.

These are likely whiteflies, and they often ride in on plants that spent summer outdoors. They’re more than a nuisance; they feed on the plant’s juices and can cause the leaves to turn yellow and die. The insects that are flying are the adults, and if you look at the undersides of the leaves you may be able to see the tiny yellow eggs and larvae.

Whiteflies feed on dozens of plant species and they reproduce quickly, so the problem could get out of hand quickly. To get rid of them, remove the badly infested leaves, then rinse the plant thoroughly and spray with an insecticidal soap. Be sure to treat the undersides of the leaves. Repeat the spraying every week or so.

Next fall, examine them closely to be sure there are no pests hitching a ride. Wash the leaves and treat the plants before you move them indoors. There are several other insect pests that you should watch for:

Aphids: they usually gather in clusters on tender young leaves. They also feed on a plant’s juices. Insecticidal soap, or washing with water or rubbing alcohol, is usually effective.

Mealybugs: You may see white, cottony clusters on stems or leaves, or where the leaf joins the stem. They also feed on the plants, so get rid of them by rubbing them off with water or alcohol.

Spider mites: They are barely visible, but you’ll certainly notice the damage – light-colored, speckled areas on top surfaces of leaves. You may see webbing stretching between leaves if there is a heavy infestation. Wash the plant with soapy water, and treat with insecticidal soap a day or two later. It may require diligence and several applications to control these insects.

UT Extension provides a booklet at its Web site that addresses these problems and more: Insects and Related Pests of House Plants (PB1157).

Poinsettias in the spotlight

QUESTION: I like to decorate with poinsettias for Christmas. What’s the best way to keep them looking good from now until New Year’s?

Poinsettias are a tropical plant, native to Mexico, so the first thing to remember is to keep them out of the extreme weather. If it’s a cold day when you bring them home (less than 50 degrees), don’t leave them in the car too long, and make sure they are protected on the trip from the car to the house.

Once inside, place them in a spot that gets indirect light. They’ll do well and last longer in a room that is not overly warm – 68 to 70 degrees is just about right. Keep the soil moist, but not soggy. Most likely the plastic pot will be wrapped in foil; it’s best to take the foil off when you water, to avoid trapping water that will cause the roots to rot. If the leaves become dry and curled, that’s a sign that it needs water. If a poinsettia wilts, that’s an indication that it may be getting too much.

Those are the basics for keeping a poinsettia looking cheerful through the holidays. If it starts to look a little sorry after that, don’t feel bad about tossing it into the compost. However, as often happens, a poinsettia can surprise you by pushing on healthy and strong into the New Year, and it’s a shame to discard something that’s growing so vigorously.

So, let it grow. Keep the soil moist and it should continue to thrive. As spring approaches, cut it back to about 8 inches tall and fertilize with an all-purpose plant food, and after there is no longer any danger of frost, re-pot it and set it outdoors, or plant it in the ground where it can survive as a nice, interesting green plant all summer (and succumb to its inevitable fate at the first sign of frost).

Here’s an interesting tidbit that comes from California poinsettia grower Paul Ecke Ranch: National Poinsettia Day is coming up! Dec. 12 marks the death of Joel Roberts Poinsett, the first United States ambassador to Mexico, who gets credit for introducing the plant to the U.S.