LN Gardening

Winter damage is apparent in bamboo culms at the Missouri Botanical Garden.

Part of the joy of gardening is the daily surprise. Sometimes, conditions conspire to make a garden look tired and worn, such as extreme summer heat compounded by drought. Those days, while disappointing, must be endured. However, on other occasions, gardeners may draw a lucky had when strange combinations of conditions bring about splendid moments. This year, for example, the long, cold soil temperatures slowed down the early varieties of spring bulbs; then good moisture and warm sun brought out the late-season kinds right on schedule. After the winter of death, we needed a break.

Worst Winter for the Evergreen Woodies

For all of our woody evergreen trees and shrubs, we are taking our lumps now. The wait is almost over in the final call for the living and the dead. The hollies took it squarely on; with big leaves dried by winter winds, most have suffered substantially. The good news is this: New leaves are beginning to push off the dead ones and stem death seems to be spotty. Expect your hollies to recover quickly. The word is not so good for camellias. If you have any that survived outside, please let me know. We are awaiting word on the cherry laurels, too.

The evergreen magnolias may look horrible, but they will pull through. This species (M. grandiflora) is a great indicator of varietal and placement differences for winter damage. I’ve seen almost-dead established trees, such as the one at the corner of Tower Grove and Magnolia Ave in Tower Grove Park, that may have been killed part way down the trunk, and others that show almost no damage at all. Learn from this that some varieties are more winter-hardy than others, that well watered plants withstand drying winds better than dry ones, and a sheltered location can make a huge difference in outcome.

The yew and boxwood hedges have had a very rough time. But the yew will be fine, and I thank the deer for a free pruning. Just stay away from my hostas! The boxwood have lost a lot of leaves and many suffered from sectoral kill. If you are brave and willing to cut off years of growth, they may recover from the base with even growth. If you only remove the dead, you will be looking at a misshapen plant for years. Judge them carefully. My neighbors lost three out of four boxwood entirely. When replanting, search out more winter-hardy varieties.

Don’t rush the Nandinas. Heavenly bamboo is a staple in Chinese gardens so we planted lots of them last year. With three different cultivars, I have some observations to share: About half of each variety seems to have perished. They still will get some time on the clock as, only yesterday, I noted small, dark reddish-brown leaves emerging. I’ll give them another month before digging them up.

There is absolutely no hope for the Confederate jasmine. The net of dead vines is brittle and the roots have no elasticity. Same holds for the Carolina jasmines, normally hardy only to Zone 7. There is one notable hardiness exception: Gelsemium sempervirens ‘Margarita’. Julie and I planted one about six years ago and it has grown lushly and bloomed happily on a trellis there ever since.

When is It Really Dead?

My long-time friend and consummate plantsman Tony Avent says, “I won’t believe I can’t grow it until I have personally killed it three times!” By that, he means that it may take more than one try to find the right microclimate, soil type or level of shade or wind protection for a particular plant to survive. Most of us try once and are done. If a plant doesn’t make it, we move on to try something else since plants are expensive and so many varieties are available for us to try instead. But some plants are worth the trouble. As a Southern girl, my garden must have magnolias, gardenias and the aforementioned jasmine. Julie loves the large-leaved tropicals like ‘hardy’ banana. We are both out shopping for replacement plants to fill these newly vacant niches.

Surprise Survivors

The snow line defined some survivors. The tiny acuba brought from my mother’s garden in North Carolina made it! It was small enough to be entirely covered with snow during the worst cold, and in the shade of the house where the snow lingered. I’d be willing to bet that in another place, it would have croaked. Other snow winners included the flowers on the forsythias. We have an older variety without total bud hardiness and the only flowers that bloomed this spring were like a skirt around the ankles of the bush. The leaf buds are more hardy and burst out perfectly.

The two plants that pulled through to my total amazement were the gerbera daisy in my cutting garden—heavily mulched and under snow—and the vitex along the drive. Julie reports no signs of life on hers yet, but mine has just popped out some little silver pearls of growth below the snow line. It was only an act of faith in nature that kept me from hacking out the stump of the vitex prematurely as I pruned out the know-to-be-dead upper branches. Waiting, in this case, paid off. The verdict on crape myrtles is still hanging in the balance. All of the top growth is surely dead. My neighbor called me in to check on her 20-year-old tree. Normally, I would have advised more waiting, but the bark split was so severe that letter-sized sheets were peeling off. Still, try taking a chainsaw to the top, leaving 4 to 6 inches and wait for another few weeks before capitulating.

The Hardy Herb Garden

Killing Thyme takes on new meaning after a winter like this one. I’ve used many varieties of thyme as fillers and spillers on the path through my country rock garden. Almost all of the ‘fancy thymes’ died: The lemon thyme is gone. And the orange-scented cultivar. So, too, the silver-edged varieties. It seemed that the wooly thyme had perished, as well; but careful waiting has provided me with strong root sprouts on almost every clump! Since most thymes are listed as hardy to Zone 4 or 5, their mortalities suggest this winter reached into those cold zone numbers.

My kitchen has a new window that we added last fall. While it faces due west, it is sheltered from the brightest light of the afternoon. The large, potted rosemary loves it. It is the only surviving rosemary in my garden; the ones in the ground perished in frigid anguish. 

On first look, it seems the oregano had away entirely, but patience proved out and sprouts are now rising from deep below the mulch. The summer savories are gone, but the winter savory is pulling itself together and making a comeback. The lavenders looked horrid but are starting to bud out again, so just trim off the dead wood. Potted mints have failed to show any signs of life yet, but the in-ground ones are beginning to rise again. And my parsleys have emerged victorious with full hardiness and a willingness to bloom early. 

Buffaloed by Blonde Bamboo?

Bamboos have raised the most frequent questions from friends and neighbors. “What do I do? Is it dead-dead or does it just look dead?”( Only a gardener has the ability to kill something more than once; we often resurrect things that are only half dead.) Bamboos—as very large grasses—have a different set of body parts than most evergreen plants. The tall, vertical shafts are called ‘culms,’ not stems. Winter damage varies by species and exposure. Most of the large, running bamboos in this area are Phyllostachys. Like my clumping Fargisias, they are all showing degrees of leaf and culm damage. Most, if well established, will be perfectly root-hardy. What remains to be seen is whether they are leaf-dead or culm-dead. Patience. Most bamboos are happier in the tropics. Wait for really warm weather. If the culms send out new leaflets at the nodes, keep them. If they don’t, cut them as cane poles and go fishing. And for those of you who were hoping that your weedy bamboo was toast…hate to disappoint you, but it may be back.

How YOU Can Help

If you have had any outdoor survivors of rosemary, jasmine, camellia, fig or banana, please let us know. Any ‘tender’ plant that survived this winter should be studied and retested for propagation and sharing. Mother Nature has put some strong selection pressures on these marginal plants, and, if any survive, they may have improved genetic resistance that others would benefit from. Drop a note to us at LNLandscape@mobot.org.

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