You know how we talk about winter hardiness and USDA Zones? The recent polar vortex provided an extreme test for many of our perennials, shrubs and trees.
The current USDA Plant Hardiness Zone Map places most of central Indiana in Zone 6a, where the extreme low temperature is minus 10. The old map had central Indiana in USDA Zone 5b, with the extreme low of minus 15 degrees. We were colder than either of those.
We can be grateful that we had snow on the ground when the big freeze hit. Snow is one of nature’s best insulators. It protects the roots of plants.
It will be spring before we know what plants were damaged by the extreme cold and wind. For trees and shrubs, we might see few or no leaves and some branch dieback on trees and shrubs. Perennials may not show up because the cold weather did them in.
Leftover spring bulbs
With the clean up from the holidays, you may have uncovered a bag of spring-blooming bulbs. I’ll admit that this has happened to me more times than I care to count.
Unfortunately, it’s too late to plant them in the ground.
I still had a bag of 25 tulips, so I potted them up in a large, all-weather container. I dug down about 6 inches, placed the tulips, covered them with soil and topped it off with a 2-inch layer of leaves for just a bit more insulation.
The pot is outdoors, subject to the polar vortex and whatever else nature throws at it. So far, the squirrels, which have been very active this winter, have not discovered the pot of tulips.
Try this with your own all-weather container if its soil is not frozen. Or, if you dumped your dirt, get a bag of potting mix at the garden center. If you don’t want to leave the container planted with bulbs outdoors, stow it in an unheated garage, or the coldest place in a heated one. Move outdoors when the leaves break ground and get about an inch high.
‘Cheyenne Spirit’ is a seed-grown coneflower that caught everyone’s eye in the Marion County Extension and Master Gardener Demonstration Garden at the Indiana State Fairgrounds. Photo courtesy All-America Selections
The National Garden Bureau has named 2014 the Year of Echinacea to celebrate our native coneflower.
A worthy and reliable proponent of the title is last year’s All-America Selections ‘Cheyenne Spirit’, an extremely well-performing coneflower that went from seed started indoors in February to flowers in the June garden.
Because it is seed grown, this perennial coneflower has a mix of purple, pink, red and orange to pale yellow, cream and white blooms. ‘Cheyenne Spirit’ gets about 24 inches tall and 20 inches wide.
It was a spectacular show-stopper in the Marion County Extension and Master Gardener Demonstration Garden at the Indiana State Fairgrounds. Lots of visitors asked about this plant.
Gardeners have been struggling with coneflower survival for the last several years. The faster breeders and marketers brought coneflowers to the market, the poorer the plants’ performance.
These pricey perennials had weak stems, poor flower power, were susceptible to disease or did not make it through winter. Breeders have gotten the message and seem to be doing a better job of trialing their plants throughout the country for several years before putting them on the garden center bench.
Still today, though, many coneflower breeders say gardeners should not let the plant bloom its first year. It’s better to snip off buds and blooms to let the plant bulk up its roots, they say.
In my mind, that’s a hard sell. Why would we pay $15, $20 or more for plant — one with native blood, no less — and not let it bloom? Why not let the professional growers hang on to the plants until they are in their second year? Although growers may have greenhouses, holding plants for more than a year becomes a space problem and winter-maintenance headache.
I know the Chicago Botanic Garden is in the midst of evaluating coneflowers (Echinacea spp.), including many of the new introductions, but it will be a while until it is released.
Meantime, check with gardeners, garden centers and others to see which coneflowers have done well for them. Perhaps we need to modify our expectations and accept that coneflowers are not a long-lived perennial. But we need to plant them anyway, because bees, butterflies and hummingbirds love them as much as we do.
'Northwind' switch grass is the 2014 Perennial Plant of the Year. Photo courtesy perennialresource.com
Every year the Perennial Plant Association names a plant of the year and in 2014, a native ornamental grass gets the nod.
‘Northwind’ switch grass (Panicum virgatum) was selected and introduced by Roy Diblik of Wisconsin’s Northwind Perennial Farm. The specialist in native plants was impressed with its excellent upright form, bluish green foliage and yellow plumes.
‘Northwind’ gets about 4 feet tall, reaching closer to 5 feet when frothy yellow flowers bloom in late summer. Switch grass, which is native perennial throughout most of the United States and Canada, does fine in average to wet soil, and is frequently a resident of rain or swale gardens. It does fine in full sun to part shade.
Cut back to the ground in late winter or early spring. Spring is also the best time to divide switch grass. This grass looks good in a mass planting, or in in a cluster of three as a specimen in a perennial bed.
If hostas are more your thing, the 2014 Hosta of the Year is ‘Abiqua Drinking Gourd’, so designated by the American Hosta Growers Association. This shade-loving perennial has dark blue, heavily puckered leaves that form a 3-inch deep cup. It gets about 18 inches tall and 3 feet wide. The more sun it gets, the more green the leaves will be and the more likely the foliage will sunburn. ‘Abiqua Drinking Gourd’ has white flowers in early summer. Cut back to the ground when leaves have been killed by frost.
'Abiqua Drinking Gourd' hosta gets the 2014 Hosta of the Year award from the American Hosta Growers Association. Photo courtesy of perennialresource.com
The International Herb Association has name Artemisia as the 2014 Herb of the Year. The familiar herb tarragon (A. dracunculus) falls in this family. So do perennial mugworts, the ornamental artemisias, such as ‘Silver King’ (A. ludoviciana) and ‘Silver Mound’ (A. schmidtiana). The potent drink absinthe comes from A. absinthium, sometimes called wormwood.
Tarragon is a member of the Artemisia family, which is the 2014 Herb of the Year. © Andris Tkachenko/iStockphoto.com
Many artemisias can be quite aggressive, spreading quickly with underground stems, so do your research. The aromatic leaves on most varieties are gray or silver. There are green and yellow variegated varieties available, too. Grow artemisia in full sun and well drained, average soil. The plant will rot if kept too wet. Cut back as necessary. Some retain their foliage all winter.
Gently brush snow from evergreen branches if they start to bend out of shape. © Jo Ellen Meyers Sharp
Most of us can weather winter by not going outdoors unless we have to. Our landscape plants, though, must withstand the relentless elements of the season along with some poisons delivered by humans.
Here are some tips for protecting landscape plants from winter hazards.
- If snipping evergreens for indoor use, do so gently. Heavy pruning at this time of year can damage conifers.
- Try not to walk repeatedly on frozen or frosted grass. Foot traffic breaks the grass blades and damages the lawn. Constantly walking on the grass any time of year compacts the soil.
- Do not remove ice from plants. Ice covered branches on trees and shrubs are brittle and can break easily and damage plants.
- For snow-laden, bowed branches on evergreens, use your hand or a broom to brush off the white stuff in gentle, sweeping motions. Arborvitae (Thuja), in particular, seems most susceptible to damage from snow loads. This evergreen can easily become misshapened by heavy loads. Consider gently binding the plant with rope or twine to keep the branches close to the plant.
- Protect plants near roadways from being sprayed with snowy sludge by passing cars. The road spray can harm plants or ice them over. If the roads have been treated with salts or other ice melts, the plants can be killed by the spray.
Care also needs to be taken when using ice-melting products on walkways around flower beds and gardens. The water that results from the melting ice will run into the beds and possibly contaminate the soil.
Ice melt products can damage concrete or flagstone by pitting the surfaces, cracking or causing other deterioration. Some ice melts also can damage the paws of pets. Look for products labeled safe for pets, plants and pathways. Always read and follow label directions on the product you use.
Chelsea Flower Show. Photo courtesy of Royal Horticultural Society
I’m thrilled that I have been invited to lead a tour of English gardens, including Chelsea Flower Show, May 14 through 23, 2014, and I invite you to come along! Europe By Design is organizing the trip.
As part of the Chelsea Flower Show and the Gardens of England tour, we will be staying in London, Oxford and the Cotswold. Many gardens on the tour, including Hidcote Manor, Sudeley Castle, University of Oxford Botanic Garden, Blenheim, Windsor Castle, London Tower, Chelsea Flower Show and more.
Chelsea Flower Show and the Gardens of England
A native bumble bee burrows into the flowers of a native bee balm. © Jo Ellen Meyers Sharp
Looking for something beneficial and incredibly easy to do in the landscape this summer? Make pollinating insects a priority.
There are many plants that will fill this desire, including annuals and perennials. Some are even easy to grow from seed.
Roughly $4 billion of our food relies on pollinators, such as bees, butterflies, wasps, flies, beetles and other insects. The insects pollinate the flowers of plants to produce the vegetables, grains and fruits that comprise our diet.
Here are some tips from the Xerces Society, a 40-year-old international, not-for-profit organization that fosters the conservation of invertebrates (insects) and their habitats.
- Flowers clustered in 4-foot-wide clumps attract more pollinators than plants scattered as onesies throughout the landscape.
- Select plants for a succession of blooms from spring through fall. Native plants tend to attract the most pollinators.
- Different shaped flowers attract different pollinators.
- Eliminate pesticides from your landscape. Pesticides are a major threat to pollinating insects.
In spring, pollinators depend on flowering trees and shrubs, but they also visit early blooming perennials, including crocus, anemone and primrose (Primula). They also spend time with poppies (Papaver), chives (Allium schoenoprasum), dianthus, peas (Pissum sativum) and viola.
In summer, herbs join the list, including basil (Ocimum basilicum), borage (Borago officinalis), cilantro (Coriandrum sativum) and thyme (Thymus). In the perennial category, good choices are coneflower (Echinacea purpurea), bee balm (Monarda) and tickseed (Coreopsis).
Asters, hyssops (Agastache), dahlias, salvias, zinnias and sunflowers (Helianthus annuum) are made for the fall buzzers.
Try your hand at growing the following annuals from seed by sowing them directly to the ground in spring: chives, peas, squash (Cucurbita moschata), cosmos, larkspur (Consolida ajacis), sunflowers, spider flower (Cleome hassleriana), zinnia, forget-me-nots (Myosotis), snapdragons (Antirrihum majus) and hyacinth bean (Lablab purpureus). Read and follow the seed packet instructions.
Even if you don’t have a large landscape, you can grow a garden for pollinators. Instead of mixed containers, plant pots with a single species of plants, such as all marigolds (Tagetes), zinnias or cosmos. Cluster the pots on your porch, deck, patio or balcony. Even a window box can be planted this way.
To solidify your commitment, take the Pollinator Protection Pledge and order a Pollinator Habitat sign for your garden.
Here’s HortusScope for January 2014, a checklist of garden and nature related events compiled as a public service by Wendy Ford of Landscape Fancies. Please click on the link below to download your copy.
HortusScope January 2014
Here’s a special note from Wendy:
Happy New Year, Gardening Friends! It’s the start of year nine for HortusScope—how the time flies! I launched this e-bulletin aiming to build community among gardeners in Central Indiana, and I’ve been richly rewarded by your sharing of information and your positive comments. Keep those news items coming! And may 2014 bring you bountiful gardens and deepening friendships. Gardeners are the best!