What's up North™ - Charlie Nardozzi
Articles:
(click on the bullets below to jump to one on the following articles.)
|
Leaves, Bark and Movement for Winter Interest
As we move into “stick” season as we call it in New England, when mostly we're looking at bare tree and shrub branches, it's good to remember we can have more than “sticks” in our yards. There are herbaceous perennial flowers, grasses and shrubs that can put on quite a show, especially in locations that have less consistent snow cover in winter.
Many gardeners are quick to cut back their perennial flower gardens in fall. Current thinking is to leave the spent flowers, branches and leaves. They provide overwintering sites for beneficial insects and pollinators. But there's another reason to leave the foliage: color. Some perennials have colorful leaves in fall and into winter. We're enjoying our Amsonia tabernaemontana 'Storm Cloud' perennials right now. They are known for their light blue flowers in spring and their foliage turns a brilliant golden color in November. It brightens up any landscape and the plant is easy to grow with few pests. I'm also impressed with the foliage color of our Heucheras or coral bells this time of year. These plants are semi-evergreen in the North and part shade lovers. Varieties, such as,' have silvery-colored foliage that turns a rosy color in the fall. 'Dolce® Toffee Tart' features amber colored leaves that hold color into winter.
For a longer lasting winter show, you can't beat ornamental grasses and shrubs. These plants feature interesting seed heads, foliage and bark. Euonymous fortunei, or winter creeper, features some beautiful, disease resistant selections with variegated, evergreen leaves. 'Gold Splash®' grows only a few feet tall, but can be trellised up a wall or fence. The leaves hold their gold and green color into winter. The shrub dogwoods also have great winter color and they're tough shrubs. It's the bark that shines. 'Arctic Fire' Cornus stolonifera grows only 3- to 5-feet tall with beautiful, bright red stems that contrast well with any snow you get. There's a yellow stemmed version as well. The key to getting great color is to cut back the shrubs hard every other year to induce more new growth. It's the new branches that are most colorful. This dogwood tolerates a variety of soils, grows well in part shade and the stems are great for cutting.
Ornamental grasses not only add color to the landscape in winter, they move! I recently was at the Montreal Botanical Garden and enjoyed their hardy, ornamental grass plantings swaying in the breeze. Some of the best ornamental grasses for the North include Maiden grass or Miscanthus sinensis. 'Morning Light' is a 3-foot tall selection that features striped leaves that look beautiful with ice or snow encrusted on them and dramatic seed heads. The native switch grass Prairie Winds® 'Niagara Falls' (Panicum virgatum) has arching, powder blue foliage and cream colored seed heads in winter. Fountain grasses are another good choice for our region. 'Prairie Winds® Desert Plains' Pennisetum alpecuroides grows more than 4 feet tall with cream colored, bottlebrush shaped, seed heads in winter. Ornamental grasses are easy to grow and deer resistant. Plant grasses where you can see them from indoors so you can enjoy their movement. Cut some of the seed heads to use in flower arrangements for the holidays.
Fall is for Color in the North
Northern forests, especially where I am in Vermont, really shine come October. Nature's fall foliage color shows the bronze and gold leaves of oaks, the yellow leaves of aspen and birch and the orange and red leaves of maple trees. We cannot top Mother Nature's show, but we certainly can supplement it with some colorful shrubs of our own. We can select plants with not only colorful fall foliage, but with colorful berries as well.
The leaf color change in fall is due to shorter days and colder temperatures. The intensity of the colors each fall is often up for debate. We do know that summer rains produce healthier leaves that will turn a more vivid color. In autumn, cool, sunny days and chilly nights promote good color change. Of course, rain and wind can prematurely drop leaves from the trees and shrubs.
But genetics plays a role, too. Look for shrubs that will consistently provide fall foliage color. One of my favorites for the North is aronia (Aronia melanocarpa). This native shrub is trouble free, has dark green leaves in summer and beautiful red foliage with black berries in autumn. I like the 'Snowfire®' selection because it grows 4- to 6-feet tall making a stunning fall foliage shrub. There are shorter aronia versions as well.
Fothergilla (Fothergilla x intermedia) does not get the attention is deserves. 'Legend of Fall® says it all. It features a shade tolerant, native shrub that grows 4- to 5-feet tall with white flowers in spring and brilliant red foliage color in fall.
Some hydrangeas have beautiful fall flowers and foliage color. Many large, panicle hydrangeas have white turning to burgundy flowers that form in summer and last into fall. 'Little Lime®' (Hydrangea paniculata) is a shorter, 3 to 5 foot tall version. The 'Gatsby Pink®' oakleaf hydrangea (Hydrangea quercifolia) not only has beautiful white turning to pink blossoms, but the foliage turns a deep mahogany color in autumn as well.
For a shorter shrub with great fall color try the native, Itea (Itea virginica). 'Little Henry®' only grows 2- to 3-feet tall but is loaded with white flower spires in summer and orange to red colored leaves in fall.
Do not forget about berry producing shrubs. Not only do they provide color, but the birds will also appreciate the food, too. 'Pearl Glam'® Beauty berry (Callicarpa) has unusual purple berries formed in clusters along the stem that hold on into winter on an upright, 4-foot-tall shrub. 'Proud Berry'® Coral berry (Symphoricarpos) has bright, pink berries that form in fall and get pinker with the cold. This native shrub is tough, hardy and the stems of berries make great additions to flower arrangements. Viburnums are known for their colorful berries, and none is better that 'Cardinal Candy®' (Viburnum dilatatum). It has pure white flowers in spring followed by bright, red berries in fall. The plant is very hardy, and deer do not seem to like it.
North Region Garden Tips and Blog
Before you run out to purchase the most alluring variety of hydrangea you see, take a moment to plan where it will be planted, what conditions it will experience and what type of plant you want. Most hydrangeas like a little afternoon shade, but need at least 4- to 6-hours of sun to flower best. This is particularly true of the big leaf (H. macrophylla) and mountain (H. serrata) hydrangeas. Others, such as the panicle hydrangea (H. paniculata), can take sun all day. Our, 'Fire Light®' panicle hydrangea is growing on the Southwest side of our house and looks fabulous. Hydrangeas love well-drained soil, but also moisture. That's why they have “hydra” in their name. The bigleaf hydrangea tends to flop in hot sun with lack of moisture, while the smooth hydrangeas (H. arborescens) and panicle hydrangeas are more tolerant of dry soils.
Size is also important. Some panicle hydrangeas, for example, can grow over 12 feet tall. Make sure you have enough space for your favorite variety. If you need dwarf varieties to fit into smaller spaces, there are some great choices. Hydrangea arborescens Invincibelle 'Mini Mauvette®' has dark pink blooms and only grows 3 feet tall and wide. It's a low maintenance darling in the landscape. 'Wee White' is another Invincibelle variety with white flowers and grows only 1- to 2-feet tall and wide. For panicle hydrangeas, try 'Little Quick Fire'. Its white flowers turn to pink and red in fall and it only grows only 3- to 5-feet tall. For a bigleaf hydrangeas try 'Wee Bit Grumpy®'. It has purple flowers and only grows 2 feet tall.
For hydrangeas that are native and good pollinator plants, grow any of the smooth (H. arborescens) and oakleaf (H. quercifolia) varieties. I like 'Gatsy Pink®' oakleaf hydrangea for its showy white turning to pink flowers and beautiful, burgundy, fall foliage color.
If your bigleaf hydrangeas (H. macrophylla) aren't producing lots of summer blooms, try reblooming varieties or the mountain hydrangea (H. serrata) such as 'Tuff Stuff™'. Unlike the bigleaf types that are native to coastal Japan and Korea, the mountain hydrangeas are native to the cooler mountains. This means the flower buds are more cold tolerant and more likely to overwinter without damage.
To get the most flowers consistently from your hydrangeas keep them well watered and mulched with wood chips and pruned properly. Most hydrangeas don't need lots of pruning, but if you do prune, it's important to do it at the right time for each type. Prune hydrangeas that bloom on new growth, such as the panicle and smooth hydrangeas, in late winter, cutting back these plants by up to 1/3rd. Prune bigleaf, mountain and oakleaf hydrangeas in summer after the first flush of blooms have finished. Just remove dead blossoms and errant branches. These bloom from flower buds formed in late summer, so don't prune a lot or now. The flower buds on these hydrangea types also benefit from late winter protection. Lay floating row covers or bed sheets over them plants when a late spring frost is expected.
Grow Shrub-Like Perennials for a Big Impact
Sometimes, you want a flowering plant that can fill a large space in summer and then disappear in winter. The space may be under an eave where snow and ice damage a woody shrub. Maybe the space is close to a deck, patio, or walkway where you want the coziness of a plant nearby in summer but want to be able to shovel snow there in winter. Maybe it's a space that's loaded with spring flowering bulbs that disappear come early summer and you want something large to take their place.
The answer is shrub-like perennials. There are some perennials that can grow 3+ feet tall and wide in one season. They provide color, flowers, interest in sun or shade, and dieback to the ground each fall. We grow Amsonia and Baptisia under our eaves for this reason. No matter how much snow buries them in winter, they pop out of the ground in spring and fill in the area near our deck each summer. Here are some other good choices for shrub-like perennials.
For a sunny spot, nothing beats the hardy hibiscus. This is a relative of the subtropical, woody hibiscus, but it's an herbaceous perennial. It emerges late and slowly from the ground in spring, but once it gets warm, the plant explodes with growth. By mid to late summer, it's flowering and continues into fall with 7-inch diameter colorful, show-stopping blooms. The plants grow up 4 feet tall and wide to quickly fill an area. The Summerific® series of hardy hibiscus are particularly striking. They're hardy to zone 4, flower well in full sun, and produce abundant flowers. I like the bi-color flowering types, such as .' It has white flowers from top to bottom on the plant with a dark red eye. 'Edge of Night' is unique for its jet-black foliage that contrasts nicely with the pink flowers with darker-colored edging. 'Lilac Crush' has lavender blue flowers with a red eye. It's a more upright perennial and nicely planted together to make a low, temporary hedge.
Another large, sun-loving perennial is goat's beard or Aruncus hybrid. Chantilly Lace grows in full sun or part shade to 4 feet tall and wide. It's a zone 4 hardy tall perennial for the back of a border, along a tall wall, house, or structure, or in a sunny nook to fill the space. Chantilly Lace has lacy, cream-colored flowers and is more drought tolerant than astilbe.
For shade, I like large perennials with showy leaves. There are hundreds of hosta varieties available to grow, and some of the best grow huge. 'Wu-La-La' has blue-green leaves edged with apple-green. 'Coast to Coast' features striking golden, puckered leaves on 3-foot-tall, wide plants. The color is even more intense in the morning.
For a truly striking, part-shade-loving, shrub-like perennial, consider 'Sun King' Spinard, Aralia cordata. This plant is a showstopper with its large, bright yellow leaves in part sun and deeper chartreuse-colored foliage in the shade. The small white flowers it produces in fall give way to black, inedible berries, adding another layer of interest to the plant. It thrives in well-drained, moist soil, making it a unique and eye-catching addition to your garden.
Using Containers For a Splash of Color
Long Season Pollinator Plants
Many gardeners love helping pollinators. But growing a pollinator garden isn't practical in every location. For small space gardeners, the solution is to work pollinator plants into existing gardens and select varieties that stay compact and are easy to manage. Before I talk about compact pollinator plants, though, let's consider other factors that help you create a bee, butterfly, and insect-friendly habitat in your yard.
Pollinators need shelter, nesting spots and water along with pollen and nectar from flowers. Have a water source, such as a bird bath, in your yard. Create a small, seldom mowed, mini meadow area on the edge of your property where wild plants and grasses can grow and pollinators can hide. Leave a snag tree and fallen logs as nesting sites for some pollinators. Many native pollinators are solitary and live in the ground, including your lawn. Mow high and avoid using pesticides to protect these important native bees.
For plants, have pollinator friendly plants blooming from spring through fall. You don't have to remove existing plants, just supplement with compact, pollinator friendly ones.
In spring, start with early flowering bulbs, such as scilla and winter aconites, followed by spring perennials. 'Pink Diamonds' (1) is a pink flowered bleeding heart (Dicentra) with attractive, cut leaves on a compact, 16 inch tall. Our hellebores are always popular with bees. 'Honeymoon® Irish Luck' (2) is a striking, single-petaled variety with green and yellow coloring. Plant hellebores where they're shaded in the afternoon. 'Mini Gallery™ Blue Bicolor' (3) is a blue-colored lupine (Lupinus polyphyllus) that grows best in light, slightly acidic soils. It has early flowering, bi-colored blue and white blooms and only grows 16 inches tall. And don't forget shrubs. 'Low Scape Mound®' (4) Aronia melanocarpa is a native, two-foot-tall, heat- and drought-tolerant variety with attractive black berries and great fall foliage color.
Come summer the plant palette expands. 'Midnight Masquerade' penstemon (5) features deep purple leaves with purple flowers on drought and salt-tolerant plants. This tall, clumping perennial doesn't spread quickly. In summer, sunflowers are loaded with bees, so why not grow a compact, perennial selection? 'Tuscan Sun' heliopsis (6) is a hardy to zone 3 nativar. It grows only 2- to 3 feet tall, blooms long, and is disease- and drought-tolerant. Of course, everyone is familiar with growing milkweed for Monarch butterflies. But other pollinators like it, too. Swamp milkweed is a good selection that spreads less aggressively than common milkweed. 'Ice Ballet' Swamp milkweed (7) (Asclepias incarnata) grows 3- to 4-feet tall with attractive white flowers and thrives in full sun or part shade. For a small shrub, try potentilla. 'Happy Face® Pink Paradise' (8) has unusual pink-colored, semi-double blooms that last most of the summer. This compact potentilla grows in part sun and is drought and salt-tolerant.
Finish the season with some pollinator favorites that will help these insects overwinter. Solidago 'Dansolitlem' Little Lemon' (9) is a dwarf goldenrod growing only 18 inches tall with lemon colored blooms. Cut back the first blooms after flowering to stimulate a second bloom. Nothing brightens up a landscape like black eyed Susan. 'Mega Millions®' Rudbeckia fulgida (10) is disease resistant, heat tolerant and keeps cranking out flowers from late summer through fall. 'Rockin Round®Superstar' (11) sedum is an upright selection with dark purple foliage and rosy pink flowers on a tough, compact plant that withstands drought, heat and salt.
After the bloom season ends, leave the dead stems and foliage in fall for overwintering sites for pollinators and clean up the gardens in spring.
Plant Selections
When buying plants for your landscape, you certainly should look for ones that match your hardiness zone, sun, soil and space in your yard. There are also other filters you can use when selecting plants. Selecting perennials, trees and shrubs that flower during the “quiet” times in your gardens, plants that attract pollinators, butterflies and birds and ones that have an intense fragrance can add beauty and pleasure to your landscape.
During my garden coaching sessions, gardeners often say they have plenty of color in their garden from spring to summer but need color in late summer. A good choice is 'Bit of Honey' False Sunflower, Heliopsis helianthoides. This perennial has bright, yellow sunflower-like blooms on plants that stand 2- to 3 feet tall. 'Bit of Honey' is unique for its variegated foliage. Rose of Sharon (Hibiscus) is another late bloomer. Pollypetite® Rose of Sharon
Hibiscus sp. is a dwarf form of this large shrub that only grows 3- to 4- feet tall. It has lavender-pink flowers and is nearly seedless so no baby plants will pop up all over your landscape.
Fragrance is one of those added bonuses in a garden. When planting fragrant plants, place them near a deck, patio, porch or a window where you can enjoy the scent. Our neighbors have a row of summer sweet shrubs next to their porch with a rich scent. Vanilla Spice® Summersweet, Clethra alnifolia perfumes the air when sitting outdoors with its large, white blooms. Even butterflies can't resist the scent and it blooms in mid-summer. Of course, lilacs are well known for their beauty and fragrance. Scentara® Double Blue Lilac is a Syringa x hyacinthiflora lilac. With “hyacinth” in its name you know it has a heady fragrance. This variety features double blue flowers, with a rich scent on a tough plant. The flowers are perfect for cutting and bringing indoors.
If you're looking to add native flowers to your landscape to attract and support pollinators, butterflies and birds, there are lots of choices for a Northern gardener. Many gardeners know the native bee balm, Monarda is a bee magnet. But many fear it will spread and take over the garden. Enter 'Pardon My Cerise,' Monarda didyma. This red flowering bee balm only stands 10-14 inch tall and fits perfectly in a small space. It stays compact and has mildew-resistant foliage. For bird-attracting shrubs, nothing beats the native viburnums. The berries are essential for migrating and overwintering birds. All That Glitters® Arrowwood Viburnum,
Viburnum dentatum var. deamii feature bright, blue berries with glossy green foliage that deer avoid. Glitters & Glows® Arrowwood Viburnum, Viburnum dentatum var. deamii are two plants in one pot so you're sure to get good pollination for berry production.
Site Issues in the Northern Garden
Knowing the amount of sun and shade you have in your garden is critical to selecting the right plants for the right place. But there are other factors in the northern garden that will influence your plant's health.
One of the fastest ways to kill a plant is to plant the wrong plant in a site with heavy clay soil and poor soil water drainage. I know this from my experience, having tried three different varieties of trees in a spot on our property until I found the right one that could cope with the clay. Before planting a tree or shrub, check the water drainage of your soil. Dig a hole 1 foot wide and deep and fill it with water. Let it drain. Then, fill it up again. Measure the depth of the water, wait 15 minutes, and measure it again to see how much water has drained. Multiply the difference by 4 to calculate how fast the water drains in an hour. Good soil water drainage should be around 2 to 3 inches an hour. If the water drains 1 inch or less per hour, this site is poor for most trees and shrubs except wet soil-adapted plants such as willows. If it drains 4 inches or more an hour, then it's best to grow drought-tolerant plants or amend the soil heavily with organic matter to help hold the water. A solution for poorly drained sites is to build a raised bed on the site and amend the soil with compost.
Another factor is wind. As the climate changes, I've noticed more severe storms in all seasons usually accompanied by heavy winds. Some plants are tough enough to withstand high winds, but young shrubs, trees and soft wooded plants, such as willows, pines and poplars, can be damaged severely by wind. Observe where the prevailing winds come from in your yard. Consider planting a windscreen of native evergreens, such as juniper, spruce, and fir trees, or deciduous trees, such as hawthorn, oak and maple, in those areas to withstand the wind. This will also create a microclimate on the leeward side of those plantings to grow perennials that often flop in the wind such as peonies and hollyhocks. You can also plant wind-tolerant perennials, such as 'Perfect Profusion' perennial salvia - Salvia nemorosa, Prairie Winds® Brush Strokes little bluestem - Schizachyrium scoparium ornamental grass, and 'New Hampshire Purple' hardy geranium, bloody cranesbill Geranium sanguineum in the windy spots.
 |  |  |
Finally, consider sight lines. In the North, we spend lots of time looking at our garden from indoors during cold, rainy springs and falls. When planting, especially blooming spring and fall flowers, choose locations to enjoy them from the comfort of your home. Also, when growing fragrant shrubs, such as Vanilla Spice® summersweet - Clethra alnifolia, and flowers, such as Oriental lilies, place them close to a window where the scent can perfume the home.
North Region Garden Tips
- With freezing and thawing temperatures, watch for any heaving of recently planted herbaceous perennial flowers. Gently sink them back into their hole and mulch with wood chips to prevent it from happening again.
- Take inventory of seed starting and gardening supplies, such as pots, stakes, garden ties and markers, and stock up now before the spring rush.
- Check overwintering dahlia and canna lily bulbs indoors. If the bulbs are shriveled, mist with water. If the bulbs are rotting, let them dry out. Then repack them for storage.
- During a warm spell over 40F on a calm day, reapply sprays of anti-desiccants to tender, broadleaf evergreens, such as Pieris and Kalmia, to prevent the leaves from drying out.
Light in the Northern Garden
During these days of shortened sunlight, it's a good time to think about light in your garden. One of the challenges we face, especially in small yards, is lack of sufficient light to grow our favorite flowers, shrubs and trees. The shade maybe from a neighbor's house or building, from our own buildings or from trees and shrubs that have grown large over the years.
Shade is caused by obstacles, but also due to the position of the sun in the sky. A full sun garden in May or June may be part shade come August and September because the sun is lower in the sky and gets blocked by even low buildings and trees.
It's also good to understand there are different types of shade and different plants adapted to these conditions.
Full sun is usually considered 6 to 8 hours of direct light a day. Part sun is when your plants get only 3 to 4 hours of direct sun. The timing is important because morning sun is generally gentler on plants than the harsh, afternoon sun. Many flowers and shrubs thrive in part sun.
Dappled shade is what's found under lacy leafed, deciduous trees such as honey locust and tall, cut leaf Japanese maples. The dappled light filters through the foliage allowing flowers, such as azalea, lamium, hellebores, brunnera, and pieris, to grow.
Medium shade is when the light may shine directly on plants for only an hour or two, early or late in the day when it's at an angle. This can occur on the North side of a building or under large deciduous trees with no limbs lower than 20 feet off the ground. Hostas and ferns are two good examples of plants that grow in medium shade.
Finally, deep shade is what's under low lying evergreen trees, such as hemlock and spruce. Moss and mulch are best under this type of shade.
Depending on the variety of plants you're growing and how they're cared for, some shade lovers may be able to grow in sunnier locations in the North. That's because the sun isn't as harsh as in Southern climes. For example, yellow and gold leafed hostas, such as 'Etched Glass' and 'Autumn Frost', can tolerate part sun without leaf burn better than blue, white or green leafed versions. It's best if they're exposed to only morning light and important the soil is kept evenly moist.
