One of the biggest challenges in creating a successful landscape here in the Chicagoland area is achieving color and interest from the first signs of spring to the doldrums of the November transition and cold harsh winters. In the challenging plant hardiness Zone 4/5, we see shortened growing seasons and drying winter winds that in extreme years, can do major damage on well established landscape plants.
In the winter of ’13-’14, we saw subzero temperatures for a record length of time, which we came to be know as the Polar Vortex. These high pressure systems created dry, freezing temperatures for weeks at a time. When this occurs, just as it happens to our skin when exposed to extreme wind and cold, plants dry out and don’t get a chance to recover and absorb available moisture in the surrounding soil of the plant’s root zone. This results in severe winter burn and ultimately the death of not just marginal plants in our zone, but typically hardy and well established plants such as Yews and Boxwood.
In the spring of 2014, most landscape professionals began their season with an industry wide record number of plant replacements, which made most reassess their use of marginal plants such as Butterfly Weed, Gaillardia, Lavender, Weigela, Hibiscus and certain varieties of Rose. Foundation plants and hedge rows of yews and boxwood all over the North Shore, that had withstood 30+ years of Chicago winters, suddenly browned and died and needed to be removed. Although this removal creates a hole in the established landscape, it also presents an opportunity for a new landscape planting that is not just hardy and sustainable in our climate, but can add interest through extended bloom time and seasonal interest.
The key to creating an interesting, colorful landscape, with long lasting, overlapping color throughout the entire growing season is found in not just successful plant combinations, but careful selection of species and cultivars to fill gaps in an otherwise dull time of year.
Starting with the earliest color coming out of the winter is a hardy native shrub, Witchhazel, which reaches peak bloom time in Jan-March. It can be used as a foundation shrub, or specimen, but should be considered for its early color, even before the earliest bulbs emerge.
Moving on from our lone, late winter bloomer, we can incorporate the earliest signs of life and color by utilizing spring bulbs (List courtesy of Breck’s), planted in the fall for the first blooms of the growing season.
Very early spring:
Snowdrops: Snowdrops, or Galanthus, are often the first blooms to appear in spring – and they’re a great choice for areas that stay cool a bit later in the year. These are incredibly hardy, and most flower before the last day of winter!
Snow crocus: The early-blooming varieties within the Crocus genus produces small flowers, with a longer blooming season, than giant crocuses. They’ll start blooming in late winter, and can flower in colours of pink, purple, yellow, white, or even blue, depending on variety.
Winter aconite: Imagine a golden floral carpet replacing your winter snow cover!
Early snow glories: Glory-of-the-snow, or Chionodoxa, are another “northern” plant that can actually perform well in both northern and temperate climates.
Dwarf iris mixture: Some varieties of Dutch irises bloom extra early – usually low-growing dwarf irises!
Grecian Windflower: Grecian windflowers, a daisy-shaped species of anemone, bloom in shades of pink, blue, violet and white in early spring.
Giant crocus: Just like smaller species crocuses,giant crocus are great for naturalizing. Plant a drift of giant Dutch crocuses of a single colour, or mix colours for a more natural effect. Their larger flowers (usually 4” to 6” in height) provide a lovely, low-growing pop of brightness.
Trumpet daffodils: Trumpet daffodils are the classic daffodils, with cups longer than their petals. They feature a single flower per stem and are very hardy – and bloom soon after the snow melts!
Hyacinths: Jewel-toned hyacinth flowers bloom in dense spikes and are among the brightest colours you’ll see in early spring.
Early tulips: Dwarf tulips, such as the Wild Blue Heart tulip, are low-growing species that flower in early spring. Emperor tulips, or Fosteriana tulips, also bloom early in the season.
Extending the season of your garden has now been established with the diligent fall planting of several varieties of spring bulbs. We now look to capture early season color with early blooming shrubs such as Forsythia, Cornelian Cherry Dogwood, Serviceberry and certain hardy varieties of Rhododendron and Azalea. These woody shrubs establish a structure and form difference that is important in creating different layers in a successful landscape composition. Shrubs with long flowering periods such as Hydrangea and Viburnum and Weigela can also be selected to keep the later season blooms coming down the pipeline.
Continuing into the months of April various perennials and groundcover should be chosen for their overlapping bloom time. Certain varieties of herbaceous species may even give you 2 rounds of flowering if pruned back at the right time such as Catmint, Salvia and Geranium. Other perennials should be chosen for their continuous blooming or extended bloom time. This group includes such plants as; Allium, Hemerocallis, Coreopsis, Echinacea and Astilbe.
Additionally, in our climate, you may find extended bloom time through the utilization of hardy Mums and Asters for fall blooming. Potted Mums can be installed in a prepared planting bed, with the likelihood that they will return for another show the following fall. To increase your chance for the return of the hardy Mums, spread compost around the base of these plants in a small mounds.
Finally, ornamental grasses round out the blooms of the season, putting on an impressive display of their seed heads, which typically stand tall and beautiful until the first heavy snow of the season knocks them down into a messy pile needing to be tamed with pruners or hedge trimmers.
Landscape interest and color displays are not limited to blooms of course. Summer foliage color, fall foliage color, winter stem color and evergreens should all be considered when planning a garden that truly performs in every month of the season. Call us to get your season of color started with a landscape plan!