It’s the time of year that we all secretly get excited for until we realize that winter’s chilly footsteps are quickly approaching: the cool down of fall. The blooms of hydrangeas are maturing to their beautiful deep fall color, the trees are starting to change and hypericum berries are blazing in an array of colors. But what do we see when we look at this year’s Farmer’s Almanac predictions for the impending winter months? The Polar Vortex is coming back with a vengeance. Especially for the for the Northern Plains and Great Lakes regions, it’s time to hunker down; we are told to expect temperatures that could drop to 40 below during the end of January and early February. So what does this mean for our gardens? How do we protect them from yet another extreme winter?
1. Hydrangeas: Hydrangeas took a massive hit last winter and many of us missed the big, beautiful blooms of hydrangeas all season long. To keep them safe this winter, start by tracking the weather, and when temperatures will be consistently below freezing, cover the crown of your hydrangea with mulch, leaves and/or straw before snow arrives. Snow insulates the crown and keeps it alive, so if you do not have snow cover, be sure the crown is fully protected from cold and wind. Covering the full plant with a garbage bag full of leaves, as well as the crown, is also effective on extremely cold nights. Another option that requires less work is to plant a re-blooming hydrangea from the Endless Summer Collection, as they bloom on previous year’s growth AND new growth. That means that even if the cold winter kills the buds on this last season’s growth, you will still see blooms on new growth in the late spring and summer. Endless Summer’s newest introduction, BloomStruck, has also proven extreme cold tolerance and has shown to be the earliest blooming and most floriferous hydrangea to bounce back after last year’s winter.
2. Roses: Roses can mean apprehension for many gardeners – especially when it comes to cold winter hardiness in the northern part of the United States – but with the right rose, they are an easy-care beauty just like any other shrub. We suggest the Easy Elegance Rose Collection, a stunning group of shrub roses that is bred for cold hardiness, heat tolerance and incredible disease resistance. Truly crown hardy through zones 4 and 5, depending on the specific variety, this is a tested collection of no-fuss roses that can survive even the coldest Minnesota winters and come back with blooming beauty each spring. These roses require little pruning, no rose cones and no special covering after their first year in the ground. In northern climates, we suggest covering new plantings with mulch, oak leaves or marsh hay in an 8” mound from the crown once the temperatures are below 32 degrees and the plant has gone completely dormant. An added tip to keep the plants disease-free throughout the winter and spring is to rake away fallen leaves and petals before mulching or snow setting in.
3. Evergreens: We all saw extreme winter burn from the cold wind on hedges of arborvitae last year. To prevent this, try different varieties of evergreen that are extremely cold tolerant and will survive even the worst of winters. We suggest Sky High Juniper from First Editions, a beautiful silvery-blue evergreen that is hardy to Zone 3. If you have a collector plant or two that tends to struggle in the winter, cover it with burlap or a protective material for the coldest and windiest days. Only do this if you have a really special evergreen that is marginally hardy. If you cover an entire hedge, then you lose the winter beauty of the evergreen, plus it simply isn’t practical to cover that many plants. A final note about evergreens: if you have heavy snow and are seeing the branches bending under the weight, they will bounce back once the snow starts to melt. Unless you are seeing breakage, allow the snow to grace the boughs and watch for them to perk back up in the spring.
4. Trees: Assuming they are zone-appropriate, there is usually little attention paid to preparing trees for winter. They are typically the reliable stand-by in the garden, and that remains true even with a fast-approaching winter. One thing to note is if your trees are starting to change color earlier than normal, especially in these first weeks of September. Trees that show fall color earlier than is normal for the species may be a sign of stress. This can be caused by poor soil conditions, too much or too little water, or if the tree is planted too deeply. Especially for younger trees, watch this for the first year or two after planting and, if necessary, transplant the tree. If you feel that moisture is an issue and have in-ground irrigation, switch from every other day to a weekly watering of your lawn to allow for a deeper soak and less frequency as to not over-water your tree’s root system. If the tree is planted too low, you can try grading the soil down so that the root flare – where the trunk flares out to the root system – is even with the soil level.
5. Container Plantings: Annuals aren’t the only plants filling containers anymore. Beautiful shrubs in decorative pots are a great way to create a focal point at an entrance, beautify a deck or patio, and accent a pool or outdoor dining area. Imagine a full container of Endless Summer hydrangeas welcoming your guests into your home! As we prepare for winter, there are a few options for what we can do with these containers: treat them like annuals, tossing the plants away and start fresh the next spring; plant in the ground to over-winter the shrubs; or keep the containers and protect them from the winter cold. Your first option, treating the shrubs as annuals, may be a bit off-putting at first, but if you look at the cost it’s the same to buy a beautiful shrub as it is to buy a hanging basket, and it allows you to bring a diverse range of plants to your landscape and home. Second, plant the shrub if you have the space, and keep it living year after year. The final option is to prepare it to over-winter in the container. If you live in Zone 6 or warmer, you can treat it like any other plant and lightly cover the crown and leave the container in place. For the colder parts of the country, cover the crown and move the container into your garage or basement once it has gone dormant. Lightly water the container throughout the winter, as it will not be receiving any moisture from the snow.
Looking ahead to another colder-than-average winter can seem daunting, but with the best plants in place and a few extra preparations, you set the stage for a beautiful and blooming spring. Wrap up, stay warm and enjoy fall before the cold sets in. Dig into the dirt and enjoy!