March is a transitional month in Massachusetts. Winter’s snow thaws into early spring slush, and temperatures are slowly starting to rise.
For shrubs, March is a great time to assess the effects of snow, salt, and freeze-thaw cycles and begin early spring shrub care to set your yard up for success in the growing season.
Step One: Check for Signs of Winter Shrub Damage
The first step to revive shrubs after winter is to closely inspect them for signs of winter injury, such as broken stems, browning, shriveling, and branch dieback. Salt damage and frost cracks are two common causes of damaged shrubs after snow.
Salt damage on shrubs affects the foliage. It can cause dehydration, root damage, and soil degradation. Crusty residue on the soil’s surface, and damaged foliage on areas of shrubs that face roads and sidewalks are signs of salt damage.
Frost cracks damage the structural wood and bark of a shrub. Vertical splits in the trunk or main branches on the southern or southwestern side of the plant are caused by rapid temperature fluctuations. Keep in mind that many of these signs may not be apparent until years after the initial damage.
In New England, boxwoods, rhododendrons, and azaleas are commonly affected by winter weather, especially if pruned heavily the year before.
Light Spring Pruning: What to Cut and What to Leave
Pruning plays a pivotal role in the health and vitality of your shrubs. It removes dead, diseased, or overgrown branches, encourages robust growth, and accentuates the natural beauty of each plant.
For deciduous species, pruning shrubs after winter but before new growth begins helps shape the shrub, remove dead or damaged branches, and encourage spring growth. For flowering shrubs, wait to prune until they finish flowering in late spring or early summer to avoid cutting off flower buds and sacrificing next year’s blooms. Anything that you can confirm is dead can be pruned at any time.
Deep Watering Tips for Thirsty Shrubs After Winter
Watering your shrubs as they emerge from dormancy is crucial for establishing root systems and supporting new growth. The key to proper watering is to find the balance between underwatering and overwatering.
A soil moisture test can help determine how much water your shrubs need. Check 2 to 6 inches below the surface for dampness. Ideal moisture levels allow soil to hold its shape without dripping water.
If a soil test indicates your shrubs need watering, use the deep-and-slow method. Water slowly at the base, 6 to 12 inches into the soil, to reach the roots without overwatering. In New England, March can bring cold nights and warmer days. Watering in the morning during this period prevents water from freezing around the roots as the day progresses and reduces afternoon evaporation.
Keep in mind that clay soils require less water, and sandy soils require more.
Fertilizing Shrubs in Early Spring for Strong Growth
Fertilizing shrubs in early spring provides a nutrient boost as they come out of dormancy and helps to fuel upcoming growth as the season ramps up.
Much like watering, a soil test to determine what nutrients your shrubs need is the first step in successful fertilization. For most Massachusetts landscapes, low-nitrogen fertilizers work best. Nitrogen content is the first of the three numbers shown for the fertilizer analysis. Slow-release fertilizers release nutrients over time, making them ideal for shrubs to maximize uptake.
Apply fertilizer before growth starts in early spring or after shoot growth in mid-summer. Maximum nutrient uptake happens during these periods.
Mulching to Protect Roots and Retain Moisture
Mulching shrubs helps retain moisture, suppresses weed growth, and regulates soil temperatures during late freeze-thaw cycles. Knowing when to mulch shrubs in spring, what type of mulch to use, and what mistakes to avoid will help keep your shrubs on track for healthy spring growth.
Apply 2 to 3 inches of mulch after the last frost, making sure to cover the root zone. Organic, wood-based mulch does double duty of improving soil health while retaining moisture and regulating soil temperatures.
Make sure to leave a gap between the mulch and the base of the shrub to avoid “volcano mulching,” which can suffocate roots and damage the plant.
When to Call a Certified Arborist for Shrub Health
Certified arborists know how to care for shrubs in spring. If your shrub isn’t budding or is showing delayed growth, or has experienced repeated winter injury or salt stress, a certified arborist can create a custom plant health care plan to help your property thrive.
At Hartney Greymont, we have both ISA- and Massachusetts-certified arborists serving Needham, Concord, Danvers, Cape Cod, and the surrounding areas for year-round shrub care.
HOW TO CARE FOR NEWLY PLANTED SHRUBS
Shrub Care FAQ
A scratch test can help determine if your shrubs are alive after winter. Scraping a small section of bark to reveal green, moist inner tissue means your shrubs are dormant and not dead.
Yes! Fertilize shrubs after the ground thaws but before growth to maximize nutrient uptake.
Flush soil with water to leach salt, and rinse foliage to help shrubs recover from salt damage. Deep, slow watering helps to push salt away from the roots.
Pruning depends on the shrub species. For deciduous shrubs, pruning now can help boost new growth. For flowering shrubs, wait until after blooming finishes to avoid cutting off buds. Anything dead can be pruned at any time.
