CULTIVATING SUCCESS IN THE FARM & GARDEN: Gardening in shady spots
Having a basic knowledge of the garden area will help you choose the plants that will grow best in your site, explains Hubbard County Extension Educator Tarah Young.
Gardening in shady areas can be quite the challenge: they are cooler; the soil remains moist longer; they may be the last areas in your landscape to thaw out in the winter; soil fertility can be a challenge to maintain; and there are different levels of shade, from dappled to deep shade.
These factors can cause some gardeners to avoid landscaping the shadier areas of their yards. By implementing these tips, your plants can thrive, not just survive.
Having a basic knowledge of the garden area will help you choose the plants that will grow best in your site. A plant won’t perform well in conditions that differ from what it needs to grow. The plant will be stressed and unable to reach its full size, form and shape, nor will it produce healthy leaves and flowers.
Plants growing in less-than-optimal conditions are also more likely to succumb to diseases and insect damage. Answering these questions can help point you in the right direction.
How much space will your shade garden occupy?
Maybe it’s just room for a few plants under a shade tree. Or a large woodland garden. Either way, measure the plantable space and keep that in mind when selecting your plants. Plants should have enough room to grow to their full, mature size.
Check plant labels, catalogs or the University of Minnesota Extension Plant Elements of Design plant database for specific plant information.
What type of shade is present?
Spend time observing the light levels in your landscape and how they change throughout the day and seasons. Put a thermometer in different areas of your landscape and observe the changes as the sun moves through the sky.
For example, morning sun is less intense and thus provides full sun conditions without extreme heat whereas afternoon sun is stronger and temperatures are warmer.
Light levels of shade:
- Dappled shade: light filtering through a tree canopy
- Light shade or part shade: about 3-6 hours of sunlight
- Full shade: less than 3 hours of sunlight
- Deep shade: almost no sunlight
Although areas with part shade receive direct sunlight for a small portion of the day, the light intensity can still be quite bright.
There are numerous plants that grow in part shade such as woodland wildflowers.
Certain herbs and leafy greens can be grown in dappled to part shade conditions.
Some plants tolerate relatively low light levels and a few actually thrive.
Many groundcovers do well in shady areas.
How much moisture is there?
Shade gardens typically retain soil moisture due to cooler temperatures and protection from sunlight. This can benefit plants that prefer cool, consistently moist growing conditions. However, this means a shade garden may warm up later in the spring. Moss and slugs may also be problematic in shade gardens.
Is it considered “dry shade?”
Dry shade is one of the most limiting for gardeners and plant lovers. Dry shade is created by:
- Tree canopies.
- Eaves and overhangs of a house.
- Competition from other plants for light and soil moisture.
- Building foundations and structures that block rainfall.
Growing plants beneath large trees or under the overhang of a building is challenging because they prevent even plentiful rainfall from reaching the plants. The dry soil and lack of sunlight create difficult growing conditions for plants.
Selecting plants that grow in dry shade will help reduce (but not totally eliminate) supplemental watering. Supplemental watering will be needed occasionally in dry shade plantings. Use a drip hose, irrigation or hand water to saturate the top 3 to 4 inches of soil when it’s dry.
What is the condition of your soil’s fertility?
Most shade plants grow well in moist, well-drained organic soil. However, adequate nutrients maintaining soil fertility can be challenging in shady sites.
Trees and some shrubs have extensive root systems or “feeder roots” in the top 18 to 20 inches of soil that compete with other plants for space, nutrients and water.
Test your soil to better understand how to improve your soil especially if plants have special soil requirements such as acidic soil pH.
As a general recommendation, apply a balanced fertilizer such as a 15-15-15 (N-P-K) in spring followed by one or two applications as the season progresses. If your soil has a high phosphorus level already, avoid applying additional phosphorus and use a 15-0-15 or similar fertilizer.
Plant lists that grow well in shade
- Zone 3 deciduous shrubs: dogwood, chokeberry, Northern Lights azalea, honeysuckle, Annabelle and panicle hydrangea, blue ice bog rosemary, hummingbird summersweet, dwarf European viburnum, highbush cranberry.
- Zone 3 evergreens: Holmstrup arborvitae, aurea compacts hemlock, Eastern hemlock (a Minnesota native plant), dwarf bright gold yew.
- Zone 3 small trees: juneberry/ serviceberry (MN native plant), witchhazel (MN native plant), hop tree/wafer ash (MN native plant), speckled alder (MN native plant), blue beech (MN native plant), Canada red chokecherry (MN native cultivar), ironwood/American hop hornbeam (MN native plant).
- Zone 3 tall perennials: big leaf ligularia, bleeding heart, cinnamon fern, royal fern, goat's beard, astilbe, Martagon lily, great bellflower/milky bellflower, queen-of-the-meadow, queen-of-the-prairie, black snakeroot/black cohosh, turtlehead
- Zone 3 ground covers: Pennsylvania sedge/sun sedge, Catlin's giant bugleweed, wild ginger
Planting the right plant in the right place will help successfully transform the shady areas of your yard.
Tarah Young is Hubbard County University of Minnesota Extension educator in agriculture, food and natural resources. If you have any questions about this topic or any others, contact her at 732-3391. If information about agriculture, gardening and natural resources interests you, consider signing up for the Hubbard County UMN Extension Agriculture, Gardening and Natural Resources E-newsletter at z.umn.edu/HCExtensionNewsletter.