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.