Garden Planning: Sun vs shade

Perennials

Class 1: Some Perennials Basics
Class 2: Garden Design
Class 3: Putting Pencil to Paper
Class 4: Soil Preparation and Planting
Class 5: Maintaining your Perennial Gardens
Class 6: Troubleshooting

After hardiness ratings, the most important factor to consider when choosing plants is their light requirements. Most resources provide the light level, or range of light levels, in which a plant will thrive. For example, some plants require full sun to thrive, while others will grow equally well in full sun or part shade. Let's look more closely at these designations.

Full sun. Full sun is commonly defined as direct sunlight for at least 6 hours during the middle part of the day during the growing season. If you’re lucky enough to have a sunny site, you’ll have a large selection of plants from which to choose, since a majority of the most common perennials perform best in full sun. (Many of these plants will survive in partial shade, but the display of flowers may not be as dramatic.) The exception to this is for gardeners in hot, dry regions, who should consider locating their gardens in a place where the plants will receive some shade during the hottest part of the day.

"Full sun" means at least 6 hours of sun during the middle of the day.

Part sun (or part shade). If your garden gets direct sunshine from sunrise until noon, even if that equals six hours in mid-summer, consider the site as receiving partial shade. Morning sunlight isn’t as strong as mid-day sunlight. The same is true for late afternoon/evening sun.

If your garden receives sunlight from 3 p.m. on, consider it partially shaded. The same goes for sites that receive filtered or dappled sunlight all day. For these gardens, look for plants designated for part sun (or part shade.)

Full Shade. However, if your garden is located on the north side of your house or shaded by a dense tree canopy, you’ll need to choose your plants adapted to full shade. Your choices will be more limited, but don’t despair! It’s possible to create a lovely and durable shade garden!

Remember that the shadows cast by buildings and trees vary with the season. In December and January, when even the mid-day sun is low in the sky, your house will cast a shadow that is much larger than the shadow it will cast in midsummer, when the sun travels almost directly overhead. Though there are all sorts of ways to calculate exactly where shadows will fall at each time of the year (factoring in the height of your house, your latitude, etc.) you don’t need to get that fancy. The easiest way to determine light levels is observation. Observe what sections of your yard are in full sun at different times of the year, and at different times of the day.

In the last class we mentioned foundation beds, island beds, and borders. Let’s look at each of these, and consider some several garden designs for each situation.

Class 3, Page 1 2 3 4 5 6 7

Lupines

You can use shade to your advantage. If you are growing plants on the southern reaches of their ranges, the plants might benefit from some protection – shade – from the blazing afternoon sun. Lupines (USDA Zones 3-7), for example, tolerate full sun in cooler regions, but if you are trying to grow them in Zone 7, they’ll appreciate some mid-day shade.

On the other hand, verbenas (Zones 7-9) prefer the heat of the midday sun, so you’ll want to make sure they get the sunniest spot available in your Zone 7 garden.

Five Favorite
Shade Perennials