No announcement yet.

Gardening in the Shade

  • Filter
  • Time
  • Show
Clear All
new posts

  • Gardening in the Shade

    Gardening in the Shade

    Christoper J. Starbuck
    Department of Horticulture

    Many gardeners view shade as a challenging situation for growing plants. While some plants do not grow well in low light, numerous others thrive under these conditions. Just as moisture, temperature, and soil conditions may limit plant growth, the amount of shade present may determine which plants will grow successfully. The key is to discover which ones are adapted to the conditions in your yard or garden.
    Landscapes change their degree of shade over time. As trees and shrubs mature, the landscape receives greater shade. What was once a sunny garden may evolve into a shady one. Analyze the degree of shade in your garden periodically to determine if changes in plant materials may be needed due to increased shade from a maturing landscape.
    Several characteristics typify shade gardening. In addition to low light levels, plants growing in the shade must compete with shading trees for nutrients and water, and tolerate poor air circulation.
    Figure 1
    Prune tree branches high to improve air circulation in shade gardens.

    Lack of light

    The best way to cope with low light levels is to choose plants that do well in less light...

    Light shade may be described as an area that is shaded but bright. It may be completely shaded for only several hours each day.

    The sun's rays may be blocked by a wall or building for several hours at midday, but the area is sunny the rest of the day.

    Light shade may also be found in areas that receive filtered or dappled sunlight for longer periods.

    Edges of shady gardens or areas under the canopy of solitary, lightly branched trees are typical of filtered sunlight.

    During the heat of summer, light shade at midday will provide a beneficial cooling effect.

    Flower and foliage color may be more brilliant when plants are shielded from intense midday sunlight.

    Partial or medium shade is present when direct sun rays are blocked from an area for most of the day.

    Many established landscapes have large areas of partial shade, where sections of the yard are shaded by mature trees for much of the day but receive some direct sun early or late in the day.

    Bright, north-facing exposures may also be classified as medium shade.

    Full shade lasts all day. Little or no direct sunlight reaches the ground at any time of the day. There may be reflected light from sunnier areas of the yard or off light-colored walls.

    Dense shade refers to full shade under thick tree canopies or in dense groves of trees. Areas under stairways, decks or covered patios on the north side of the house receive full shade.

    Keep in mind that light patterns change with the seasons. An area that is in full sun in summer when the sun is high in the sky may have medium shade in spring and fall, when the sun is at a lower angle.

    Study your garden through the seasons to accurately determine what type of shade is present.

    Available sunlight may be increased by selective pruning (Figure 1). Removal of lower limbs on large trees may increase light levels significantly. Large shade trees are a valuable resource that in most cases should be preserved. However, removal of diseased, unattractive, or poorly placed trees improves the beauty of your property and increases the light available for plant growth.

    Take advantage of reflected light, if possible. White or light-colored surfaces reflect more light than dark-colored ones. Light-colored house siding or fences may increase available light to plants.

    Plants growing in the shade often must also compete with roots of shading trees for nutrients and moisture. Shallow rooted trees such as maples and willows are particularly troublesome.

    Adding organic matter to shade garden soils will help. Most woodland species are accustomed to growing in soils rich in leaf litter compost. Raking and removal of leaves each fall in the typical landscape disrupts this natural nutrient recycling process. If leaves are not removed, they can mat down and smother shade garden plants, but shredded leaves can be safely applied as a mulch.

    Another option is to compost the leaves first, and apply the compost in core aeration holes or in small pockets dug into the garden.

    Do not haul in several inches of compost-rich amendment to till into soil under shade trees. Some species, such as oaks, are extremely sensitive to changes in soil depth within their root zone.

    In addition, tillage will damage many of the tree's roots, starting a decline from which the tree may never recover.

    If the gardener is patient, earthworms will eventually incorporate surface-applied organic matter. Organic matter loosens heavy clay soils, improving drainage. In sandy soils, organic matter will increase the water-holding capacity. As organic matter breaks down, it also releases nutrients to the plants.

    Roots competing for limited surface water may cause shade gardens to dry out more quickly than sunny sites during extended dry periods. Some shade-tolerant plants are adapted to low moisture situations, while others require moist shade. Provide water according to the plants' needs.
    Poor air circulation

    Branches or walls that cast shade also block air movement.

    Poor air circulation coupled with lower light levels means foliage of plants stays wet longer in the shade than in sunny areas.
    Most plant disease problems are worse under these conditions.

    Prevent disease problems by selecting disease-resistant varieties when available. Space plants farther apart in the shade to allow more air movement around each individual plant. Water with soaker hoses or drip irrigation systems to avoid wetting the foliage. Removal of lower tree limbs may funnel breezes underneath the tree canopy, thereby improving air circulation.

    Fruits and vegetables

    Almost all food crops grow best in sunny locations. Not only do they need full sunlight for good growth, few tolerate root competition from trees.

    Cool-season salad vegetables such as lettuce, spinach and radishes may benefit from light shading through the heat of the summer.

    Beans, beets, broccoli, cabbage, kohlrabi, peas, potatoes, rhubarb and turnips will grow in light shade but not produce as large a crop as plants growing in full sun.

    Currants and gooseberries are fruits which tolerate medium shade and still produce a crop. Bramble fruits such as blackberries and raspberries grow in light shade, but yields will be reduced.

  • #2
    Re: Gardening in the Shade

    Vegetables for the Shady Garden

    John Durham, Colorado State University Cooperative Extension Master Gardener, Denver County

    If you've tried vegetable gardening in Colorado -- especially if you have relocated from more garden friendly areas of rich soil and high precipitation -- you know the importance of appropriate plant selection and manipulation of soil and microclimates.

    The shady spot is a microclimate that can work to your advantage in the vegetable garden. Whether created by towering trees or adjacent man-made structures, shade can become your friend, especially in Colorado where heat from the summer sun is intense.

    Many of our favorite vegetables succeed because of the sun, but a wide range of interesting and delicious varieties thrive in the cooler microclimate within our garden's shady areas.

    In general, leafy vegetables are the most shade-tolerant, while those that fruit from a flower (tomatoes, peppers, squash, eggplants) are the least. In between are the root vegetables requiring at least a half day of full sun: potatoes, beets, carrots and turnips. Shade tolerant leafy vegetables include lettuce, spinach, Swiss chard, arugula, endive and radiccio. Broccoli (and its relatives -- kale, kohlrabi, turnips, mustard and cabbage -- also grow in partial shade.

    Leafy vegetables display another advantage: they can be picked and enjoyed at any stage of maturity, unlike sun-loving vegetables that must ripen. Yet another advantage to these shade-tolerant plants is their conduciveness to successive plantings. Planted early in the spring, they are ready to enjoy before the intense heat of mid-summer. Planted in mid-to-late summer, they thrive in the cooler days of early fall. Accordingly, they can be used to fill in gaps where summer-harvested vegetables have been picked, or even planted to take advantage of shade created by adjacent larger plants. One leafy vegetable, spinach, can be planted in mid- September, allowed to overwinter, and harvested earlier in the spring than if it were spring-seeded.

    In planning your garden, don't overlook the shady spots---they can be the source of both your earliest and latest harvests.


    • #3
      Re: Gardening in the Shade

      Ten Vegetables You Can Grow in Shade

      It's a common misconception that the only site to grow vegetables in s one that's in full sun. For some vegetables, such as tomatoes, peppers, and squash, this is entirely true. But those of us who have shade are not doomed to a life without homegrown produce.

      Basically, a good rule to remember is that if you grow a plant for the fruit or the root, it needs full sun. If you grow it for the leaves, stems, or buds, shade is just fine.

      Keep in mind, no vegetable will grow in full shade. The following crops will produce with three to six hours of sun per day.
      1. Salad Greens, such as leaf lettuce, arugula, endive, cress, and radicchio
      2. Broccoli
      3. Cauliflower
      4. Peas
      5. Beets
      6. Brussels Sprouts
      7. Radishes
      8. Swiss Chard
      9. Leafy Greens, such as collards, mustard greens, spinach, and kale
      10. Beans

      The best thing about knowing that these crops will successfully grow in some shade is that you'll be able to get more produce from your garden. Suppose, like most home gardeners, you've sited the vegetable garden in the one area of your yard that gets full sun. Use that space to grow the sun-lovers: the peppers, tomatoes, eggplants, corn, and squashes. The other crops, those that do well in the shade, can be tucked in anywhere.

      Grow some beets or swiss chard in your part-sun perennial border. Grow some lettuce or radishes in a container or window box.

      Make use of the space you have, in both sun and shade, can easily double the amount of vegetables you usually get.

      And homegrown produce, whether it's a fresh, juicy beefsteak tomato or a crisp, spicy radish, will spoil you forever against the bland, boring produce at your local grocer. Being able to step out into your own yard to gather ingredients for an impromptu salad or side dish is a joy, and if you make the most of your space, you'll be harvesting the fruits of your labor from spring through fall, and quite possibly beyond.