Many of our ornamental and edible plants perform multiple functions in the landscape: provide an aesthetically pleasing view, supply food for people and wildlife, support beneficial insects, butterflies and birds, deter insect pests, attract insect pests away from specific plants, provide shade, food, and shelter for insects, and support an environmentally sustainable landscape.
A number of factors must be considered when developing a sustainable, edible landscapes.
Soil pH: Soil pH requirements vary between species of ornamentals, fruits, vegetables and herbs. When incorporating and mixing such variety in the same garden bed, knowing the pH requirements is important. Although the majority will grow and thrive with a soil pH of 6.0-7.0, acid loving plants, such as blueberry, cranberry (Vaccinium macrocarpon), azalea, and rhododendron, will need to be planted together in a lower soil pH in order to thrive.
Organic matter: Organic matter supplies valuable nutrients to plants and provides a healthy environment for soil microbes. Organic matter increases with the addition of compost, and as plant material and mulch break down in the garden over time. Understanding the percent organic matter in the soil is important, because not all plants thrive in high organic matter soils. For example, in high organic matter soils, grapes will put on excessive growth, to the detriment of fruit.
Sunlight: Sunlight requirements of plants also vary. Most vegetables and fruit prefer full sun conditions (minimum of eight hours of sun), although currants, alpine strawberries (Fragaria vesca) and highbush cranberry (Viburnum opulus var. americana) will do well in partial shade conditions. Most herbs prefer full sun, although chervil and parsley will also grow well in partial shade. Ornamentals run the gamut of preferring full sun to full shade. It is acceptable to plant shade-loving plants on the shady side of buildings or under larger shrubs or trees as long as they do not excessively compete for available water and nutrients.
Water: Water requirements vary. All plants require water during establishment and most require one to two inches per week during the peak growing season. Group plants according to their water requirements to maximize water efficiency and support plant health. Plants that favor more water will continue to grow, but may require more frequent watering than drought loving plants. Once established, drought tolerant plants will continue to grow during extended dry periods in the growing season, but may require less watering. Avoid overhead irrigation, if possible, to reduce leaf wetness and limit potential plant disease issues. If overhead irrigation is the only option, be sure to water early in the morning to allow plants to dry quickly.
Nutrient requirements: Some vegetables require more fertilizer to support flower or fruit production, such as asparagus, tomatoes, and members of the brassica family, while members of the root family (e.g., carrots, onion, potato, squash) typically require less fertilizer. Group vegetables that require the same level of nitrogen fertilization together to maintain optimum plant health. Be aware that mature fruit trees, as well as fruiting ornamental shrubs and trees, remove a substantial quantity of nutrients from the soil, especially nitrogen and potassium, as the plants grow and fruit develops. It is important to regularly complete a soil test to determine the fertility needs of the soil. Soil test kits are available from the UConn Soil Lab (soiltest.uconn.edu).
Pollination: Be aware of the pollination requirements of all plants in the edible garden, especially plants that require cross-pollination. Most fruit trees require two varieties for cross-pollination. Berry crops are self-fruitful (self-pollinated), although for blueberries, black currants, and elderberries, planting two varieties will increase the fruit set and size. Most fruiting vegetables do not need a second variety to produce a crop.
