Hedges

Most of us think of tidy, green walls when someone mentions hedges, but there’s a lot more to them than that.

Hedges add structure to a front yard (Kate Russell)

What are hedges?

Generally speaking, hedges are shrubs or trees grown very closely together. People started planting hedges some 6,000 years ago. Before long, they began weaving dead twigs and branches into hedges to create impenetrable barriers that kept livestock in and predators out. This practice is called pleaching. Some of the hedgerows in Ireland and the United Kingdom are more than 700 years old. I’m sorry to say, but hedges will not keep deer out of your garden.

Sometimes a hedge can protect your home from a drunk driver (Kate Russell)

Hedges can be massive, unruly walls of living plants, neatly trimmed parterre perimeters, or anything in between. Hedgerows muffle sounds, prevent erosion, and reduce flooding. They can be ornamental or edible and shaped to your heart’s delight. This topiary is a popular attraction at many public gardens and amusement parks.

Topiary in India's Thiruvananthapuram Botanical Garden (Vijayanrajapuram) CC BY-SA 4.0

Hedges harbor hundreds of other living things

Hedges may look static, but there’s a lot going on inside. According to one journal, a single hedge can host more than 2,000 different plant and animal species in a single year. Another study found that Belgium’s hedges held a greater variety of species than their forests. This biodiversity occurs because hedges create their own microclimates.

Hedges block and redirect wind. They shade and keep the soil moist. That moisture provides for a variety of insects and fungi. Those, in turn, attract parasites, pollinators, predators, and prey. Birds are also attracted to hedges. Those birds often eat insect pests. One Berkley study found that farmers saved $4,000 a year in insecticide costs for every 1,000 feet of hedgerow installed. Imagine saving $400 a year because of a 100-foot hedge.

Birds often nest in hedges so be careful when pruning (tommileew) Pixabay

Hedges provide food and shelter. They act as migratory corridors in a day and age when safe havens can be difficult to come by. Did you know that bats and moths use hedgerows as flight paths? I didn’t either. Some of the insects attracted to hedges, including braconid wasps, honey bees, ichneumon wasps, and predatory beetles, are beneficial. Others, such as brown stink bugs and thrips, are pests. Hedges can also create the perfect conditions for diseases, such as sooty blotch and flyspeck.

Hedge maintenance

Hedges require regular pruning to stay attractive. In most cases, that pruning is done by shearing. Shearing cuts everything into uniform lines. This practice can lead to dead zones inside your hedge that occasionally need to be removed. This can give your hedge a pockmarked appearance. You can prevent this problem by investing some time in hand-pruning your hedge from the inside out.

Massive hedge at Mission San Juan Capistrano in California (Billy Hathorn) CC BY-SA 3.0

Hedges also benefit from an occasional hosing-off. This cuts down on the amount of dust and debris that collect on all those leaves. A dusty hedge is an open invitation to wooly aphids, mealybugs, mites, and whiteflies.

Choosing hedge plants

Hedges can consist of a single plant species or many different species. Boxwood and privet are common hedge plants. They stay green year-round and respond relatively well to shearing. You can choose native plants for your hedge.  Or, you can create a shorter, insectary hedgelike border with yarrow or sweet alyssum.

Edible hedges are a little trickier. You can create a blueberry hedge, just be sure to select a variety that is evergreen. Raspberry and blackberry hedges are delicious, but you’ll have bare canes in winter. Rosemary makes a beautiful, fragrant edible hedge, though you’ll end up with more rosemary than you could use in fifteen lifetimes. The same is true for lavender, tarragon, and thyme. You can also create a hedge using espaliered fruit or nut trees. Citrus, hazelnuts, pineapple guava, and pomegranate are just a few of the edibles that lend themselves well to hedge-making.

Hedges are important components of copycat gardens, fruit cocktail gardens, rain gardens, sensory gardens, soundscapes, and storybook gardens. Whatever your garden theme, it can probably benefit from a hedge.

My apartment balcony is another story altogether.