Don’t Fence Me In: Hedges in the Landscape

Using Hedges in the Landscape

Hedges are one of the most fundamental applications of plants in the landscape. They are the living equivalent of a solid wall or fence and therefore serve pretty much the same functions. Unlike solid walls, however, they are dynamic and flowing and are much softer in their impact.

They are the ideal element to delineate boundaries in the landscape. They can mark off property lines, borders between outdoor rooms in a landscape sense, walkways, driveways, gardens, and more.  They can screen out undesirable views onto adjacent properties, and they can block noise from traffic or other sources. They can also screen views from the outside of your property; screening can create private spaces for you and your family that are pleasantly isolated from the rest of the world.

Hedges can be used to modify the local climate and create favourable microclimates. They block frigid winter blasts and the drying summer winds, which actually raise the ambient temperature in their immediate vicinity, permitting “out-of-zone” shrubs and perennials to survive the winter in regions where they may otherwise not stand a chance.

Different Kinds of Hedges

There are two basic styles of hedges; formal and natural. Formal hedges are those that are pruned to a specific shape, looking for all purposes, like walls built of plants. Natural hedges are those in which naturally shapely plants are allowed to grow to their natural forms but which are placed close enough in proximity to each other that they still function as a hedge.

When selecting plants for your hedge, you should choose varieties that are vigorous, durable and tough. You don’t want every third plant in your row dying because it is too tender for our cold winters!

A specific note of caution is in order here. Many people desire formal trimmed hedges with the beautiful fragrance and colour of flowers. So why not just construct a hedge using flowering shrubs? The trick is that the majority of flowering shrubs bloom on wood that was developed the previous summer or fall. Any branches that are pruned or trimmed between the time the flowers are formed and the bloom time represent lost bloom. If enough of the new branches are removed, there will be no flowers at all. So while lilacs and viburnums make wonderful hedges, pruning them as a formal hedge all but ensures that they will not be blooming in the coming season. Save these for natural hedges.

As you can see, the type of hedge you like will help determine the kinds of plants you will need for your hedge and how many of each you will need.  Plants in a formal hedge tend to be spaced closer together than in natural hedges.  The spacing of plants will also be determined by how large the individual plants can grow and how long it will take to reach that width.  For smaller shrubs like boxwoods, it is usually best to plant them approximately 12’ apart.  For larger growing hedging, spacing to 24” to 30” would work well.  Wider spacing would be possible, but it would take a much longer time for the hedge to fill in, and there would be a greater risk of gaps forming in the row.  To calculate the actual number of plants, you’ll need to purchase for your hedge, take the full length of the hedge run as per your design and divide it by the spacing between the plants as you have calculated above. Subtract one plant from this number to correct for the end spacing, and there you have the number of plants you’ll need to buy.

Preparing the Site & Planting Your Hedge

It is best that you excavate a full rectangular plot for the hedge, as opposed to simply digging individual holes in the lawn. It will become nightmarishly challenging to maintain grass between individual plants that are spaced closely together while at the same time keeping it away from the base of the plants, so don’t even bother setting yourself up for this heartache.  Start by staking off the plot for the hedge row. Get yourself a few handy wooden stakes, a hammer, and some string.  Now, if you’re digging the plot out of an existing lawn, use a lawn edger to cut the sod along the string. This will help give you a sharp edge on the border. Once the plot has been completely edged on all sides, you can use a spade or a sod cutter to lift the sod from the inside.

Using the edges as a reference point, take your wooden stakes and mark off the exact centers of the planting locations for each plant in the hedge. Planting a hedge plant is no different from planting any other tree or shrub.  Dig your individual holes, amend with compost or triple mix and apply transplant fertilizer to encourage fast root development.  Continue planting each hedge plant, maintaining the exact spacing of each plant and keeping the plants centred within the plot.  Once all the plants have been planted, use a rake to smooth over the soil around the individual plants along the entire length of the hedge and give the entire hedge a good watering.  As a final step, it is advisable to apply a 2-3” layer of mulch over the planting area to minimize weeds and to keep moisture in.

After-Care of Your New Hedge

As with any new garden, the plants in your hedge will require additional care and attention over the first year. This means frequent watering while the hedge plants are establishing deep roots in their new home. Keep weeds and grass from growing into your hedge.  They will rob it of nutrients and moisture, besides making it look unkempt and messy.