Tips for planting and maintaining an open hedge

The free-standing hedge is a modern-day hedge in which the gardener has intervened. This means that the plants have been consciously chosen and planted, unlike the natural hedge.

Choice of species for an open hedge

In the free hedge, local species are preferred, respecting the following proportion in its composition: 1/3 deciduous plants (hazelnut) and 2/3 evergreen plants (tin laurel) or the opposite, but in all cases conifers are to be avoided.

Regarding the choice of deciduous species, we prefer melliferous species (buddleia) to provide pollen and nectar to foragers, as well as flowering species (hibiscus) for their aesthetic side.

Advice:

• The use of 1, 2 or 3 trees can give verticality to a horizontal hedge.
• The combination of upright and stocky species is more aesthetically pleasing than the use of a single type of plant.

Advantages of an open hedge

• It is a place that attracts and protects beneficial insects;
• It is a hedge that evolves with the seasons, that is "alive";
• It is a hedge that requires much less maintenance than a pruned hedge: 0 to 1 pruning per year for the free hedge against 2 to 4 prunings per year for the pruned hedge.

To obtain the minimum of maintenance, it is necessary to choose the species that will compose it. Ideally, you should seek the help of a professional.

To help gardeners, nurserymen offer "ready-to-plant" hedge kits.

Planting an open hedge

An open hedge takes up a lot of space, precisely because it is not very well trimmed. Plan on a minimum width of 1.50 meters.

Indoors, the plants can be spaced 1 meter apart. To obtain a beautiful, dense hedge, opt for a staggered planting, in two rows spaced about 60 cm apart. This arrangement allows you to obtain a closed visual while giving relief to the whole.

Pruning an open hedge

In an open hedge, if you choose to prune, you must respect the physiology of each plant. Pruning is therefore done according to the flowering period of the plant: spring flowering plants will be pruned just after flowering while summer flowering shrubs will be pruned in February/March.

Tip

Install a tarp at the foot of the shrubs to limit the development of weeds and to keep the soil moist, which is necessary for the plants to recover.

Pruning and maintenance tips for boxwoods

The right tools to prune boxwood

Pruning a boxwood hedge is not the same as pruning a traditional hedge: the work must be precise, and the cuts must be clean and sharp. A hedge trimmer does not allow for quality work: it causes many small wounds that are open doors for diseases or pests.

It is therefore necessary to use adequate and clean tools: shears, secateurs or boxwood shears.

The right time to prune boxwood

• Young boxwoods are pruned at the end of winter or at the very beginning of spring (February/March/April), excluding periods of frost.
• Adult boxwoods can be pruned a second time during the year. In this case, it is best to proceed in August / September / November. In any case, not before May.
• Older trees that need to be pruned for rejuvenation are pruned in August; this allows the plant to heal properly.

How to prune boxwood?

In the first few years, or when planting, it is advisable to reduce the foliage by a maximum of 5 or 6 cm. This pruning aims to stimulate rooting.

In the following years, it is advisable to select the carpenters to be kept (this will depend on the shape you want to give to your box tree: in a ball, in a strict hedge...) and then to cut back the foliage by 5 cm.

Finally, a special fertilizer containing a photosynthesis activator is sprayed to help heal wounds caused by pruning.

Tip: after pruning, collect the waste to prevent pests from settling on it.

Fertilizing boxwoods

It is important not to use a fertilizer that contains too much nitrogen, which would encourage the production of young, tender leaves that are susceptible to disease. It is necessary to use a fertilizer that reinforces the rooting (because boxwoods need water), as well as the walls of the leaf cells.

Remember: boxwoods should be planted in sun or partial shade.

Tips for planting an open hedge

An open hedge provides a varied hedge that will reward you with different colors and shapes throughout the year.

When should I plant a hedge?

From mid-October to the end of March, you can plant all deciduous species, especially bower trees, which grow quite quickly. Subjects offered in containers, i.e. with their entire root system, can be installed without risk at any time of the year, simply by providing regular and generous watering.

What are the planting distances?

For a good spacing between plants, count 50 cm for subjects less than 1 m high; space 60 to 80 cm for shrubs of 1 to 2 m, and 1 to 1.50 m for the largest species. If you need to plant a long distance (more than 15 m), consider renting an auger or a bucket trencher. This will save you a lot of effort in excavating the soil. It is better to dig a linear trench and install the plants at the right spacing than to make individual holes, especially if you are planting small specimens.

To avoid any problems, respect article 671 of the civil code. It stipulates that plants that reach a maximum height of 2 m should be planted 50 cm from the boundary. Plants exceeding 2 m in height at maturity must be planted at least 2 m from the boundary between the two properties.

Black plastic mulch film during planting?

When it comes to planting long hedges, the use of a mulch film saves a considerable amount of time, which explains why it is so widely used by green space professionals. Polyethylene is a non-polluting plastic, since its combustion only releases water vapor. It prevents the evaporation of water, warms the soil and prevents the proliferation of weeds. In addition, in very sloping soils (slopes), the mulch film prevents runoff. The main problem is that these films, once used, are left in place and scattered in shreds.

In a home garden, the plastic can be replaced by the new natural mulches made from coconut fibers or the unsightly films can be covered with pine bark.

Create a windbreak

Nothing is more unpleasant than a garden exposed to strong winds. Crops that are damaged by the cold in winter and by the drying action of the wind in summer need protection. The creation of a windbreak hedge is a good solution.

Better understand the action of the wind

In exposed areas, wind can cause many problems. It cools the atmosphere in winter, making plants even more susceptible to frost. In summer, it burns the plants with its powerful breath, drying out the soil and the aerial parts at high speed. This often leads to breakage and makes the cultivation of tall or heavy flowering plants more difficult.

Fortunately, the wind can be deflected or attenuated thanks to various arrangements. Faced with a "hard" obstacle such as a wall, the wind will tend to go around it to create a very disturbed zone just behind it. The effect will therefore be the opposite of what was intended. On the contrary, when faced with a penetrable obstacle such as a plant hedge, the wind will be slowed down, reducing its speed by two over a length equivalent to nearly ten times the height of the hedge. It will therefore have less impact on the crops behind it.

Choice of shrubs

Never forget that to make a success of your hedge, it will be necessary to plant plants adapted to the climate and soil of your region. Take a good look at nature to determine the pH of your soil and ask your neighbors and nearby nurseries for advice.

Don't forget that if you are planning to plant trees that are more than 2 meters high, they must be installed at least 2 meters from the property line.

Finally, for optimal protection, it is always preferable to plant a first hedge as a fence and then a second one to protect a specific area of the garden such as a vegetable garden, a swimming pool or a garden room.

Once these parameters are defined, the choice of plants is vast. Charmilles hedges, used in the past to protect orchards, have the particularity of attracting many birds. Laurier tin and eleagnus will diffuse a delicate winter perfume, while cytises, forsythias and other lilacs will ensure beautiful spring blooms. For the beauty of the foliage, photinias, dogwoods and of course maples will be wonderful. Among the taller subjects, acacias, mulberry trees or catalpas are to be preferred.

Bamboos can also make great windbreaks if they are planted in staggered rows to create a nice thickness. Beware, some subjects can reach 20m in height!

Let's not forget the classic conifers such as cypress, chamaecyparis or tuyas, always appreciated for their dense and evergreen foliage.

Planting period

The best time to create this type of hedge is from autumn to the end of winter, when the trees and shrubs are resting. Always proceed outside of the frost period and when the soil is not completely soggy. If you have received your plants and it is impossible to plant them for climatic reasons, put them in gauges until the right time.

Cypress or cedar?

Hedge trees, cedar and cypress have been sharing the limelight in gardens for decades. Windbreaks, privacy screens, these coniferous hedges are very appreciated by gardeners for their thick and persistent foliage in winter. But what is really the difference between cedar and cypress?

A strange resemblance

It's hard to tell the difference between a cedar or cypress hedge!

The Lawson cypress (Chamaecyparis lawsoniana) is not a true cypress (Cupressus) in the botanical sense of the term, whereas the Leyland cypress (Cupressocyparis x leylandii), is a natural hybrid between the Lambert cypress (Cupressus macrocarpa), and the Nootka cypress (Cupressus nootkatensis)

Cedars and false cypresses are conifers, very similar in appearance that share certain characteristics:

• a green foliage (except the cultivars in vogue, golden or blue) persistent composed of flattened scales;
• a slender, conical to pyramidal habit in the first years;
• they provide compact, dense hedges, ideal as privacy and windbreaks throughout the year;
• they are well suited to pruning;
• they must be pruned once to three times a year, when they are grown as hedges to contain them.

Discreet differences

There are a few ways to differentiate cedars from false cypress and cypress trees used to create hedges:

• cedars have slightly wider, slightly less dense branches than false cypresses;
• False cypresses grow much faster (up to 70 cm to 1m/year for the Leyland cypress) and appear finer in their young age;
• several pruning actions are required to contain the false cypresses each year;
• false cypresses are a little less resistant to frost than cedars (-20°C all the same!);
• The shape of the cones is elongated on the cedars and rounded on the false cypresses;
• The scales of true cypresses are never flattened but rather spiral or 3D;
• the spire (top of the tree) is thinner on the cedar;
• There are many varieties of Lawson cypress, for example 'Stardust' with golden foliage or 'Pembury Blue' with bluish foliage.

Cedar, the star of the 80s

For decades, cedar was the dominant plant in the creation of blackout hedges.

Thuja plicata, better known as 'western red cedar', is very appreciated for its average growth (30 cm/year), which limits pruning. It has the advantage of growing in height (up to 50 m) but also in width, which ensures a well-filled and dense hedge.

• Thuja occidentalis 'Brabant', or 'Brabant cedar', has its followers because it is very resistant to cold (-25°C) and easy to maintain. Its average growth (30 cm/year), and its light green color are unanimously appreciated, especially since it only grows up to 5 m high and is very easy to prune.
• Despite all these advantages, the use of cedar in hedges is more and more controversial, especially because of its sensitivity to cryptogamic diseases (Phytophthora cinnamomi, Didymascella thujina, Coryneum cardinale...). These diseases, frequent in heavy and humid soil, cause the browning of the foliage and its fall. In the case of Phytophthora, the cedar will not survive.

Another concern is a small parasitic insect: the bupreste, which has been devastating many plantations for several years.

In southern regions, cedar can be sensitive to drought unless an automatic watering system is installed so that the tree can really produce its root system. Let's not forget that the lack of water is a stress factor, which can weaken the tree and make it much more susceptible to diseases and parasites.

Cypresses, very trendy in hedges

As we have seen, cedar has been gradually replaced by other species more resistant to diseases and pests. Cypresses grow very quickly, are very hardy and for the moment are less sensitive to pests and diseases.

They do not really appreciate very calcareous and dry soils.

Available in ornamental foliage (blue, golden...), Lawson cypresses also appeal for their ease of growing and pruning.

On the Leyland side, beware! It grows so fast that to obtain a regular hedge and keep a dense aspect, it will be necessary to prune often (up to 3 times a year) and to call a professional to avoid the formation of unsightly holes with time.

So cypress or cedar?

It's all a question of choice, but with these conifers, you will only obtain monospecific hedges, which certainly attract certain birds but will remain unicolored in all circumstances and will require very regular maintenance (pruning).

The current trend is to have a variety of hedges, composed of flowering shrubs of different species to stagger the blooms throughout the year and encourage the presence of pollinating insects. Some of them have berries that attract birds and small mammals. Biodiversity is thus favored with a better balance in your garden!

Plant tools in an all-purpose hedge!

Bocage, windbreak, flowering, fruiting, defensive, evergreen ... The hedge comes in all forms. Forgotten, the old hedges were used by man as diversified tools, links, handles, stakes... Let's discover these practical and handy tools for the modern gardener.

The hedge and the farmer

A few decades ago, hedges crisscrossed the landscape, bordered plots of land and kept herds at bay. Sources of biodiversity, regulating water flows, windbreaks, for generations they found their place in the agricultural ecosystem. Farmers combined ecological interest and practical utility.

The branches of the "tetards", pruned and re-pruned trees with thick and twisted trunks, were used as fodder. The faggots heated the bread ovens. The bunches of flexible branches were used as brooms. Most of the wooden tools were renewed at the edge of the cultivated plots, from the simple tie to the pickaxe handle.

A piece of string

The gardener always needs a link, a piece of string, raffia, copper wire... A tomato to tie, a vine to guide, two stakes to tie, and the search for a tie begins. Pocket money? No. Going back home ? For a branch... What about the hedge, at the edge of the garden, within reach?

The willows, pruned near the short trunk, have given off young shoots, long, thin and flexible. They turn without bending, without breaking, and can tie, bind. From time immemorial, wicker has followed the vine, the ancient link of the winegrowers.

Other shrubs of the hedge were used as a link, then in braiding for basketry. Baskets, hats, trellises, were conceived, repaired, near the blood dogwood, Vitex agnus-castus, viburnum lantana, clematis...

The spade handle broke...

If the link is essential to the gardener, the handle is no less so. Spade, hoe, weed, plant... Every tool needs a handle, which always breaks at the wrong moment. Sundays and holidays, the old hedge is always there. If the ash was known for its flexibility, its tenacity, the field maple, less used, compact and homogeneous, was also used for any tool handle.

Mediterranean, renowned in its time for its properties equal to ash, the hackberry outclasses it for its robustness and flexibility. Wood of all the manufactures, stretchers, oars, axles, it was cultivated to produce forks. The shoots were pruned and shaped in order to harvest the ready-made tool. Shrub of the hot regions, the climatic warming encourages to register it in any plantation of hedge.

Tomato stakes

Less demanding in terms of mechanical properties, stakes are found on shrubs with straight branches, with straight and vigorous shoots. Hazelnut will provide beautiful stems that can be reused for several years if they are protected in winter. This gives the hedge time to regenerate.

The black locust, commonly called acacia, grows beautiful vertical shoots, thorny but solid, durable.

The blood dogwood produces long, flexible branches in the spring, then rigid, with branches that are easily lopped off. The longest stems are used as stakes to support large plants and climbers.

Another hedge shrub, with the hardest wood and the tastiest berries, the male dogwood. It was used as a wedge to split wood, harrow teeth, ladder rungs. Its stakes are extremely solid. The grandfathers found a certain interest there...

Grandfathers and children

...And knew how to recognize reliable wood that could withstand the weight of years. The cane was harvested on the edge of the meadow. Dogwoods, but also serviceberry and hazelnut trees, were appreciated. Sometimes honeysuckle was mixed in, and its imprint marked the wood with an elegant spiral. The male dogwood, so hard, became also javelin... For the pleasure of children, who remember their grandfather, find the yew, the cytise and the ash to make bows, the elder for whistles and blowpipes, the boxwood for toys, buttons and spoons.

Maintaining an old hedge, planting an all-purpose hedge, in spite of the blackthorn's readiness to escape, the bramble's readiness to go prospecting, is an encounter. Locate the handles of his future grelinette, the flexible branch that will be used to repair his straw hat. Twine the honeysuckle around the grandfather's next cane. Preparing a long vine stake. So many gestures of another rhythm. And new plantings to be made, for shrubs combining diversity, flowering, and practicality.