Choosing the right hedge plants

Growing conditions

The first thing to know about a plant, when you want to buy it, is the way it has been cultivated?

Cold resistance 

Has the plant been grown in a heated greenhouse, cold greenhouse or outdoors? A plant grown in a greenhouse, where temperatures do not go below 0°C for a cold greenhouse, does not have the same capacity to resist the cold as a plant grown outside. The first climatic hazard will be fatal.

Disease resistance 

Has the plant received phytosanitary treatments or not? If, during its first months or years of cultivation, it has received treatments, its capacity to defend itself against external aggressions is null; it will thus remain dependent on its treatments, to face possible future diseases.

The capacity to feed itself 

Has the plant received regular fertilization or not? A plant that has grown with a lot of fertilizer has not developed an efficient root system. If, once planted, you stop giving it nutrients, its recovery may be compromised.

A plant from an organic nursery that uses natural treatments in a reasonable way is prepared to grow and prosper later on with a minimum of care.

Points to check

At a glance you can also verify, in part, the quality of a plant for sale.

The root system

A plant that is not sufficiently rooted has little chance of recovering after being transplanted.

If when you gently pull the plant by the stem to remove the root ball from the pot and some soil remains stuck on the edges of the pot, the rooting is bad.

On the other hand, too strong a rooting, visible by roots that turn at the bottom of the pot, can cause the formation of a root bun, which will eventually suffocate the plant.

Tip: good rooting can be seen when the root ball is firm and keeps the shape of the pot when unstuck.

Branching

Numerous branches are a sign that the plant has been pruned several times, by a professional, to give it a bushy and dense habit, ideal for a hedge.

The root ball

The trunk, just below the collar, must be attached to the root ball. If it is not the case, do not buy it.

Create a themed hedge

A hedge doesn't have to be a plain green wall with no surprises! Ecological, scented, flowery, country-style... Hedges come in a variety of forms and themes. Here is a quick overview...

Hedges adapted to the soil

Many themes revolve around the climate, the nature of the soil or the specificities of your region. The choice will be made according to these criteria.

The seaside hedge: it will be composed of shrubs that can withstand sea spray, sandy soil and sometimes violent winds. Among them are eleagnus, escallonia, juniper or phormium.

The hedge for mild climates: it will include moderately hardy shrubs that can withstand the heat well. Oleanders, grevilleas or tamarisk are perfectly adapted to this use.

Hedges for limestone soils: limestone is not tolerated by all plants, which is why there are "ready-to-plant" kits for hedges in limestone soils. You will find buddleias, lilacs or seringats.

Hedges for shady gardens: most plants like the sun and will not grow well in the shade, fortunately some plants are still adapted to it. Among them, camellias, hollies, or even large rustic fuchsias.

Ornamental hedges

Beauty will be the criterion for selecting the shrubs that make up these hedges, but always following a very specific theme.

The hedge with colored foliage: as its name indicates, it is composed of shrubs with remarkable foliage that can vary with the seasons. The choice is vast among the cultivars of holly, spindle trees with variegated foliage, but let's not forget the warm colored foliage of dogwoods, photinias or cotinus.

The flowering hedge: the shrubs chosen will be for their opulent flowering and staggered over several months. Ceanothes, spireas, choisyas, deutzias or forsythias are perfect for this purpose.

The decorative berry hedge: some shrubs produce bunches of red berries after flowering, such as Nandina and holly, but also purple fruits such as the amazing Callicarpa and Mahonia, or black ones such as sambuscus.

Practical hedges

This type of hedge is bound to be useful in the garden.

The windbreak or privacy hedge: it should be composed exclusively of evergreen shrubs to ensure its protective function throughout the year. Bamboos, conifers but also boxwoods will have these assets.

The ecological hedge: it attracts the gardener's helpers by offering them shelter and food. Low shrubs, but also taller subjects will compose it. Flowers, berries... a maximum of diversity should be made available to the animals. Berberis, Cornus, viburnum or prunus can be used.

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.