The Mediterranean Garden

The greatest challenge in designing a garden is finding a balance between the climate in which it will be configured and the resource that will allow it to flourish: water.

In Mediterranean garden, in fact, it is good practice to use native plants to ensure sustainable development over time.

Similarly, for example, the so-called English garden derives from this, which will follow the same climatic conditions, and therefore with a different water supply and solar radiation compared to the Mediterranean one.

In both cases, it is possible that some native plant types can also be used in different climate zones, but it is necessary to take into account the compensation effort required during the design and maintenance phase of the garden (sustainable garden).

The Mediterranean garden, in climates like the Italian one, besides promoting local diversity, contributes to the reduction of maintenance over time by self-regulating.

The evolution of the context of the territory and its landscape is linked to its use in relation to human activity dating back to the Ice Age. These particular conditions have meant that the flora of the “Mediterranean” basin has developed with an immense wealth of vegetation over time. This high biodiversity is a characteristic element to be preserved through the preference for native species that preserve its characteristics.

The aridity in the Mediterranean represents an extraordinary possibility, since the bad use of irrigation limits the growth and development of the garden itself. In soils with a lower water supply, the development of plants is favored by the conditions of their origin, since if irrigated especially in the hottest seasons they tend to obtain the opposite effect and therefore develop very little; in the worst case scenario they might not even survive. 

Il cistus, ceanothus and Capparis spinosa (caper) for example do not tolerate heat combined with humidity, which in this case tends to cause the plant to die completely.

Instinct leads us to think that water is synonymous with a lush garden, while dryness is synonymous with shrinkage. In the case of the Mediterranean garden, it is exactly the opposite, in fact in nature the flora in these climates is richer than in temperate ones.

Plants of this type of climate have had to specialize in adverse conditions during their evolution; their diversification is due to the great ease of adaptation to the extreme situations of their different types of soil, exposure, latitude and altitude. This diversity constitutes an inexhaustible source for gardens.

The composition of a Mediterranean garden implies, in addition to the use of species typical of the climatic zone with specific characteristics that we will see later, the types of soil that in most cases must ensure:

• a feature of high and dry drainage.

• a substantial reduction in irrigation especially in the summer months.

• the use of layers of mulch to limit the evapotranspiration of water which we will address specifically in the next articles.

In composing a Mediterranean garden, therefore, in order to compose it at its best, in addition to the diversification of species, it is necessary to understand how to plant and care for vegetation in different types of arid soils, enhancing the diversity of their survival techniques, composing a green space that is aesthetically pleasing, original and functional.

The types of plants are many and different, they vary according to our needs, we can choose and dose the quantity of each of them and by mixing them, create the desired effect.

To do this we need to use, understand and comprehend the different types of plants that differ in species behavior.

Annual plants

The characteristic of annual plants is that they bloom in a certain period of time; their main characteristic is that they disappear completely or partially when the climatic conditions become difficult. Annual plants germinate and at the right time they drop seeds that in the next vegetative cycle will be ready to develop a new vegetative cycle.

With the rainy season the seeds will be able to develop shoots to be able to flower again, generally the vegetative rest is in winter, followed by a more vigorous phase in conjunction with the more favorable climate of spring, to then explode with flowering. 

This type of plant has very showy flowers, this characteristic is given by the urgency to attract pollinating insects to proceed to the next cycle after death.

In regions characterized by a desert climate, for example, the vegetative cycle is very short because rains are very rare during the year; in this case the plant, which is generally native, germinates the same day it rains, flowers quickly and dies in a few days, meaning that the seeds will remain hidden for the rest of the year until the time of new germination. 

Here too the colours are very vivid and the flowers can form a covering on the ground, almost as if it were a ground cover. The landscape of these deserts suddenly covered with flowers is an attraction in South Africa in Namaqualand, or on the Atacama coast in Chile.

In the case of the Mediterranean climate, annuals have a similar function. To support the growth of these plants, maintenance work will be carried out for selective weeding, in order to maintain the wild annual plants, whose decorative flowering can represent an additional element of value in the construction of a Mediterranean garden.
 

In building a zero-impact garden, the goal is to learn and understand in depth the types of local plants and to favor these in the composition of a sustainable garden.

A small corner of annual species in the sustainable garden can be for example an important reserve for pollinating insects and local fauna; this increases biodiversity, improves the natural balance and decreases diseases caused by parasites in the rest of the garden.

To choose the most optimal position for the placement of a detailed corner of a garden I invite you to delve deeper into the Archweb article: Basic Guide: Garden Design

The Geophytes

Geophytes are plants commonly called "bulbous", their characteristic is essentially given by the fact that they "hide" from the sun. There are different types of bulbs, such as those with onion tulips and daffodils, pseudobulbs that have a swollen base of the stems such as cyclamens and Stembergia, tuberous rhizomes which have fleshy horizontal stems like asphodels and irises.

In this case, the adaptation to aridity is very similar to annual plants, they disappear completely to survive. During the rest period, the plant takes in all the nutrients and assimilates them in the underground tuberous organs. During the hot season, the plant withers completely but recovers completely during the vegetative cycle corresponding to the rainy season in autumn.

The blooms are usually very short but extremely decorative, an example is theAgapanthus which blooms in the month of July and theIris unguicularis.

The sclerophylls

Sclerophyllous plants limit transpiration, developing persistent, thick, leathery leaves, whose upper surface is covered by a waterproof waxy cuticle, from which the Greek term derives scleros = hard, phyllo = leaf

In this type of leaves all the flocks are located on the lower surface of the leaf protected from the sun. The ostiole (small opening of the epidermal tissues of the plant) of the stomata, in summer is reduced to a minimum to slow down dehydration. In some plants, the stomata are housed in "somatic crypts", that is, very deep holes equipped with "hair crypts" for the hairs that allow to further reduce the loss of water, such as the nerium oleander.

The sclerophyllous plants of the Mediterranean scrub are many and varied. Oak Ilex (holm oak), Arbutus Unedo (strawberry tree), Phillyrea, lentiscus pistachio (mastic tree), myrtus communis (myrtle).

Deciduous plants

Deciduous plants are typical of areas with a very arid climate. To resist this type of climate they completely lose their leaves at the beginning of the dry season. In this phase of plant development we have a total saving of energy given both by the production of leaves and by the non-existent photosynthesis. The fall of leaves can also be considered ornamental, some plants such as the silhouette of Sarcopoterium, without leaves takes on a curious and original shape. We can therefore affirm that plants tend to show strategies to accumulate water more if there are conditions of water shortage.

To do this they apply some different strategies such as reducing the surface exposed to the sun and evapotranspiration, through the epidermal cells. Rosemary for example has a singular characteristic, if you observe it closely you can notice that the edges of the leaf are rolled up on themselves towards the lower page, this causes the surface of the leaf to be much larger allowing it an optimal photosynthesis, but reducing direct exposure to the sun's rays and therefore a loss of water through evapotranspiration.

In the case of cacti, however, the optimization of water loss becomes a priority process, the leaves disappear completely and transform into spines that guarantee defense against predators and the stem ensures photosynthesis.
By decreasing the leaf surface there will obviously be less photosynthesis which in turn will greatly decrease the growth of the species (slow growing plants). 
Another strategy of plants to reduce the exposed surface is to keep the leaves in a horizontal position to receive the sun's rays perpendicularly, an example of this are grasses.

In order to reduce water loss by the plant, some plants in certain climatic conditions develop, as an adaptation, protection with hairs, which now allows to reflect light and reduce heat at the leaf surface level, directly decreasing evapotranspiration.

The hairs also act as a windbreak, in fact they create a microclimate useful for preserving the gaseous exchanges of photosynthesis. This diversity offers a variety of choices in the composition of a garden given both by the color tones of the plants, and by the type of leaves and their appearance. In an arid garden therefore the silvery foliage of the Tanacetum dense It can become an excellent base for enhancing plants with brighter and more gaudy colours such as salvias.
 

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Cover photo: Assogna Stefano

References
For a Mediterranean Garden. Green without irrigation O. Filippi
Tracanni.it
actaplantarum.org