When designing a garden in areas near the sea, or in soils that tend to be saline, it is essential to understand that not all plant species thrive under these conditions. Salinity can significantly affect the development and survival capacity of ornamental plants, fruit trees, lawns and grovesHowever, there is a very diverse set of species especially adapted to tolerate saline environments, both in the soil and in irrigation water.
What is soil salinity and how does it affect plants?
La soil salinity It refers to the accumulation of soluble salts (primarily sodium chloride, sulfates, and other dissolved minerals) in the substrate on which plants grow. This condition is common in coastal soils, dunes, and marshes, and can also occur in dry areas where irrigation or poor drainage causes salt buildup. Plants not adapted to salinity often show symptoms of stress. such as yellowing leaves, slowed growth, and even death.
The plants halophytes They are species capable of growing and developing in soils with a high concentration of salts, being vital for the creation of sustainable gardens in these adverse conditions.
Salt toxicity in the substrate can block the absorption of water and essential nutrients, leading to nutritional and physiological imbalances. Therefore, Choosing the right species ensures a vigorous and aesthetically appealing garden even in marine or brackish environments.
How to know if your soil is saline?
Identifying salinity in a garden can be done professionally through laboratory analysis, although there are simple home methods. One of the most practical is sow beans on the ground and observe the color of its leaves: If they turn purple instead of green, it is a sign of saline soil, since beans are extremely sensitive to salt and act as indicator plants.
Other signs include:
- Presence of whitish crusts on the soil surface.
- Poor growth and dry or deformed leaves in non-adapted plants.
- Recurring problems after rain, such as poor drainage or soil stains.
El degree of salinity can be classified as low, medium, or high. It is important to evaluate both the soil and irrigation water to ensure the selection of compatible species.
What mechanisms do plants use to combat salinity?
The salt-resistant plants They have evolved different physiological strategies that allow them to survive:
- Expulsion of salts through glands in the leaves.
- Salt accumulation in specialized tissues to prevent damage to vital organs.
- Dilution of salts increasing the water content in their cells.
- Development of deep roots to access less saline waters.
- Hormonal alterations and photoprotection processes, according to studies such as that of The Plant Journal on Arabidopsis.
The above explains the tolerance of many halophytes and their usefulness in restoration projects, sustainable landscaping and even improvement of agricultural soils affected by salt.
Best grass species for saline gardens
One of the common demands in areas near the sea is turf. To prevent growth problems and facilitate maintenance, It is recommended to select species that are especially resistant to salinity:
- Bermudagrass (Bermuda): very attractive and easy-care grass, although it is not very resistant to cold.
- Stenotaphrum (Gramón, St. Augustine Herb): the most resistant to salt and with excellent adaptation to all types of soils.
- pennisetum clandestinum (Kikuyu): very aggressive, low maintenance and high efficiency in saline and dry soils.
- Zoysia Japanese lawn grass (Zoysia): warm and dense grass, ideal for areas with high temperatures and slightly saline soils.
- Paspalum (Bahia grass): very hardy, tolerates salt, shade and frequent trampling well, recommended for warm areas.
A lawn suitable for saline soils will offer a homogeneous and resistant green cover even with irrigation with slightly brackish water or exposure to sea breezes.
Trees, shrubs, palms and climbers for saline soils
Depending on the design and the needs for shade, height, or privacy, there are numerous halophytic trees and shrubs suitable for marine or saltwater soils:
Trees resistant to salinity
- Olive (Olea europaea)
- Acacia (all species)
- Eucalyptus (all species)
- Holm oak
- Mulberry (Broussonetia papyrifera y Morus)
- Pinos (stone, maritime, holm oak, canary)
- black maple (acer negundo)
- Ailanthus (Ailanthus altissima)
- Araucaria (excellent araucaria)
- Arbutus (Arbutus unedo)
- Casuarina (Casuarina equisetifolia)
- cedrus deodara (Himalayan Cedar)
- Algarrobo (Ceratonia siliqua)
- Tree of love (Cercis siliquastrum)
- White poplar (the white)
- Granado (Punica granatum)
- Robinia, False acacia
- Soft tendons (Fake pepper shaker)
Halophytic and native shrubs
- Rosemary (Rosmarinus officinalis)
- Oleander (nerium oleander)
- jaras (cistus)
- Lavender (Lavandula spp.)
- Mastic (lentiscus pistachio)
- Myrtle (myrtle common)
- Teucry (Teucrium fruticans)
- White salty (atriplex halimus)
- Sabinas and junipers (Juniperus spp.)
- durillo (Viburnum tinus)
- Brooms (scented broom spartium junceum and white broom Monosperm broom)
- Cotoneaster
- Wild asparagus (Asparagus acutifolius)
- Caragana, Heather, Heather (calluna vulgaris, Erica spp.)
Palm trees and hardy exotic plants
- Canarian palm tree (Phoenix canariensis)
- Date palm (Phoenix dactylifera)
- Palm hearts (Chamaerops humilis)
- butia capitata
- Robust Washingtonia y filifera
- Trachycarpus fortunei (raised palm)
- Feathery coconut (Arecastrum romanzofiana)
- Blue palm tree (Erythea armata)
- royal palm (Roystonea regia)
- Dragon (dracaena draco)
Climbers, cacti and halophytic succulents
- Buganvilla (Bougainvillea)
- Ivy (Hedera helix)
- Honeysuckle (lonicera japonica)
- Passionate (Passiflora caerulea)
- Celestina (plumbago auriculata)
- Tecomaria (Tecomaria capensis)
- Cactus and succulents: Agaves, Aloes, Euphorbia, Kalanchoe, Lampranthus, Sedum.
Herbaceous plants, flowering plants and salt grasses
- Achillea millefolium (Yarrow)
- alyssum saxatile (Golden basket)
- Antirrhinus major (Snapdragon)
- Maritime armory (Coastal Armory)
- canna indica (Indian cane)
- Gazania spp. (Gazanias)
- Helichrysum petiolare (Always alive)
- Lavender spp. (Lavender and lavender)
- Fescue glauca (Ornamental grass)
- Woolly Stachys (Hare's ear)
- Romneya coulteri (Poppy tree)
These species provide color throughout different seasons and many of them stand out for their ability to withstand drought, light frosts and direct sunlight exposureTo learn about other plants that adapt to similar conditions, you can explore resources such as characteristics of aquatic plants.
Native selection: native species of the peninsula adapted to salinity
Bet for native plants It is essential to create sustainable gardens, as they present a natural adaptation to the local environment and require less watering and maintenance. In Spain and Mediterranean areas, the following stand out:
- Oleander
- Privet
- Jujube (Zizyphus lotus)
- Heather
- Cotoneaster
- durillo
- Wild asparagus
- jaras
- Lavender, spike lavender and cantuoso
- Mastic
- Myrtle
- Rosemary
- White salty (atriplex halimus)
- Sabina and junipers
- Taray, Tamariz, Taraje
- Teucry
- Canary Island date palm, dragon tree and fan palm
Ornamental, ecological and agricultural uses of halophytic plants
The salt-resistant plants Not only do they beautify gardens, but they also offer environmental and agricultural benefits. They help:
- Recover soils degraded by salinization.
- Protect fragile ecosystems of dunes, marshes and estuaries.
- Serve as a refuge and food for wildlife.
- Allow alternative crops in saline agricultural areas (plants that grow in saline soils).
- Provide natural coastal protection against erosion and sea wind.
Growing and management tips for salt gardens
- Know the degree of salinity before selecting species and making irrigation decisions.
- Use drainage layers and organic substrates that reduce salt accumulation.
- Add organic matter regularly to improve soil structure and reduce salt retention.
- Carry out abundant, evenly spaced irrigation to displace salts towards deeper layers.
- Avoid fertilizers with high saline content, such as those rich in potassium chloride.
Proper management will allow you to enjoy colorful, climate-resilient gardens with low water requirements. To improve mineral absorption in these soils, you may be interested in consulting information on magnesium sulphate.
Current research in salinity tolerance
Recent studies, such as the one published in The Plant Journal, have identified genetic and hormonal factors in species such as Arabidopsis that influence salinity tolerance, opening up new opportunities for genetic and biotechnological improvement Crops to address the challenges of salinization in agriculture and gardening. To learn more about this research, you can visit Actions and challenges in palm tree conservation.
