The acidophilic plants They stand out among the plant world for their beauty, color and, especially, for their specific substrate needs. These species require acid soils To grow healthy and vigorous, it's essential to know how to care for them to enjoy vibrant gardens and terraces. Although they are native to regions with frequent rainfall, they can now be successfully grown in a variety of environments by following certain key recommendations.
What are acidophilic plants?
The acidophilic plants are those that need to grow in soils with an acidic pH, below 7, ideally between 4,5 and 6,5. This allows them to absorb essential nutrients such as iron, manganese and zinc, essential for photosynthesis and the healthy development of foliage and flowers.
The pH of the soil determines the availability of nutrients and the health of these plants. If they are planted in alkaline soils or "hard" soils, symptoms of chlorosis (yellowing due to iron deficiency) can quickly appear on the leaves, compromising the plant's well-being and longevity. Therefore, knowing and controlling the substrate's pH is the first step to proper cultivation.
Main species of acidophilic plants
Among the most popular species are:
- Hydrangeas (Hydrangea macrophylla): They are notable for their large inflorescences and require very acidic soils for their flowers to acquire intense blue tones. They prefer semi-shade and constant humidity.
- Camellias (Camellia japonica): Winter-flowering shrubs with spectacular flowers and lustrous leaves. They require soft water and a well-drained, acidic substrate.
- Azaleas and rhododendrons (Rhododendron spp.): Highly prized for their colorful spring blooms. They prefer acidic soils, lots of organic matter, and humid environments.
- Gardenias (Gardenia jasminoides): Known for their fragrant white flowers, they require very acidic soil and protection from frost and extreme temperatures.
- Heathers and heathers (Erica spp., Calluna vulgaris): Small shrubs with abundant flowering in shades of pink, purple, and white. They are very hardy and extremely acid-loving.
- Other species: Skimmia, Pieris japonica, Ebúrnea (Gultheria procumbens), Magnolia soulangeana, Hamamelis, Leucothoe, Pernettya, Osmanthus fragans and Clerodendrum trichotomum.
Not only in the ornamental garden do we find acidophilic species; some horticultural and aromatic plants such as basil, dill, parsley, mint y eggplants, pumpkins, melons, beans or lettuce They also benefit from acidic soils to optimize their harvests.
Basic characteristics and needs
Acidophilic plants have some very marked characteristics as for its development:
- pH Requirements: They require soils with an acidic pH, between 4,5 and 6,5.
- Humidity and environment: They prefer humid, rainy environments without prolonged exposure to direct sunlight or severe frost. They are common in regions with temperate summers and mild winters.
- Nutrients: They need balanced intakes of macronutrients (nitrogen, phosphorus, potassium) and micronutrients, paying special attention to iron, which is essential to prevent chlorosis.
- Limescale protection: Limescale in water or soil can be very harmful; watering with rainwater or acidified water is recommended.
It is important to perform periodic soil analysis to check the pH and adjust it if necessary. This can be done with electronic meters or with litmus strips made from a mixture of distilled water and garden soil.
How to prepare and maintain acid substrate
To successfully grow acidophilic plants, it is essential prepare a specific substrate:
- Employ special commercial substrates for acidophilus (heather, chestnut or blond peat), which are already prepared with the appropriate pH.
- In gardens, if the soil is alkaline, remove about 40 cm of soil and replace it with this specialized substrate.
- If you prefer to amend the soil, mix the original soil with blond peat and well-rotted leaf mulch, approximately half and half.
- Make mulches with pine bark, which in addition to retaining moisture helps maintain acidity.
- Repeat these amendment operations every 2-3 years to ensure an optimal environment.
Using pots makes it easier to control the substrate and pH, making it a great alternative in areas where natural soils are unsuitable.
Irrigation and water acidification
Irrigation water plays an essential role:
- El rain water It is always the best option, as it is naturally low in lime.
- If tap water is used, it should be acidified, for example by adding a few drops of vinegar or citric acid to the watering can or by using commercial products (iron sulfate or citric acid powder/dose).
- It is advisable to alternate acidified water and regular irrigation, taking care not to overdo it to avoid salt build-up.
- For large surfaces, iron sulfate can be applied at least once a month to neutralize limescale, suspending treatment in winter.
It is advisable to measure the pH of the irrigation water periodically and adjust the acidifier doses as needed.
Fertilization and frequent deficiencies
In addition to an optimal pH, acidophiles require specific fertilizers which, in addition to feeding, help maintain the acidity of the substrate:
- Fertilizers for acidophiles They must contain iron in the form of chelates, sulfur, magnesium and micronutrients, in addition to having an adjusted pH.
- La iron chlorosis (yellowing of young leaves with green veins) is one of the most common deficiencies; it is combated by applying iron chelates to the soil, either through irrigation or foliar application.
- Controlled-release fertilizers provide nutrients gradually, avoiding excess and ensuring long-lasting nutrition.
- Avoid fertilizing with lime-rich products, as they can raise the pH of the substrate and block the absorption of micronutrients.
The frequency of fertilization should be adapted to the stage of development, and it is also important to conduct periodic analyses to correct any deficiencies in a timely manner.
Location, light and protection from environmental factors
Correctly placing acidophilus is one of the keys to their proper development:
- Semi-shade: It is ideal in most cases, protecting plants from excessive sunlight, especially during the central hours of the day.
- Frost protection: The roots and flowers of many acidophilic plants are affected by intense frost or sudden thaws, so in cold climates it is advisable to use mulch or move pots indoors.
- Avoid exposure to this in areas with frost, as rapid thawing can damage flowers and leaves.
- Choose locations away from sunny walls to prevent reverberation damage.
Combinations and garden design with acidophilus
Acidophilus offers a great ornamental versatility, allowing the creation of flowerbeds with species of different heights, colors and cycles:
- In small gardens, prioritize compact, slow-growing species.
- Play with height: place the tallest ones at the back or in the center if the flowerbed is circular.
- Combine staggered flowering varieties for year-round color.
- Alternate deciduous and evergreen plants to avoid bare areas in winter.
The use of acidophilic plants in landscape design allows to obtain lush and colorful spaces, similar to those of Japanese and Northern European gardens, as long as their soil and water requirements are respected.
Acidophilic plants, due to their beauty and uniqueness, allow you to enjoy gardens and spaces full of life and color. By understanding and addressing their specific pH, substrate, irrigation, and location requirements, they can be grown successfully even in less favorable environments. Controlling soil and water acidity, choosing specific fertilizers, and providing them with a moist, protected habitat will ensure your garden remains in all its splendor for many seasons to come.