Growing a vegetable garden in acidic soil
Knowing the acidity of your soil is an important element for the gardener. Not all plants have the same needs and do not all grow in the same environmental conditions. Soil acidity has a significant influence on their growth, development, and productivity. Selecting plant species adapted to the nature of your soil is therefore essential to the well-being of both the plant and the gardener!
What is soil acidity?
Acidity is measured by a pH scale ranging from 1 to 14, which assesses the presence of H+ ions. Below 7, the soil is considered acidic. Above 7, the soil is considered alkaline or basic. The optimal pH range for plant growth and development is between 6 and 7.5.
Having soil with a pH below 6 doesn't mean that every crop is doomed to failure! Some plants even prefer these environments.
How can you recognize acidic soil?
Analyzing a soil sample in a laboratory is the most accurate method for determining soil acidity. However, observing wild vegetation can also provide clues! Heathers, ferns, broom, meadow sorrel, chestnut trees, pines, blueberries, creeping buttercups, and nettles are all "acidophilic" plants, literally plants that "like" acidic environments. Acidic soils are generally darker in color; the typical acidic soil is heather, but sandy soils are also predominantly acidic.
What makes soil more acidic?
Three main elements are at the origin of progressive acidification of a soil: organic and mineral matter which are naturally acidic, leaching by heavy rain or excessive irrigation which carries away minerals if the crops are not protected by mulch and finally ammonia-based fertilizers.
What to sow or plant in acidic soil?
With a pH between 6 and 7, the soil is balanced and provides good mineral nutrition. Most plants thrive in this type of slightly acidic environment.
Fruits and vegetables: cauliflower, kale, Brussels sprouts and broccoli, asparagus, leeks, radishes, celery, peppers, tomatoes, cucumbers, lettuce, beans, strawberries.
Aromatic herbs: garlic, basil, chives, thyme
Flowers: sweet peas, asters, chrysanthemums, dahlias, delphiniums, foxgloves, gladioli, hyacinths, roses...
The number of fruits and vegetables suited to more acidic soils (pH between 5 and 6) is slightly smaller. However, certain acid-loving plants play an important role in our diet. They generally have high iron requirements, a mineral that is good for our health and which they generously provide when they are found on our plates.
Fruits and vegetables: artichokes, carrots, peppers, chives, parsnips, rhubarb, shallots, spinach, raspberries, blackberries, blueberries, cranberries...Potatoes and squash particularly like acidic environments.
Aromatic herbs: Fennel, parsley, sorrel...
Flowers: Coreopsis, cosmos, iris...
Avoid headed cabbages, thyme, poppies, geraniums, lavender, mustards, centauries, primroses and hellebores, which would not thrive there.
