Soil acidity refers to the pH level of the soil, with a pH of less than 7 for acidic soils or pH greater than 7 for alkaline soils. Most garden centres will test the acidity of a soil sample and recommend amounts of lime to add to raise soil pH or sulphur to lower soil pH to optimal levels. Vegetables grow in soil ranging from pH 5 to pH 8, with most vegetables growing well in slightly acidic soil with a pH between 6 and 7. However, a few types of plants grow in especially acidic soil.
White potatoes and sweet potatoes are two of the most acid-loving vegetables you can grow in your acidic soil. According to Mississippi State University, both will grow in soil with a pH as low as 5. Colorado State University extends the pH range to as low as 4.5 for sweet potatoes and 4.8 for white potatoes. Potatoes will not grow very well in soil that has a pH over 6, so you should set aside a portion of your garden with especially acidic soil for potatoes.
The nightshade family of vegetables includes summer favourites such as tomatoes, peppers and eggplants, all of which thrive in acidic soil. Plant peppers, tomatoes and eggplants in acidic soil with a pH between about 5.5 and 7. All three types of plants do best in warm weather, so start seedlings indoors and move them outside only after the danger of frost has passed.
In addition to potatoes, a number of other root vegetables grow in acidic soil. Carrots, rutabagas, parsnips, turnips and radishes all grow in soil with a pH as low as 5.5, according to Colorado State University and Extension.org. These vegetables will also do well in only slightly acidic soil with a pH closer to 6.5 or 7.
Some Other Vegetables
Beans, rhubarb, corn, cucumbers, endive, soybean, summer squash, winter squash and celery all grow in acidic soil with a pH of 5.5 to 7. Sweetcorn and pumpkins may even grow in alkaline soil with a pH between 7 and 7.5, according to Extension.org. If you are unsure of whether a particular vegetable will grow in acidic soil, ask your local garden centre or look it up on a university extension website.