At planting time, organic gardeners might think about pH, the acid/alkalinity balance in the soil. Some plants prefer an acid soil, while others do not. Planting your acid-lovers together will help them grow, because you can use acid soil amendments. For example, you could plant lilies, roses, and alyssum in the same bed, because they all prefer acid soil.
If you grow plants that are native to your neighborhood, your soil will be just fine. But if you want to add non-native fruits and vegetables, or anything non-native, you might want to think about pH.
Never add something to change the pH of your soil before testing the pH of your soil.
To find the pH of soil:
- Get pH test strips from a pharmacy or organic garden store.
- Test your water.
- Dilute some soil in your water; test the result and compare it to the pH of your water.
Compost tends to be neural and will tend to correct an imbalance in your soil. In general, most plants prefer neutral or slightly lower: pH 6.0 to 7.0. Do not over-correct.
To make soil more acid (lower pH) mulch with leaves, pine needles or coffee grounds (which you can get for free from Starbucks or other espresso places) or buy organic fertilizer labeled "for acid-loving plants."
To make your soil more alkaline (higher pH) add wood ashes or lime (not too much!) to the soil or to your compost.
See organic gardening books and websites for other options. Look for what is easily available in your neighborhood.
Do you really have to worry about all this? No, not really. Most gardeners don't. But if you are worrying about it, you can print out this chart and take it out in the garden at planting time, so you don't have to drag garden dirt into your house to find your organic gardening books to look up the pH of what you are planting.