My potatoes have just finished coming up and my soil test is showing the ph at around7.5.Is it to late to add something to the soil to lower it?I believe it should be around 4.5 – 6.Also my garlic is in the same planter.
Most gardeners don't have to be that particular about the soil pH of their potato rows. You can raise good potatoes with a pH ranging from 6.0 to 6.5, the slightly acid condition that is still suitable for many vegetable crops. However, lower pH is better if you want greater yields and less disease. Commercial growers monitor their soil ph carefully to avoid scab in the crop.
If scab disfigures too much of your crop, you should try to reduce the soil pH. While scab doesn't look great, it won't cause your potatoes to rot or decay, so you may decide to accept a little on some potatoes rather than start tinkering with your soil's pH. It's okay to eat scabby potatoes; simply peel and cook them normally.