Gardeners understand that plants have specific ph requirements. most plants thrive in soil with a ph that is slightly acidic, neutral, or slightly basic. imagine your soil is very acidic, with a ph of 3.5. how can you raise the ph to an appropriate level so your garden plants will survive? a) add fertilizer. b) water frequently to wash away the acid. c) add organic matter like peat moss or humus. d) add a base like limestone or calcium carbonate.