If your soil is below 6.0 (for turf type tall fescue) lime must be added to correct the pH. There are two primary types of lime, calcitic or dolomitic. Dolomitic lime contains naturally occurring magnesium that may well not be required for your soil, if your Magnesium level is low, then you should use dolomitic lime to raise the pH. Also dolomitic lime will take several weeks to months to affect the pH. Calcitic lime contains more Calcium than Magnesium, and should be used to raise the pH when the soil’s Calcium level is low and the Magnesium level is optimal.It also begins to raise the pH within a matter of weeks. Either way be sure to apply the granular variety.
If your soil tests alkaline, i.e., above 7.0 for turf type tall fescue it may be necessary to apply sulfur. Again, correction of a high pH will take months, if not years and many applications. NOTE: Sulfur is best absorbed into the ground when temperatures are high and in those seasons when we receive plenty of rainfall.