As explained in our Soil PH Adjustment article, you can raise the local PH with some Liquid Lime. Each gallon of concentrate can effectively raise the PH .5-1.0 per 17,500 sq/ft. Test weekly following the application and if it's not high enough in one month, apply some more. In most cases, the impact from the application can be seen in 2-3 weeks but wait a month just to be sure. Use a lot of water to apply the Lime. The more water used the faster the impact the treatment will have.