No worries man,
It would have been more effective to adjust the PH a few months ago. The very best bet is to prep your spots in the fall for next spring. But you can still do it now and get a good result. MJ is very hardy and withstands a wide range of conditions. Just check the PH and if it's low, add the lime when you plant. Check it again in 5-6 weeks and add more if its still low. Even if you plant it in real acidic low PH dirt it will still grow. But making a best effort to get it closer to 6.5-7.0 will give you a better grow. Dont forget to prep the spot thouroughly by turning over the dirt several times down to 10 inches or more. Dig up at least a 2X2 area for each plant. Add some compost at least 10 quatrts for each 2X2 area. Add TR ferts, and water crystals for best results.

good luck