Weeds will grow almost anywhere; the best defense is proper maintenance.
Moss will grow on almost any surface in the right conditions. Over time, airborne particles such as dust and dirt will combine with the sand in the joints to create a perfect place for moss to thrive. Shady spots, humid conditions, damp areas and periods of prolonged wet weather will accelerate growth. The best way to get rid of moss is to be proactive and remove it early.
Properly sealed pavers will minimize maintenance and will help prevent oil, grease, food, drink, leaf and pet stains. (If pavers are sealed, stains are less likely to penetrate into the paver pores.) Sealing can also reduce wear and tear, slow fading, retard the growth of moss or mildew and inhibit weed infestation. Sealing will keep your pavers looking like new for a longer time.