Suede is a delicate fabric, easily damaged by the elements. But a number of waterproofing products create a protective barrier that will keep the fabric healthy and maintain the original color. Available at most shoe and outdoor/camping stores, these products are an inexpensive way to protect your boots from weather and stains.
Brush the suede of the boots so that the grain is all facing in the same direction. Run your hand across the surface of the suede; any portion that is darker than the rest is pushed against the grain. Brush gently until no darker portions remain, as this will prevent clumping during the waterproofing process.
Hold a boot in one hand and spray around the entire suede surface. Do not to miss any sections. Spray evenly, as a heavier coating in places may cause permanent discoloration. Repeat this process on the second boot. Do not attempt to spray them both at the same time or the waterproofing may be uneven.
Set the boots on a towel to dry, preferably not in a closed room. The spray will leave an odor that may make people nauseated if the room is not properly ventilated.
Allow the boots to dry fully, about 24 hours, before wearing them again. Test for dryness by touching a small portion toward the sole of the boot.
While the spray creates a water-repelling seal on the boots, the suede is not immune to saturation. To maintain the seal, pat the suede dry after every encounter with rain or water and allow to dry once again. This will keep the boots protected from damage.
Certain waterproofing products may cause change in fabric color, so spot test on an inconspicuous area of the boot prior to application.
Make sure that the product is designed for suede, not just leather. While similar, some leather treatments will not react the same and may ruin the fabric of the shoes.
Look for a spray that touts "breath-ability" as some waterproofing products will close off the skin and cause feet to sweat.