Select an iron-on patch material that is close to the color of the patio cushion cover.
Cut the patch material so it is longer than the rip in the cushion by at least one inch.
Slide the patch material through the rip. Position the patch material adhesive-side up to cover the full length of the rip plus 1/2-inch on each end.
Bring the torn fabric together with your fingers and hold the patch and fabric firmly in place.
Heat your iron to the cotton setting and iron the torn fabric onto the adhesive side of the patch. Keep your iron moving. You can place a linen hand towel over the ripped area so the movement of the iron does not disturb the placement of the fabric. Iron until the adhesive sets well. Check the manufacturer's suggestions for how long this should take for your product.