An irrigation device has a single layer flexible tube having an inner portion and an outer portion. A plurality of outlets extend through the tube in a spaced relationship along a length of the tube. Finely-divided hydrophilic silica particles are dispersed in the outer portion of the tube and not the inner portion of the tube, the tube thereby having an increased surface hardness to deter rodent, worm or insect damage. The tube is a low-density polyethylene or a flexible polyvinylchloride (PVC).
