The Hart Plant Hole Diggger system isn’t just about the diggers! Be sure to complete your purchase with a Nutrient Tube. The PHD Nutrient Tube is made of high quality tubing with stainless steel handles to last just as long as your digger. With the Nutrient Tube, finally; there’s a simple solution to easily get fertilizer in your plants’ holes! The Hart Plant Hole Digger’s best complementary product is this Nurtrient Tube that allows you to get fertilizer, bulbs and more directly into your freshly planted holes, without any bending.