When you talk about the work of gardeners, you think about digging, planting, weeding, and making spur of the moment trips to the Farmers Coop, Home Depot or some such place. Those shopping trips can range from fertilizer, soil, tools – and more plants. Of course there is a price to pay at the check-our counter. Or, you can take the suggestions of Gardening Hacks, a small book by Jon VanZile (Adams Media $15.99) with over 300 Time…