
The problem I had in my garden was trying to find bulbs I planted once the foliage had died down. You can easily add plant markers and stakes in the ground to mark where your plants are planted but when you go to dig up the bulbs, tubers or rhizomes you may end up damaging the plant with the trowel or shovel.
It occurred to me that what I need was something that surrounded the bulbs and gave me a visual clue when I was getting close to the bulb. What I did was place one of those plastic baskets that strawberries come in at the grocery store in the ground and then placed my Calla Lily bulbs inside that. You can see an image of what I'm describing at the link above.
A few days ago when I went to lift my Calla Lilies from the ground to store them for the winter I was easily able to locate them in the ground and bring them out of the soil without damaging them as you can see from the photo above. I noticed this also made it easier to locate any offsets or "bulb babies" produced by the plants I did this to. I'm going to do this in the garden again next year and expand it to include more bulbs-but I'll make larger trays with chicken wire so I can add more bulbs and lift them all at once.