I read this to the 3-5 yr old children at the daycare every time they visit my library for storytime. I always start with the explanation that "Enormous means really, REALLY BIG!" And then we talk about how a potato eye is a potato seed before we launch into this story. The kids absolutely adore this story and the rhythm it gets into. It's become a requested book and I even purchased a copy for our library to have because the kids want to take it home. Several times they have asked me to read it multiple times during the same story time session! It's gotten so popular that we even did a small lesson for them, bringing in a potato to show them the eyes and I created a coloring sheet to go with it. 
This book has been very popular with my daycare classes for years and it's a 10/10 from every 3-5 yr old I've ever met.