In a “one-of-a-kind” research project in 1927, John Weaver and William Brunder, botanists at the University of Nebraska, grew many different vegetable crops and, over time, excavated and mapped the course of the root systems. They published their work in a book titled “Root Development of Vegetable Crops,” published by McGraw-Hill Company, New York. To my knowledgy, no one since has attempted such a difficult task.
Vines of ‘Small Sugar’ pumpkin were about 16 feet long at maturity and the top 12 inches of soil were filled with roots. The taproot of mature pumpkins grew 6 feet deep and had 10 or more lateral branches that extensively branched outward for 5 to 17 feet or more. Many of these lateral roots were 2 to 4 feet long and all complexly and minutely rebranched, forming a “wonderfully efficient root complex”. The second and third feet of soil were also thoroughly filled with roots, with the fourth foot of soil containing many vertically descending roots. Plant size of pie pumpkins, like ‘Small Sugar’, may not be as large and vigorous as the jack-o-lantern types. It is probable that the root systems of larger pumpkins such as Atlantic Giants may be more extensive than those reported in this book.