Monday, April 8, 2019

Pumpkin MythBusters: How Big is a Pumpkin Root System?

I often see posts from growers asking how far down the tap root goes down and how far out the root system goes out from the stump on a pumpkin plant.  I found this old study many years ago and thought I would share it here again.  Too often I hear growers share their opinion about the width and depth of a pumpkin plants root system that are just wrong.  I think the best growers understand that when you bury vines, the entire patch can be covered in roots if the proper environment is created.

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 knowledge, 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.

It is probable that the root systems of larger pumpkins varieties such as Atlantic Giants may be much more extensive than those reported in this book.  In no post asking about the depth of the roots have I ever seen anyone post that the roots go 6 feet deep.  Usually comments are about just a few feet.  I'm busting that myth here.  Would be interesting to see how much bigger a root system of a 2145 McMullen in world class soil would look like in comparison to a Small Sugar variety.

Growers should carefully consider their walking boards and how far out they are properly preparing their growing area.  If you aren't prepping at least 16 feet out from the stump in all directions you may be missing some opportunities.

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