Root depth and breadth

December 15, 2011 4:03 PM

I want to know how deep and how wide the roots of various plants will normally grow. Trees, gourd vines, wheat, clover, tomatoes, garlic, cilantro, marigolds, everything. I want to make sure my raised beds are high enough and also want to prevent plants from choking each other out.
posted by gray17 to home & garden (4 answers total)

http://www.harvestwizard.com/2009/04/interplanting_vegetables_root.html

This is all I've found so far.
posted by gray17 at 4:05 PM on December 15, 2011

It varies widely. Some annuals have the merest wisp of a root system which dies out quickly at the end of the season, leaving nary a trace by the next spring. Tubers don't really get much of one either, but they've got this huge honking bulb at the bottom which does send out roots somewhat. Then there's things like deciduous trees, which can have a root system that's actually almost as extensive underground as the tree is above ground. A lot of shrubs work that way too. Some plants have roots that run quite a distance over the surface but don't go all that deep, while things like dandelions don't spread at all but have a huge amount of depth. There's even plants that don't spread by seeds nearly as much as they do by just sending out shoots and starting "new" plants that way, i.e. an entire bed full of something like pachysandra or periwinkle may only consist of a half-dozen individual "plants". Then there's some plants, like wheat and corn, that really won't grow well on their own and need to be planted in close proximity to other plants. And mint just infests everything, to the point that a lot of people actually plant it inside buried PVC pipes to prevent it from taking over the entire garden in a year or three.

Really, you need to look up each plant you're interested in cultivating, as it's going to vary so much that I don't think anyone has produced a table of sorts.
posted by valkyryn at 4:30 PM on December 15, 2011

Vegetable root depth [PDF]
posted by unliteral at 5:33 PM on December 15, 2011 [3 favorites]

Steve Solomon's excellent Gardening When it Counts contains illustrations of the root systems of many common garden vegetables, with information on required soil depth and spacing.
posted by ryanshepard at 7:28 PM on December 15, 2011 [1 favorite]