By Jim McCausland, Sunset senior garden writer

Robert Kourik is crazy about roots. He’s studied them, collected specimens that are displayed all over his property, and now written a remarkable book about them. Called Roots Demystified (Metamorphic Press, Occidental, CA, 2008; $25), it is based in part on meticulous, decades-old drawings of actual root systems from many kinds of plants.

In support of the drawings and the theme, the book includes a mountain of trivia, to wit:
—Half or more of the total mass of many trees is below ground;
—Growing root tips (caps) produce their own lubricant that helps them force their way through the soil;
—About 90 percent of a tree’s roots typically grow in the top 18 inches of soil, and in some forest trees, half of that grows in the leaf litter above the soil surface (so keep your trees well mulched);
—Some trees send roots down 200 feet, and out many times the radius of the tree’s canopy.

You get the drift. Yet Kourik’s prupose isn’t to amaze you, but to instruct. To that end, the book is filled with practical tips for gardeners that are geared toward making the soil a better environment for roots. Along the way, Kourik necessarily covers composting, weed control, watering, no-till vegetable gardening, planting, and much more.

I recommend this as a standard reference. You can get it from the author at www.robert-kourik.com; $25 includes tax and shipping.