069 Understanding Roots with Robert Kourik


What do roots tell us about how to take care of plants? That’s the topic of this week’s Root Simple Podcast with our guest Robert Kourik. Kourik is the author of many books including Designing and Maintaining Your Edible Landscape Naturally and Drip Irrigation. The discussion begins with the remarkable tree root diagrams pioneered by Dr. John Weaver in the 1920s and 30s and featured in Kourik’s new book Understanding Roots. From there we touch on how to plant fruit trees and the intricacies of how to water trees, vegetables and native plants. Then we delve deep into drip irrigation, dynamic accumulators and phytoremediation.

If you’d like to pick up a copy of one of Robert’s books visit robertkourik.com.

If you want to leave a question for the Root Simple Podcast please call (213) 537-2591 or send an email to [email protected]. You can subscribe to our podcast in the iTunes store and on Stitcher. The theme music is by Dr. Frankenstein. A downloadable version of this podcast is here.

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  1. As someone who jumped on the Comfrey bio-accumulator bandwagon and has dug up many to divide and transplant, I have noticed that the roots do not, as Mr Kourik said, go that crazy deep into the soil. Not nearly as deep as, say, plantain weed or rhubarb. Anyways, thanks for this interview. Great topic as always!

  2. The comfrey root drawing in my book shows the roots growing less than 2 feet deep. My chapter is on the subject the comfrey does not grow 10 feet deep like a lot of Permaculture literature says.

  3. Great podcast, Robert and Eric! I hope Robert will speak again at SF Flower and Garden Show.

    I wonder if you have any thoughts on respecting roots when using greywater. I’m designing a simple laundry-to-landscape system for my fruit tree/perennial area and I’ve been stumped on designing the receiving mulch basins. I worry mulch basins, even a wide shallow ones, could limit root growth of a young tree if no broader irrigation were also applied. I also worry about damaging roots of my older fruit trees when digging basins around them.

    • Yes too much water in the same place near the trunk will tend to localize the roots and reduce their growth outside of the basin area. Make the basin out at the dripline and perhaps redo it every couple of years to match the growth of the dripline. There will be some damage to existing roots when digging a basin. But a one-time dig is not that bad, the roots will recover with a permanent mulch.

  4. Another reason I have Root Simple bookmarked. You provide so much in the way of interviews, with great subjects, that cut through the hype commercial crap. I write things down, and make a point of further researching, and using the info in my efforts in home and garden activities! I am very thankful for all that you do at Root Simple and for the great wealth of information from Mr. Kourik.

  5. Really enjoyed the podcast! Mr. Kourik’s Roots Demystified book earned a spot in the slim bookbag I schlep when working a Ask-A-Master-Gardener booth. Those pictures are such a huge help when talking to people about watering and how plants grow. I’ll definitely check out the new book – thanks for highlighting it.

  6. This was a great podcast. It is true that we can support the existing AM networks with mulching and low-till methods. This indeed is the way to go.

    However, I disagree with Kourick’s concerns about innoculating plants’ roots with AM especially with new plantings or putting out new seedlings into a garden. Gardens and yards are areas of high activity and with many of us, also areas of great disturbance as we cultivate our edibles form season to season whereby we break or shred many existing soil fungal relationships.

    Secondly, one need not buy AM, one can inoculate and area with AM simply by using some soil from a relatively undisturbed natural area or other part of the garden incorporating it with the root zone of the new planting.

    Thirdly, he worries about a ‘war’ transpiring underground when store bought AM is added with AM already present. There is always a microbial ‘war’ or ‘party or ‘circus’ going on in the soil with comings and goings every moment. Are we making a better or worse ‘soil party’ when we add compost or mulch – both loaded with microbes?

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