Root washed perennials – 3 months later

You’ll recall that in July I posted about root-washing perennials before planting them in the middle of our typically hot and dry summer in the Pacific Northwest.  I wanted to update everyone on how they performed now that we’re heading into our cooler and wetter fall months.

Just to remind you, here’s a photo of the garden right after planting:

South-facing pollinator garden

And here is the same garden, 3 months later:

Made it through the summer!

No plants died; in fact, as you can tell, they all thrived. They were watered twice a day during the hottest months and now are rain watered only.  (The underlying soil is an excessively drained glacial till, which is why we water frequently during esablishment and why we don’t worry about the drainspout. Water doesn’t stay around long.)

I used no fertilizer. I did add the soilless media from the root washing to the top of the soil and then covered with woodchip mulch.

There was, of course, a period of about 6 weeks post planting where there was no above-ground growth. But all of these plants retained their flowers, which kept our bees and other pollinators (butterflies and hummingbirds) happy. In August, the plants started to put on new growth at a furious rate now that roots have established.

Native bumblebee on salvia.

Take some time and go back to the original post (which is linked in the first sentence. Look at the roots – before and after washing and pruning. Now look at the results.

Why wouldn’t you plant this way?

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Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and a Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook page - "The Garden Professors" Facebook group - Books:

3 thoughts on “Root washed perennials – 3 months later”

    1. I’m not willing to sacrifice my personal plants even for science!

      Yes, further study would be helpful. But the facts are – we understand root physiology; we know enough about soil/water relations to know that differences in soil textures interfere with water and air movement; and nothing that’s being recommended disagrees with anything scientific. It only disagrees with common practice, which too often than not is not based in known science.

      (Rock dust holds little interest for me as a charity project. I would hope manufacturers/sellers would see fit to fund independent research. So far no one has proposed such a partnership.)

  1. This is good information that confirms what I’ve actually been doing as a gardener but have NOT advocated as a nursery employee. Why the disconnect? First of all, I didn’t have this affirmation that what I was doing instinctively was “correct” even though it’s worked for me. I’m not treating my customers as dumb or unable to understand this method, but I have a limited amount of time with them. If I advocated bare-rooting plants, I may be held liable by customers who did not follow through with appropriate aftercare or who might complain about the lack of growth or of flowering. I try to impress upon them about digging wide holes, pulling the roots outwards and spreading them horizontally, and then mulching heavily. Then my 3 minutes are up! I wanted you to know that not all nurseries and nursery employees are willfully spreading misinformation.

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