Author: 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 - www.facebook.com/TheGardenProfessors "The Garden Professors" Facebook group - www.facebook.com/groups/GardenProfessors Books: http://www.sustainablelandscapesandgardens.com

Podcast Season 2 is here!

My abject apologies for being late in posting this week.  I’ve been in Angel’s Camp, California since Tuesday – a lovely, wonderful place – but without anything above 2G wifi.  Needless to say, posting on the blog was impossible.  So I’m in the Sacramento airport, enjoying a glass of wine and a crab Louis before I leave for Seattle, and finally able to access a 4G connection!

In any case, here’s the beginning of Season 2’s podcasts.  I’m assured that soon we will be on i-Tunes, but for now you can download the podcasts here.  The first podcast is built around the theme of “Scary Garden.”  A little late for Halloween, but there you are.  For this first podcast, I take on lasagna mulching and bring you some garden tips for the fall/winter season.

Let me know if you’ve got some ideas for upcoming themes throughout November and December!

Phosphate toxicity and iron deficiency

Bert’s post yesterday reminded me of some work one of my graduate students did about 10 years ago.  We were curious to see whether a transplant fertilizer containing phosphate was correlated with foliar iron deficiency, which is visualized as interveinal chlorosis:

 What Scott did was to plant 10 rhododendrons per treatment into pots containing containing a name brand azalea, camellia and rhododendron food (5-5-3) at 0, 0.5, 1.0, and 2.0 times the recommended amount. Here are some of the results of that study:

 
Total number of chlorotic plants

Total foliar iron vs. fertilizer treatment

Chlorosis as a result of phosphate fertilizer. 1= Normal (green leaves), 2= Light chlorosis in young leaves, 3= Moderate chlorosis, 4= Severe chlorosis, young leaves white

 For gardeners, the take home message might be that the control plants – those without any transplant fertilizer added – did the best. Don’t add phosphate to your landscape and garden soils unless you have a verified deficiency.  And only a soil test will tell you this conclusively.

You can’t fly by the seat of your pants on this one, folks.

Green candles identified

Not many guesses this week – too many Halloween parties?  In any case, Hap was correct – this is a closeup of the growing edge of Euphorbia lactea ‘Cristata.’  The "candles" on the edge are tiny leaves that appear whenever water is abundant but shed quickly during dry periods:

Thanks for playing, and Happy Halloween!

A little about bugs

I’m not much of an entomologist.  (Okay, I’ve never had a single bug-related class.)  But I do appreciate insects in all of their bewildering shapes and behaviors.  And after this weekend I’ve become a little more entomologically educated.

I spent the weekend in Prescott, Arizona at the annual MG conference.  Besides meeting lots of great Master Gardeners (and Extension educators) in that state, I also met Dr. Whitney Cranshaw from Colorado State University.  He gave a keynote talk called “Gardening for Insects – or not!”  This was a seminar that presented positive and negative aspects of gardening for butterflies, honeybees, and other favorite insects.

Here are just a few of the nifty things Whitney had us consider:

  • Not all butterflies are nectar feeders; some prefer rotting fruit or dung.  Hmmm.  I might have to limit my varieties.
  • The caterpillars of some striking butterflies might need you to share some garden greens.  Larvae of black swallowtail butterflies eat parsley, fennel, and dill, for example.  Accepting damage on these plants will ensure a healthy population of adults for your viewing pleasure.
  • It’s best to accept some degree of pest insect presence, like aphids, to provide food for beneficial insects.  Insecticides are not part of a successful garden for insects.
  • The first bumblebees of the season are always small; they’re produced by overwintering queens whose resources are limited.  These new workers help gather more food, so that those produced later are larger.

Whitney has a fantastic collection of photos of insects, up close and personal.  Some of these are also in his book Garden Insects of North America (Princeton Press). It’s over 600 pages of full-color photos and engaging text.  Instead of being organized by family, it’s organized by feeding habit, so you can quickly look up and identify whatever weird bug you’ve found snacking on your snapdragons. There are sections on how to manage pest insects, and a chapter dedicated to beneficial bugs. 

 

Amazingly, this book is only $29.95.  I bought one.   

Finally, I have to recognize Dr. Cranshaw as one of an unusual breed of faculty.  He is passionate about educating adult audiences like Master Gardeners, and indeed his book is dedicated to entomology educators and the nationwide Extension system.  What a great resource for gardeners everywhere!

Reader input wanted for new book

(Note:  I’ll be doing another blog posting later today.  Just want to be sure I get this out.)

I’m writing a new book on plant physiology for gardeners – a book that explains how plants work and why they sometimes do weird and unexpected things. I’d like to hear what kind of “how” or “why” questions you’d like to see answered in this type of book.  Please add your comments to this post, or send them to me directly. And if there are other gardeners you know who might want to send suggestions, be sure to send them the link!

Opening up a can of roots (or worms as the case may be)

Blog reader Alan Haigh asked if we could start a discussion about tree planting recommendations.  He sent along these guidelines from the Colorado State Master Gardener Program.

While I’m glad to see that the consensus now seems to be that burlap, wire, twine etc. do not belong in the planting hole, there’s still plenty of issues to contest.  Here are just a few that I found on my first read:

1)  Not mulching over the root ball;

2)  Assuming that all B&B trees are “field grown,” which I *know* is incorrect for so very, very many B&B trees;

3)  Not including the root-washing technique for B&B, which is not only research-based but is actively promoted through the International Society for Arboriculture’s workshops (see this posting for instance).  This is the only way to find and correct circling and girdling woody roots, and the easiest way to find the root crown for planting at grade.


Without root washing you’d have to dig through 10″ of clay to find the root crown (the duct tape marks the top of the clay root ball prior to washing)

I’ve written about this topic before.  And many people argue that it would “take too much time” and “be too expensive” to root wash specimens.  But when you read this publication, note that it takes 13 pages to describe how to plant containerized and B&B trees.

It takes 1 page to describe how to plant a bare root tree.

Amazing water slices!

Here it’s already Wednesday and no GP postings!  My excuse is that I had a seminar to give yesterday before catching a late night flight to Pullman.  Bert (who should have posted Monday) must still be lost in a mai-tai fog somewhere in Hawaii.  Or maybe he’s looking for Holly, who’s been AWOL for a week.  They’re supposedly at the ASHS meetings.  Right.

I’m kind of liking the idea of finding fun new products for the busy gardener.  Much to my delight, after Goggling the phrase “best new garden product of 2011” I was introduced to amazing water slices.  Here’s the text of the announcement/sales information:

“WINNER OF BEST NEW GARDEN PRODUCT OF THE YEAR AT THE HORTICULTURE WEEK/HTA AWARDS & GARDEN RETAIL AWARDS

“A pack of four amazing water slices – so simple to use, they can retain enough water to keep your plants happy for up to 3 weeks.

“Simply soak each slice in water for 3 hours. Use inside or underneath pot plants, hanging baskets, flower pouches, etc.

“Use in layers, too: one slice=one week’s watering. So three slices will give up to 3 weeks watering.

“Cut to shape – one slice can fit two smaller pot plants.

“An extremely efficient and water-saving product – highly recommended.”

And here’s what a “water slice” looks like:

It’s a sponge.

They said to write about it, so I will…

Please tell me – am I crazy?  Or just not the gardening trend-setter that I should be?  Should I be spending $10 on this? Check out this excerpt from Garden Cuttings Newsletter, with the note “Please feel free to use this information in your stories and columns”:

“Instead of sending dried leaves and other yard waste to the landfill, compost it! DeComp-9 Organic Compost Booster speeds up the composting process with patented microorganisms that quickly break down leaves, grass clippings and other yard waste. When added to compost, the microorganisms in all-natural DeComp-9 will grow on organic material, feed on decaying and dead plant matter and convert this waste to nutrient-rich compost that helps build stronger and healthier plants. Just mix DeComp-9 with water according to the product label and apply on compost piles. Each 20-gram package of DeComp-9 makes 10 gallons of solution – enough to treat 27 cubic feet of compost material. DeComp-9 is available for about $10.”

 

High-end WOW (Why oh why)

A few weeks ago I was lucky enough to speak to the Portland Garden Club and see some absolutely gorgeous private gardens.  But alas…even in the midst of such botanical riches I still managed to find something to make me shudder.

Now I have nothing against garden remodels – or boxwood hedges (though I generally find them unimaginative).  But here’s a good example of shrub salvaging gone horribly wrong:


Deadwood boxwood

And again

It will take a long time for these boxwoods to fill in.  If you’re going to spend the kind of money that’s going into this remodel, why get chintzy with the hedge plants?

Maybe green spray paint is in order?