Fast food is unhealthy for plants, too

In early December, I posted my thoughts about fertilizing crops vs. landscapes.  An anonymous reader asked if we could follow up by discussing the relationship between excessive fertilizers and plant susceptibility to pests and disease.  It’s taken a month to get the scientific literature (and my act) together, but here it is.

There are decades’ worth of articles about the direct relationship between increased nutrient availability and increased susceptibility to pests, disease, and disorders.  One of the earliest articles linked the incidence of celery blackheart to over-fertilization. … Continue reading this article “Fast food is unhealthy for plants, too”

A comment about home remedies from Catherine Daniels

In case you didn’t see yesterday’s comment that was added to Jeff Gillman’s January 6 post on home remedies, I’ve posted it here.  Dr. Catherine Daniels is WSU’s pesticide coordinator:

I’ve enjoyed reading the science-based information on your site. Keep up the good work. As regards home remedies, that is slippery slope, both legally and morally. Having a written definition of what you will or will not accept is helpful, especially if done in advance. Then you can be sure of being consistent and deliberate at least.… Continue reading this article “A comment about home remedies from Catherine Daniels”

Landscape conifers: The Good, the Bad, and the Underused

This week is our annual Great Lakes Trade Expo, the main trade show and education venue for Michigan nursery and landscape industry. One of my talks was for the Arboriculture track on landscapes conifers. The theme this year was “The Good, the Bad, and the Underused.” Hey, you try giving a dozen talks a year for 10 years and see if you can come up with an original title!

 

The selections were based the following, admittedly subjective, criteria.… Continue reading this article “Landscape conifers: The Good, the Bad, and the Underused”

Pampas unpuzzled

Great discussion and answers on this one, gang!  Yes indeed, this is a plant out of place – as several of you noted.  But not only has it escaped from an ornamental landscape, it’s decided to grow, quite happily, in the median strip of I-5:

Another odd thing is that the species has not been officially recognized as invasive in Washington State.  It’s been languishing on the “Monitor” weed list for at least two years.  Our climate is a bit chilly for it, which may be part of the reason it looks so bad right now. … Continue reading this article “Pampas unpuzzled”

Pampas puzzler

Here’s a photo of some pampas grass (Cortaderia selloana), much beloved by many homeowners in their landscapes:

But what’s unusual – and undesirable – about this particular specimen?  Hint:  the landscape has been modified a little.

Answer on Monday!

Where to Draw The Line on Home Remedies

On Tuesday Holly posted an extremely interesting article about how Bounce could help control fungus gnats.  Then one of our frequent commenters (and all around great guy) Ray Eckhart pointed out that he has a problem with promulgating an off-label use of a product.  And that got me to thinking.  What household products is it OK for us to suggest that a consumer use for a non-labeled purpose, and what products shouldn’t we suggest?  This is a question that has haunted me for a long time, so with this post I want to give you my line of thinking – I’m not trying to tell you what’s right or wrong – just trying to let you know my thoughts on the topic.… Continue reading this article “Where to Draw The Line on Home Remedies”

Will cabling a tree’s crown make it stronger?

In a previous column (December 1, 2010) I discussed the problems that wet, heavy snow can cause for trees and shrubs – particularly evergreens.  In response my colleague Terry Ettinger mentioned a cabling technique discussed in the 2nd edition of Arboriculture (1991).  I think it’s worth looking at the science behind this practice and some of the unintended consequences.

Harris’s Arboriculture text is considered the bible for landscape professionals, including certified arborists.  In the late 1990’s, Dick Harris was joined by Jim Clark and Nelda Matheny, two other gifted academics who have crossed over into practical writing. … Continue reading this article “Will cabling a tree’s crown make it stronger?”

Bounce – it’s not just a fabric softening sheet…

…it’s an Integrated Pest Management tool!

[Note added after-the-fact: this was a  tongue-in-cheek bit of  hyperbole – kind of like “it’s not just a Job, it’s an Adventure.” Did not mean to imply that it actually IS an IPM tool. Very badly worded. Hence the beating I took in the comments. Live and learn.]

Fungus gnats (Bradysia spp.) are a pain in the bottom for commercial greenhouse growers. The adults are more of a nuisance than anything else –it just looks bad when a customer picks up your 6” pot of pansies and a bunch of little black gnats take flight. … Continue reading this article “Bounce – it’s not just a fabric softening sheet…”

New Year’s Prediction: Invasive Fire Continues to Burn

Happy New Year!  I hope everyone had restful and enjoyable holidays.  In addition to looking back over the year that just past, a common New Year’s tradition is to make predictions for the coming year.  Without going too far out on a limb, one of my predictions for the upcoming year is that the debate over invasive plants will continue to intensify, especially as it relates to Landscape Horticulture.  Along these lines, a couple of recent articles by Gregorio Gavier-Pizarro and his colleagues at the University of Wisconsin and the USDA Forest Service caught my eye.… Continue reading this article “New Year’s Prediction: Invasive Fire Continues to Burn”

Friday puzzle uprooted!

Wow, we had some very creative answers on this one – and all of them made sense!  Peter, however, was spot on with his identification of roots (of a Thanksgiving cactus) growing in water (in an antique graduated cylinder).  I made it tricker by turning the photo upside down on Friday.  Here it is right side up:

What I love about this photo is that the various parts of actively growing roots are clear (more or less):  starting from the bottom you can begin to see the root tip and the hairless zone of elongation, followed by the zone of maturation with fuzzy root hairs, followed at the top by the area where lateral roots develop.</d