The Latest Hort Research that Gardeners Can Use


1. Wiseman, P. E., and C. E. Wells.  2009.
Arbuscular mycorrhizal inoculation affects root development of Acer and Magnolia species. Journal of
Environmental Horticulture 27(2): 70-79.

2. Wolf, K. L.,Strip malls, city trees, and community values. Arboriculture
& Urban Forestry 35(1): 33-40.

3. Doxey, J. S., T. M. Waliczek, and J. M.
Zajicek. 2009. The impact of interior plants in university
classrooms on student course performance and on student perceptions of the
course and instructor. HortScience
44(2): 384-391.

4. Cochran, D. R., C. H. Gilliam, D. J. Eakes, G. R.
Wehtje, P. R. Knight, and J. Olive. 
2009. Mulch depth affects weed
germination. Journal of Environmental
Horticulture 27(2): 85-90.

5. Kowalewski,
A. R., D. D. Buhler, N. S. Lang, M. G. Nair, and J. N. Rogers, III. 2009. Mulched
maple and oak leaves associated with a reduction in common dandelion populations
in Established Kentucky Bluegrass. HortTechnology
19: 297-304.


  1. Thanks for the information Jeff. I was trying to come up with some diatribe to go off on, just for fun, but I just got giggling instead. I’m glad that you just find it funny when people call you an idiot. We wouldn’t want you to stop telling us all your findings!

  2. Jeff, the gardening world is medieval–superstitious and intolerant and willing to enrich some really bad priests–and you represent the Enlightenment.

    Have you ever looked into pea innoculant? I started balking a few years ago when my Agway wanted $6 for a little package. I have noticed absolutely no difference in my pea crop without it. I’m wondering if it’s only useful in soil that’s been sterilized by the overuse of chemicals.

  3. I wonder if research point 4 – isn’t that ANY mulch applied is better than none as a weed block – did they compare other kinds? I think pebbles, leaf mulch, etc. would work just as well as a container top dressing. Just seems most folks don’t do it, for whatever reason. I usually thrown on a handful of Leafgro just to keep in some of the soil moisture esp in my containers that sit in full blazing sun.

  4. Jeff, thanks for the info. The research on micorrhizae makes sense – local is always best.

    As for plants in the classroom, I do innovation workshops and always insist on plants in the room and windows with views of greenery. Research shows that this increases creativity and idea generation. So next year not only will your students like you better, but they may be more creative to boot!

  5. I haven’t mulched my containers, but I will now – and leave enough room for the mulch. This will make the pots neater when there is heavy rain splashing mud. However I’m hoping some fine wood chips (mine are free) will work as well.

  6. Hey now, Michele, don’t knock the Middle Ages. We could use a few more thinkers like John of Salisbury or William of Occam!

    I’d characterise the mycorrhizae issue as being much more like Renaissance alchemy. Anyone got a philosopher’s stone?

  7. Love your books and love this information. The gardening world is comprised of much more than Medieval and intolerant people.

    Keep up the steady stream of useful information. Thanks.

  8. GELL FIGHT!!!!!!

    Just kidding…

    I take a pinch of “new research” (which I find most of the time to be excellent at discerning what happens on the plots of ground where the research was conducted and does not always apply to my plot of ground–except in certain cases re certain things…like the effects of “blue poison” and the efficacy of purchasing mycorrhizae)

    and a dash of superstition/old wive’s tales/local wisdom garnered from folks who have great gardens

    cross my fingers

    spit downwind

    and then hope for the best.

  9. Thanks for the info. I’m really curious about the mycorrhizae research. Is it across-the-board or relative to specific plants/specific fungi applications? I followed some of the links above, but wasn’t clear where I could find the meat of the findings — help?

  10. I totally appreciate Jeff’s stright forward no nonsense approach. Jeff: welcome to the “idiot club” I am a member myself. I did read in a hydroponic magazine ana rticle proclaiming the benefits of mychorrizae but I do not think it works either.

    The TROLL

  11. The Extension Service provides science based garden advice as part of their mission statement. Most resources provide garden advice while trying to sell something.

    Isn’t the right choice obvious?

    Thanks for bringing it up.

    You are the front line for scientific, new, landscape information.

    Garden & Be Well, XO Tara

  12. Hi Everyone,

    Michele, You make me sound so cool! I think I’m going to write “I represent the Enlightenment” as a header on my webpage! In terms of pea inoculants, I have read about them, but I haven’t tried them. I would expect them to be beneficial in a location where peas or other legumes hadn’t been grown before, but not in a location where they had been grown.

    Kathy J — This research was specifically on those nuggets, but yes, I’d expect almost any mulch to be beneficial.

    Gardenmentor — This research is available from the sources that I listed. Unfortunately I don’t think the Journal of Environmental Horticulture is available online yet, so you’ll need to get to a University library to see it.

    5998b — I received your e-mail regarding the mycorrhizae that you sell. Right now you’re not much different from everyone else who tells me that their product works and everyone else’s doesn’t. When you have some research published in a peer reviewed journal (or at least by independent University faculty) demonstrating that your specific product works in a non-sterilized in vivo situation I will be happy to review it. Right now I consider anything that you say to be rhetoric.


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