New Hort Research that Gardeners Can Use, Second Edition


S.J.B., J.J. Griffin, and E.E. Carey. 2009. Application of two microbial teas
did not affect collard or spinach yield. 
HortScience 44(1):73-78.

2Wiseman, P.E.,
K.H. Colvin, and C.E. Wells.  2009.  Performance of mycorrhizal products marketed
for woody landscape plants.  Journal of
Environmental Horticulture 27(1):41-50.

3Yeargan, K.V.
and S.M. Colvin.  2009.  Butterfly feeding preference for four zinnia
cultivars. Journal of Environmental Horticulture 27(1):37-41.

4Stigarll, A. and
E. Elam.  2009.  Impact of improved landscape quality and tree
cover on the price of single-family homes. 
Journal of Environmental Horticulture 27(1):24-30.

5Koeser, A.K.,
J.R. Stewart, G.A. Bollero, D.G. Bullock, and D.K. Struve.  2009. 
Impacts of handling and transport on the growth and survival of
balled-and-burlapped trees.  HortScience

6Park, S.H. and
R.H. Mattson.  2009.  Therapeutic influences of plants in hospital
rooms on surgical recovery.  HortScience


  1. I’m very curious–what is a “high quality landscape” and what is an “average landscape”–as defined in Lubbock Texas?

  2. I’m curious about how the benefits of landscaping were calculated….were the percent increases calculated on a base of expenditures during the previous year? Previous five years? Also, were gardens included as landscape? My own experience (sigh) is that unless potential buyers are gardeners themselves, gardens = work, and don’t increase the value.

  3. Jeff,
    Thanks for the helpful Mojave Desert analogy. I’ve had this [delicate] conversation with compost tea enthusiasts; expressing that if the environment was right for sustaining microbial growth, they’d be there regardless. Though I completely understand their POV…all the steps and effort [tea ceremony?]does make it seem like the right thing to do.

  4. Obviously the value of landscaping deserves an entire issue of articles in a magazine. Possibly its own magazine?

    Most of my out-of-state landscape design work is from clients formerly living in my city. They credit their landscape with helping to sell their house. Enough to fly me to do it again.

    A Scottish study confirmed a link between living in view of a landscape & longevity. Not gardening, simply living in view of a landscape. Brain dead at the moment about the name of the study.

    Steve’s comment is correct about potential buyers thinking gardens = work. I know getting the ‘landscape designed’ garden correct equals a quickly sold house.

    If a home is ‘landscaped’ and the ‘landscape’ hurts the sale of the home the’landscape’ was poorly done.

    Another topic for a magazine article!

    Garden & Be Well, XO Tara

  5. I found all these points very interesting – but I’m really curious about the statement:
    “As a side note, last spring I tried planting B&B trees after very carefully washing off the root ball and of the five trees I treated this way, all died. The five trees I planted using more standard practices all lived”

    What are ‘standard practices” – do you mean simply planting B&B without washing the rootball or is there something else involved?

  6. Hi Chris,

    By washing off the root ball I mean that I washed most of the soil off of the root ball — the tree ended up “bare-root”. Standard practice is to plant the tree without removing the soil — only as much of the cage and burlap as you can without disturbing the soil ball (it may be helpful to look at the picture of a B&B tree which Susan included here.

  7. Hi Sara,

    Here’s the basics “Landscape was evaluated on tree cover and quality, grass quality, volume and diversity of foundation plants, plant maintenance, concrete condition and size, amount of soft- and hardscapes, and design coordination.” Based on these criteria scores were given — If you’re really interested you should look up this article — it gets a little elaborate for me to explain in detail here.

  8. Hi Steve,

    The authors spend pages talking about how they came up with these figures — much too much for me to summarize appropriately here, so I recommend you take a look at the original article when you have the chance.

    That said, the authors estimated that a landscape would need five years to reach maturity.

    I do not believe that gardens were considered part of the landscape.

    Sorry for the cop-out answer, but this wasn’t a simple equation.

  9. Thanks very much for writing up summaries of research findings – this is how science progresses!

    It’s important to try lots of new and innovative techniques (such as compost tea) but then also subject them to randomized controlled trials. So keep the science coming!

  10. People use compost tea for different things — usually to increase microbe levels. If you’re just using compost tea to add some nutrients then go for it — it’ll work.

  11. Interesting thing about the B&B trees, as I’ve planted quite a few bareroot perennials in the past 2 years and nearly all of them survived.

    On the other hand, shrubs and tree starts I’ve planted or moved, whose rootballs disintegrated during the process (not intentionally), pretty consistently didn’t survive.

    Wondering if dormant vs active (that is, did your trees have leaves, Jeff?) is the key? All the bareroots I received were dormant and were planted early in our season (mid- to late April, before last frost date).

  12. We did plant “in leaf” which makes for a tougher transplant. It is well known that transplants tend to be more successful if they’re planted dormant. The trees we were planting were Turkish filberts about 1 3/4 inches in caliper.

  13. Plant doctors have my respect and I mostly agree with what they have to say. Never followed Linda Chalker Scott’s advice on how to plant balled and burlapped specimans. Would never advise it. Washington State University
    The Myth of Collapsing Root Balls
    “Balled and burlapped root balls must be left intact during transplanting”
    The Myth
    While shopping for trees at my favorite nursery, we recently overheard another customer ask a staff
    person about installing her newly purchased B&B tree. “When I plant my tree I should take off the burlap
    and twine, right?” she asked. “Oh no,” exclaimed the staffer. “You don’t want to disturb the root ball.
    Just peel the burlap back from the trunk and leave the rest intact. Otherwise, the root ball will collapse
    and the tree will die.”
    At first glance, this appears to be reasonable advice. Balled and burlapped, or B&B trees, are much
    heavier than containerized plants and one can visualize the root ball collapsing and crushing the root
    system. The weight of the root ball also helps stabilize the tree and prevent tilting or falling. Finally, the
    root ball soil contains beneficial microbes and other soil organisms that can help ease transplant shock to
    the root system. With these benefits in mind, why would you consider doing anything differently?
    The Reality
    Many nurseries will not guarantee their plant materials if the customer disturbs the root ball, so customers
    are loathe to do anything that might negate this policy. This is unfortunate, as disturbing the root ball is
    exactly what you want to do to maximize survival of your newly transplanted tree.
    A previous column discussed how to transplant containerized plant materials properly, and some of the
    same issues apply to B&B trees as well. The most important reason to disturb the root ball of a balled
    and burlapped tree is to inspect the root system. The circling, girdling, kinked, and hooked root systems
    often found in containerized plants occur frequently with B&B materials, too. Nearly every B&B tree I
    have purchased and installed, either in my own landscape or as part of a project, has had serious root
    defects. By removing the heavy clay one can find and correct many of these defects. Without corrective
    pruning these defects will significantly lower the life span of your tree. Remember, root pruning
    stimulates the growth and development of new roots that will enhance tree establishment in the landscape.
    A second reason to break up the root ball is to remove the clay soil that makes the tree so heavy in the
    first place. Most B&B trees are grown in a soil with clay characteristics so that when the tree is dug the
    root ball it will hold its shape: sandy soil will simply fall away from the roots. The clay soil not only
    maintains its shape but also retains water, so that B&B materials are usually more stable in terms of
    optimal water conditions during the time they are out of the ground. When the tree is planted into the
    landscape, however, the clay character of the soil is often different than that of the surrounding native
    soil. Differences between soil textures will impede water movement and therefore inhibit root
    A final reason to remove the bagging materials and root ball soil is that many of the B&B specimens at
    the nursery have been burlapped too high during field digging and bagging. Burlap and soil that covers
    the trunk above the root crown will lead to trunk disease and death. In every nursery I’ve visited I have
    found more than one tree trunk literally rotting in the bag. Before purchasing any B&B stock you should
    ensure that a healthy trunk lives beneath the burlap.
    The best practice for transplanting B&B trees is relatively straight-forward. (The rationale for many of
    the practices listed below are detailed in previous B&B columns):
    1) Remove all wire baskets, twine, and burlap from the root ball. Working on top of a tarp will
    allow you to transport the root ball remnants elsewhere.
    2) Remove all clay from the root ball. This can be done most easily by using a water bath or a
    hose. Use your fingers to work out clumps of clay from between the roots.
    3) Look for and prune out defects in your freshly denuded roots. Be sure to keep the roots moist
    during this procedure and work in the shade if possible.
    4) Dig the planting hole to be only as deep as the root system and at least twice as wide. The
    hole will resemble a shallow bowl.
    5) Form a soil mound in the center of the hole to support the root crown of the tree, and arrange
    the roots radially.
    6) Backfill with native soil; do not use any type of soil amendment.
    7) Water in well, preferably using the water from step 2 which will contain nutrients and
    microbes. Do not step on the root zone, but gently firm using your hands. Add an
    appropriate fertilizer (i.e. primarily nitrogen and little or no phosphorus)
    8) Mulch the entire planting region with at least 4” of organic mulch, keeping a buffer between
    the trunk and the mulch to prevent disease.
    9) Stake your tree low and loose with 3 stakes for no longer than one year after planting.
    10) Keep your tree well watered during the first year of establishment. You may have removed a
    good portion of the root system and its ability to take up water and nutrients will be
    temporarily impaired. Do not succumb to the temptation to crown prune or add expensive,
    but pointless, transplant supplements.
    This method is radically different from historically accepted practices. Yet recent and ongoing research
    demonstrates that bare-rooting B&B trees leads to substantial increases in tree establishment and survival.
    Investing the time to prepare and install trees properly will pay future dividends of reduced maintenance
    and mortality for the lifetime of your landscape.
    The Bottom Line
    • Balled and burlapped plant materials usually contain soil significantly different than that of the
    transplant site.
    • Differences in soil texture will impede both water movement and root establishment.
    • Root defects can only be found and corrected if root ball soil is removed.
    • Proper root preparation combined with best practices for installation will greatly improve tree
    establishment and survival in any landscape.
    For more information, please visit Dr. Chalker-Scott’s web page at

  14. I have used compost and manure teas since the late 60’s – for vegetables, ornamentals and interestingly for disease suppression on golf course putting greens.

    I was one of the first to develop a non-chemical approach to golf course management, and much of my success resulted from regular applications of home-brewed compost teas sprayed directly on turf. The “unnatural” culture required by the golf course environment puts incredible stress on the plants and normally requires huge chemical inputs. Almost all chemical input was unnecessary in this program.

    Though current science may indicate otherwise, the efficacy of disease suppression with compost solutions was first pointed out to me by scientists in Germany, who have been successfully controlling phytophora and other fungal diseases with compost solutions.

    I’ve seen excellent response from compost tea solutions for almost four decades. The proof is in the pudding.

  15. Jeff, I am very sad that my $129 oxygen-bubbling compost tea maker won’t get me more soil microbes but relieved that at least it might get me some nutrients. A question: If the nutrients already made by microbes are the only useful part, does that mean I don’t have to worry about applying my compost tea within 4 hours after I finish the bubbling? I can just let those microbes die off, because the tea will still contain the elemental nutrients they made, right?
    I planted a B&B Canadian hemlock last September and despite assiduous watering through the fall it looks like a goner. I pulled back the burlap but didn’t break up the root ball. I should have planted a smaller container one and skipped the B&B issue altogether.

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