Inspecting nursery plants, part lll

By now you’re probably ready to stand up, brush off your pants, and stretch your back after crawling around looking for surface roots and root crowns.  Not so fast!  There’s one more thing to look for – and to avoid.

Take a look at these two photos:

 

You can easily see the suckers at the base of these trees.  Whether or not they are actually suckers (coming from the roots) or watersprouts (coming from the base of the trunk) doesn’t matter. … Continue reading this article “Inspecting nursery plants, part lll”

Advice Requested!

Greetings, all!

I am not a tree-care expert, having invested most of my mental capital into herbaceous plant stuff.  But I know enough to be dangerous: spiraling/strangling roots and narrow crotch angles are bad news. But at what point do they become “unfixable”? So I’m asking my illustrious colleagues and diligent readers (a.k.a “all y’all) for advice.

We have a lovely specimen in our campus Horticulture Garden…Acer ‘White Tigress’ – a hybrid between A. davidii and A.Continue reading this article “Advice Requested!”

Inspecting nursery plants, part ll

Well, I’m recovering from this simply horrific chest cold or whatever it is and feeling brain function returning.  The last time we were at our virtual nursery, we were looking for root flare and inspecting the trunk for damage from improper bagging.  Since we’re already down on our hands and knees, let’s consider roots.  In general, you really don’t want to SEE roots, except where they meet the trunk (the root flare).  The presence of coyly crossed “knees” in this photo is a clear indicator of a plant that wasn’t potted up quickly enough:

Likewise, while the fused, circling woody root mass in this next photo might be aesthetically interesting, it sure doesn’t make a functional root system:

It’s pretty easy to avoid these types of plants, because you can see the root problems before purchasing. … Continue reading this article “Inspecting nursery plants, part ll”

What Makes Growers Change?

Over the last few weeks I’ve said a lot of complimentary things about the Minnesota Nursery Industry and how they’re careful to avoid situations where trees are planted too deeply.  What I haven’t mentioned is that there is a reason for this.  During the 1980s and early ’90s trees were usually planted deeply with lots of soil over the uppermost roots.  It was just common practice.  Unfortunately this practice led to roots growing across the trees stems and, when those roots cross the stem, the roots always win  (as you saw in Linda’s quiz last week)! … Continue reading this article “What Makes Growers Change?”

Inspecting nursery plants, part 1

I’m frequently asked to give seminars on selecting healthy plants at the nursery, especially trees and shrubs which can run hundreds of dollars.  (Nobody seems to want a seminar on how to pick out a flat of petunias.)  I routinely visit nurseries with my camera so I can record examples of good and not-so-good choices.  What better forum to share these than on our blog?   I’m also curious whether the problems we see in the Pacific NW are found elsewhere in the country, or in the world for that matter. … Continue reading this article “Inspecting nursery plants, part 1”

Mysterious tree failure exposed!

end about the tree failure question!  Many of you zoned in on an important point visible in the two photos I shared.  The tree’s base was obviously quite narrow where the trunk broke, and with the tree’s vase-like architecture this led to breakage. But why was the base so narrow?

Again, several of you thought about root issues, such as a restricted root zone, or possible damage to the lower trunk.  Actually, it’s a combination of root and trunk issues, as this last photo shows:

Tree failure 3

What we have is a large circling root (you can see it at the soil surface to the left and right of the trunk) that has girdled the trunk completely and prevented it from growing in diameter. … Continue reading this article “Mysterious tree failure exposed!”

Mysterious tree failure…

Here is this week’s plant puzzler.  This mature tree just fell over one summer day.  There had not been any significant wind, the soil was well-irrigated (but not overly wet), there had been no construction work or other root-zone disruption.  There were no significant pest or disease problems.  I’ve posted two photos from different angles, and will show one more photo on Monday.  Why do you think the tree failed?

Baring it all, again.

Earlier in this blog we had a rather robust discussion about the merits of transplanting trees bare-root.  Bare-root transplanting has had a renaissance in arboricultural circles, based in large part on the work of Dr. Nina Bassuk and her colleagues at the Urban Horticulture Institute at Cornell.

As our bloggers noted, transplanting trees bare-root has advantages over balled and burlap trees (larger portion of the root system stays with the tree) and over container-grown trees (more natural root system development).   … Continue reading this article “Baring it all, again.”

Take it all off (cue bow-chicka-bow-bow music)

OK, I know there are skeptics out there including many of my dear colleagues.  Though it seems that at least some of my photos are making an impression.  So here is another little photo tour through bare-rooting – this time with a bigger tree.

This demonstration was given at the 2006 ISA conference in Washington.  This is a good sized tree…

…that we plopped into a Rubbermaid watering trough after removing the burlap…

…and washed off all the clay. … Continue reading this article “Take it all off (cue bow-chicka-bow-bow music)”

Health care reform (of trees)

Nothing is more frustrating to a gardener than watching a newly installed tree or shrub slowly die.  In performing “post mortem” analyses on failed landscape plantings, I’ve identified four common errors that can be easily avoided:

  • inadequate root preparation
  • improper soil preparation
  • planting below grade
  • inadequate aftercare

This blog entry will be dedicated to the first point – but before I do so, we need to understand how nursery plant production has changed over the last several decades.… Continue reading this article “Health care reform (of trees)”