Category: Trees and shrubs

Bad power line pruning

Driving home today, I saw this lovely sight:

powerlinepruningOur local utility company has been busy butchering trees around the power lines.

Every plant person I know complains about this, but I honestly don’t think there is much hope for a change. Power companies don’t want limbs falling on the electric cables during storms, and they’re not likely to start spending money to hire real arborists to do the pruning.

What I really wish is that people would start thinking a little more before putting in a tall tree directly under electric lines.… Continue reading this article “Bad power line pruning”

Little ball of horrors

One of the great things about doing a multi-author science blog is that there will be topics about which colleagues will disagree. One of those topics revolves around the best way to prepare woody rooted plants (trees and shrubs) before planting them. This is an area in arboricultural science that is evolving. A search through our blog archives will find many of these posts and for convenience’s sake I’ve linked one from each of us here.… Continue reading this article “Little ball of horrors”

The Science Behind Fall Color

In many parts of the U.S., particularly the northern U.S., we are blessed each year by nature’s display of bright color dotted through the landscape. Fall color of leaves at the end of the growing season provides a remarkable encore in the landscape. There are many trees and shrubs with great autumn leaf color and I will address some of them in my next week’s post, but this week, I will talk about what actually happens inside the plant during autumn.… Continue reading this article “The Science Behind Fall Color”

Another unnecessary tree failure

The end of August brought an unseasonable rain- and windstorm to the Puget Sound region. We had some spectacular tree failures which I missed seeing as I was out of town. But one of our Facebook group members, Grace Hensley, was on the ball and took some great photos of a fallen purple-leafed plum. The first thing you see is the complete lack of a stabilizing root system.

Now look at the base of the trunk, which is actually a massive circling root that has girdled the trunk over time.… Continue reading this article “Another unnecessary tree failure”

It’s the Next Best Thing Since Draft Beer: New Plants and Their Proper Evaluation

With many new nursery catalogs arriving in my mailbox at work for 2016 introductions, I thought I would focus this blog on “new” plants. With all the publicity and marketing that goes on for new plant introductions, you would think that they are the next best thing since draft beer or even bread! I am a bit cynical and question whether these new plants really live up to their performance expectations and ornamental attributes. With so many new hydrangeas, coneflowers, coralbells, spireas, etc.… Continue reading this article “It’s the Next Best Thing Since Draft Beer: New Plants and Their Proper Evaluation”

A new excuse for bad pruning

I spent last week in Orlando at the ISA annual meeting (that’s the International Society for Arboriculture). It’s a great venue for networking with colleagues and hearing about the latest tree research. And once in a while I’ll have a WTF moment. (That stands for Why Trees Fail in case you’re wondering.)

My WTF experience this year revolved around some new terminology and techniques. I learned there are now “environmental arborists” who practice “retrenchment pruning.” In the last few days I’ve tried mightily to find some standard definitions from reputable sources.… Continue reading this article “A new excuse for bad pruning”

Cool Plants for Late Summer

I thought today’s post would feature two awesome plants that are relatively new or unheard of in the industry. Both of these plants have performed well in my own garden and survived our two hardest winters recorded since the 1970’s. Many plants suffered severe winterburn or even death due to extremely low temperatures, but not these two plants. They may be harder to find in the nursery/garden center, but are well worth it and have huge ornamental impact all growing season.… Continue reading this article “Cool Plants for Late Summer”

Why doesn’t my plant flower? Part 2

As promised last week, here is Part 2 of “Why doesn’t my plant flower?”. If any of you know of more reasons that are not listed here or in the previous week’s blog, please let me know. Happy gardening!

There may be several reasons why a landscape plant does not flower (see last week for more reasons):

1) Over fertilization may inhibit flowering.

  • Do not fertilize newly planted trees and shrubs the first 2-3 years after planting
  • Plants need to put their energy into establishing a healthy root system to support future shoot growth
  • Once the plant is established (2-3 years), fertilizers may be added if a soil test suggests fertilization is needed
  • Over fertilization with quick-release, high nitrogen (N) fertilizers can lead to excessive leaf growth at the expense of flower bud development
  • Avoid using lawn fertilizers around the base of your plants, as they are often high in nitrogen
  • More is not better; follow all fertilizer label directions and do not add more than is required
  • Your landscape plants might not even need fertilization, especially if compost is added or the soil conditions are favorable for plant growth

2) Poorly-drained, heavy clay soils can result in leggy, unhealthy looking plants that may not flower or will die.… Continue reading this article “Why doesn’t my plant flower? Part 2”

Why doesn’t my plant flower? Part 1

I often get horticulture questions from county extension agents, Green Industry professional, gardeners and my next door neighbors. One of the most common questions I get is why their plant did not flower that year. There are many reasons why a plant, either woody or herbaceous perennial, will not flower and both new and established plants can be affected. Some of the below reasons are obvious, some not so obvious.

There may be several reasons why a landscape plant does not flower (more to come next week):

1) Plants requiring full sun are not receiving enough sunlight.… Continue reading this article “Why doesn’t my plant flower? Part 1”

Dogwood rescue – an update

Long-time readers of this blog might remember a Friday quiz I gave back in 2010. It involved the slow but inexplicable decline of our dogwood (Cornus kousa). On the following Monday I revealed the reason for the decline and reported that we were moving this nearly dead tree to another location without the offending perched water table.

In 2011 I posted my first update along with photos of the new leaves and flowers. And today I reveal its obvious recovery to a fully functional if somewhat still spindly tree (several of its multiple leaders died as a result of the rotted root system).… Continue reading this article “Dogwood rescue – an update”