Month: March 2012

Dry doesn’t have to mean dull!

I’m on vacation this week in Palm Desert, California – part of an annual ritual that I’ve enjoyed for about 30 years. Nearly the first thing I do while I’m down here is get away from the golf courses and shopping malls into the high desert mountains. Yesterday my daughter and I hiked Horsethief Creek trail (great name, huh?) in the San Bernardino Wilderness and admired the spring flowers that are just starting to emerge.

One half of my brain was busy noticing all of the native plants that I felt had great ornamental value for home landscapes, while the other half worried about what to do for my blog posting this week. And finally both sides of my brain got together for a chat and here we are with today’s posting.

For many years, the home landscapes down here were primarily of the petunias-and-palms persuasion (or in this case snapdragons and olive trees).

That’s been changing as water has become more limited (i.e., more expensive) and people’s appreciation of native plants has increased. Still, an awful lot of native landscapes rely on traditional desert plants like barrel cacti or agave. They’re pretty – but predictable. And the results are often not natural looking.

So…why not shake things up a bit by using some lesser known, but nonetheless stunning species? While many nurseries might not carry these, the only way to change that is to request them. Savvy nurseries respond to customer requests. Or check with native plant societies, who often have plant sales featuring unusual native species.

Without further ado, here are some great plants from yesterday’s hike, which tolerate low water conditions but have great ornamental and/or functional value.


Arctostaphylos glauca (manzanita) – deceptively tough green leaves against a red-striped bark

The lovely Charlotte displays a good-sized manzanita

Juniperus californica (California juniper) – because every desert landscape needs its own gin mill

Opuntia basilaris (beavertail cactus) – the symmetrical arrangement of tiny spines is aesthetically appealing

                           

Nolina parryi (Parry’s beargrass) – absolutely stunning plant with wickedly sharp leaves

Pentagramma triangularis (goldenback fern) – yes, you can even find ferns in the desert

                             

Astragalus spp. (vetch) – sturdy groundcover with brilliant purple flowers. And it fixes nitrogen!

(A final note: don’t dig these up in the wild and try to transplant them. It’s doubtful they would survive, and in many instances it’s illegal. Do the right thing – support your local native plant nursery and buy them legally.

The Cold Truth

Last week I decided to continue my discussion on cold hardiness and so now, of course, temperatures are forecast in the mid-70’s for this week.  Oh well, I’m still convinced we’ve got one more blast of winter to go and some of this will still matter to someone.

One of the questions posed in response to last week’s post was how much cold hardiness changes during the winter.  Before I get into that, it’s good to review how cold hardiness can be quantified.  Cold hardiness is essentially how much cold a plant can withstand before it suffers damage.  There are two common ways by which this can be measured.  The simplest and most straightforward method is through a whole plant (or whole shoot) freeze test.  In this test, entire plants, usually seedlings, are placed in freezer that is programmed to drop the temperature progressively colder, say from 3 deg C to -36 deg. C

At set intervals, often 3 deg. C, a group of plants are removed.  The plants are allowed to slowly thaw and are then examined for needle damage or bud kill.  At the warmest temperatures, plants are undamaged.  As we examine plants subjected to colder temperatures, we’ll begin to find some with damage.  Eventually we’ll find a temperature where all the plants are damaged.  When we plot the percent of damaged plants versus temperature we can identify an LT50, or lethal threshold where 50% of plants are damaged.


Examples of determining bud damage during whole shoot freeze tests.

The second common assay for cold hardiness is termed Freeze-induced electrolyte leakage or FIEL.  FIEL testing is similar to the whole plant freeze test except that instead of freezing the entire plant or shoot, just a small portion of tissue, such as a conifer needle segment is needed.  The FIEL test is based on the fact that plants can withstand inter-cellular ice (ice between cells) but not intra-cellular ice (ice within cells).  When intra-cellular ice forms it disrupts the cell membranes and cell contents are released into solution.  The amount of leakage of cell contents into solution can be easily measured using a standard conductivity meter.  Again, we can estimate an LT50 by plotting the amount of damage versus exposure temperature.

By assessing cold hardiness periodically through the winter, we can assess changes in hardiness associated with acclimation and de-acclimation processes.  A classic study by Karen Burr and her colleagues demonstrates how quickly acclimation can change.  In their study they tracked cold hardiness of conifer seedlings that we exposed to acclimating conditions (short days and progressively colder temps) and then de-acclimating conditions (longer days and warming temps).  The resulting chart demonstrates how dynamic cold hardiness can be.  When we describe plans based on Hardiness zone we’re talking about their maximum hardiness or the temps they can stand in the mid-winter period.  But note how quickly the lethal temperature rises during de-acclimation.
Seasonal trend in phases of cold hardiness: Acclimation, Maximum hardiness, and De-acclimation

Typically, our most common winter injury problems occur during the de-acclimation phase as temps warm and hardiness is lost.  We saw a dramatic example of this several years ago in western Michigan when an early March warm-up with temperatures in the 50’s F was followed by nights with temps as low a -5 deg.  This resulted in widespread bud-kill in conifer plantations.  With a week of highs in the 60’s and 70’s forecast, it’s easy to see why our current warm-up has everyone nervous.

Maximum and minimum temperatures from a west Michigan weather station

Terry E. for the win!!!

Ray E. was heading in the right direction because he picked up on some family characteristics.

Terry E. got it…

"Blue Ginger (Dichorisandra thyrsiflora).
As per Ray’s offering above, this species is in the same family, Commelinaceae, as the spiderworts, dayflowers, etc."

To any plant i.d. students that may accidentally read this:  family identification is important and helpful. The characteristic triangular flower shape (three petals) and six stamens is a dead giveaway (I get some guff for making them learn families).

Plant photos taken at the Hawaii Tropical Botanical Garden near Hilo.  Lush and gorgeous!




We grow it as a tropical here, but it certainly doesn’t reach 6′ tall as in Hawaii. Easy enough to dig up and overwinter (and share with your friends – we got our clump from local plant goddess Elissa Steeves). 

Quiz (a day early)

Well, I was swamped on my usual posting day, and now I certainly can’t top Jeff”s post – I laughed so hard it took away my initiative.  "Throw and Go" indeed. 

I think we should start our own line of Garden Professors Soil Amendments – "Dr. Holly for Hollies," "Dr. Linda’s Flingable Compost (Not For Tea Dammit)",  and "Dr. Bert’s Conifer Special".  Dr. Jeff would have his own line of slug repellants and traps – available in six-packs. 

Back to my post… you get a quiz!  I’ve rooted through my stockpile o’ photos and found one that just may fool a few of you.  Or not.

 Guess away!

Should I trust Dr. Earth?

Most of us were taught from an early age to trust doctors (I mean the medical kind).  They’re supposed to be smart, committed, and loving, and most of the doctors I’ve had over my life have fit that mold.  And Earth, what an awesome name!  It makes me think of dark, warm, rich soil in the spring.  Damn it makes me feel good!  So it’s no wonder that some clever marketer thought up the name Dr. Earth and slapped it on a bunch of organic products, because hey, if you can’t trust Dr. Earth who can you trust?  When I see a Dr. Earth package I want to buy it!  I mean look at it:

How can you not trust this guy?  But as most wise shoppers have learned over the years, whenever you purchase a product you should look at the ingredients to see what you’re buying.  This product includes Probiotics — microbes which are probably dead when you buy the fertilizer — or which may not even be compatible with your soil.  It is a “balanced” fertilizer meaning it has equal parts nitrogen, phosphorus and potassium — which means too much phosphorus and potassium.  And finally, while it does have a number of good renewable ingredients, it also contains bat guano and rock phosphate, two ingredients which are non-renewable and which damage the earth when they are mined.

You can’t judge a book by it’s cover, or, apparently, a fertilizer, by the cute farmer-looking guy on the front of the package.

Taking gardens to a new level

I spent the last few days in New Jersey, with a quick day trip into NYC.  It was a perfect East Coast winter day – sunny and cold – while back home in Seattle it rained.  So it was with real joy that I hoofed it through some of the city’s greenspaces, ending up at The High Line.

I won’t go into detail about the site’s history and development of this city landscape, because the link will do that much better and with more authority than I can.  But briefly, the High Line was the elevated freight train line used in the industrial district.  After it was decommissioned, it was developed into a public greenspace.  And an important note – it is entirely funded through private money.  Its future won’t be affected by city budget cuts.

I was enchanted by the landscaping: it looks like an abandoned trainyard that’s being taken over by a re-emerging forest.  Rather than being centered in a planting space, most of the trees and shrubs pop up right next to a rail or crossbeam; dead grasses remain in place, and you can see crocus and other spring flowers poking through.  It’s obviously a designed space, but it’s not unnatural.

There are benches everywhere – some big enough for two people to sunbathe.  There’s an outdoor movie projector across from a white-painted wall for showing movies in the summer; bleachers are built against the opposite wall.  It’s an interesting, inviting, and unique landscape, allowing you see the city from a completely different perspective.

Hot enough for ya?!

Ok, ‘Hot’ might not be exactly the right word, but winter in the Midwest has certainly been warmer than average this year.  I did a little trolling around on Michigan State University’s Automated Weather Network website, which has been logging temperatures and other weather variables around the state for the past 15 years and compared our current winter here in East Lansing to recent years.  Since the middle of December our average daily temperatures are 5.2 deg. F above the previous 15-year mean.  The departure from the 15-year mean is even greater (+5.6 deg. F) when we look at minimum temperatures. 


15-year average Minimum daily temperature and Current-winter daily minimum for East Lansing, MI.

Minimum temperatures are especially important when discussing winter injury to landscape plants since extreme low temps (and the conditions immediately preceding them) are often responsible for many of our winter injury problems.  With a generally mild winter and only a few, brief temperature dips below average, one might expect that we will see few winter-related plant problems this spring.  However, prolonged exposure to temperatures above average means that plants are beginning to deharden early.  We see several signs of this already; such as witch-hazels blooming in protected locations and sap in maple trees running 2-3 weeks ahead of normal http://www.michiganradio.org/post/michigan-maple-syrup-producers-say-season-extra-early-year


February 28, 2012. Witch-hazel in bloom on MSU campus.

While other trees and shrubs may not provide the same outward signs, they are progressively becoming less cold-hardy by the day.  Unfortunately, temperatures, like the stock market, rarely move in a straight line. Here in mid-Michigan, temperatures in the single digits are possible throughout the month of March.  Given the preceding mild conditions, a sudden, severe cold snap still holds the potential to cause considerable damage to developing buds on trees and shrubs.  This type of late from damage may be evidenced by shoot die-back, bud-kill or death of newly-emerging shoots.  As always with winter injury, the final result won’t be known until late May or early June. 

Madison Wisconsin takes care of bees-ness

The bee blogosphere (hiveosphere?) and listservs were abuzz the past two
days with news that Madison, Wisconsin, has taken an active role in
encouraging beekeeping within the city limits.   The version of the
story I found a link to was in the Madison Commons.

Apparently beekeeping was prohibited in town (though the prohibition was
rarely enforced, except in the case of complaints).  The ordinance was
changed to allow urban beekeepers to keep hives.

There are specific regulations, such as 25′ distance to the nearest
neighbor as well as a  requirement to supply a fresh water source near
the bees (very important – especially in urban settings). 

Flight barriers – fences, shrubbery, or  sheds are also required.  This
is a simple bit of beekeeping etiquette if you have close neighbors.
Bees will fly straight in and out of the hive entrance, usually just a
foot or two off the ground.  They’ll maintain this altitude until 
forced to go up or down.  Constructing, planting, or placing the hives
in front of an existing barrier they must fly over ensures they will
maintain a higher altitude coming and going and not zip across your
neighbor’s lawn at kid-eyeball height. 

I’m currently learning stuff like this and much, much more in the
brand-new Virginia Master Beekeeper Program, taught by the most
excellent Bee Professor on the planet, Dr. Rick Fell. Honeybee
physiology and sociology is absolutely astounding.  I’ve been beekeeping
for four years now, and am just finding out with this class how much I
didn’t know.  I was also unaware that incidences of beehive thievery are
at an all-time high, hence the out-of-site suggestion.

I’ll probably continue to pop out with the occasional post on bees,
because I just can’t curb my enthusiasm.  "Cleansing flights" might be a
good topic…



   Slide from Dr. Richard Fell’s immense bastion of knowledge.