A warmer than normal winter? Looks like it.

I’ve been pondering all the forecasts that I’ve seen for this coming winter. Without going into painful detail I will state this. Put all together they point to a warmer and drier winter than normal. As you have probably noticed the leaves are tardy to show color this year. That is because not only August, but both September and October were the warmest ever recorded in Portland.

There seems to be no real change in this regime until at least January.  One thing to think of is that last year was abnormally cold- we had two winter blasts- how could we forget?  The cold wave last December was a once in a decade event- in Eugene where it was an astonishing -10ºF at the airport it was a 40 year event.

We typically do not see two cold winters in a row. That is just a fact and beyond that it has no real basis but if you look at the climate record for the last 60 years that is one pattern that holds true. A cold winter is characterized by more than 2 days below 20ºF. Remember that our thirty year average lowest temperature at the airport is 20.3ºF (Zone 8b). Two cold winters in a row has happened in the past but there is a whopping 80% chance based on records from 1940 to the present that supports at least a year of mild/normal winter weather between massive arctic intrusions.

One of the best ways to think about weather is to divide it into averages that gives a better overall picture. For instance, in a 10 year period we typically average 6 winters that fail to drop below 20ºF, (Zone 9) 3 years that drop between 10º and 20ºF (Zone 8)  and one year below 10ºF (Zone 7).  That last figure is becoming more and more rare. The Portland Airport has not seen a temperature below 10ºF since it registered 9ºF back in 1990. Thats almost a quarter century. (It was 11ºF in 1998 and 12ºF in 2009 as well as 12ºF last December. )

Things are quite a bit different in the suburbs. Hillsboro dropped to 7ºF last December, 9ºF in 2009. The average annual low at the Hillsboro Airport is 14ºF (Zone 8a). Its important for gardeners away from the urban core to account for lower temperatures when they choose plants. This is true for Clark County as well.

There is a weak to almost neutral ENSO (El Nino).  Whether or not it gains strength remains to be seen. In a word the weather during an El Nino winter is Bland, Bland, Bland. The northern jet stream weakens and weak troughs are split before then enter the PNW. The weather is warmer than normal (but there can still be an arctic outbreak- its just much, much, lower chances.) Split storms give us mild, dry weather.  We have more than one reason to cheer on El Nino- it strengthens the sub-tropical jet aimed into California providing them with prodigious moisture. I know that everyone wants this to happen to have at least some effect on the historic drought.

Als0- the NOAA predicts a colder than normal winter in the eastern U. S.  This also brings us warmer weather as a ridge remains over the west and a trough over the east ushering arctic Canadian Air far to the south.

So, if you are a gardener expect a milder than average winter- there is always the chance- even if it is much less for an arctic event (and as we know it only takes one arctic night to do all the damage).  If I see anything like that coming I will post it here.

So, in the mean time. The leaves have yet to change color and the next several months do not look to be below climate normals.

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The Natives are Restless

Platitudes and Plants

A recent article that I found compelling and posted on Facebook that was originally posted on Huffington Post has me thinking very seriously about the subject of native plants.

It posited the idea that the same plants are planted in similar climates the world over. It was an opinion piece that decried the lack of diversity that imperils native fauna by the lack of native flora.  Here is the link to the story:

‘Just Because It’ll Grow in Your Yard Doesn’t Mean You Should Plant It’ -Lisa Novick

http://www.huffingtonpost.com/lisa-novick/just-because-itll-grow-in_b_3621351.html

Native plants is a term bandied about by well meaning people, it has real practical applications and it is so much more complicated than politically correct buzz words. As with any idea it is subject to both narrow and broad interpretation but to really make an informed opinion I think there should be some background information. I’m not going to espouse an opinion that is right or wrong. Rather, I will give you perameters that I hope will help you as gardeners make up your own mind. At Xera we have our own interpretation of the term and I will describe our philosophy that shapes what we choose to grow and promote.

Vocabulary- Words shape the garden

For a more comprehensive understanding of where plants grow and why there are a group of vocabulary words that I think are useful. Once they are combined they can give the gardener a clearer picture of how to view native plants.

Edaphic- Soil and the composition of soil- this greatly influence the plant community that resides there. I.E. Scree- loose rocky soil. Clay- tightly compacted particles with a heavy silica component. Soils can range from poor nutrient content (Sand) to high nutrient content (humus). Plants are greatly influenced by edaphic conditions. A striking example of this is found in serpentine soils of Southern Oregon. These soils are high in toxic heavy elements such as zinc and nickle. In this environment- where serpentine conditions rise to the surface it can abruptly influence plant communities. Plants not adapted to this stop abruptly and a whole new adapted community dominates. This is a severe example of edaphic adaptation but it makes an important example.

Mesic- Soil conditions with a positive influx of moisture. Plants can also be described as mesic and those rely on a continuous supply of moisture and are less adapted to dry conditions. Mesic designated plants often have lush, foliage with little adaptation to drought. As an example the foliage of mesic plants has little ability to inhibit moisture loss through transpiration. A majority of shade plants are mesic. Plants that are shielded from direct sunlight put more energy into photosynthesis and less into structure that limits moisture loss. They often lose moisture at the same rate they accrue it. These are the plants that require constant summer irrigation in our gardens. Think of native ferns and native Bleeding Heart (Dicentra formosa).

*Transpiration- The loss of moisture through plant foliage.

Hydric-These are soils that are predisposed to seasonal or continuous water inundation. This can be stagnant (anaerobic ) and/or temporarily inundated. Riparian zones- along water ways  typify this description. For instance the plants in these areas are primarily mesic in nature. Two species in Western Oregon that typify Hydric soils are the beloved blue Camas (Cammasia quamash) and Oregon Ash (Fraxinus latifolia).

*Riparian- Wetlands adjacent to rivers and streams.

Xeric- An environment that is starved for moisture. Xeric also describes the adaptation of plants to deal with a continuous moisture loss. Xeric plants may employ a variety of ways to limit this. Hair on leaves, waxy leaves, succulent foliage, leaves held perpendicular to the sun are examples of adaptations of Xeric plants that interrupts the loss of moisture.  In Western Oregon xeric conditions are often found on south facing hillsides. It can also occur in urban areas adjacent to asphalt- which is taking the idea one step further.

What can be tricky is that many (most?) plants do not adhere to one or the other, Xeric or Mesic they all have their own adaptation. But by describing the extremes you get a better idea of how they work. And how they can work for you.

Biome- A region of similar climate and conditions that harbors like flora in a continuous zone. It is defined by conterminous precipitation, temperatures, and soils.

Ecotone- The margins between two biomes- a transition zone.  For instance the boundary between a forest and a grassland. This may be abrupt- in several tens of feet or gradual, many miles.  Differing soil conditions (edaphic), moisture, exposure, elevation, or latitude can drive this change.

These words can give you a rudimentary description of the places where plants grow. Just saying that a native plant will grow in any situation is horribly flawed. Now most people do not really mean to simplify it into one category- and yet you often see “native plant” gardens with species from all different biomes jammed together into one space. It really is a problem that people are not educated to understand the different circumstances that each plant requires. For instance a Biome can extend far beyond our political borders. The Willamette Valley which receives between 35-50″ inches of rain on average and low temperatures annually between 10º and 20ºF is not discrete. The same situation occurs at higher elevations though out Californias mountains. Gradually rising in elevation as you move south. These areas have surprisingly similar flora. Douglas Fir (Pseudotsuga menziesii) Ponderosa (Pinus ponderosa) Oregon White Oak (Quercus garryana) and Western Dogwood (Cornus nutallii) repeatedly show up in this continuous biome south to the lower third of California.  In fact Douglas Fir extends as far south as central Mexico at very high elevations. (It is thought that Mexico is the paleo origin of this species that is so iconic of the Pacific Northwest).

Plants Are on the Move

We may think of the range of plants as permanent- and in a humans lifetime their ranges don’t really extend that dramatically. In the course of natures timeline this is far from the case. In reality species are in nearly constant movement increasing their range in one direction, withdrawing in another- driven by the change in climate that has waxed and waned with the ice ages and interstadials (warm periods between ice ages).

During the cold dry periods of the ice age in Western Oregon species of trees that now dominate the highest elevations of the Cascades dominated all of the lower elevations of our state. At the glacial maxima 11,000 BP the Willamette Valley was a vast forest of Tsuga mertensiana (Mountain Hemlock), Picea englemannii (Engleman’s Spruce), Pinus contorta var. murrayana (Lodgepole Pine)- a current assemblage of flora that now occurs at Government Camp at 4800’+ on the slopes of Mt. Hood. The question this poses is are these locally native plants if only separated by a few thousand years?

The Right Plant in the Right Place

So, if you take the time to learn the correct biome where a plant occurs you will successfully grow many native plants. As an example Ribes sanguineum (Flowering Currant) is a plant of the forest margin ecotone. It thrives on the borders of woods. Luckily it can take full sun as well- to which it has been committed in untold blasting hot landscapes. But forest margins are where it thrives. Trilliums such as Trillium ovatum which decorates the woodlands in early spring is clearly a mesic plant – but it avoids the heat of summer by going safely dormant.

At Xera we have taken a broad approach to native plants. Instead of confining them to their specific political boundaries we try to embrace the whole extension of their occurrence in a biome. To extend that further we seek out plants in similar biomes throughout the world. That is not all of what we grow but its an overall important component. And as we like to say, native plants are great, especially if you know what to do with them.

Summer 2014 Review and Winter 2014/15 what may be?

Lagerstroemia x fauriei 'Yuma' Crape Myrtle

(above) Lagerstroemia x fauriei ‘Yuma’- click for a larger picture.

Crape Myrtles LOVED this past summer- they responded to the extended heat, ample June moisture, and warm over night lows by blooming extremely early and a lot.

Wet, Wet, Dry, Dry, Fry, Fry, Fry

Here are some statistics of the above normal hot summer that we just left. There are some interesting surprises. If you thought it was exceptionally dry- it ended that way but began very differently.  These statistics are from the Portland National Weather Service (NOAA) at Portland International Airport.

We ended the summer with a grand total of 22 days above 90ºF- which is impressive since our average is 13 days. This was the highest number of days since the scorching summer of 2009 (Remember two days of 106ºF, yuck). That year we fried with 27 days. In 2014 we first hit 90º on May 14 when it was 91º and our last day of 90º was 94ºF on September 20th. One important feature of August was not its ultimate high temperatures- though it was above normal in 90ºF days,  it was the nearly continuous stretch of overnight lows (22) above 60ºF.

Sleepless Nights

Our warmest overnight low occurred on August 11th of 69ºF preceding that days high of 99ºF which tied with July 1st which also reached 99ºF for the highest yearly maximum. (Portland’s average annual hottest day is 101.3ºF).  Our average overnight low in August was a very warm 61.4ºF compared with a historical average of 58.1ºF. That might not sound like a big difference but in the world of weather averages its impressive. And in Portland that is downright tropical.

One half wet, one half dry and a parched early Fall

Rainfall- and I’m sure everyone can attest to how dry our gardens are.  This was the big surprise. June (which failed to have any days above 90ºF) was quite a bit above normal  with a total of 2.33″ compared to the average 1.70″.  July also had above normal precipitation with 1.05″ above the average of .65″ (It doesn’t take much to go above average in summer here).  August was dry with just .01″ of rain far below the average of  .67″.  September rounds it out below average at .98″. Normal is 1.47″. This autumns rainy season has been tardy in arriving.

So, if you thought it was dry (and it still is) it was/is a product of several factors. Our heat was very consistent with 80’s and 90’s spaced out evenly over July, August, and September and this was efficient at depleting  soil moisture. August was essentially devoid of rain and this deficit continued well into September. The modest amount of rain that fell in mid September was erased by temperatures that rebounded into successive days in the 90’s. As of early October above normal temperatures and parched soil have left a lot of summer rainfall plants flagging or just plain fried. These conditions are far from historically dry conditions- though it seems extreme to gardeners.

Winter 2014/15 Prognostication

If you would like to know what our winter has in store you should make a trip to the annual Winter Weather Forecast Conference  at 10 am on October 25th at OMSI. Its free and open to the public. Seven locally prominent meteorologists will give their forecasts for winter. This is useful for not just Ski areas and ODOT but for gardeners as well. AND AGAIN it is free. But it gets crowded so get there early. There is quite a bit of meteorological jargon but the forecasts are pretty straight forward. I’ll provide a synopsis on this blog following the meeting.

Now bring on Fall and fingers crossed for a mild winter.

The Xera Plants Blog Introduction

Featured image

Hello from Xera

Welcome to Xera Plants new blog.  I’ll be updating this site on a regular basis. This blog will feature a lot of different things. I’ll be profiling plants that are new, interesting, or over looked and they will be available at our our retail shop.

I’ll have discussions on design, native plants, weather/climate….well just about anything else that seems important. Its geared specifically towards the Portland area- I’ll try to include information for other parts of the country as best I can. I’ll reserve the right to go into full geek mode. Since I am a geek and so are most plant people. (Embrace it, it is good).

Our Gardening world

We love to garden here and at Xera we firmly believe this is one of the best places to garden in the world. We have (mostly) mild winters (USDA Zn8a-8b), plentiful rainfall- but very dry summers. Our summer heat- though not sweltering is sufficient to expand our list and success with many plants. These favorable conditions tempt the most intrepid gardeners to try just about anything. There are successes and failures- but above all this leads to education and savvy gardeners use these lessons to expand the envelope even further.

Plants + Climate + Soil

Xera Plants focuses on what we call ‘Climate Adapted Plants for Gardeners in the PNW’. This takes into account several ideas. We believe that working with the climate rather than against it is a smart way to conserve resources. Match the plant to the site- plants occupy every conceivable niche in the world. We seek out plants that are adapted to specific soils, sites, and irrigation. That lessens the need for continually modified soil. And this saves not only on water but fertilizer which unfortunately ends up as run off into our water ways- which is detrimental. Of course many plants require compost enriched and fertilizer enhanced soil but not all. Each plant should be considered on a case by case basis- and then organized into similar communities. Good sound garden practices will lead to the most success.

Efficient plants, efficient water use

That means plants that are adapted to our winter wet/summer dry climate- that still thrive and do not limp through summer pathetically without constant irrigation . An emphasis on plants that survive our winters as well- though gardeners like to experiment and that is where ‘For Gardeners in the PNW ‘ is important. We do not necessarily grow generic landscape plants but a wide array of plants that gardeners can experiment with and that can require more specific care than, say, the ultitarian and (tortured) plants found in commercial landscapes. But if a common plant is good or exceptional you may be surprised to see it on our shelves.

Why did my special plant freeze?

Inherent in gardening is the interaction between plants and weather. I try to offer my very best estimation of a plants hardiness to cold based on careful (some say obsessive) observation.  Its not as simple as a single temperature. Plant health, establishment, weather preceding a freeze, duration of freeze, cultivar, a plants natural adaptation and origin, provenance….damn I consider all that and try to distill it down to a a five degree spread. Thats where the A and B appear in the USDA Zones.  Considering all those parameters it really just comes down to a gut feeling. Every plant is different, every freeze is different. If a plant consistently croaks in just slightly below average temperatures- its a candidate for the compost heap of time. Pushing the limits of your climate is a time honored tradition in gardening and know that it leads to great discoveries and horrible disappointments. I’m a weather geek and a plant geek and combine the two to learn. And I swear to you that the minute a plant freezes out and we discontinue it I find or hear about the same plant as large as a Baluga whale thriving away in someones garden. I try.

We grow local, buy local

We grow all of our plants at our facility in Sherwood and we are very proud of this. We grow local so you can buy local. Its imperative that gardeners be supplied with the healthiest and most well grown plants. Poorly grown plants seldom recover or need exceptional coddling. Thats a pact that we make with gardeners. Also- we have dropped nearly all pesticides at our facility. We rely on good horticultural practices to discourage pests. Diversity, correct irrigation, and appropriate potting medium and culture are the key. Whenever we can we rely on organic fertilizer- if you are interested to know which we use we will be happy to share. If a plant is prone to disease or pests and proves to be too difficult to grow- and will offer problems to the gardener- it will be evaluated and can be dropped. There’s an infinite number of plants in the great vegetable kingdom. And, if it shows a propensity to poor behavior, become a headache for gardeners, and generally invade into the wild. We won’t grow it. (though its a little hard to compete with the rampant weeds that are already here…Hedera, Ilex, Rubus, Pyrus, Prunus avium, Buddleia davidii, Cytisus – and your ilk- I’m talking to you.).

Plants from the west are the best

We love our native plants and they should be included in our gardens. We don’t confine native to just the Willamette Valley though but the entire west. Plants don’t observe  political borders in their natural ranges and neither do we.

I’ll try not to be too long winded so you don’t have to plow through a novel. Its my promise to be succinct and easy to understand.

Thank you,

Paul Bonine

And come back to visit ‘The PDX Gardener’- The Xera Plants Blog again and again. Updates will also appear on our website http://www.xeraplants.com and you can find these plants at our retail nursery at 1114 SE Clay St. Portland Oregon 97217 it is open from February to the first of November Thursday to Sunday 10am-6pm (503) 236.8563 http://www.xeraplants.com

We do not do mail order at this time. For wholesale info call (503)612.9950