Monthly Archives: January 2015

Flowers people! We have FLOWERS!

Is winter on hiatus?

This excellent winter for gardeners (not so for skiers) had me thinking about the weather. So far we’ve had typical El Nino conditions. Weak storms, dirty ridges, fog and inversions and mild temperatures.  California has had an improved rainy season. Its all playing out as forecast. And the forecast for the next month is for temperatures above normal and precipitation below normal. So, we shall see, its more than possible that winter is pretty much over.

What happened to all the fish?

El Nino or ENSO (El Nino Southern Oscillation) is a powerful weather phenomenon that occurs typically 3 out of 10 years. Essentially, it is caused by a reversal in wind flow along the equator in the Pacific Ocean. Typically the flow is from east to west. The wind near South America (Ecuador, Peru) blows off shore. This blows the warmer surface waters to the west and results in upwelling of rich, oxygen dense cold water from below. This is a boon to living creatures and this is a fantastic place to fish. Fisherman noticed almost immediately that every few years though that fishing was AWFUL. The ocean became warm (thus less oxygen) and sea life was scarce. It could be so catastrophic to kill even native animals.  This phenomenon was noted as occurring beginning in December- Hence, the fisherman named it El Nino- after the Christ child. Now we know that this 6-9 month long reversal of winds is part of a large pattern and it has specific effects on the weather all around the globe.

El Nino and the Pacific Northwest

The global effects of El Nino are extensive. In the Pacific it can energize the subtropical jet and merge with the polar jet stream- thus wet storms are more prone to move into California- the whole southern United States is wetter. El Nino even quashes the formation of Hurricanes in the Atlantic- good news.  In the northern tier of the US, including us- there is a different set of effects. The weakened polar jet  is often obstructed by a ridge of high pressure. (We are currently as of 1.27.15 under this regime). This prevents storms from moving inland. Less rain. Instead dry conditions appear and often with a strong inversion. An inversion is just that- cold air trapped at the surface (and often foggy and stagnant) and warm air above- it forms a virtual lid on the atmosphere. The atmosphere is inverted.  On 1.25.15 this was in full evidence- would you believe that while we were in the upper 50’s in the Willamette Valley up at the 3,000-4,000′ elevation temperatures were basking in the 70’s?  Not good news for skiers. This lid can trap pollutants at the surface and often fog forms as the lowest elevations cool and the saturation point is reached.

How long?

El Nino typically lasts 6-9 months and its effects can linger a bit longer than that. By the way La Nina is the opposite of El Nino- the wind blows very strong the other direction at the equator and ocean temperatures plummet.  Its effects on us are just as you would guess. Wetter and colder weather. Cold wet springs and summers that are slow to warm. These conditions results in what  gardeners know as bad ‘tomato years’. As far as we can tell La Nina is about 1/2 as likely to occur as El Nino. And there is growing evidence that global warming could spawn more frequent ENSO. Only in the future by judging the past will we know for sure.

My house, my numbers!

People often confuse facts with opinion and the weather is one such casualty. Everyone’s perception is different. Hot for one person is comfortable for another and so on. It occurred to me that it might be good to describe exactly how weather statistics are measured- and what the home gardener can do to REALLY get to know their garden and its micro-climates.

Temperature:  Place your thermometer 5′ off of the ground on the north side of a structure. It should always be in the shade. Yes, the official temperature is the shade temperature. Just several minutes in the sun will wreck your readings. This is especially important if you are tracking the highs and lows.  So no cheating- it must be in the shade. Also, you are taking the air temperature where we live at 5′ above the ground- not at the ground and not 20′ above the ground. 5′ above the ground is where the official temperature occurs.  Personally, I like my Taylor Min/Max mercury thermometer- though there are better more reliable digital units out there. Just be wary of dying batteries- this can skew your results. It goes without saying that the remote sensor for digitally broadcast thermometers be placed in the shade, 5′ off the ground.

Note: The coldest temperature of the day often occurs briefly AFTER the sun has risen so be patient. On the other hand our hottest temperatures (in summer) occurs between 5:00pm and 7:00pm. Wait to reset your thermometer for the truest readings.

Rain: Rain gauges are pretty self explanatory. They must be in the full OPEN air with NO overhead obstructions. Empty them out at the same time every day for the most complete picture. Remember that Portland has HUGE differences in average precipitation with in its boundaries.  The Airport at 90′ above sea level records 37.10″ of rain on average. In the West Hills above 500′ to 1000′ the average is more like 60″ to 65″. Elevation has a huge impact on precipitation. Because we are in Oregon algae can grow in the bottom of your receptacle- If you can’t scrub it out a few drops of bleach will kill it.

Snow measurement: Take a ruler and then find 3 even surfaces covered with snow. Do NOT  immediately go over to a drift of snow and measure it. Take the depth of each place, record it and then divide by three. That average is your official snow depth. Typically, .05″ of precipitation yields 1″ of snow.

Wind: Wind is typically measured 10’+ above the ground. A gust of wind is the average speed over 3 second intervals. A hand held anemometer will record slightly lower speeds than a professionally placed device.  Generally, though you can make estimate  the wind speed using the Beaufort scale of observation. For instance: Smoke rising perfectly vertical is obviously calm. Whistling noises

Agave bracteosa in the snow last winter.

Agave bracteosa in the snow last winter.

through power lines is a gale (33 mph +)  Entire large trees in motion and losing small branches is likely to be 58 mph+- storm force winds. Above that all hell breaks loose and you should be in your house anyway.

Its fun to take the time to record weather in your own garden. If you compare it to your closest reporting station for the NOAA. (There’s a map on the website). You’ll be amazed at the difference.


Our shop is open from 10 to 5pm Fridays and Saturdays. We will open with our regular spring hours Thursday through Sunday  (10am to 6pm) starting on February 5.


New Bottlebrushes Sweep Oregon Gardens.

Callistemon or Bottlebrush is a genus that we have special interest in at Xera. They may be ubiquitous in California and through out zone 9 – where two red varieties dominate. Callistemon citrinus ‘Splendens’ Zn9a and Callistemon viminalis Zn9b. Neither of these large shrubs, small trees are sufficiently hardy anywhere in the PNW north of Bandon on the southern Oregon Coast. That doesn’t mean we can’t grow some red flowered bottlebrushes. Callistemon (ka’-LIST-ee-mon) which means beautiful stamens- the main structure of the conspicuous flowers-is actually a very large genus- replete with a multitude of  species in their native Australia. They occupy nearly every biome on that continent and are aromatic members of the Myrtle family (Myrteaceae)- which also includes Eucalyptus among other cultivated plants. Its those from the highest, alpine elevations of the interior that thrive in our gardens. There are two reds that have been successful in the mildest gardens west of the Cascades.

Callistemon subulatus 'Dark Red' Is a good red for mild gardens.

Callistemon rigidus ‘Woodlander’s Red’ has become a classic red Bottlebrush for the milder PNW (above)

Callistemon rigidus ‘Woodlander’s Red’ is the most commonly seen red variety. It is hardy to Zone 8a (10º to 15ºF), It requires placement in the warmest locations of a garden- against a south or west facing wall or near the reflected heat of asphalt. It can be damaged in our coldest winters (below 10ºF). Recovery happens though if dead parts are removed  regular irrigation speeds its re-growth during the dry summer months.


Callistemon subulatus ‘Dark Red’ has some of the deepest sanguine flowers of the genus. It requires the protection of a wall.  (above)                                                  Xera Plants Introduction

Another red flowered bottlebrush that has shown a fair amount of cold resistance is the species Callistemon subulatus ‘Dark Red’. Its a fine, fine textured arching shrub to 3′ x 5′ in our region. Deep red flowers appear on new growth throughout the growing season. It also blooms well in a pot and can be kept in a container that can be moved into protection when temperatures  plunge. It is hardy to about 15ºF and it can vigorously recover if frozen back. (Not all Bottlebrushes have the vigor to regrow and this one does). Place it next to a warm wall, south or west facing. Blooms appear for months. This is a wonderful species for the Oregon Coast (Zn9a).

The Hills are alive with Bottlebrushes

A very hardy species that is  wonderful west of the Cascades is Callistemon pityoides or Alpine Bottlebrush.. As its common name alludes it is from the high mountainous regions of Australia- in snowy, frosty conditions.  It is a very variable species with the two most common traits  fine, needle-like leaves and pale yellow flowers. Nearly 20 years ago, touring a garden in Corvallis I found an Alpine Bottlebrush whose owners pledged that it was growing there and undamaged by cold (that means bouts of 0ºF) for more than 30 years. It is a thin, fine textured shrub with globose small pale yellow flowers that remind me of baby chicks when they decorate each branch tip in May/June and again in September. All selections of this species share the propensity for two seasons of bloom. Callistemon pityoides ‘Corvallis’ grows to 5′ tall and 3′ wide in 10 years. As with all in this genus it absolutely requires full, all day sun to perform. Regular water speeds growth in this species, which is drought tolerant if pressed into that service. It should also be noted that these aromatic and somewhat sparse shrubs are excellent where deer are a problem. These will be left alone or they will be the last thing molested by Bambi in the garden.


Callistemon pityoides ‘Corvallis’ is an alpine bottlebrush that is the hardiest of the genus to 0ºF. The flowers are adorably reminiscent of little fluffy chicks. 5′ tall by 3′ wide. Zone 7a (0º to 5ºF). (above)  Xera Plants Introduction

One of our finest discoveries of this species is our selection that we have simply christened ‘Excellent’. Its a crazy growing shrub with the finest needle like leaves that would make a pine tree blush. Its greatest attribute is its 5″ long pale yellow wonderful Bottlebrush flowers (again in spring and then fall). Its a winding, arching shrub with great personality and it is a very, very heavy blooming selection .  To 3′ tall and 5′ wide for full sun in any type of soil. Very drought adapted. Cold hardy to Zone 7b (5º to 10ºF)- it shows slight damage below 10ºF- but its recovery is perhaps the fastest of any Callistemon I have grown. This is my own personal favorite Bottlebrush. Its flowers are luminous and cohabitates gracefully with other flower colors. Short of a wacked out conifer, nothing else approaches it in fine textured good looks. New growth in this species is conspicuously furry which is also adorable.

Callistemon pityoides 'Excellent' is just that a subtle flower color and wonderful textural plant.

Callistemon pityoides ‘Excellent’ is just that. A subtle flower color and wonderful textural plant. Fine needle like foliage, superior long brushes decorate this graceful plant in May/June and again in September/Ocober.  (above)  Xera Plants Introduction

Another perfectly hardy species for our gardens is the wonderful Mountain Bottlebrush from Tasmania, Callistemon viridiflorus. This is a remarkably handsome shrub with fantastic leaves, corky, white bark and large beautiful bottlebrush flowers from late May to early July. This is a cold hardy shrub, unperturbed by 5ºF and sports the largest flowers of the hardiest varieties. 1″ wide 4″ long chartreuse/yellow brushes glow from the branch tips and it is a very heavy blooming plant. The nectar  filled flowers (as they all have) are obsessed by hummingbirds for the weeks it is  in bloom. Almost 10 years ago we did a batch from the seed of a parent plant that had survived 0ºF with light damage, just to see what we might get. Out of hundreds we separated out 4 seedlings that had distinctive traits. Our first selection of that brood is a phenomenal plant that we are proud to grow. We have dubbed it Callistemon viridiflorus ‘Xera Compact’. To just 4′ tall and 3′ wide it is an insanely floriferous shrub, thick, vivid 3″ bottlebrush flowers smother each branch tip. The scimitar shaped foliage lines the stems with a pronounced vertical component that is different than the species. This Mountain Bottlebrush has everything for greatness and we are focusing on making as much as we possibly can. The deep green leaves take on maroon tints in winter- which contrasts with the taupe bark in a wonderful way. Look for this great plant at our retail shop- thats the only place it will be available.

Swept Away

Bottlebrush have the unenviable trait of not looking the best in nursery containers- they really find their own in the ground. So with an open mind and a happy heart try out these Aussies in your garden. We are always on the look out for new selections. Allow yourself to be swept away.

Callistemon viridiflorus ‘Xera Compact’ one of our greatest introductions to date. To only 4′ tall and half as wide, it blooms like a fiend popping off brilliant chartreuse yellow flowers for six weeks from late May to early July. So floriferous and its also perfectly hardy to cold down to 5ºF.  (below)     Xera Plants Introduction

Image 6

Unplanned gardens and a summary of the weather year at Portland

Take a quick look at your garden.

I spent this cool and dry January day in my garden tidying up and checking the progress of the garden. Our first real freeze of the year has rendered the soil rock hard and though it dropped to 19ºF in my garden on the coldest night there was very little freeze damage. A few tender things that I slip into the garden were noticeably unhappy. And that is how it should be. 19ºF is just one degree below our average annual low of 20ºF. The coldest temperature was 21ºF at PDX and it went down to 17ºF at Vancouver Pearson Airpark. That is the closest recording station to my north Portland garden.

But, I like to check these things because every freeze, even as inconsequential as this brings new surprises.  I was at the beach for New Years and I stupidly forgot to empty my Koi pot  and it was full to the brim. It froze about 6″ deep and mercifully did not crack. I won’t take that risk again.  Flora had my back.

Limp and sad

One surprise was that my Clematis cirrhosa ‘Wisley Cream’ really got hammered. It was in full bloom and growing happily on a fence. Its limp and discolored and it may be very wounded. Strange, it sailed through 9ºF last year and was unphased. I suspect our warm wet fall and December left it a little lush and perky. We’ll see how this plant recovers. I hope it does because not only do I love it but the over wintering hummers love it too.

Reap what is sown

The longer I garden the more I come to love and cherish plants that reseed themselves. Its a wonderful surprise and can yield really special things. Cleaning up my Hellebores I found a carpet of seedlings- those I dispatched- I like what I have already and they are the product of very careful hybridization by the masters the O’byrnes.  Along side the Hellebores was an equally prolific group of Cyclamen coum seedlings. I had planted the best leaf forms we have grown with an eye to this self propagation. It worked, the majority of the seedlings were all silver or heavily marked swirly leaves. Not only will they stay but I will spread them around the garden. This unobtrusive, tough winter blooming corm is one of the cheeriest parts of the winter garden. I have grown them in full sun as well as dense shade- They thrive anywhere. The only disappointment is when you spear one in the summer when they are quietly dormant. I mark the best ones now with a little blue toothpick. They can go dust dry in summer and all will still be fine.

Surprise, surprise, surprise

Several seedlings of my long dead Grevillea x ‘Constance’ that I have been observing also made it through unscathed. This hybrid of two VERY different species of Grevilleas has yielded some cool things in the past. Grevillea x ‘Neil Bell’ is a seedling of this plant and as I found last winter it was undamaged while its parent plant croaked. Hard. The three new seedlings are all very different in their leaf shapes. I hope they stick around because it might yield a fun surprise. The moral being do not be too hasty to hock out seedlings- a new flower color, form, exceptional thing might be right before you. The also presents the opportunity to share with fellow gardeners. My fecund Daphne tangutica has already yielded several gifts to garden friends.

The Weather Year in Review mild and wild 2014

We already know it was a warm summer and the statistics prove this. Our warmest temperature was 99ºF on two different days July 1st and August 16th. Thats two degrees below our average hottest day which is 101.3ºF. The real story was the warm overnight lows. 2014 set a new record for the most overnight lows above 60ºF- 50. That was 5 days more than the previous record of 45 set in 2013- we may focus on highs and ultimate lows but this may be the real story of global warming. It pays to dig down to the details.  Also, 2014 was the second warmest year ever at PDX.  The record warm year was 1992. So we may not have breached 100ºF but warming can appear in different ways.

Some hard facts just for fun: Statistics courtesy of Portland NOAA

Last day below 32ºF- March 22 normal is March 19th.

First 70º Day- April 7 normal is March 30th

First 80º day- April 30th, normal is May 10th

First 90º day- May 14th, normal is June 16th

Last 90º day was September 20th, normal is September 8th.

First 32º day was November 12th, normal is November 15th

August, September, October were the warmest ever recorded in Portland. See? its not the extremes as much as the details and the trends.

A weak El Nino is chugging along.

If you are a skier you know that this season so far has really sucked. And El Nino is gearing up. January is looking fairly dry and above normal in temperatures.  Remember that an arctic episode can still occur in an El Nino winter but this is shaping up to be typical for a weak ENSO.  We will remain vigilant and post any surprising trends on this blog.  Have a wonderful New Year and happy gardening in 2015!