Category Archives: Horticulture

Tools of the Trade: Pruning Shears, Loppers and Saws

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(This is a slightly edited version of the same article published a few years ago in the HPSO Bulletin.)

The Pruning Series, 1

If you garden you will need to prune. Pruning is necessary not only for garden aesthetics but for the health and survival of plants in your garden. Gardens are our own inventions. They are infused with our intentions while the natural forces at play in any landscape work toward their own conclusion. We gather plants from disparate places around the world, put them together on soils in climates they did not evolve with, in intimate relationships we impose. We will have to be involved in an ‘editing’ process that is ongoing within the ebb and flow of plant growth and death that will include shuffling, removals, additions and pruning. Gardens are dynamic. Whether we make ‘good’ plant choices or not our continued involvement is a given. If we are good observers and modify our actions accordingly, we can move our gardens toward a balance that will require less of us. If we have aesthetic priorities that we are unwilling to relinquish, we will have to work to assure they continue. If our knowledge of how the plant will perform on our site is less than perfect and we fail to take all of it into consideration when we planted, we will have to intervene, maybe regularly.

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Landscape and Culture: Redefining the Urban Landscape – Single Use Corridors – Railroads

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R x R below Division St. and 9th

R x R below Division St. and 7th

Landscape, is a human concept. It is more than simply a place, or the land that we occupy. Land becomes landscape when it passes through the lens of our eyes and we ascribe to it not only our own values and emotions, but also the value and emotions of the culture we share as members of this society. Just as we are shaped by the laws and culture of our society so to is the landscape. Without, sometimes, considerable conscious effort we cannot see the landscape free of this ‘cultural looking-glass’. As individuals I don’t think it’s ever possible to look at the landscape neutrally, though over time, our experiences can change us, and so, also, how we value and view the landscape. This is important if we ever want to change our relationship with the landscape we live in, if our role as an actor in the landscape is to change, if we are to, individually and collectively, become responsible stewards of the places within which we live…because it is one thing to say we are good stewards and something else entirely to actually be one.

People continue to be drawn here to the landscape of the Pacific Northwest. We all have our favorite places that hold us, and, unfortunately, over time, can come to sadden us as we see them degraded and homogenized by the momentum of our culture, the economic engine we all depend on, that is still systematically converting our landscape into one that can be found almost anywhere with the exception sometimes of a geography too expensive to alter. Even climate, we are beginning to realize, is within our ability to change, though we are finding, such changes are likely beyond our control. Continue reading →

Photosynthesis Types: C3, C4 and CAM a simple overview

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If you’re curious I found a relatively simple, not too technical, overview on-line titled: 

Photosynthesis – An Overview

There are 3 basic types of photosynthesis:  C3, C4, and CAM.  Each has advantages and disadvantages for plants living in different habitats.

Check it out at: http://www.marietta.edu/~biol/biomes/photosynthesis.htm

The bulk of plant species, around 90%, utilize C3, while C4 plants comprise 3% (7,600) of all plant species, but account for 30% of terrestrial carbon fixation.  46% of the Grass Family are C4s, including Corn, Sugar Cane, Millet and Sorgum.  They make up 61% of all C4 plants.  Most C4s are monocots, obviously.  Among the dicots are many species from the Aster, Brassica, Amaranth and Euphorbia families.

C4 plants have a competitive advantage over C3 plants when grown under higher temperature conditions, 30+ C (C4 plants are concentrated in the tropics and sub-tropics where temps are higher), with lower available nitrogen and drought.  With moderate temperatures, available N and water, C3 has the advantage.  CAM have the greatest advantage under desert conditions.

Among other things scientists are trying to engineer Rice, a C3 plant, into a C4 plant, increasing yields and lowering their water requirements for growth.  Rice is the most commonly consumed food plant in the world.

Crassulacean Miracles

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Some of my CAM plants: back, Agave colorata, A. americana Medio-Picta; middle, Hechtia 'Texas Red' w/ Sedum 'Anglina', Agave gentryi 'Jaws', Puya venusta, Aloe (?); front, Puya chiliense, Dyckia 'Big Red', Senecio mandraliscae and Agave parryi 'Cream Sickle'

Some of my CAM plants: back, Agave colorata, A. americana Medio-Picta; middle, Hechtia texensis’ Big Red’ w/ Sedum ‘Angelina’, Agave gentryi ‘Jaws’, Puya venusta, Aloe (?); front, Puya chiliensis, Dyckia ‘Red Devil’, Senecio mandraliscae and Agave parryi ‘Cream Spike’

Plants for me are little windows into the working of the world. Beautiful, exotic, grand or seemingly simplistic, perfectly attuned to their place. We are simple animals ourselves our attentions grabbed and later lost by what shimmers and glitters in our minds for a moment. We look, but only partially see. Each plant is an opportunity, maybe a lesson and later forgotten by most of us, unaware that there is anything there to learn beyond our initial attraction to the physical plant itself. The unrolling of a leaf of Liriodendron, like a flag, happening 10 thousand times on one tree, each year across the span of its years, for generations for millions of years. The perfectly memorized pattern of the single enormous leaf of an Amorphophallus as it stretches up out of its corm, fully formed, each leaflet revealed as a piece, entire, not expanding through a growing tip, adding tissue, but revealing itself wholly if we watch. Each plant a miracle to all but the blind.

I was reading an article on UBC’s botany photo of the day site, on Crassula ovata (Jade Plant). It is one of the most common of the Crassula species in South Africa growing on sandy loam soils, with around 12”-18” of rain as part of what some call the ‘Albany Thicket’. Continue reading →

Katsuras as Street Trees: picking the right tree

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photo 1

Sometimes it pains me to take walks.  I was on my way home from the Imperial Bottle Shop and Tap Room, walking down SE 26th south of Powell Blvd when I came across these four Katsura trees planted in a 4′ wide parking strip, no curb parking with a painted bike lane right next to the curb.  Katsura trees 24″ from the bike lane.  How is that going to work?  Trees grow.  Branches extend and caliper up.  Branches hit bicyclists and pedestrians in the face and people crash and or break branches. (Yes, I know these can be limbed up over time but we all know how often that doesn’t happen and what are these trees going to look like if all of the branches are cut off of the street side up to 14′ for traffic clearance.  Trucks regularly use this street.)  And then there’s the whole it’s just the wrong plant for the growing conditions thing.  Katsuras grow in the mixed woodlands of Japan with moderate temps and summer rainfall.  So that looks like 3 strikes out of 4 pitches.  Landscape architects still love these…so do I, but planting them in positions with reflected heat with limited root runs through compacted mineral soils!!!! It’s 90 degrees today, their foliage is stressed even with their water bags filled around their bases.  I have seen many more bad examples of Katsura use over the last 25 years than i’ve seen appropriate.  If you’re going to plant them plant them in a woodland or along the edge where they will be protected from intense direct  sun and make sure they have a long cool root run.  This is so wrong.  Now we’ll all have to watch these limp along getting by stressing until they die or become so damaged someone removes them. Continue reading →

Drought Tolerant Plantings: A Review of Riverplace and South Waterfront, Summer ‘12 (updated Aug. ’14)

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Riverplace Esplanade Bank looking south along the Marina toward the Marquam Bridge

Riverplace Esplanade Bank looking south along the Marina toward the Marquam Bridge.  My last big xeriscape experiment.

The following is an evaluation I initially did while still working for Portland Parks and Recreation.  I’ve edited it a bit and added a few things to make it more current.  I think it’s important for people to know what others are doing, what they’ve tried and what were the successes and failures.  While kind of long it is still a brief look at the conditions on a few sites that were under my care and my observations concerning their performance.  As Downtown area Parks these landscapes are very accessible for those curious to see how these plants have done on the ground.  Now, most of you if your gardening is limited to your own backyards will never have to deal with landscapes so large, nor will your growing conditions, specifically your soil, be the same, I thought that it would be interesting to share this anyway, in addition to letting you know where you can come see how these plants can look in a landscape.  All were planted small as they tend to better adapt to their sites when small, but some are beginning to mature and show what they can do.  Anyway, I view our Parks as a public asset.  There are many valuable and important plantings around us, that the public is largely unaware of.  Part of my role here is to change this situation through promotions like this and by continuing to work with horticulturist to create some kind of database of public and private plantings that is accessible for viewing by the general public. Continue reading →

Erythrina x bidwillii: Coral Bean Shrub

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Erythrina x bidwillii from Piece of Eden

Erythrina x bidwillii from Piece of Eden

Every gardener makes decisions about which plants to buy, which to increase, limit or get rid of. It’s part of gardening. We each have our biases that cause us to tolerate plant ‘behavior’ that an otherwise ‘rational’ person would never choose. A ‘rational’ gardener would not knowingly acquire plants they knew to be tender in their zone nor would they collect plants with growing requirements they cannot provide. Who said gardeners were rational?  Much of our lives as gardeners we spend learning just these things about ourselves and our little plats of earth. Most gardeners are hopeless optimists and find themselves constantly tempering their runaway excitement for a never ending parade of plants, after all we have limited budgets for replacements and only so much energy to deal with too much attrition. Besides, all of that plant death can get kind of depressing.

The reality is that we each draw this line differently. Continue reading →

Evaluating Your Garden Site

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Perhaps the most important question any gardener can ask is, “Where do I garden.” While this may not be as sexy as choosing the plants we’ve always wanted or re-creating a spectacular garden we’ve seen, it is absolutely essential over the long term for the health and success of your garden or landscape. While we can stray from the limitations of our sites, it will cost us. So it is still important to know our sites, to make the necessary modifications whether they be protection from winter winds, improving soil drainage to whether or not we will even need to irrigate, how often and how long. If you go to considerable expense to install your landscape and it fails to meet your expectations, you will need to re-evaluate either your site, your expectations or both.

There is more to gardening than locating yourself on the Sunset zone map and simply plugging in plants, though this is where many of us start. Continue reading →

Hello…is anybody there?

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Horticulture: the art and science of growing plants.

Riot: noun; 1, a violent disturbance of the peace by a crowd.  “riots broke out in the capital”

2, an impressively large or varied display of something.  “the garden was a riot of color”

verb; take part in a violent public disturbance.  “students rioted in Paris

To pursue the practice of good horticulture today in the public landscape is a political act.  It is an act of defiance.  It tells people that horticulture and the landscapes we live in matter.  Landscapes are not simply backdrops to human activities.  Landscapes are a wedding of life to place.  They reflect society’s relationship with the  green world.  Ours today demonstrate our lack of connection, as a people, to the landscape around us.  My purpose with this blog is to advocate for good horticultural practice and I intend to do that with both good and bad examples, primarily in the ‘green’ city in which I live, Portland, OR.

I also intend to use this site to discuss just what is good horticultural practice from the importance of knowing your site and the requirements of what you chose to grow on it to good pruning practice and the tools that we use to do the work.  There are no ‘green thumbs’ only people who care enough to pay attention.

There will also be the occasional article discussing plants I have grown well and those I’ve been less successful with. The plant combo shown in my header, Iris x pacifica ‘ Simply Wild’ and Fabiana imbricata is indicative of the scope of plants I choose to grow myself.  The Iris is a hybrid of several of the native species found only on the west coast of North America, grown and selected from the garden, supremely well adapted to our region, but nowhere else in North America.  The Fabiana comes from the dry uplands of Chile and Argentina, an area that shares a climate very similar to our own here.  I love the textural contrast of the two and as a member of the Tomato family or Solanaceae this speaks to my interest in the exotic…familiar and different.  As we begin to confront the issues of sustainable landscapes and climate change, we need to be looking to such mediterranean regions like these.  Gardeners and horticulturists in other parts of the country will have to evaluate there home regions and how their climate is shifting to know which climatic regions of the world they can look to to find candidates to fill the gaps in their own broken landscapes.

That, is something we all share today, the fact that our landscapes are broken and that we are continuing to push them out of balance as we build and attempt to maintain our modern and destabilized world.  It is my intention to refocus the discussion and provide you with some needed support because most  of our institutions and practices are still moving us in the wrong direction.  Green-washing, can never work.  Conflicting priorities and a consistent under valuing of our landscapes lead to too small budgets and understaffing.  Politics often get in the way.  Good horticultural practice can move us in the right direction, because it is firmly grounded in place and health.  It can serve to illuminate the discrepancy between words and deeds.  It is a firm personal belief of mine that everything we choose to either do or not do is a political decision.  Horticulture matters.  Consider this a call to action.  Be bold.  Never doubt the transformative power of gardening.