Tom’s Garden

Growing by the Bay

Month: June 2016

fame un spritz video capture detail

Fame un spritz!

It’s summertime, which means it’s time for a refreshing spritz, the signature drink of northern Italy. And while we’re at it, let’s repost this fun video, Fame un spritz (Make me a spritz) by Sir Oliver Skardy & Fahrenheit 451, which I originally posted over at blog.rightreading.com back in 2010.

At that time, also at rightreading, in a post titled “it’s a small world apertol,” I also posted some early thoughts about spritzes, along with with the simple basic recipe.

I’m reminded of this by an article by Robert Siminson in today’s New York Times food section. In the print edition it’s called “The Spritz: It’s All Built on Bubbles.” The online version is called “Bitter and Bubbly, the Spritz Evolves.”

So fame un spritz!

mediterranean zone map detail

How to Make a Climate Summary Graph Showing Duration and Intensity of Hydric Deficit

Mediterranean climate zones, from Olivier Filippi, The Dry Gardening Handbook

Mediterranean climate zones, from Olivier Filippi, The Dry Gardening Handbook.

Those of us who live in one of the world’s five Mediterranean climate areas can take cheer from the fact that these regions are home to some of the world’s greatest biodiversity. As an example, according to Olivier Filippi’s The Dry Gardening Handbook (translated from the French by Caroline Harbouri), 25,000 plant species grow in the Mediterranean Basin proper (about 10 percent of all the world’s flora), compared to just 6,000 species in all of non-Mediterranean Europe.

These plants have adapted to our dry summers in various ways and to various degrees. We need to recognize that there are many variant subregions within the Mediterranean Climate zone. In general, however, gardeners who regularly water native plants over the summer months will end up killing them. Turn off that irrigation timer!

Donald Trump’s comments to the contrary notwithstanding, California has been in a multiyear drought. That is a fact, based on recorded annual precipitation. But for gardeners and farmers there is another meaning of drought—“physiological drought”—which refers to periods of hydric deficit. Hydric deficit occurs when plants transpire more water than they can take in through their roots. It is not just a function of water but of the relationship between water and temperature. This is critical for an understanding of Mediterranean climates.

We should not think of plants as either “drought tolerant” or not. Instead we should understand them on a scale of hydric deficit tolerance and seasonable adaptability, as this map from Filippi’s book suggests.

Mediterranean drought map, from Olivier Filippi, The Dry Gardening Handbook

Mediterranean drought map, from Olivier Filippi, The Dry Gardening Handbook.

It is helpful to create a line graph that enables visualizing the extent and duration of physiological drought conditions in your location. Following is Filippi’s chart for Marseille, France. Note how the graph displays both duration and intensity of physiological drought. (Further below is the graph I have done for my garden.)

Marseille climate diagram, from Olivier Filippi, The Dry Gardening Handbook

Marseille climate diagram, from Olivier Filippi, The Dry Gardening Handbook.

I have made such a graph for my garden (further down the page). Here is how to do it:

  1. Acquire monthly precipitation and high/low temperature data.The chart is based on sixty-five-year averages of temperature and precipitation. This data is not available for my location because we don’t have a weather station that has been keeping track of this data near enough (currently there are some nearby Weather Underground stations, but their data is only from recent years). Unfortunately for the present purpose, conditions vary quite a lot across short distances here. So I acquired data from Richmond, Berkeley, Orinda, and Martinez (google “climate summary [you location]” and look for results from the domain www.wrcc.dri.edu), and estimated my data using those.
  1. Average the high and low monthly temperatures by adding them together and dividing by two.
  1. Convert from Fahrenheit to Celcius with the formula (F-32)/1.8.
  1. Convert precipitation from inches to millimeters by multiplying by 25.4.
  1. Create a graph with two Y axes. P is precipitation in millimeters and T in temperature in Celcius. T-axis intervals must be twice the P axis intervals, so that, for example, 80 on the P axis corresponds to 40 on the T axis. The X axis is simply the months of the year.

Unfortunately, I don’t know how to create a line chart in Excel with two different Y axes with different scales. So I had to draw the lines by hand, which is not a real precise technique but might be close enough for visualizing. If anyone can tell me how to do this in Excel, I’m all ears.

  1. Draw lines connecting the data points. Conventional is red for temperature and blue for precipitation.
Climate map of Tom's Garden, showing duration and intensity of summer hydric deficit

Climate map of Tom’s Garden, showing duration and intensity of summer hydric deficit.

So there you go. The part of the year where the red line rises above the blue line is the period of hydric deficit. You can see that the duration of drought in my area is from May through September, and that August is the month when hydric deficit is greatest.

Armed with this data you can select plants that are optimized for your region.

 

Garden, May 2016

May Day Garden (part 2 of 2)

Garden detail, May 2016

Garden detail, May 1, 2016.

It’s taken me a long time to complete what was meant to be a quick survey of the garden after returning from a trip. These photos are now a month old. I’m starting to feel like Lawrence Sterne.

Papaver glaucum, May 1, 2016

Papaver glaucum, May 1, 2016

Last time I looked at Gruss-an-Aachen and Citrus Burst roses, Senicio talinoides ssp azoides, Aeonium ‘Blushing Beauty’, Brugmansia ‘Charles Grimaldi’, Datura wrightii, and Papaver glaucum. We left off with the poppies, so let’s continue with the above view of the same plant (it can also be seen in the banner atop this blog). This is our best year for these poppies ever.

Limes, May 2016

Limes.

Some of the edibles are looking good. The limes are a couple of years old, and this one is producing fruit quite well (the other one is recalcitrant for some reason, though it appears healthy). I’m growing them in containers. Limes are, of course, essential for the cocktail garden — more on that soon.

Leaf lettuce

Leaf lettuce.

This lettuce didn’t seem to mind being left to its own devices for a while.

Cunonia capensis, Butterknife Bush

Cunonia capensis, Butterknife Bush.

Butterknife Bush, Cunonia capensis, is one of my favorites. I lost some in our long drought. This one is starting up in a large container, and it’s looking beautiful. This plant is sold at Annie’s Annuals, where it is also called Butterspoon Tree (personally, I use a knife with butter). Most things at Annie’s are sold (either at the nursery or online) in 4-inch pots, but Cunonia grows quickly.

Salvia spathacea, Hummingbird Sage

Salvia spathacea, Hummingbird Sage.

Though Cunonia, native to South Africa, is a little exotic, we’ve been growing a lot more natives recently. I’ve always been put off by the moralistic anti-immigrant tone of some proponents of native plants. (I’ll bet they don’t mind apples and tomatoes.) But I love them for their practicality. Appropriate natives are easy to grow, have a very high success rate, and in our area can be quite drought tolerant. Each spring here in the East Bay Bringing Back the Natives hosts a garden tour, which is well worth joining. Above is Salvia spathacea, Hummingbird Sage, which is doing great, and the hummingbirds really do love it. It spreads by runners, so I will have to keep an eye on it. By the way, one of the best sources of information about California native plants is Las Pilitas Nursery, which is in SoCal. Our local Watershed Nursery, in Point Richmond, is also good, though it generally provides less detailed information. It’s where we buy most of our natives.

Plantago subnuda and Crassula muscosa 'Petite'

Plantago subnuda and Crassula muscosa ‘Petite’.

Another native I like is Plantago subnuda, Coastal Plantain. I has veined basal leaves and puts up interesting tall stalks. The plant in the container behind it is Crassula muscosa ‘Petite’, another South African native. It loves our Mediterranean climate, and I will have to uppot it soon. I like to intersperse container plants throughout the garden.

Camissoniopsis cheiranthifolia, Beach Primrose

Camissoniopsis cheiranthifolia, Beach Primrose.

Camissoniopsis cheiranthifolia, Beach Primrose, another native, is a favorite of Carol’s. It grows in coastal dunes, so I made a soil mix for it with a good bit of sand. I see that Annie says it is showiest in loamy soil though. I’ll have to propagate a couple of cuttings and experiment.

I could go on, but let’s leave something for another time.

Garden detail, May 2016

Garden detail, May 2016.

Some rights reserved 2017 Tom’s Garden. This work is licensed under a Creative Commons (attribution, noncommercial, no derivs: 3.0) License (US), although some of the work this blog incorporates may be separately licensed. Text and images by Thomas Christensen unless otherwise noted. For print permissions or other inquiries please request via rightreading.com/contact.htm.