Sunday, February 7, 2016

Drought Survivability Study Follow up

Just how much can we cut back on watering plants and still have a great looking landscape?  An experiment conducted summer of 2015 in San Antonio seeks to answer that question.  Last spring I wrote about the drought survivability study by Texas A&M Institute of Renewable Natural Resources in San Antonio to test popular landscape plants under various irrigation conditions over the summer.  When the test ended this past fall I went down to check out how some of my favorite plants had fared.

The project site is off the beaten track to say the least.  It's down that road a fair piece.

The welcoming committee was out.  Nice to know I was expected.

This house near the drought simulator features stucco over stone and seems to be quite old.

First, a quick recap and you can also read more here.  The test was designed to demonstrate plant tolerance for various levels of watering to determine how far water usage can be reduced without unacceptable loss of plant health.   Inputs from nurseries, landscapers, and the three cities involved in the study were used to select 100 different plants for the test, generally according to local popularity among consumers.  Four irrigation zones were established within the simulator.  After an initial watering in period to get all plants established, the plants in the different zones received varying amounts of hydration, including one section which received no water.  As summer approached, each plot received different amounts of water based on percentage of "evapotranspiration."  

Below is an overview of two of the four plots after a summer's worth of growth and two more are beyond the rolling roof.  This is a bit of a "dry" subject for a post since the gardens here are meant for research and not prime examples of local landscaping design.  The two plots shown below received the least amount of water.  

The shed roof moves automatically to cover the low water planted areas during rain events and control the amount of water received.  With limited rain the roof didn't move much at all during the test phase.

What looks like a donation can for the A&M folks is actually the rain sensor which closes the roof in the background over the plants when it rains.

This is the newer sensor.

Just to prove it was a very dry summer.

Drip emitters were used for the plants receiving water.

A research report based on technical evaluation is in the works, but I discovered some useful information by observation.  
The plot layout below shows the plant locations for a single quadrant, so all four quadrants were exactly the same.  Each species had four plants per quadrant shown in the guide for a total of 1600 plants in the study.  With this handy plant list for reference lets see what happened over the long hot summer.  

I'll take each of the four sections in order from driest to wettest and use my own decidedly non-scientific terminology for this post.


My primary interest in returning to the project was to see which plants survived without any water at all.  With another water rate increase for 2016, it's an incentive to save even more water in the garden.

Looking first at the No Water Zone, we see the plants have generally survived, probably better than expected.  Remember, this zone received no rain and no irrigation.  This is pretty much how my garden would have looked with no watering in the summer of 2015 and I'm suprised at how good some plants looked.  For instance, Chile Pequin in the foreground is still green, airy Pride of Barbados (center) looks great and probably bloomed shortly after this visit.  To the right and behind Pride of Barbados is Turk's Cap looking good too.

Purple fountaingrass (back center) looked outstanding.  Most ornamental grasses did quite well in this and all sections of the study.

Those four yellow plants (back right) are were boxwood.  Blue Grama Grass in the center looks pretty sad.  Blackfoot Daisy, a reliable drought-tolerant native is alive and blooming.

Silvery Cenizo or Texas Sage doing well, not a surprise.  The green plant to the right is Esperanza.

Turk's Cap proves it is a survivor yet again.  Happy in deep shade or sun, water or not, Turk's Cap is a great garden plant.  It's been hot out here, no trees and this part of town is consistently a few degrees warmer than where I live.

Dutch Iris in the foreground are singed by summer heat and sun.  Pale pink Guara to the left is blooming away with no water.  Viburnum didn't make it but Salvia 'Mystic Spires' looks great considering no water all summer.

  Henry Duelberg Salvia, Rock Rose, and especially Guara are blooming.  I've made a note to plant Guara now that the deer are not a factor in the back garden.  Overall the No Water Zone looks stunted but most plants survived.


Next I headed across the central pathway to the area which received a little more water or 20% of evapotranspiration.  For contrast, the No Water Zone is on the right and the Low Water Zone is on the left, where plants received minimal irrigation.

The low-water section looked surprisingly good considering our especially hot summer weather. I'd be quite happy with my garden plants looking this good at summer's end.  But of course not every plant did well.

Quite a contrast how well plants do with just a little irrigation.  Sabal Palms in the foreground look good.  Burford Holly looks crispy brown.

Guara receiving some water looked about the same as the one receiving no water.  Dutch Iris are much improved with limited watering.

Coneflowers bloomed and have gone to seed so this looks pretty typical.  Rosemary looks better than mine at home.

Gulf Muhly grasses look great with limited water.  The red flowers are Knockout Roses.  Belinda's Dream Rose was also in the study and did well though I don't have a photo.

Lindheimer's Muhly (center left) and Mexican Feather Grass (right) all looking good in the limited water section.  Gray Santolina is very happy back along the path.


The section receiving 40% of evapotranspiration looked good but only slightly better than the 20% section.  Of course, the key to the study is how individual plants fared with varying amounts of water.  Pink Rock Rose, Blue Plumbago, and others are blooming nicely.

Dry and heat-loving esperanza (yellow flowers) looks even better with a little water.

Fountain Grasses are standouts here.


Of course the 60% of evapotranspiration section looked the best although there were a few surprises. Tropical Milkweed, Gulf Muhly, and Martha Gonzales roses all doing beautifully.  The milkweed was even hosting Monarch butterflies.  Gregg's Mistflower doing great on the right, it performs well with or without irrigation.

The A&M team inspecting the irrigation system.

It all looks good, I'd be interested to know just how much water was applied here.

One of the surprises was how good the Blackfoot Daisy (low-growing white flowers) looks with irrigation since it generally does not like a lot of water.

It's a common saying among local gardeners that the "fastest way to kill Blackfoot Daisy is to water it."  Yet here it is looking great in the maximum water section.  One caveat would be that the soil here is sandy compared to my rocky clay so drainage is the key.

Bat-faced cuphea, one of my favorites, looks great with all that irrigation while the Guara (pink flowers, far right) which survived with no water looks good, but not that much better than in the other sections.  

Yellow Flowering Senna, bright red Firebush and Mexican Bush Sage all did well with irrigation though one of the Rosemary plants looks similar to several of mine which succumbed to too much spring rain.

This post is simply an overview of my observations from that day.  I'd also enjoy seeing the details on just how much irrigation was delivered to compensate for evapotranspiration.  I took tons of photos which will be useful references when deciding what to plant in the future.  The second phase of the study irrigated the plants which received the least water to see how they responded to fall rains.  I'm looking forward to the formal Texas A&M results of the study detailing each plant and learning more about just how much (or how little) water my plants need to look good in the garden.

Wednesday, February 3, 2016

Wildlife Wednesday February 2016

It's Wildlife Wednesday hosted by Tina at "My Gardener Says..." on the first Wednesday of each month providing an opportunity to share wildlife from our gardens.  With our mild winter this year  we've had visitors like this Gulf Fritillary butterfly posing on faded Gomphrena 'Fireworks' for a striking color combination.

Otherwise, it's been another slow month for wildlife.  I actually spent some time trying to photo a Skink which is the very definition of an exercise in futility.  Aggie Horticulture has some photos on their website if you're interested.  Skinks are beneficial in the garden since their favorite food source is grasshoppers.  It seems we have several but they are so fast I might be seeing the same one in different places!

Just like last month I've returned to the archives for more bird antics.

There's a backstory on how it went down that day.   Lesser Goldfinches, two look like young chicks, having a bath in the saucer when a Black Crested Titmouse shows up to the party.  Stern looks are exchanged.

Things get a bit crowded.  Surprised looks follow.

Some objections are raised.  Feathers fly.  But not the Titmouse.

Black Crested Titmouse exits the pool, shaking butt as it leaves.

"Hey, wait a minute!"

Now we have a staring contest underway.  You lookin' at me?

Some trash talkin'

"We'll just finish up here"

Maybe there's enough room after all

Almost done here.  What we we arguing about?

Okay, I'm out...

I spent a nice day earlier this week cutting back Inland Sea Oats which were looking a bit tatty and never seem to mind a late freeze.  A doe showed up looking for an free lunch in the compost pile.  Since deer don't typically go for grasses, I cut a few Ruellia stalks and added them to the pile for which she rewarded me with a smile.  It's tough for deer out there right now with so many winter dormant plants.

That's the roundup of wildlife in my garden for this month.  Tina has a post on the value of native bees in the garden.  You'll want to check out how to attract native bees to your garden.  I definitely will give her bee townhouse a try.

Wednesday, January 27, 2016

Wings of the City at San Antonio Botanical Garden

"Wings of the City," a series of bronze sculptures by Mexican artist Jorge Marín, are on display at the San Antonio Botanical Garden through June 6, 2016 presenting a special opportunity to view classic sculpture in the garden.

Designed as a traveling exhibition shown in cities around the world and sponsored by the Consulate of Mexico along with local businesses, I was thrilled to see eight of the sculptures in November.  A ninth work from the series is on display at the Southwest School of Art.

The artist worked from a lofty concept:
“I wanted to share with a major audience one of my obsessions, which is the possibility of going beyond our physical limitations — metaphorically, we can fly to the place we wish to.” (from Marín's interview with the Dallas Morning News)
Angel Perselidas has just landed.  Beaked masks are designed to encourage interaction according to the artist.  Marín's placement of the sculptures within the gardens and in context of surrounding structures was particularly compelling.

Cycads evoke the wing theme and are a good textural match for the sculpture.  Agaves in the bed below make closeup viewing a challenge.

Tiempo crouches in the ornamental grasses with missing arms and partial skull.   Wing details are exquisite.  Marín began forming wings with modeling clay as a child and sculpted his first wings in art class at age 18. 

A bit battle weary still with intact wings, ready for action.

Well sited among specimen plants.

Wingless Split with angled legs reinforced by the form of surrounding buildings.

Placed at the highest point in the garden Split has a view of the city:

“In each city the experience is different, because the people make what the city is: their own dreams, aspirations, wishes” (Marín's interview with the Dallas Morning News)

Archivaldo strikes a powerful pose.

Details in relief evoke strength.

With an aviator's helmet and hands crossed behind Bernardo Oriental rests near a grove of ripening citrus.

Overlooking the formal gardens emphasizes his classic lines.  Photos from the exhibit in other cities show these pieces set against busy city scapes in contrast to this more restful garden setting.

Set in the palm room, Embrazo, an angel comforting a woman Pieta style.

It's the only sculpture in the exhibit displayed indoors.

Equilibrista 90 evokes balance and strength in a magnolia grove.

Alas de Mexico (Wings of Mexico) near the entrance invites us to climb the steps and become a part of the exhibit.  Appearing static on their own...

...then quite dynamic moments later when my garden club friends encountered them.

For a different perspective check out Pam's photos at Digging from the Houston stop on the tour. "Wings of the City" will be at the San Antonio Botanical Garden through June 6, 2016 so you have plenty of time to visit this spring for a view of art with the garden in bloom.