photo: Retama
2006-06-28. A roadside planting of retama forms an airy hedge along a path in Sunset Valley, TX.

June 28th, 2006
Retama Jerusalem Thorn

Retama (Parkinsonia aculeata) forms a small, airy, lime green tree that appears as fresh as spring on even the most droughty summer days. You can use it as a specimen plant or to create a vicious hedge. The smooth green trunks and branches are covered with serious spiny thorns hinted at by one of its common names, Jerusalem thorn. Retama can photosynthesize through its green bark; its Spanish name is palo verde (green bark). From a distance retama looks like it’s covered in stringy green streamers which cast a filtered shade. Having such very small leaves it loses little moisture to transpiration making it extremly drought and heat tolerant. Overall, it has a delicate, feathery appearance. Flowers are bright yellow.

Latin names are a bit confusing as the Parkinsonia clan used to be called Cercidium. The common names are worse as nurseries in Austin usually sell this as retama but it’s not the same as weeping white broom, Retama raetam. The City of Austin Grow Green site hedges its bet and calls it Retama Jerusalem Thorn.

Perhaps, as one reader suggested, it is overused in Phoenix. I imagine that when people first brought it under cultivation in those desert towns they were thinking, “Green! Green! Green!” And it’s such a carefree plant that it’s perfect for those median plantings along highways and outside of subdivisions. However, in Australia it’s an introduced invasive weed.

In addition to being spiny, retama has a reputation for being a messy tree. Mine is too small to make much of a mess. If you have small children, or a small yard, you might prefer to admire retama from the comfortable distance of your car. I’ve neither, so I’ve taken a chance with it. Give me another five years or so and I’ll tell you whether I think it’s a curse or a blessing.
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photo: rose die back
My white China rose ‘Ducher’ succumbs to rose dieback.

June 27th, 2006
Rose Dieback

Rose dieback is not a disease, I’ve read, but it sure acts like one. The canes begin turning brown and dying back. At first, it’s difficult to tell whether or not the rose just needs a little more water and extra loving care. Then, more and more canes die back and the rose is dead.

Your supposed to be able to squelch the spread of the dieback by pruning the cane low where it is still green. If you look at the the place you cut, there should be no brown center. Howeever, with ‘Ducher’ and major cane had died and I couldn’t cut it out without cutting the bush in half. No matter. The whole thing is dead now, to my regret. I always thought of ‘Ducher as my New Year’s rose as, here in Austin, it seemed to bloom best in the winter. I don’t know if that’s because it preferred temperatures in the 50s, or it was just relieved to be out of the shade of the pecan. I loved its lemony scent, its very reddish new growth, and that it formed a neat, dense shrub.

I lost “Caldwell Pink” to dieback last year about this same time.

I’ve always thought I was good pruner, but the primary cause of rose dieback is poor pruning–pruning too far above a node. Given that ‘Ducher’ was very dense and twiggy, she was difficult to prune. So I guess it’s my fault. Darn!

John Powell
2006-06-20. John Powell, who interns in the Adachi Museum gardens, demonstrates Japanese shearing techniques during a presentation at the Austin Area Garden Center.

June 20th, 2006
High Maintenance Gardening at the Adachi Museum Gardens

For us Austin gardeners worried about the effects of drought, heat, overuse and abuse on Zilker Botanical Garden, the gardens at Japan’s Adachi Museum of Art demonstrate what is possible under very different circumstances. Tuesday (6/20) Waturu Takeda and John Powell provided a window into another world of gardening to a room packed with eager gardeners at the Austin Area Garden Center .

Imagine a garden where a staff of gardeners works often 14 hours a day, every day of the year…a garden where vast beds and paths of gravel are swept every morning using a special technique, where the zoysia grass is clipped with small, electric hand shears, where brown leaves and clippings are brushed off the bushes and mosses, where hundreds of pine trees are pruned several times a year. And if there has been no rain by the end of the day, the entire garden is carefully drenched by hand with huge hoses.

In Austin, we argue about charging an admission to Zilker Botanical Garden to help protect it from boneheads who treat the garden like another playscape and thieves who walk off with the plants. In stark contrast, no visitor is allowed to walk through the gardens at the Adachi Museum of Art. Rather, the gardens are viewed from inside the museum, through windows designed to look like hanging scrolls. Each view of the gardens appears to be a living picture. All the intensive work of the gardeners is to ensure that the gardens remain picture perfect. The garden becomes part of the museum collection, complementing the seasonal changes of the artwork. The garden surrounds the museum, but the museum encapsulates the garden.

I’m curious whether other people at the presentation found inspiration in the beautiful film shown, “The Garden in Fours Season”. (I thought this mistitled as it showed the garden in spring, May, rainy season, summer, fall, winter, and early spring.) Is such perfection even desirable in a garden outside of the museum concept? Or did it feel sterile? too manicured? Each view of the garden is beautifully composed. But the real interest was noticing how the garden changed in time, through the seasons and through varying degrees of sunlight, rain, mist, and snow. The one view that I wanted to see that wasn’t in the film was the garden in moonlight.

Although John Powell hinted that concepts and techniques of Japanese gardening are transferable to the heart of Texas, the presentation did not touch much on that. Certainly there’s a big part of the summer in Austin where our gardens are best viewed from indoors. Aside from the concepts of borrowed views, strolling and viewing gardens, what can we learn from Japanese gardens?

I’m a hands-on person and a garden that is experienced primarily through sight ignores the textures, scents, and sounds that I think are vital to a garden. Zenko Adachi’s accomplishment in creating this magnificient garden must be admired. I’d love to visit it in person but it is not a garden I would want to replicate even on a small scale. Lacking the same resources of helping hands and water, my tiny Zanthan Gardens will remain mostly a garden of the imagination, hardly recognizable as a garden what with the laundry on the line, the sawhorses in the driveway, and hoses and tools lying about.

The upside of fire ants.

June 18th, 2006
Our Friends the Fire Ants?

When those enemies of biodiversity, the fire ants, came marching in they cleared Texas pastures of chiggers and ticks, our suburbs of fleas and cockroaches. However, fire ants like moisture and our recent years of drought have driven them underground resulting in a such a resurgence of ticks that some Texas ranchers are wondering how to bring back the fire ants.

Of course, fire ants don’t just ravage populations of insects that humans find pesky. They kill young bird and reptile hatchlings and eat up wildflower seeds. They aren’t too kind to electrical wiring either.

In defense of the fire ants is Messina Hof Winery owner, Paul Bonarrigo, who says that having fire ants in the vineyards means he doesn’t have to use as much pesticide to protect his vines as he once did.

Entomologist John Ruberson is studying how fire ants loosen the soil with their many tunnels. Compacted soils make it difficult for plants to get optimum water and oxygen to their roots, which is why gardeners have embraced our friends the earthworms. But, our friends the fire ants? As the Dixie Chicks would say, “I’m not ready to make nice.”

— Via incandragon. The original article appeared in the June 12, 2006 edition of The Wall Street Journal. A reprint is available here.

photo: Duranta erecta Sapphire Showers
2006-06-15. Austin, TX. Duranta erecta ‘Sapphire Showers’…or possibly ‘Geisha Girl’. The nursery didn’t identify it and some sources say that it’s the same cultivar under different names–ruffled, violet-blue flowers with white edges.

June 15th, 2006
Duranta erecta

That last cool and rainy week in May I popped in at Barton Springs Nursery as a reward for my taking my car in for it’s yearly inspection before the sticker expired. My wandering into a nursery is as wise as an alcoholic browsing at a liquor store. The last two years I’ve put myself under a strict plant-purchasing moratorium, taking advantage of these drought years to focus on the hardscaping of the garden in hopes of adding some structure and manageability.

Like everything marketable, plants are subject to human whims in taste, to horticultural fashion. Before me lay all sorts of plants I didn’t know, but the first to catch my eye was a tropical looking plant with lime-green leaves and delicate panicles of violet blue flowers, Duranta erecta. It’s common names are golden dewdrop, or pigeonberry, for its golden fruit which is poisonous to humans but beloved by birds. It is an attractive nectar plant for butterflies and hummingbird. Golden dewdrop is very trendy in Austin this year because it’s been named a Texas Superstar plant.

Disregarding my own advice about buying plants in the summer, seduced by the cool light drizzle stirring up memories of my recent week in England, I bought three of them. After all, they were on sale. [They’re on sale because it’s summer. They’re doomed. Don’t do it! — Your Rational Mind]

Everything about golden dewdrop reminds me of plumbago: its multiple, arching stems form a small fountain of a bush; its five-petaled flowers hang in loose racemes at the tip of each branch; its glossy, green leaves withstand heat and sun. Also like plumbago, golden dewdrop will die back to the ground in a freeze. So, although it is naturally a large bush or small tree, in Austin it will remain a mid-sized shrub. In colder climes than Austin, golden dewdrop is often grown as a potted plant and brought indoors to overwinter.

In its native South America golden dewdrop grows on limestone which means it should be happy in Austin soils as long as it is planted in a well-drained spot and not in heavy clay. (The requisite caveat in all garden writing.) It is reputed to tolerate drought (What do gardeners in Puerto Rico consider a drought?), poor soils, and some shade but it grows and flowers best if planted in a nice garden bed and watered.

photo: Duranta erecta Sapphire Showers

In order to get them through the summer, I put the golden dewdrops in the front planter as potted plants. Recently, in order to clear the driveway of the gravel pile, AJM moved the stone into the reconstructed planter until I can use it elsewhere in the garden. Then I thought, hmmm, this looks like a design.
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photo: Texas bluebonnet
2006-06-11. The last bluebonnet of the year.

June 14th, 2006
Week 24: 6/11-6/17

Dateline: 2006
Austin’s heat wave continues, but it could be worse. It has been worse. In 1998, we hit a record high of 108 degrees on June 14. Today it was a mere 95–a breath of fresh air after yesterday’s 101.

We typically get an average of 4 inches of rain in June, making it one of our rainiest months. So if we Austin gardeners are grumbling and shaking our fists at the sky, we feel completely justified. Looking back over the last eleven years I see I note every shower and thunderstorm, wondering if it will be the last before the heat of real summer sets in. Not to worry. This year misery has already arrived. You northern gardeners can imagine it as the equivalent of an early frost which cuts down your plants in their glory and then is followed by a balmy Indian summer.

When June is a wet and mild month, I find it easy to succumb to the tempations of the nursery and plan and plant. Over the years, I’ve become suspicious of June’s charms and learned to put off any planting until fall. As heat wave 2006 continues, I am only in the garden between 7 and 9 in the morning. Almost all my time is spent watering with little time left for cleaning up seedy plants and dead-heading.
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St Augustine and buffalograss2006-06-11. Austin Texas. 9:30AM 80 degrees. Lawns and politics: patchy buffalograss in the foreground; St Augustine in the background.

June 11th, 2006
Tale of Two Lawns

Garden blogs have been all abuzz this week over lawns. In Austin we’re encouraged to replace our lawns with beds of native or xeriscape plants in order to cut down on our water usage especially if we want to enjoy our yards without being enslaved to a high-maintenance landscape. I don’t think the issue is so cut and dry. Typical homeowners, at least in South “Keep Austin Weird” Austin, don’t spend a lot of time watering or mowing their grass. Replace what passes for lawns in a lot of Austin with other plants and I think a lot more people will be spending a lot more time using a lot more water.

Those people unfortunate enough to live in places like Circle C where they’re required by neighborhood covenant to keep the grass greener on their side of the fence, even in periods of extended drought when we are under rationing, I’m guessing are rich enough to pay other people to do the maintenance. (How will this dynamic change with the current crackdown on illegal immigration?) Are they even allowed to replace their lawns? Ah, I digress.

When I acquired this house in April 1993, the entire front and back yards were covered in St Augustine grass. I was happy to have inherited an automatic sprinkling system until we got our first water bill. After I recovered from the shock and swore never to use the system again, I bought a sprinkler to fit on the end of the hose and watered only the healthiest parts of the lawn. In June of 1993, one of the cedar elms snapped in half during a storm. Suddenly the north quadrant of the backyard was baking in full sun. I let the marginal grass die, covered it with mulch, and began planning a wildflower meadow.

Over the next few years, I planted buffalograss, bluebonnets, larkspur and various small bulbs like rainlilies, species tulips, and fall crocuses. The meadow looked great in the spring, but very patchy and weedy the other 9 months of the year. Although buffalograss spreads by runners, it forms clumps rather than a smooth lawn. Therefore I don’t think it looks particularly nice mown. And the same characteristics that make it a haven for small bulbs and flowers, provide the same haven for weeds. I’m constantly battling horse herb (which grows up over buffalograss, shading and killing it) and other undersirables.

The blades of buffalograss are narrow and sharp. It is not a grass to wiggle your toes in or lie back in and watch the clouds. Over the years, various trees on the border have made the once sunny meadow area quite shady. Buffalograss does not like the shade at all. I like its color of dry hay (of green tatami), but in the worst heat of summer, it is not a color which is restful to our parched eyes.

In contrast, the deep green coarse blades of the St Augustine grass makes me want to fling off my shoes and throw myself back on it in delight. I do not spend a great of water on the St Augustine lawn. Unlike some other grasses, St Augustine likes mulch. I learned this from watching how it took over any path I made around the yard. So every time I see a bare spot or thin grass, I mulch it with a combination of Dillo Dirt and Texas native bark mulch. I don’t feed it any lawn food and it rewards me by not growing too fast.

I think of St Augustine as a southern grass. It evokes summer days under shady live oak tree with the whine of cicadas filling the air. Buffalograss creates a praire mood with its tall, wispy blades and loosely filled clumps undulating in billowing waves under a withering wind. Austin sits on Balcones Fault and shares characteristics of both the old South and the desert West. I pleased to have a little of both in my backyard.

I’ve gotten rid of all the lawn I’m getting rid of. Compared to the rest of the yard, it is low maintenace especially in ratio to the pleasure it provides.

photo: Acanthus Mollis
People are always writing to me and asking how to eradicate Acanthus mollis. Perhaps the best thing to do is move where the temperature tops 95.

June 6th, 2006
Hellishly Hot on 6/6/6

Last week May ended on a cool and rainy note. This week we’ve skipped straight to July. The sun is shining as soon as it’s risen; no cloud cover to burn off, nor any of the towering cumulus clouds that seem to me so much like summer in Austin. Just stark blue skies and the kind of sunshine that you can feel burning your flesh the second you’ve stepped into the sunlight. However, desert-like, this is a dry heat. As long as you stay in the shade, it’s more pleasant than a typical humid June day, even if the temperatures are reaching for record highs. Margaritas, anyone?