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2019 Topics

Peckerwood Garden Lecture Series Topics

Peckerwood Garden Insider Tour Topics

  • September 21, TBD
December 21, TBD
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Amoreuxia wrightii – Wright’s Yellowshow

Wright’s Yellowshow (Amoreuxia wrightii)

During my first year at Peckerwood, a strange plant suddenly appeared in a raised bed near John’s house. The intriguing foliage was unfamiliar to me, with each leaf bearing toothy-edged finger-like lobes jutting out in all directions. At first, the leaf looked green, but the more I focused on it, a blue hue became increasingly apparent. The point from which the lobes radiate out from is accentuated with a silvery splotch.

I noticed flower buds, but I missed blooms that quickly aged to amber. More buds, and the next day they were again crumpled vestiges of this mystery flower. Then pendulous fruits began to form, green and roughly the size and shape of a small chicken egg. This still didn’t give me any further clues as to the plant family. Finally, one day a flash of gold through the vine-covered lattice immediately got my attention, and I realized it was a flower that was actually open. I rushed over, not wanting to miss this opportunity, and there it was, a pleasantly gaudy, bright-yellow five-sepaled flower. Four of the petal-like sepals bore brush strokes of blood red at their bases, the fifth solid gold individual seemed to be the outcast, shunned in the opposite direction from the red-marked cohorts crowded on the opposite side. I realized I had seen this flower in one of my books, a photo online…somewhere, but the name still eluded me. A friend homed in on the genus – Amoreuxia – when he saw the photo I posted on Facebook.

Later, John confirmed it was A. wrightii, one of the several species native to the southwestern U.S. and northern Mexico, all with similar flowers that earned the collective common name “Yellowshow”.  Wright’s Yellowshow is native to southern Texas and into Mexico. John said he has seen extensive desert flats covered with flowering plants across the border, but in Texas, it is found more infrequently. The plant currently in the garden was descendant from the original that John received from the late noted San Antonio gardener Margaret Kane around 1985.
John’s description of the fruit left me checking the plant daily, looking forward to the green pod transitioning to a translucent thin shell “resembling a sheet of mica” as he put it. Every day I checked it remained green, then it was gone. This plant, first eluding me with the flowers, which only are open for a few hours in the late morning, was now frustrating me with the anticipated mature fruits. I then learned that Adolfo, our head gardener, also had been watching and collected the mature fruit and extracted the seeds.
This year, I finally saw a mature fruit, hanging like a miniature Japanese lantern with the delicate, see-through membrane unveiled by the formerly green covering that had split and shrunken back to the fruit’s three longitudinal ridges. Visible inside the three conjoined capsules were dark clusters of seed adhered to the center of the inside wall in a neat cluster.
Though easy to grow in full sun and well-drained soil, Wright’s Yellowshow will always offer the busy gardener the anticipation of one day being at the right place at the right time, to finally observe a flower in its full glory after finding many taunting remnants of flowers missed. Then you then will need to pay close attention to catch the fruits when they mature, deceptively hidden under the foliage, into their easily overlooked works of delicate art. Germinating easily from seed, it can be one of those pass-along plants that can continually offer the same challenges of timing to those who wish to catch a glimpse of the Yellowshow’s elusive beauty.
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Zamia integrifolia – Coontie

In my home state of Florida, the native cycad is a staple landscape plant in parking lot islands, foundation plantings…anywhere. These cycads are planted as individual textural specimens or massed in clumps or rows. Aside from their attractiveness, their popularity also is due to their propensity for being a durable, drought-tolerant and frost-hardy option for a tough spot in sun or shade. Peckerwood founder John Fairey has utilized this species for its various attributes in many areas of the garden, yet I was surprised upon moving here that the plant is still rather unknown in Texas horticulture. It is not difficult to find in the nurseries, but it should be just as popular here as it is in Florida.

Confusingly known by a few scientific names, most commonly Zamia floridana, most researchers consider Z. integrifolia to be the most current name. At least two forms exist, the “southeast” form ranging from southernmost Georgia to the tip of the peninsula which bears broad leaflets and compact form, and tends to be the most common selection in cultivation. Another form localized in the sandhills of the northwest portion of the Florida peninsula has thin leaflets that stand upright in a V arrangement on the fronds. A giant form from northeast Florida called the ‘Palatka Giant’ can be found in collector circles, and a mature clump can reach heights of at 5 feet. On the opposite end of the spectrum, John has a dwarf mutant in his personal collection that was a surprise among numerous seedlings derived from our garden’s plants.

When I guided members of The Cycad Society around Peckerwood, cycad biologist and Zamia specialist Michael Calonje from Miami’s Montgomery Botanical Center noted how our mature female clumps of Z. integrifolia were scattering their shocking red seeds from their crumbling cones throughout the garden. A common sight in Florida, I never thought about what is pollinating these cones in Texas until Michael asked if we had one or both of their specific beetle pollinators here. Though it is entirely possible that the pollinators hitchhiked from Florida in nursery stock and became established here, nobody has documented them in the state. We have since learned that fertile seeds are produced in other Texas counties from Houston to Austin without human intervention. We will have to pay attention next year to see if we can catch the culprit in the act and officially document its presence in the state.

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Prunus mume – Flowering Apricot

Prunus mume ‘Josephine’ bending well with woody lilies at the edge of the south dry garden
One of the stars among Peckerwood’s many winter-interest plants is Prunus mume, also known as the flowering apricot. For quite some time, as evidenced by some large trees on the property, John Fairey has been amassing various cultivars for trial here in Texas. Though originally native to southern China, it has been popular as an ornamental cultivated throughout Asia for a few thousand years, especially in Japan, where many selections have been perpetuated. Flowers range from white to deep red, with all shades of pink in between from pale to deep rose. Beyond color selections, there are forms with double flowers, large flowers as well as those with weeping and contorted branches. Like many plums, apricots and cherries in the genus Prunus, these deciduous trees flower profusely in winter before they leaf out. At Peckerwood, it seems that flowering time varies depending on the cultivar, and careful selection of specimens can result in a succession of flowering through winter and early spring. Though best known for their flowers, the trees also have wonderful bark and even produce reasonable fall color, especially striking with a backdrop of other evergreen plants. These ornamental selections produce inferior fruit to those intentionally selected or bred for palatability.
Camellia Forest Nursery in Chapel Hill, N.C. has been the primary source for these plants in the U.S. introducing many cultivars from Asia along with their own selections. Some nurseries graft the cultivars on other species of Prunus, some of which might not be as adaptable in our region, so it is best to investigate this with your source. Camellia Forest offers plants grown from rooted cuttings, which is the best option.
Prunus mume ‘Contorta’ is interesting even when defoliated
The winter flowers of Prunus mume show up most strikingly when grown among evergreen neighbors.
As we saw this past winter, one drawback in our gulf coast climate is that we don’t always receive the required amount of chilling this plant needs every winter. I’ve only witnessed the 2016 and 2017 flowering, and both years were quite floriferous. However, earlier this year, with our minimal cumulative chilling hours last winter, we saw erratic behavior when leafing out following flowering. Some cultivars leafed out fully, others sparsely, with some almost devoid of foliage all year. Though the trees are still alive, I doubt they will flower at all this winter, and it will be interesting to see if they have enough stored energy to leaf out this spring. It also will be of interest to see how those that did leaf out will flower this winter. This will be valuable data to continue to monitor in upcoming years in finding cultivars to recommend as reliable performers in our region.
So how much chilling do flowering apricots need on average? First we have to note that there are different methods of measuring chill requirements over a particular region’s winter, including chill hours, chill units and chill portions, all of which take into account several variables. In a study “Evaluation of Chilling and Heat Requirements in Japanese Apricot with Three Models” by Zhihong Gao, Weibing Zhuang, et al., they determined that the “dynamic model” which is displayed as chill portions (calculated differently from chill hours) was the most accurate way of determining chill requirements for this species. Their research showed the optimum required units for flowering apricot ranging from 26.3 to 75.7 chill portions depending on the clone. As a frame of reference, the chill portions for us here in Hempstead the past three years were 53, 36 and most recently, 22. We are currently at 15 chill portions here in late December, so hopefully in the remaining winter months we can double that and be back on schedule.
Though often not considered for its fall color, Prunus mume can indeed put on a show
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Platanus rzedowskii (formerly P. mexicana) – Mexican Sycamore

Taken in late October, the green foliage of Populus rzedowskii contrasts against the browned leaves of surrounding native P. occidentalis.
I recently learned that likely every Mexican sycamore in cultivation, widely known under the Latin name Platanus mexicana is actually a different species altogether – Platanus rzedowskii. I am now doubtful if the “true” P. mexicana is actually cultivated in the U.S. This incorrect naming is not due to a mistake, but to past taxonomic confusion among the Mexican sycamore species prior to more recent clarification.
This started a year ago when plantsman and landscape designer Scott Ogden was telling me about the champion Mexican sycamore in San Antonio at Trinity University, which he referred to as P. rzedowskii. I knew there were other species of sycamores in Mexico, and Scott’s comment piqued my interest about “another” Mexican species in cultivation. That conversation diverted to another subject and I didn’t get a chance to discuss in more detail with him. Flash forward a year, and I was talking with landscape designer Patrick Kirwin about a named cultivar of Mexican sycamore I had seen incorporated in one of his Austin area landscapes. He told me it was called ‘Alamo’, introduced by California’s Orange County Nursery as a selection from one of Scott Ogden’s wild seed collections from Mexico. Patrick relayed some additional information from Scott indicating that these, and everything in cultivation, were all P. rzedowskii.
The US national championPlatanus rzedowskii
Single fruits are an easy way to discern Platanus rzedowskii
While researching to determine what features separate the two species, I found the clear answers in Kevin Nixon and Jackie Poole’s 2003 paper titled “Revision of the Mexican and Guatemalan species of Platanus ( Platanaceae).” Nixon and Poole note that sycamores in Tamaulipas and Nuevo Leon, although previously referred to in horticulture as P. mexicana, were quite different from those matching the original description of the species, which is found farther south from Hildago and Veracruz all the way down to Guatemala. Therefore, they gave the name P. rzedowskii to this form from northeast Mexico in honor of prominent Mexican botanist Jerzy Rzedowski. True P. mexicana has the round fruits held in clusters of 3 or more and trilobed leaves with untoothed margins, while P. rzedowskii has solitary fruits like our native P. occidentalis, and the leaves are 5-lobed with jagged marginal teeth. All material in cultivation seems to originate from Nuevo Leon or Tamaulipas, and otherwise matches perfectly the description of P. rzedowskii.
Regardless of the name, this sycamore is an example of a tree superior to our Texas counterpart. While our native P. occidentalisnaturally thrives here, it looks quite ugly by late summer with patchy or browned leaves due to a number of diseases and insects. In stark contrast, the Mexican sycamore remains a clean dark green well into fall. Adding to the appeal is the startling contrast of the silvery white undersides of the leaves. Unfortunately, many nurseries propagate this plant from open-pollinated seed from cultivated trees, which almost always yields hybrids with P. occidentalis that tend to be quite inferior in appearance and disease resistance, which Patrick referred to as “Tex-Mex sycamores”. Mid-summer cuttings root very easily and therefore more nurseries could only offer pure P. rzedowskii propagated from superior trees.
Bark detail of Populus rzedowskii
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Trillium species – Toadshades and Wakerobins

Trillium texanum , a pedicillate wakerobin, in our conservation collection.
In many cooler parts of the country, trilliums are the heralds of spring in the woodland garden, with their beautifully patterned leaves and striking flowers serving as a cheerful farewell to winter.  Many gardeners are surprised to find that we are able to grow various Trillium species in our climate. Even more surprising to them is the fact that there are several species that are native to the woodlands of east Texas. There are, in fact, quite a few other species perfectly adapted to the Gulf Coast climate with native ranges from the coastal plain of Louisiana through northern Florida. These southern species are still deemed difficult to impossible by savvy local gardeners who have tried them. However, If specific requirements are taken into consideration, they are not too difficult and can even naturalize in the woodland gardens in our region.
Often referred to as “wakerobins” and “toadshades,” the latter common name usually refers to the mostly northern types that have flowers held on a noticeable stalk (pedicile), which in some species arches downward below the leaves, and in others holds the flowers proudly upright. Their leaves are solid green. These wakerobins are more technically known as “pedicilate” flowered species. Most of the southern species we can grow in our region are the “sessile” flowered toadshades which have a stalkless flower fixed in the center of the three leaves, with the petals held erect. Unlike the wakerobins, toadshades’ leaves are in most cases decorated with ornate mottling of various purple, silver and green tones, ornamental to the point that the foliage rivals their flowers.
Trillium gracile , an east Texas native, growing happily here at Peckerwood
Nearly all of the options found from Texas to Florida have the same general requirements that have been learned through my own trial and error, experiences of others, and by observations made in their natural habitat. In the wild, most southern species, with a few exceptions, are always growing on moist but well-drained ravine slopes in soil that tends to be neutral to alkaline. In the garden, planting in a level garden bed, even if well-drained, usually results in the plants being unhappy, returning every year smaller and smaller and eventually disappearing. Simply building a small berm of good quality soil even 18” – 24” high can drastically improve results. Planted in the pockets of soil among a shady rock garden also can work. Though southern trilliums can handle acidic soil, they seem to do even better with annual additions of horticultural lime. I would mix this into the soil when planting, and every year I would scatter a liberal amount on the surface to be washed in.
Though generally thought of as spring ephemerals, southern trillium species can emerge late fall or in the dead of winter. This can be as early as Thanksgiving in the north Florida species to February among the remainder of the species found along the Gulf Coast. Their emergence coincides with the increased light reaching the forest floor after the deciduous trees have dropped their leaves. In our region, they can only tolerate a few hours of direct sun in the morning, with dappled shade the remainder of the day.
A solid purple selection of Trillium maculatum
Trillum lancifolium ‘Ballerina’, a Plant Delights selection with pewter foliage.
By early summer, trilliums are getting ready to die back for the season. Their foliage can look quite disheveled by May or June, but, as with most geophytes, resist the temptation to cut it back before it dries entirely to encourage a more vigorous plant the following season. As long as any green remains on the tattered foliage, it is supplying more energy to be stored in its underground rhizome. Even after the foliage disappears, occasional watering of the soil during extended dry spells is necessary. Trilliums aren’t like other geophytes (bulbs, corms, rhizomes, tubers) in that their rhizomes don’t actually go dormant. Instead, their rhizomes are growing and branching underground during the summer when no leaves are present. If the soil dries considerably during the summer, it can result in a stunted plant the following season, or a complete loss.
Though formerly rare in mail-order nurseries, a few businesses are delving into the southern species. Tony Avent and staff at Plant Delights Nursery have been leading the way and are an excellent source for a variety of species and selections. The prices may seem steep, but when you consider that a trillium from seed takes 5-7 years in even the best nursery conditions to attain a reasonable salable, flowering size, it makes better sense. Tony has been collecting a variety of unusual variants of the species ranging from pure silver leaf forms, atypical patterning or growth habit, and unusual flower colors. It is best to stick with reputable nurseries and avoid wild-collected plants that can sometimes be found at low prices online, as these are often unethically collected from sensitive environments.
Trilliums can be very tricky in pots long-term. If you need to keep them containerized, it is recommended to use a very open, freely draining mix, and repot in new soil annually. If not regularly repotted, the soil can break down creating a thick muddy layer around the bottom of the pots that can result in a rotting rhizome. Even in pots, they never are as vigorous as they are in a proper garden setting.
What can be accomplished over a few decades – a huge patch ofTrillium maculatum at Kanapaha Botanical Gardens in Gainesville FL.
If you are ready to be the envy of your gardening friends and try your luck with trilliums, I would recommend the following species for beginners: T. gracile (Texas native), T. underwoodii,T. maculatum, T. decipiens, T. lancifolia, T. ludovicianum, T. foetidissimum and T. oostingii. These are all the sessile-flowered toadshade types. There are few pedicillate-flowered wakerobin types suitable for our region. A couple of more northerly species reach their southern extent in the coastal plain, but plants collected specifically from these isolated, southernmost populations would be needed to succeed, and aren’t present in cultivation yet. T. texanum, a rare bog-growing species known from only a few sites in east central Texas, is a pedicillate species we are trying to conserve at Peckerwood that is not available from nurseries. Peckerwood will be offering limited numbers of several species of trilliums this spring, including T. maculatum from Florida, T. gracile from Texas, and T. foetidissimum.
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Trillium ludovicianum

Debatably a native to east Texas, this trillium is better known from Louisiana so it is used to heat and humidity. It prefers moist but well-drained woodland garden conditions, such as on a berm with supplemental irrigation during dry spells. It dies back in late spring/early summer but will re-emerge in February the following year.

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Agave sp. ‘Miquihuana Silver ’

At first glance, young plants might resemble just another common silvery blue agave abundant in the area’s landscapes. However, once this plant gains some size, it is a real standout with an elegant form to the 6 feet long leaves, most of which point straight up, creating a vase-like shape. Unlike the more common silver species, this great selection maintains a clean matte coloration free of blemishes. It’s one of John’s favorite agaves, as of yet unidentified, that he collected around Miquihuana, Tamaulipas, Mexico.