Focus on building sustainable ecosystems: While planting groves of native canopy trees to eventually become tall shade trees is the first phase of Project ACORN, the establishment of under-story vegetation essential for providing a resilient and bio-diverse ecosystem will become the focus of subsequent planting events across several additional years. Native animals are adapted to participate in seed dispersal as are the plants adapted for both animal and environmental dispersal of seeds further down the creek corridor during rain events. Documentation by students of vigor and self-sufficiency by the increase in ecosystem richness and diversity will be made available to various project partners and will remain available to the students themselves as they move into middle school, high school, and even into their college studies. Additional observations will focus on the plant community of vines, shrubs, annuals, and understory trees providing “migration stations” for migrating species such as monarch butterflies, hummingbirds, and purple martins.
Trees, Shrubs, and Vines of the Texas Hill Country 2nd edition, by Jan Wrede
Grasses of the Texas Hill Country, A Field Guide, by Brian and Shirley Loflin
*Canopy shade trees:
Note that we are avoiding Red Oak (Quercus buckleyi) and Live Oak (Q. virginiana) due to oak wilt susceptibility)
-Anacua (Ehretia anacua aka Cordia boissieri) almost evergreen and attracts birds
-Bur Oak (Quercus macrocarpa) deciduous and with the biggest of all the oak acorns that attract squirrels
-Cedar Elm (Ulmus crassifolia) deciduous, upright, pollution tolerant, a good street tree
-Chinkapin Oak (Quercus muehlenbergii) oak wilt resistant, deciduous and very tolerant of limestone soils
-Mexican Sycamore (Platanus Mexicana) deciduous & droughty with attractive white bark , abundant leaf drop helps build-up organic material in soil
-Mexican White Oak a.k.a. Monterey Oak (Quercus polymorpha) oak wilt resistant
-Pecan (Carya illionoiensis) only native varieties are used with smaller nuts but much tastier than improved varieties also more droughty and pest resistant – it is being planted so extensively using it might violate the concept of building diversity
-Texas Ash (Fraxinus texensis) the only Ash appropriate for the Edwards Plateau
-Anachacho Orchid Tree (Bauhinia lunarioides (congesta) ) white blooms in spring & after rains
-Carolina Buckthorn (Rhanmus caroliniana) red berries attract birds
-Creek Plum (Prunus rivularis)
-Evergreen Sumac (Rhus virens) berries are food for wildlife and tolerant of sun or deep shade
– Bigtooth Maple (Acer grandidentatum): The locally adapted native maple is called Uvalde Maple, Bigtooth Maple, or Hill Country Maple (Acer grandidentatum) is the species used in the Boerne Maple Project to extend the range of this tree by planting it more extensively in our area. It is the heat & drought adapted variety of the famous sugar maple of the North East. They apparently survived the disappearance of the maple forests here after the last ice-age by sheltering in Hill Country canyons, most famously at Lost Maples State Park. They are not as droughty as a yucca, and are almost never successful when planted in the open with full sun, however they are stunning understory trees, especially if situated for a bit more moisture (such as at the base of a retaining wall, a lower area where water drains, or maybe in the landscape of a homeowner who is willing to supplement rainfall with a bit of irrigation in July and August.) I have six of these trees around my home, with the largest producing seeds for the first time this year. After their first summer with me, I have not provided any supplemental water to the maples, including over the past two summers with heat and drought records. I have given several to family members in Amarillo in the panhandle and in Denton near Dallas as Christmas presents. Their trees grow faster and are more vigorous than mine, apparently because they are genetically pre-disposed toward cooler weather, and possibly because my family isn’t a fanatic against landscape watering the way I am.
Propagation: just before the seeds fall they will start to turn brown, usually early in August. Collect the samaras, the term for the double winged seeds that spin like a helicopter, probably for wind assisted seed dispersal. Rub the seeds between both palms to break the two seeds apart and remove the wings. Winnow the seeds by pouring from one bucket into another on a breezy day or in front of a fan to get the wing debris out of the seeds. Then do a float test and discard the floaters. In each samara, one seed will be fertile & the other sterile. In the nursery trade there is a elaborate procedure for germination. I imitate Nature and do okay with less effort, even if it can’t match the germination percentage of professionals who have access to mist benches, acid titration, etc. I prepare a fluffy, mounded bed, in the shade, with good soil, compost, and fallen leaves. Then I plant the maple seeds in rows about a foot apart, press them against the soil, and sprinkle with about a quarter of an inch of soil. Lightly water the area through the winter if the weather turns dry. My planting bed is often raided by raccoons, armadillos, skunks, deer, etc. If I don’t put some sort of fence around the bed, critters dig through it all through the winter. Don’t get discouraged when spring comes if it seems nothing is going to happen. Maples like to sleep late and are one of the last trees to leaf out or sprout from seed. Because maples are wind pollinated, there is a considerable difference in vigor among seedlings. Don’t’ hesitate about discarding maple seedlings that languish since they won’t make it past the first summer but will cause you to waste a lot of water trying in vain to keep them alive.
–Blanco Crabapple, Texas Crabapple (Malus ioensis var. texana) fall foliage, spring flowers, summer fruit for birds. Avoid recent nursery-bred cultivars which are sold as ornamental trees with showy blooms which do not attract pollinators such as honey bees. Growing to 12’-15’ and native to only a few counties in central Texas, use only the locally native Texas variety of the Prairie Crabapple identifiable by smaller, broader leaves covered with dense white hairs on the lower surface. Blooms and fruit are best when planted in full sun, but is becoming scarce in the wild due to expanding deer populations usually requiring some caging for protection.
-Desert Willow (Chiliopsis linaris) Thin leaves like oleander with purple, orchid-like blooms. Despite common name it is very droughty.
Evergreen Sumac (Rhus virens) Tolerates sun or deep shade with fruit for birds & attractive cinnamon stick bark when young and rough bark with age
-Golden Ball Lead Tree (leucanthus) Yellow puff ball flowers in late spring and lime green, lacy foliage, and long seed pods suitable as gifts
-Mountain Laurel (Sophora secundiflora) evergreen with grape kool-aide scented flowers in early spring and bright red seeds used in jewelry and other crafts
-Lacy Oak also known as Blue Oak (Quercus glaucoides) oak wilt resistant, very tolerant of drought and limestone soils, less than 20 feet tall with attractive leaves of bluish, gray tint. Endemic to northern Bexar county so adapted to weather, pests, and our rocky, alkaline soil. Pink bud burst in the spring rivals the displays of flowering ornamentals.
-Possumhaw Holly (Ilex decidua) deciduous with bright red berries in the winter
-Redbud (Cercis canadensis) flowers early in spring and has attractive bark
-Rough Leaf Dogwood (Cornus drummondii) native Hill Country Dogwood with spring flowers and ability to sucker into a small grove
-Rusty Blackhaw (Viburnum rufidulum) spring flowers, summer berries that attract wildlife, and outstanding fall color
-Texas Kidneywood (Eysenhardtia texana) small, white, fragrant flowers important for native pollinators with light, lacey shade, citrus fragrant leaves
-Texas Persimmon (Diospyros texana) female plants if possible to provide fruit for wildlife with attractive smooth trunk and branches
-Wafer Ash aka Hop Tree (Ptelea trifoliata ) interesting wafer shaped seeds and elegant white flowers in spring
-Yaupon Holly (Ilex vomitoria) look for fruit on the plants in winter to select female plants if possible since they provide the attractive red berries eaten by birds (such as Cedar Waxwing and Mockingbird) in late winter
*Shade tolerant shrubs:
-Agarita (Berberis trifoliata) and Texas Barberry (Berberis swaseyi) evergreen with interesting tri-lobed leaves and prickly foliage like a holly. Yellow blooms smell like a summer rain shower followed by red berries loved by mocking birds & jelly makers.
-American Beautyberry (Callicarpa americana) attractive, delicate looking blooms during heat with clusters of berries on long, arching stems through fall and winter.
-Anachacho Orchid Tree (Bauhinia lunariodes) white flowers in spring with leaves shaped like a cow hoof print, like many Texas Hill Country native “trees” this might be best described as a woody shrub that grows about 5’- 9’ tall.
-Aromatic Sumac or Fragrant Sumac (Rhus aromatica)
-Barbados Cherry (Malpighia glabra) bright cherry-like berries loved by birds and evergreen
-Chili Pequin (Capsicum annuum) perfectly adapted for seed dispersal by birds, and delicious native pepper with quick, clean heat that doesn’t linger on the tongue (used in my home with a pepper grinder over deserts, eggs, and hot chocolate)
-Cedar Sage (Salvia roemeriana) red blooms attractive to pollinators
-Elbow Bush (Forestirera pubescens) waist high and thicket forming, very attractive shelter for birds that stay close to the ground
-Fairy Duster (Calliandra eriophylla) pink puff ball blooms after each summer rain with lacy foliage
-Gregg Mistflower (Eupatorium greggii or Conoclinium greggii) Very attractive to butterflies, especially Monarchs as a lounge plant while feeding
-Pigeon Berry (Rivivna humilis) feathery pink flowers and small red berries and tolerant of shade
-Texas Buckeye (Aesculus arguta) and Mexican Buckeye (Ungnadia speciosa) also Red Buckeye (Aesculus pavia.) It is the Red Buckeye that leafs out in February and goes dormant with bare branches by August.
-Texas Leather Leaf (Chamaedaphne calyculata) Native that tolerates dry shade
-Turks Cap (Malvaviscus drummondii) twisted red flower with edible fruit high in vitamin C which is seldom seen because the wildlife is fond of the taste.
-Rock Rose (Pavonia lasiopetala) light pink, open faced flowers, very droughty and tolerant of deep shady conditions
-Sacahuista aka Nolina (Nolina texana) almost like a grass plume with leaves that are long, sturdy straps used since prehistory for weaving sturdy baskets, mats, and shoes
-Salvias : Cedar Sage (S. roemeriana ) / Big Red Sage (S. penstemonoides ) / Scarlet or Tropical Sage (S. coccinea)
-Yucca aka Twisted Yucca (Yucca rupicola) These aren’t as spiky as most yuccas. In the sun they stay compact and make interesting twisted leaves, but get a bit bigger and straighter in shadier conditions. In the spring they grow impressive and showy, cream-colored flowers that only last about a week. They generally make a sort of spiky mound that is about the size of a basket ball. In the summer, they can disappear into a filled planting community, but in the winter the rich green helps keep the garden interesting. Sometimes it looks good to cluster them in small clumps of 3 plants, each about a foot from each other, that way they can combine with each other to make an evergreen patch nearly as big as Dwarf Yaupons. They make good companions plants with Lantana since yuccas hide the lantana when it looks ugly in the fall, and the lantana drapes the yucca in the spring and summer.
-White Mistflower, aka Thoroughwort (Ageratina havanensis aka Eupatorium havanense) attracts many types of butterflies especially the late migrating species in the fall.
-Frost Weed (Verbesina virginica) a perennial wildflower which tolerates both full sun and full shade, self-sows readily, and grows to about 4-6 feet tall. It is said to attract butterflies in the fall.
-Balsam Gourd (Ibervillea lindheimeri)
-Carolina Snailseed (Cocculus carolinus)
-Cross Vine (Bignonia capreolata)
-Cypress Vine (Convolvulaceae Ipomea quamoclit)
-Lindheimer’s Morning Glory (Ipomoea lindheimeri)
-Old Man’s Beard aka Virgin’s Bower (Clematis drummondii) Another good example of why the Latin binomial is helpful for positive identification.
-Passion Vine(s) (Passiflora tenuiloba also P. affinis and P. lutea) So attractive as a butterfly larvae plant it often has almost no leaves.
-Pearl Milkweed Vine (Matelea reticulate) and Plateau Milkvine (M. edwardsensis) also Wavey Leaf Milkweed Vine (Sarcostemma crispum aka Funastrum crispum) host for Monarch Butterflies
-Purple Leather Flower (Clematis pitcheri)
-Scarlet Clematis Vine (Clematis texensis)
-Snap Dragon Vine (Maurandella antirrhiniflora) Small lacy vine that only looks delicate since it can smother smaller plants nearby so use freely next to invasive mustard and star thistle, but not too near the seedling trees.
-Texas Bindweed (Convolvulus equtans) with bright white flowers and a red throat indicative of its Convolvulaceae family doesn’t grow huge vegetative masses like Alamo Vine
-Virginia Creeper (Parthenocissus quinquefolia) New leaves look just like poison ivy, but before ripping it out, look at the older leaves with 5 to 7 leaves.
-Calyophus (Calyophus berlandieri)
-Columbine (Aquilegia chrysantha var. hinckleyana)
-Blackfoot Daisy (Melampodium leucanthum)
-Dwarf Mexican Petunia (Ruellia x brittonia ‘Katie’) smaller and better behaved than the invasive non-dwarf wild variety, purple flowers after rain
-Englemann Daisy (Engelmannia peristenia)
-Four Nerve Daisy (Tetraneuris scaposa) sometimes starts the spring displays in January
-Frog Fruit (Phyla nudiflora)
-Gregg’s Tubetongue or Hairy Tube-Tongue (Justicia pilosella)
-Heartleaf Skullcap (Scutelleria ovate sp. Bracteata)
-Horse Herb or Straggler Daisy (Calyptocarpus vialus) tolerates very deep shade
-Inland Sea Oats (Chasmantium latifolium) One of the few grasses that grows well in shady conditions with attractive seed heads.
-Mountain Pea (Orbexilum pedunculatum) evergreen, one foot tall, small purple flowers during warm weather especially after rains.
-Penstemon aka Hill Country Penstemon (Penstemon triflorus)
-Purple Poppy Mallow aka Winecup (Callirhoe involucrata)
-Snake Herb (Dyschoriste linearis)
-Sage, Big Red Sage (Salvia penstemonoides)
-Scarlet Sage (Salvia coccinea)
-Hill Country Sedge aka Meadow Sedge, aka Sand Sedge (Carex perdentata) also Texas Sedge (C. texensis) This looks like short grass that is evergreen, shade tolerant, and the deer leave it alone
-Texas Betony (Stacys coccinea)
-Texas Spiderwort (Tradescantia humilis) intricate purple flowers seldom seen because deer herds eat the flowers the night before they would have bloomed. When I have lingered late into the evening in my yard during the early spring and disrupted the grazers moving through, I have been rewarding by dazzling flowers
-Zexmenia (Wedelia texana)
-Blue-eyed grass (Sysirinchium graminoides) – small – pale blue to purple flowers
-Rain Lily (Zephyranthes candida) – natives are white but many colors available
Cycles of drought significantly threaten biodiversity in the region. Due to changes in rainfall, food supplies, timing, and human activity, many plant and animal populations are stressed. Ongoing infestations of non-native species, such as Chinaberry (Melia azedarach,) and Waxleaf Ligustrum aka Japanese Privet (Ligustrum japonicum,) compound problems by competing for scarce resources, further disrupting the environment in the Edwards Plateau area. Loss of biodiversity makes for an environment that is less resilient and more vulnerable to disease and drought. One local example of the negative impact of reduced biodiversity is found in the City of Live Oak near the greater San Antonio metropolitan area. The trees in this area are overwhelmingly oaks, making the community particularly vulnerable to the oak wilt that is killing massive numbers of Central Texas live oak and red oak trees.