Here is the promised post from the 04 August lecture.
I have left out invasive species whenever I could identify them. This is not an exhaustive list; I relied heavily on Trees and hrubs for Dry California Landscapes by Bob Perry, although I left out most California Native Plants because that's Orchid's bailiwick and I don't want to step on her toes...
Most of these plants are deciduous – they loose their leaves as a response to lack of water... deciduousness is a hard sell in LA...
01 - Acacia baileyana Bailey Acacia, Feathery, finely cut, blue-gray leaves, yellow fragrant flowers, to 30 feet. Attractive shrub or small tree – excellent for accent, slopes and background plantings. Very very showy yelllow flower balls – Jan to March. Prone to litter and built up dead branches as it ages, but consistent, prudent pruning will mitigate a lot of that. Still, has a reputation for being cranky and I swear I have seen fireblight take morethan one of these out – it has naturalized along the coast by Monterrey and that's not a good thing – plant deep in the city and not near the WUI.
02 – Acacia cultriformis Rounded shrub to a small tree, about 10-15' tall and equal wingspan. Showy yellow flowers Jan – March. Can be formally hedged and like almost all acacia's, is adapted to drought conditions.
03 - Agonis flexuosa Peppermint tree – Sunset says this is one of the best small trees for California gardens! 25 to 35 feet tall, spreading to 15 to 30 feet wide. Leaves smell like peppermint when crushed. Responds well to pruning, is highly adaptable; can be used as a yard specimen, background plant, espalier and a street tree. Small white flowers, May and June. An Australian tree related to Melaleuca and Leptospermum, both of which are really drought tolerant.
04 – Arbutus unedo Strawberry Tree – 10-25' tall with equal spread – evergreen tree or shrub. Reg-brown bark on trucks that twist and gnarl with age – flowers Oct to Jan, red to yellow fruit late Fall to winter... relatively slow growing which means 'low maintenance'
05 - Bauhinia purpurea (syn. B. variegata) Purple Orchid Tree – semi-evergreen to deciduous shrub or tree, attractive tree 20-35’ tall spectacular street tree in places where spring is dependably warm – of all the Bauhinia's this one is the least thirsty. B. x bakeana has larger flowers and color from cranberry, through purple and rose to orchid pink.
06 – Bougainvillea
07 - Broussonetia papyrifera – Paper Mulberry, deciduous tree that can is somewhat drought tolerant – Sunset describes it as moderately fast to 50’, then says “often considerably smaller and shrublike in gardens while the LA City Street guide, calls it 20 to 40’ needs moderate pruning – can be subject of sucker growth in cultivated and/or wet gardens – inner bark was used to make paper – once established takes little water.
Most alders and birches are water suckers and should not be considered for dry landscapes. Even Alnus rhombifolia, the native species is riparian and is not suitable for drought resistant gardening.
08 – Cercidium microphyllum – (syn. Parkinsonia microphyllum) Littleleaf Palo Verde, or Yellow Palo Verde – 20 feet tall, extremely drought tolerant, pale yellow flowers – a completely underutilized tree in our landscapes – lovely! Also C. flloridum, Blue Palo Verde.
09 Cercis occidentalis – Western Redbud, small tree or shrub, 10-18’ notched blue-green 3” leaves seedpods, which are magenta in summer… foliage turns light yellow or red in fall, bare branches with reddish brown seedpods look cool in winter – under used because of deciduousness
10 - Chilopsis linearis – Dessert Willow or Desert Catalpa - 15-30’ tall, 10-20’ wide, like most humans, develops shaggy and twisting bark with age, fragrant trumpet shaped blooms similar to small cattleya orchids and attracts hummingbirds
11 - Dodonaea viscosa – the other Dondonaea are more tropical, but this one is from SW US and takes any kind of soil, ocean wind and dry desert heat. Lovely.
12 Dodonaea viscosa in a pot....
13 - Echium candicans (E. fastuosum) Pride of Madeira. Large plants to 6' and to 10' wide. Great spikes of clusters of blue to purple flowers. Can be invasive and should not be planted near wild areas – self sows 'joyously' and will naturalize!!!
14 - Eucalpytus macrocarpa– some 700 species, and most of them are large tree, with brittle wood. Sprawling and awkward, but showy – useful as an espalier on a sunny fence or wall.
15 Feijoa sellowiana (syn. Acca sellowiana) Pineapple Guava Large multi-stemmed plant, 18-25' with equal spread if not pruned, can take lots of training and pruning – espalier, screen or hedge or small tree. Blooms in late spring, flowers are edible in fruit salads or made into jams, is drought tolerant but best fruiting comes with some water. Soft fruit reminiscent of pineapple – other wise bland.
17 - Fremontodendron californicum – to 20' tall, 12' wide Spectacular in bloom and steal the show; Hillside planting is recommend because any water out of their water season can be fatal. Short-lived under even ideal conditions, but oh what a bloom!
18 - Garryana elliptica – Coast silk tassel – slow growing drought tolerant native to the Coast Ranges 10-20' high and as wide, can be trained as a small tree usually seen as a climbing shrub – stunning in bloom – James Roof cultivar is the one to get
19 – Geijera parviflora, Australian Willow 25-30’ tall and 20’ wide, but casts light shade, trouble free patio or street tree, needs very little pruning. Deep noninvasive roots..
20 - Gossypium arboreum – Tree Cotton a lovely small tree, about 12 feet tall, 5 wide. Needs annual pruning to maximize its look – reportedly not long lived. Yellow flowers fade to mauve then black before dehissing and forming a cotton boll. Will produce cotton almost year round. Great conversation piece , hummingbirds will use the cotton for nests.
20A - Grevillea robusta – Silk Oak tree – Australian – popular tree – look up to about the 4th floor to see the golden flowers. Picturesque against the skyline. Many folks allergic to their golden orange flowers – lots of litter. Although I find it lovely to look at as I drive along, I believe
Slide 21 – Hymenosporum flavum, Sweet Shade – a pittosporum family member, graceful upright narrow tree early summer flowers have an orange-honey fragrance that is a knock out. Frequent pinching of tip growth is necessary for a stronger more dense plant. Poor in strong winds. Moderate water.
21 Hyptis emoryi - Desert Lavender an evergreen shrub – little to no water Erect to 10' and up to 8' wide. Woolly gray roundish leaves Tiny blue-violet flowers can bloom any time through out the year, but usually in Spring. Pleasant lavender fragrance.
22 – Laurus nobilis, Sweet bay 12 – 40’ tall and as wide – not fussy about soil except needs good drainage – will adapt to container culture - moderate water
Slide 23 – Leptospermum laevigatum Australian Tea Tree – usually a shrub, but can be pruned into a smallish tree – 10-30’ tall and as wide, oval or teardrop shaped dull green to gray-green leaves, if allowed to go grow to full sized (vs. constant hedging) they develop picturesque shaggy, gray-brown trunks with a definite muscular look, can be used as a screen or even clipped hedge.
Slide 25 – Luma apiculata Chilean Myrtle tree – to 20’ tall and wide – dense foliage, older trees develop beautiful smooth cinnamon colored bark, ½” wide flowers, white to pinkish in late summer to early fall
26 - Lyonothamnus floribundus – Catalina Ironwood – Seldom seen in cultivation, Red brown bark peals off in strips, reddish young twigs. Leaves are divided into lobed leaflets making a pleasing appearance. Needs excellent drainage. Handsome in groves and best near the coast
27 - Lysiloma microphylla thonberi (L. thornberi) Fern of the Desert – native to Arizona's foothills – to 15' tall and wide finely cut leaves like acacia -0 masses of 1” creamy white clusters of flowers like little puffballs followed by brown flat seedpods – takes pruning for a more formal look
28 - Mahonia aquifolium – Organ Grape Can take any exposure – best with late shade in hottest climes – easy to grow and good looking all year – foliage can be prickly so avoid setting them near pathways – fruits attract birds.
*Melaleuca sp – more than 140 and most are pretty drought tolerant -
28B - Olneya tesota – Desert Ironwood - Sonoran Desert native 15 to 30' high with equal spread... slow grower, single or multi-trunked sweet pea flowers in late spring (Fabaceae)
29 – Prosopis pubescens Screw Bean, Mesquite - Heat Tolerance: Excellent Sun Exposure: Full sun to light shade Origin: Southern New Mexico and Texas, west to northern Baja California, throughout much of southeastern California, southern Nevada, eastern Arizona, and extreme southwestern Utah, mostly in river bottoms Growth Habits: Thorny deciduous tree or shrub, up to 25 feet tall (7.5 m), 25 feet spread (7.5 m) Watering Needs: Little water can be used as a thorny hedge plant or pruned into a small specimen tree… Rod shaped yellow flowers in late spring.
Rod shaped yellow flowers in late spring.
34 – P. lusitanica – Portugal Laurel From Spain and Portugal… densely branched shrub 10-20’ high and wide… Very glossy, oval dark green leaves – creamy white small flowers in 5-10” spikes in spring and early summer. Attractive background/screen slow growing! Tolerant of heat, drought, strong sunlight, wind. Little or no water… ‘Variegata’ has leaves with narrow irregular white margins and fruit that ripens from brightish red to black.
35 & 36 – Psorothamnus spinosus (Dalea spinosa) Smoke Tree – Native to desert washes, small leafless tree with brilliant lavender flowers from April to June, 10-20’ tall to 10-15’ wide; sparsely foliaged in small hairy white leaves that drop in early spring; slivery gray spiny branches; leafless plant supposedly resembles a cloud of smoke… Fragrant sweet pea shaped flowers in spring… Cut branches in and out of bloom are impressive in floral arrangements. Easily started from seed in warm weather if not found in the trade. Needs good drainage and little other care.
45 – Robinia neomexicana, New Mexican Locust – from a genus of mostly larger trees, is a thorny plant to 6’ tall and as wide… drooping 6” pink flower clusters – gorgeous compound leaves
*Rosmarinius officinalis – Rosemary and lavender (Lavendula spp.) lives longer on less water – otherwise shortlived in gardens
Salvias – the California natives have lower water requirements than the exotics look for S. apiana, leucophylla and others
49– Simmondsia chinensis Jojoba, goatnut tree – Native to the Southern CA, AZ and Mexican deserts, Fruit’s high oil content makes it a prized crop for skin and cosmetic use. Useful as informal or clipped hedge, or a foundation plant in a desert garden. Hard to find in the trade at times.Simmondsia chinensis – jojoba – deserts of California to 6' high – dioeceous, females bear a large edible nutlike fruit tastes a little bit like a filbert – high oil content make this fruit a cash crop for cosmetics etc.
51 - Tecomaria capensis (also Tecoma capensis) Cape Honeysuckle to 30' by about 8' wide – honeysuckle flowers attract hummingbirds – needs little water but is reluctant to stop growing and will engulf a small home in a season
52 – Vitex agnus-castus, Chasteberry – Chaste Tree – deciduous small tree or shrub – variable habit from specimen to specimen – Native to the Mediterranean to Asia. Can grow to a 25’ tall and wide tree – most are much more shrubby, can be trained into a multi-stemmed tree. Aromatic leaves are palmately compound and some cultivars, such as the one pictured here are quite showy. Thrives in heat, makes a good plant in the back of a shrub border. You can cut the plants like a perennial to 1’ foot high in spring, blooms on new growth
58 – Zizyphus jujuba Chinese Date Tree - Small or medium sized tree, can grow up to 40’ more usually about 15-20’ tall. Trees are deciduous and are deciduous in cold months. Jujube's are fairly adaptable, but should be grown in full sun. They can stand extremely hot desert temperatures, as well as cold temperatures to -25F. They are very tolerant of drought, but moderate to heavy watering should be provided during growth season to ensure the best fruit. Flowers bloom in summer, followed by fall ripening fruit. The hard "nut" inside the fruit contains two seeds. Pinnately compound leaves are quite showy for a small tree.
Fruit and nut trees are often less water suckers than many common ornamentals. Among them:
Almonds, Apples, Apricots, Filberts (Hazelnuts), Pears, Persimmons, a number of oak species, including natives,