A WORD OR TWO ABOUT GARDENING

A Selection of Less Fam iliar Red Flow ering for M iam i-Dade Landscapes

Follow ing tw o previous articles on red in Miam i-Dade landscapes (first on flow ering trees then som e popular shrubs) this series concludes w ith a look at som e less w idely used tropical shrubs. In addition to the fam iliar bougainvilleas, ixoras, hibiscus, plum erias and oleanders described in the last article, there are several other red flowering shrubs that are fairly com m on in Miam i-Dade landscapes. Calliandra haematocephala, the red pow derpuff is a large (12 – 15’) w oody stem m ed w ith bipinnately com pound leaves, each pinnae com posed of 5-8 pairs of ¼ -2” leaflets. The tight, globose, m im osa-like inflorescences ow e their ornam ental appeal to the m any prom inent, red, exserted stam ens of the com ponent flow ers. Pow derpuffs are drought tolerant, preferring soils that rem ain on the dry side, and although they w ill take som e shade, full sun results in m ore prolific flow ering. Flow er production is stim ulated as days shorten, lasting from late fall - early spring. Once flow ering ceases the shrub can be cut back hard if necessary and given an application of a com plete slow release fertilizer. The dw arf cv. C. haematocephala ‘Nana’, grow ing slow ly to no m ore than 5’, is a better choice where space is at a prem ium . Although the inflorescence is not as spectacular, this cultivar flow ers on and of year round. Calliandra tergemina var. emarginata (syn. C. emarginata) is also suitable w here space is lim ited; often spraw ling and low growing in open sunny sites it assum es a m ore erect grow th habit w here there is som e shade (grow ing to 5 - 6’). The leaves are com posed of paired pinnae each w ith 2-4 sm ooth, shiny leaflets. The inflorescence is sim ilar (but sm aller) to C. haematocephala w ith the stam ens deep pink to red. This w as a Florida Nursery Growers ‘2006 of the Year’ selection, but is still not w idely available locally. Thornbugs are the m ost frequent insect pest of pow derpuffs, plus occasional infestations w ith w hite flies and scale insects. A group of unrelated shrubs (Callistemon sp.) also feature flow ers w ith prom inently exserted stam ens, though arranged in a cylindrical rather than globose inflorescence. An earlier article on red flow ering trees described the w eeping bottlebrush (C. viminalis). Although usually grow n as a sm all tree, it can assum e a m ore shrubby form ; indeed m ost bottlebrushes grow as sm all to large shrubs. Useful w here space is lim ited, the 3-4’ cultivar ‘Little John’ (probably derived from C. citrinus), is a slow grow ing extrem ely com pact shrub covered w ith deep red flow ers for m uch of the sum m er. It requires full sun and free draining preferably m oist soil (som e lim ited drought tolerance) and should be m ulched. Prune lightly to shape as necessary after flow ering. Useful on its’ ow n as a sm all accent plant, spaced 3’ o,c, to form a low inform al hedge, or as a group of 4 or 5 in a sunny corner of the landscape, under-planted w ith w hite Mexican heather or dw arf Carissa. Like the bottlebrush, the dw arf poinciana or pride of Barbados (Caesalpinia pulcherrima) is som etim es grow n as a sm all tree but m ore often develops into a som ew hat open shrub (to 10’) w ith a few scattered thorns. Not as w idely used in Miam i-Dade as in the past, its’ superior ability to tolerate drought and poor soils point to a possible resurgence of interest as increasing em phasis is placed on low m aintenance landscapes. Dw arf poinciana is a colorful shrub, the inflorescence an upright panicle having flow ers w ith yellow m argined, orangey red petals (all yellow form s also found). Fast grow ing w ith irregular branching, it can becom e som ew hat untidy necessitating regular pruning to help m aintain a neat appearance. ‘Com pton’ is a m ore upright cultivar (easier to m aintain as a sm all tree) having w hite m argined deep pink to scarlet petals. Much less com m on is C. cassioides the cassia- leafed caesalpinia w ith em arginate (notched) grayish green leaflets and bright scarlet, bell- shaped to tubular flowers. Found as a sparsely thorny, large shrub or sm all tree, it grow s locally to about 15’. Caesalpinias require full sun, free draining soil and are w ell adapted to sandy/rocky soils. Descriptions of other red flow ering w oody shrubs can be found in previous articles for this colum n. Am ong these are several m em ber of the Rubiaceae (ixora fam ily) including the fam iliar Hamelia patens (fire-bush) and less fam iliar Rondeletia leucophylla (bush pentas). The form er is native to Florida and although drought tolerant grow s better w here there is regular soil m oisture. The so-called ‘African’ fire-bush, now believed to be H. patens var. glabra, is found from northern S. Am erica through northern Mexico - it is native to neither Africa nor Florida. It has orangey yellow rather than orangey red flow ers and sm aller, glabrous (sm ooth) leaves rather than the larger roughly hairy leaves of the species type. Bush pentas, grow ing up to 10’, bloom s w inter into late spring w ith deep pinkish-red flow er heads and is drought tolerant in addition to being w ell adapted to local Miam i lim estone. It is occasionally found in local garden centers. Rondeletia. strigosa is a sem i-w oody species, rare in local landscapes, but w hich could be used m ore. From the base of the plant arise num erous long, slender, som ew hat bow ed, green, cane- like stem s (to 4’ locally) bearing bright green, lanceolate to ovate leaves. The flow ers, w hich occur in term inal clusters, are an eye-catching bright pink to crim son w ith a prom inent golden yellow eye. Flow ering occurs on and off throughout the w arm er m onths of the year – stem s should be deadheaded as they finish flow ering. W ell adapted to local lim estone soils, it is also an especially attractive subject for a large urn-shaped planter; situate in full sun and provide a free-draining soil. Portlandia coccinea and P. proctorii (syn. P. coccinea var. proctorii) are tw o other underutilized m em bers of the Rubiaceae. The flow ers of these tw o species are trum pet-shaped, scarlet and dark red respectively; the bell flow er P. grandiflora, w hich m ay be fam iliar to som e readers, has sim ilar shaped flow ers, though these are tw ice as long (6-8’) and pearly w hite. Like the bellflow er these tw o other portlandias are slow grow ing to at m ost 10’ and can be grow n as shrubs or sm all trees. Best situated w here there is som e high shifting shade, they adapt w ell to local lim estone if supplem ented w ith som e added organic m atter. Far m ore fam iliar in local landscapes, peregrina (Jatropha integerrima) a m em ber of the spurge fam ily (Euphorbiaceae), is also know n sim ply as jatropha or spicy jatropha, and popular w ith local Cuban Am ericans (it is native to Cuba). Locally it form s an open w oody shrub up to 10’, the dark green leaves m ore or less elliptic, often w ith slightly lobed m argins, or occasionally m ore deeply lobed w ith a prom inent term inal lobe. The inflorescence com prises a term inal branched cym e, each flow er (in clusters of three) having a bright red tubular corolla. The cultivar ‘Com pacta’ is tighter grow ing and narrow er, ideal for planters (use a soil m ix w ith added coarse sand and Perm a-Til) w here it can be kept at 3-4’. The m ore com pact form also m akes it easier to train as a sm all tree, eventually attaining a height of ≈ 10’. Peregrina thrives in poor soil, including the rocky/sandy soils found in Miam i- Dade, is drought tolerant and requires m inim al care. Choose a free draining site in full sun, prune as necessary (can be cut back hard in late w inter if necessary) and apply a slow release fertilizer in spring. W atch for scale insects (m ore likely w here there is poor air circulation) and to a lesser extent dam age from m ites. Tw o other jatrophas are occasionally seen in local landscapes, the gout plant (J. podagrica) and coral plant (J. multifida). The form er is of m ore ornam ental appeal and grow n as m uch for the unusual sw ollen knobby trunk as the flat topped clusters of sm all, brilliant orangey red flowers. The leaves, w hich are large (to 12” w ide) and deeply lobed (like a fig leaf), are concentrated near the branch tips on long petioles. Flow er clusters are borne on long, red tinted stem s, and are found on and off throughout the year. Gout plant can grow to about 6’, how ever thinning m ost of the leaves is used to lessen vertical grow th and encourage the ‘trunk’ to becom e m ore sw ollen (pachycaulous). Depending on how cool it is during w inter, there m ay be som e yellow ing and loss of leaves. Situate gout plant in full sun, providing a rapidly draining soil (should contain  coarse sand/grit), otherw ise it is very prone to rot. Do not w ater during w inter. Make a light application of a slow release fertilizer som e tim e in late spring. Apart from root and stem rots w atch for scale insects and m ites (especially in late w inter/spring). Gout plant is also sold as Budhas belly and Guatem ala rhubarb and is especially useful as a source of flow er color in a dry rock garden w here it can be com bined w ith plants such as agaves, aloes and cactus-like euphorbias. The coral plant is larger, grow ing locally to about 15’ as a sm all tree or large shrub. The leaves are about the sam e size as the gout plant, how ever they are parted into such thin lobes (each lobe itself is also often dissected) that they appear far less coarse. The flow er clusters are sim ilar to those of the gout plant though a m ore pinkish red. All jatrophas are poisonous causing severe vom iting and prolonged diarrhea, especially the coral plant and in particular the seeds (w hich unfortunately have a rather appealing taste). Another group of euphorbias that are ideal for full sun sites and dry sandy/rocky soil are varieties/cultivars of crow n of thorns, E. milii. In particular look for E. x lomi Poysean Group hybrids, several of w hich have red inflorescences. These Poysean hybrids have thicker stem s and do not spraw l as m uch as E. milii and produce m uch large flow er heads. More inform ation on these and other crow n of thorns w ill be found in an earlier article. Of all the red flow ering m em bers of the spurge fam ily none is m ore popular than Euphorbia pulcherrima, the poinsettia. As w as pointed out in a previous article, this should be considered as m ore than just a disposable Christm as houseplant; w ith a little care it can find a m ore perm anent place in local yards. Also in the spurge fam ily another sem i-w oody shrub the chenille plant (Acalypha hispida), is easily recognized from its’ unique inflorescence, a long, pendent, tassel-like spike containing hundreds of tiny, fuzzy, red flow ers. These are found only on plants w ith fem ale flowers (i.e. w ith red m ulti-branched styles), so those bearing m ale flow ers are of no landscaping interest – chenille plant is dioecious. Propagation is lim ited therefore to vegetative m ethods, usually from soft or sem i-ripe cuttings. Chenille plant is a vigorous fast grow ing rather coarse textured shrub w ith large, thin, bright green, oval leaves and can quickly grow to 10-12’. Once established it w ill form a large clum p (on Miam i lim estone it frequently form s root suckers, and any prostrate stem s that contact m oist soil readily root). Cut back (no m ore than  on any one occasion) to keep it w ithin bounds. W ater regular as necessary (only lim ited drought tolerance), and apply a slow release fertilizer 2-3x per year to ensure bright green foliage and fully colored flow er spikes. Scale insects, m ealybugs and occasionally m ites can be pests. The trailing chenille plant or kittens tail (A. reptans var. pygmaea) is a m iniature version w ith trailing stem s that finds use in hanging baskets or as a colorful groundcover for areas w here lim ited coverage is needed. Like A. hispida w ater as required and apply fertilizer on a regular basis; although not as fast grow ing, stem s should be thinned if grow th becom es congested. On lim estone leaves m ay becom e chlorotic – if so, apply a trace elem ent nutritional spray. Other sem i-w oody shrubs include tw o striking, red flow ering m em bers of the . The first of these, the firespike, Odontanema cuspidatum is the easiest to grow , am enable to either full sun or part shade. This is a clum p form ing shrub to 6’ w ith m ultiple green stem s w hich becom e w oody at the base and exhibit lim ited branching. The leaves are som ew hat glossy, oblong to elliptic, w ith w avy m argins and acum inate (pointed) tips. Individual flow ers are bright red, tubular (≈ 1’) w ith five sm all lobes, have a w axy appearance and are found in term inal, som etim es branched, racem es. The flow ers are not only show y (m ainly spring into fall), but are excellent attractants for hum m ingbirds and butterflies. In som e cases inflorescences becom e fasciated (individual flow ers develop as if fused together), giving them an unusual, flattened, alm ost strap-like appearance. Once established firespike, although drought tolerant, thrives m ore if soil m oisture rem ains constant. It has few pests and on sandy soils prone to nem atode problem s is of particular utility, being resistant to root knot nem atodes. Pruning to rem ove spent inflorescences, dead stem s and excessive root suckers w ill be required, plus an application of a com plete slow release fertilizer in late spring. Cardinal’s guard, Pachystachys coccinea also in the Acanthaceae can grow locally to about 5’ w ith sem i w oody stem s, 8” lightly w rinkled bright green leaves, and som ew hat square, upright, 8” spikes of overlapping green bracts and scarlet tubular flow ers. Although quite spectacular, only a lim ited num ber of spikes form , w ith flow ering occurring from late w inter into spring. Each spike opens from the base up over a period of about 2-3 w eeks. Cardinal’s guard requires regular applications of a com plete slow release fertilizer and evenly m oist soil – add som e Canadian peat and m ulch to help retain soil m oisture. It is ideal for areas of the yard offering som e shade; lim it full sun exposure to no m ore than the first 2 hours after sunrise follow ed by bright light - insufficient light w ill reduce flow ering. Exposure to hot sun greatly increases the risk of w ilting w ith subsequent leaf drop; since new leaves only form at stem tips the shrub becom es open and bare. Cardinal’s guard is sensitive to cold and this too can cause leaves to drop - som e overhead shade also helps protect plants w hen tem peratures approach freezing. Many shrubs in the Acanthaceae have a tendency to becom e leggy and this is certainly true of Pachystachys; w hen com bined w ith alm ost leafless stem s the result is an unattractive plant. In such instances cut back cardinal’s guard severely to a m ain stem to stim ulate new com pact leafy grow th. There is som e confusion over the identity of cardinal’s guard: tw o distinct species, P. spicata and P. coccinea, are know n by that com m on nam e w ith the form er species having been m isidentified as the latter in the past. Most m aterial sold as cardinal’s guard is listed as P. coccinea. Like P. coccinea the red plum bago, Plumbago indica, flow ers during w inter and into early spring. This is a red flow ering m ore tropical relative of the fam iliar blue flow ering P. auriculata. The leaves are a darker green and m uch larger (ovate to elliptic, ≈ 4”x2”), the scarlet flowers borne term inally on long arching racem ose spikes (to 18”) com pared to the m uch shorter spikes on P. auriculata. Red plum bago is a lax clum p form ing plant though not as spraw ling as blue plum bago. Com pared to the Mediterranean type clim ate of S. Africa’s Cape (w here P.auriculata is native), the red plum bago favors a hotter m ore hum id clim ate, being endem ic to SE Asia. Situate in full sun and plant in evenly m oist soil enriched w ith som e organic m atter - w ater during periods of hot dry w eather, less so during w inter. As flow ering ends in spring red plum bago can be heavily cut back. Flow ering is induced as days shorten so avoid pruning after Septem ber. Several shrubs and vines w ith sm all tubular red flow ers have com m on nam es that include the term firecracker (e.g., Cuphea ignea, cigar or firecracker plant and M anettia luteorubra firecracker vine). Another, Russelia equisetiformis (firecracker or fountain bush) is fairly com m on locally, though probably not as w idely used as 20-30 years ago – it found favor grow n in large concrete planters. A clum p form ing m uch branched shrub to 4’, this firecracker has green, pendent, w iry, angular stem s that are practically leafless (leaves reduced to scales). These bear clusters of thin 1¼ ” red tubular flow ers throughout m ost of the year. Provide a free draining gritty soil – R. equisetiformis is highly drought tolerant and grow s w ell even on nutrient poor soils, but is intolerant of soils that rem ain w et. W hen used in-ground, the clum p can expand to m ore than 5’ and should be cut back to keep it w ithin bounds. Russelia sarmentosa (coral plant – yes, yet another com m on nam e applied to m ore than one plant!) has stiffer m ore erect stem s along w hich at intervals are w horled three 2” heart-shaped leaves. The tubular flow ers are in loose axillary clusters, rosy red and in evidence for m uch of the year. Grow ing to 6-7’ coral plant responds w ell to pruning and can be used as a low , airy, inform al hedge, or foundation plant. There are several scandent or clim bing shubs w ith red flow ers/inflorescences (e.g., M anettia luteorubra, Bauhinia galpini, Holmskjoldia sanguinea, M ucuna bennetti and M usseanda erythrophylla as w ell as species/cultivars of Hoya, and Passiflora). Details of these w ill be found in previous articles on vines and clim bers. Also consult previous detailed articles on red flow ering gingers, costas and heliconias; these are excellent choices to spark up a shade garden.

John McLaughlin Septem ber 21, 2007

Figure 1 Pachystachys coccinea (cardinal's guard)