For The Answer
Palms are being
used more extensively as ornamental plants over a wider area. These
exotic trees and shrubs are adapted to a greater climatic range in
Plant When Warm
Plant palms during the growing season when the soil is warm. Palms have a fibrous root system, with each root fiber growing from a root collar When part of the root is severed by moving, it dies back completely. Severed roots must be replaced by new roots if the plant is to survive.
soil temperatures are needed to encourage this new growth or the plant may rot
before growth begins. Thus balled palms should be moved in warm weather
with several weeks of the growing season remaining before they are subjected to cold soil temperatures. A good rule of thumb is to
plant balled palms before September 1 in all but the
Know Cold Temperature Zones
The palm grower should understand the juvenile tenderness to cold temperatures in marginal hardiness zones. Young palms cannot survive as many sub-freezing hours as older palms which have developed protective "wood" around the vascular bundles and the central "shoot." Survival also is probably related to the development of a fibrous root system in relation to freezing soil temperatures. Try to use older palms, preferably those container grown, when subjecting these plants to temperature-limited sites.
The most limiting and extending
consideration in palm culture in
The zoned list shows that different species vary in cold tolerance. If the less hardy species are desired, consider the foregoing factors. A more juvenile palm or a more tender species might survive in a mild microclimate, such as near a house on a south exposure. Keeping these influences in mind makes wider selection of palm species possible.
Provide Good Soil
Palms prefer well-drained soil, rich in organic matter and with adequate water and nutrient-holding capacity. Loams and clays with good subsoil drainage are preferred over sands or soils with impervious pans or parent material. In areas of high water tables, the planting grade should be raised. Terraces, berms or raised planters are techniques growers can use to improve subsoil drainage.
On rocky or chalky sites, remove the undesirable topsoil and fill in with loam or silty clay. Well-rotted manure, sludge or composted debris, mixed generously with the backfill, provides productive growing medium.
If added water does not drain downward from the excavated pit within a few hours, a drain tile may be needed.
This European fan palm adorns a courtyard at the
In the following
descriptive list of palm species, the Roman numerals indicate the area in
With extra protection, such as mulching and wrapping, many species in the list should survive winter temperatures north of the area indicated.
Chamaerops humilis —European Fan Palm. A multiple-trunk palm forming a compact crown. Slow grower. Excellent in large planter on patio. I, II
Erythea armata — Blue Hesper Palm. Much overlooked, attractive blue fan palm. Suited to sunny sites and better soils. Its northern hardiness range has not been well-tested. I, II
Livistonia australis — Fountain Palm. Believed hardier and grows taller and faster than L. chinensis. I, II.
Livistonia chinensis — Chinese Fountain Palm. Once believed
hardy only in southern
Nannarops ritcheana — Mazari Palm. From arid mountains of
wrightii — Saw Cabbage Palm. Native to Florida Everglades, this
attractive clustered trunk palm survived recent
Rhapis excelsa— Lady Palm. Multiple cane-like trunks and slow growth make it an ideal understory or hedge plant in shady protected areas.
Rhapidophyllum hystrix — Needle Palm. Native in
Sabal causiarum —
Sabal etonia— Scrub Palmetto. A trunk-less palm, native to
Sabal minor —Dwarf Palmetto. Native to
Sabal palmetto—Cabbage Palmetto. Taller, faster grower than S. texana, slender trunk. Good landscape specimen. I, II, III
Sabal texana — Texas Palmetto. Native
Sabal umbraculifera — Hispaniolan
Palmetto. Most massive of the palmettos. Thriving in
Trachycarpus fortunei — Windmill Palm. Reputedly the hardiest of palms, has
withstood two degrees F. in
Washingtonia filifera —
Washingtonia robusta — Mexican Fan Palm. Fast-growing slender trunk, tall, readily available. I, II
FEATHER PALMS Pinnate-leafed
Acrocomia total — Gru Gru. Solitary trunk and leaves armed with sharp prickles excludes its use to the hobbyist or botanical garden. I
Arecastrum romanzoffianum (Cocos plumosa) — Queen Palm. A popular palm in warmer areas with graceful arching feathery leaves. Needs some protection from freezing winds. Suffers from manganese deficiency. I
capitata (Cocos australis)
— Pindo Palm.
Jelly Palm. Slow-growing, arching blue-green fronds, hardy in North '
spectabilis—Chilean Honey Palm. Similar in
appearance to Canary Island Date
Palm, but believed hardier. Growing in
sprouts from the trunk can be used for propagation. I, II
This attractive scene in a
This feather palm is a Pindo
Palm, Butia capitata, and has survived near zero degree temperatures in
Another feather palm,
the Canary Island Date Palm,
This fan palm is the Chinese
Fountain Palm, Livistonia chinensis, growing on North St. Mary's Street in
Palm hardiness map of
Zone I — Average annual minimum temperature (AAMT of 20 to 30 degrees F. or warmer.
Zone II and III — AAMT 10 to 20 degrees.
Zone IV — AAMT 10 degrees or colder. Not recommended for outdoor growing of palms without freeze protection.
The map above is the most accurate available, although it would be more useful to palm growers to indicate average daily hours below freezing rather than average minimum temperatures.
Texas Agricultural Extension Service, and city horticulturist,
by Wilbur Watje in 2006. See: http://www.plantanswers.com/wilbur_que.htm
Scanned by Wilbur Watje in 2006. See: http://www.plantanswers.com/wilbur_que.htm