Monday, September 21, 2009

PALMS FOR AUSTIN? WHY NOT!



Here in Austin, we live in a stressful gardening environment which tends to limit our plant selection to those which are very drought tolerant, can endure temperature extremes, low humidity, and our alkaline soils. Although non-native, there are several plants that one wouldn’t think belongs in Austin or is adaptable to our environment, but think again - it’s PALMS. They are not only for tropical regions of the world or Zone 9 and higher. In fact, there are many genera and species that are native to desert regions, and others which are very cold hardy.


Most of the palms that fall into this category are fan leafed , shrubby , not tall, and many come in colorful silver/blue hues. Since palms are slow growing and are propagated from seed only, they will be on the expensive side to purchase, but a good landscaping investment. Let’s explore a few.

The most cold hardy palm in the world is the Needle Palm (Rhyphidophyllum histrix). It matures at about 4 – 6 ft, develops a short trunk only with age, but is gets it’s name from the 6” black spiny needles that project from the leaf petiole at the base of the plant. This palm is hardy to below zero in winter. A mature Needle palm survived -27 degrees in Knoxville, TN. The foliage is a rich deep green, palmate and fan shaped. A slow grower, it is virtually maintenance free and will endure sun and shade.

Another excellent choice is Nannorrhops ritchiana , a cold hardy palm from Afghanistan. This palm comes in both a green or a silver/blue leafed form and grows shrub—like with multiple trunks. Give this one a little bit of spreading space. It loves full sun and dry conditions and is impervious to our temperature extremes.

Serenoa repens is considered a natural weed in Florida – seen overtaking pastureland and dominant in the natural landscape in Florida, but it’s rare to find this plant in Texas. Although it comes in green and silver leafed forms, the latter is definitely most desirable for it’s silvery/blue foliage. Like Nannorrhops, this plant grows shrubby with no trunk developing and spreads by side shooting from the base. It is hardy down to around 15 degrees, loves full sun or shade (although the silver form will color better in sun). This plant won’t grow taller than 6’ at full maturity.

Native to the SW U. S. and northern Mexico in dry, caliche desert regions is Brahea armata. This naturally silver leafed beauty is very slow growing, and prefers dry climate conditions with poorer soils. It’s beautiful silvery leaf color begs to be in full sun, silver being a protective reflective adaptation for it.  Brahea will eventually develop a small trunk but never exceed about 8’ over a lengthy time. This is one of the best palms for our hill country climate and environment.

Another cold hardy palm (to 20 degrees) that develops a trunk and gets rather sizable in spread is Butia capitata. This palm is not in the fan palm category. Getting ultimately to 15’ tall and as wide in spread, this palm has a unique bluish tint to the foliage that makes it stand out and easy to identify. The fruiting clusters are also very colorful and good food for wildlife.

The Mediterranean Fan Palm (Trachycarpos fortunei) is another cold hardy palm, but it doesn’t like our high light intensity so should be grown as an understory tree or in a shaded location where it can be protected from the bright afternoon sun. This palm forms trunks up to 10’ with many years of age and has a looser palmate leaf arrangement. It is drought tolerant but prefers moderate watering.

Having a similar name, but being a completely different plant is the Blue Mediterranean Fan Palm (Chamaerops humilis var. cerifera ) which is native to Morocco. Right there is a clue that it is drought tolerant and can take desert temperature extremes, from triple digit to low 20’s. The foliage is a natural bluish/silver tint which is also reflective of the high light adaptation of desert plants. Give this one full sun. This has been recently introduced into the nursery trade and become popular as a landscaping palm.

Trithrinax compestris, also known as the Blue Needle Palm is yet another of the lovely bluish tinted palms worth trying. Hard to find, this trunked palm can get tall in it’s native environment in Argentina and Brazil, but would be much slower growing in central TX. It’s hardiness is thought to be 20-25 degrees so a slightly protected spot might be advisable. It likes full sun and is water friendly.

A perfect palm for a shady deck or patio would be the Lady Palm (Rhapis excelsa) which can get over 8’ tall unless you get a dwarf variety such as ‘Koban’. This split stiff leaved palm is hardy down to 25 degrees and survives winter in Austin in a protected place, but does need shade. It is clumping and fills out a décor planter very nicely.

Palms in general are shallow rooted with tight clumps of fibrous roots which makes them relatively easy to plant . As the foliage of fan palms is rather different from our local and native plants, they look best when planted as a specimen plant so that they are the featured attraction. Palms make excellent container plants as well. Do beware as there are some palms sold at local garden centers that won’t make it through the winter in central TX, such as Pigmy Date Palm (Phoenix roebelenii). If you invest in a quality palm, you certainly don’t want to risk losing it, so stay with tried and tested varieties.

Try these recommended durable and adaptable palms in your landscape and you will be very pleased. Finding them may be a challenge but the reward is great. I suggest searching Google using the botanical name for best results.

Palms are one of Austin’s most underutilized plants. See what you are missing out on!