ISLAND PLANTS
Gardening -- island style
JOHN FUCIK

Word filtering into the South Jetty offices suggested its readership would appreciate, nay, may even benefit from, articles about gardening and growing plants here in Port Aransas on a barrier island in the Coastal Bend of South Texas. That our location is different from central Texas, southern Wisconsin or western Kansas brooks little argument. But how all the characteristics that define our environment, and especially those that affect plant growth and health, may not be as obvious.

We hope that, with the initiation of this series, enlightenment is forthcoming. If sage advice might be leavened with a few astounding facts and a bit of humor...so be it. Time and space permitting, these articles will appear as near the beginning of each month as possible. Thereby, timely gardening tips and the experiences of local "green thumbers " may be hopefully helpfully included. Here goes.

Starting from the ground up, let's talk about our soil. According to Nueces County soil maps, what's underfoot is designated as Galveston- Mustang Tidal Flats. The uninformed might call it pure sand.

Sand it is but far from pure. Practically all soils consist of four constituents -- minerals, animal/vegetable matter, water and air. The minerals are the millenniums-in-the-making, weathered products of the earth's crust, granite, lava, limestone, etcetera.

The animal/vegetable matter may be living or dead, the latter a residue ranging from recently demised and quite distinguishable plant and animal remains to their highly decomposed, amorphous end product, humus.

The spaces between the mineral and organic constituents are filled with water and air. Over time, the proportion of these spaces filled with water and air is just as important to the plant's growth and survival. Okay, so what's the latest dirt on dirt for Port Aransas gardeners and plant tenders? In the higher elevations of town (4 or more feet to the water table) your major challenge is probably providing a sufficient and consistent supply of water and nutrients. Contrarily, in the low areas (water table less than 4 feet) providing adequate drainage for deep-rooted trees and shrubs can be a problem. In some areas, on the west side of town especially, low areas have been filled with several feet of sand from some other location. This can provide the additional needed rooting depth, and has been especially successful where the fill is dredging material from adjacent channels, as in Island Moorings. In such situations, not only is rooting depth increased, but the channels improve lateral drainage.

Regarding fertility, the most important features of a soil are pH, i.e., its degree of acidity or alkalinity, and its nutrient retention and storage capacity. Island sands are predominantly alkaline with pH ranging perhaps from 7 (neutral) to 7.6, and most have very low nutrient holding capacity. From test results I've seen, nitrogen is the major element most lacking in our soils. Potassium is on the low side, while calcium and phosphorous seem to be in plentiful supply. The minor elements, iron, zinc, manganese, copper and a few others, while minimally available, can, with a few exceptions, meet most plants' needs.

The key to optimum water and nutrient management of our island soil is maintaining high levels of organic matter ... manuring, mulching, adding compost, incorporating growing vegetation...one can hardly provide too much organic matter.

OCTOBER TIP

PLANT or TRANSPLANT winter vegetables and cool season flowers through the middle of October. Hold off FERTILIZING and PRUNING of trees and shrubs until the first of the year.

Dr. John Fucik is a retired horticulturalist with the Texas A&M Extension Service.