Primetime Newspapers

By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist

Week of December 31, 2007


“January Gardening Calendar”


            January is usually the coldest month in San Antonio, but it is still a very pleasant month to garden and there are plenty of tasks to keep gardeners busy. 


In the vegetable garden, plant your onion transplants.  The 1015’s are the most popular selection, but Bermuda, Granex, red hamburger, and other varieties work well.  Place the transplants every two inches in the row so that the middle two onions can be used for green onions as the winter progresses.


The onions will be ready for harvest in May.  The tops fall over when they are ready.  Onions require considerable nitrogen to produce nice five inch bulbs.  Spread one cup of fertilizer per eight feet of row at or before planting and then side dress with a cup every month.  Slow release or winterizer lawn fertilizer works well. 


Thrips are usually the only insect pest that bothers onions.  They are the insect that causes the onion leaves to turn milky looking.  Thrips are sucking insects.  At first sight of any color change in your onion leaves you can apply a Spinosad product. 


            Keep the broccoli harvested.  The plants will produce side shoots after the central head as removed.  Cauliflower curd will turn yellow if you do not shade the head.  The easiest way to do it is to use spring mechanism clothes pins to pin up the leaves over the head.


            Harvest spinach and other greens as you need them.  Only remove one-third of any plants foliage at one time and the plants should produce until the end of April.  Bt and/or Spinosad products are the controls of choice for caterpillars on greens and cole crops.  Use slug and snail bait to control slugs, snails and pill bugs. 


            The lawn does not need much attention in January.  Irrigate once if it is warm and we do not have rain.  Mow once to keep winter weeds in check.  A product – Weed Free Zone works in the winter as a contact herbicide to control broadleaf weeds.  Do not fertilize the lawn until late Spring (May 1).  The nutrients are wasted if the lawn grass is not growing. 


Keep the winter annuals watered.  Snapdragons, pansies, cyclamen, dianthus, primulas, and calendulas can tolerate considerable cold weather if they are not dried out.  Water when the soil is dry to .5 inch.  If your snapdragons are regularly attacked by stem borers, consider spraying every week with Spinosad. 


Wildflowers and larkspur should have germinated by now.  There isn’t anything you need to do with the wildflowers, but the naturalized larkspurs produce showier blooms if they are thinned to 18 inches between plants.  The nurseries quite often have larkspur and bluebonnet transplants available in January.  Plant them in full sun.


Fruit trees also arrive at the nursery this month.  Visit to find which varieties are recommended.  The recommended varieties can cope with our weather, our soils, and the diseases and insects that are prevalent. 


            Plant trees, shrubs, perennials, and fruits in January to take advantage of cool weather for root development before the summer heat arrives. 


            The American goldfinches usually arrive for their winter vacation this month.  Observe their acrobatic feeding techniques by using thistle seed in tubular feeders with the roosts above the feeder holes.  Cardinals are attracted to sunflower seeds or safflower seeds.


            Make yourself some gardening resolutions for 2008.  Consider resolutions concerning reduced water use, recycling garden waste, introducing youngsters to gardening, planting a tree, and more careful use of pesticides.