Garden Checklist for June 2013

Dr. William C. Welch, Professor & Landscape Horticulturist
Texas A&M AgriLife Extension
    Self-sown zinnias
    Self-sown zinnias
  • Supplemental irrigation is essential for all but the hardiest plants in times of extended drought. Water lawn and garden thoroughly, but not too frequently. As a general rule, soak to a depth of 8 inches. Finish watering by early afternoon, to lessen the chance of disease.
  • Check watermelons for ripeness regularly. They are usually ready when the bottom portion is definitely yellow green or even yellow in color.
  • Take a critical look at your landscape while at the height of summer development. Make notes of how you think it can be better arranged, plants that need replacement, overgrown plants that need to be removed, and possible activity areas that can be enjoyed by family members.
  • Check for insects and diseases. Destroy badly infested plants. Spider mites can be especially troublesome at this time. Select a chemical or organic control, or use insecticidal soap.
  • Especially during dry summers, soil moisture becomes extremely important and essential for good plant production. Because continual watering is oftentimes costly and time consuming, it pays to conserve the moisture around plants. This is best done by mulching. A good mulch will retain valuable moisture needed for plant growth, and improve overall gardening success. Mulches are usually applied 2 to 6 inches deep, depending on the material used. In general, the coarser the material, the deeper the mulch. For example, a 2-inch layer of cottonseed hulls will have about the same mulching effect as 6 inches of oat straw or 4 inches of coastal Bermuda hay.
  • There is still time to plant some of the colorful, heat-tolerant summer annuals. Direct-seed zinnias and portulaca, and purchase plants of periwinkle, salvia, marigold, and purslane. Be sure to water transplants as needed until roots become established.
  • Removing faded flowers from plants before they set seed will keep them growing and producing flowers. A light application of fertilizer every 4 to 6 weeks will also be helpful.
  • House plants can be moved out of doors this month. Sink the pots in a cool, shaded garden bed to prevent them from drying out so quickly; water pots, container plants, and hanging baskets often. Monthly feedings with house plant fertilizer will encourage continued growth.
  • Now is the time to plan for next spring. Consider digging and dividing any crowded spring bulbs. Once the bulbs have matured and the foliage has turned brown, it is time to spade them up and thin out the stand. Crowded bulbs produce fewer and smaller blooms. They usually need thinning every 3 to 4 years.
  • June is the time to select daylily varieties as they reach their peak of bloom.
  • Fertilize roses every 4 to 6 weeks. Apply a high-nitrogen fertilizer immediately after a flush of bloom.
  • Continue to spray susceptible roses with a black-spot control such a Funginex every 7 to 10 days.
  • Re-blooming salvias, such as Salvia greggii and S. farinacea, should be pruned back periodically during the summer. To make the job easier, use hedging shears, and remove only the spent flowers and a few inches of stem below. Fall-blooming perennials, such as Mexican marigold mint (Tagetes lucida), chrysanthemums, physostegia, and Salvia leucantha, should be pruned in the same manner during the summer to keep them compact, reducing the need for staking. This type of pruning should be completed prior to September 1, since flower buds begin forming about that time.

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