Monthly Gardening Tips

May 2019


  • Water lawns, gardens, trees and shrubs twice a week.
  • Water annuals and perennials in containers two or three times week, depending on pot size and temperatures.
  • Adjust timers on your automatic sprinkler systems.
  • Remember to water more frequently as the weather warms up.


  • Apply a good fertilizer to established trees, shrubs and ornamental grasses if you have not done so.
  • Fertilize cool-season lawns such as bluegrass or park blend. Do not fertilize in temperatures over 85 degrees.
  • Fertilize warm-season lawns such as buffalo, bermuda and gramma with a good fertilizer for warm season lawns.
  • Continue to fertilize houseplants with a good water-soluble fertilizer. Be sure not to over-fertilize or over-water houseplants and never fertilize a sick plant.
  • Continue improving your garden soil by tilling in some organic material such as compost.
  • Continue to fertilize established roses with a good rose food.
  • Fertilize annual container gardens with a high phosphorus blooming formula weekly for more frequent blooming.
  • Fertilize your vegetables with a good organic vegetable food.

Yard and Garden

  • Plant shade trees such as ash, elm, sycamores and cottonwoods for cooling shade in the hot summer.
  • Plant ornamental trees such as flowering plums, flowering plums and crabapples for their gorgeous flowers in spring.
  • Plant fruit trees such as apples, cherries, pears, plums, apricots and pomegranate for delicious fruit for years to come. Thin young fruit out so that fruits will have room to grow to a good fruit size.
  • Plant flowering annuals and perennials in your garden for wonderful flowering all summer.
  • Plant up or refresh your containers with annuals, perennials or small shrubs. Remember the saying, “Thriller, filler and spiller.”
  • Plant native trees, shrubs and perennials for beautiful low water xeric landscape.
  • Plant ornamental grasses for a spectacular showing in the fall.
  • Plant your summer bulbs such as dahlia, canna, gladiolus and lilies.
  • Plant roses for their sheer beauty.
  • Now is the perfect time to lay cool or warm season sod or seed a new lawn. Mow weekly.
  • Annual flowers such as sunflowers, cosmos, zinnias or morning glories can be directly sown in the garden. You can also seed perennial wildflower mixes.
  • Continue to remove spent flower blossoms from roses and flowering plants to promote repeat flowering.
  • Refresh mulches as necessary to conserve moisture.

Insects And Diseases

  • Continue to clean your garden area by removing all debris to prevent unwanted over-wintering pests, but watch out for cocoons that may be harboring a butterfly! Refresh with a fresh layer of cypress, cedar or pecan mulch to conserve moisture.
  • Keep an eye out for aphids, spider mites and other insects. Eliminate as needed.
  • Use BT to prevent damage on your plants from budworms in geraniums and petunias blossoms and tomato horn worm on tomato plants.
  • Bring in samples of insects or damaged plants to our pharmacy in plastic baggies for solutions to the problem areas.
  • Inspect roses and other foliage for powdery mildew and other diseases. Treat as needed.
  • Apply chelated iron or soil acidifier with iron to chlorosis prone trees and shrubs, chitalpa, maples, aspens, willows, euonymus and photinia.
  • Apply a systemic insecticide to trees and shrubs for yearlong protection from insects.
  • Kill early weeds with a good weed killer.
  • Apply pre-emergent to prevent seed germination, if you have not already done so.


  • Continue to plant warm-season vegetables such as tomatoes, green chili, bell peppers, eggplant, beans, cucumbers, squash and melons.
  • Continue to improve soils in vegetable beds by adding BTE compost or home compost.
  • Continue planting vegetable and herb seeds for the upcoming summer season!
  • Plant onion sets, strawberries, rhubarb and asparagus.
  • Plant herbs such as basil, rosemary, and tarragon.
  • Continue to plant vegetables in successive planting so that you have continuous harvesting throughout the growing season.
  • Plant okra later in the month as they do better in warmer soil.


  • Start a new compost bin.
  • Attend Osuna University! We’ll see you on Saturdays!