GV Gardeners: Gardening guidelines for Southern Arizonans

This blooming Trichocereus Cactus originally was a piece broken off by the wind one year ago. After the bruised end healed, it was planted and recently produced flowers at The Arid Garden.

Understanding what makes a desert landscape work often seems like an unsolved mystery, especially to newcomers. Gardening is not an exact science with concrete rules; however, the following may act as guidelines to achieving more success.

Q: Recent winds broke off one of my tall cactus which I then threw away. If it happens again, is there a way to salvage the broken piece?

A: If the broken piece was damaged at the point of the break, cut away any bruised flesh. Mark the south side of the piece so it can later be planted facing the same direction. Then set the broken piece to the side, perhaps under a shrub out of the sun until it heals, or calluses over. Within a week or so, a scab will form on the end. It is then ready to plant, either in a container or the ground, just as you would a new cactus. Place healed side down in a hole only deep enough so it can stand on its own. Water thoroughly at planting and then once a month during growing season.

Q: How do I make a natural soap spray to combat insects in my garden?

A: Mix a solution of one tablespoon of dishwashing liquid such as Dawn to one gallon of water. Pour into a clean spray bottle, and be sure to spray both sides of the leaves.

Q: The leaves on my orange tree are “curling.” Do I have a problem?

A: Citrus trees have high water requirements. Leaf curling is often a sign of insufficient water. You may try increasing the area and depth of watering. Three drip emitters are suggested per tree. If you are watering into a surrounding basin, extend it to the drip line, or beneath the outer branches. Enlarge the basin as your tree grows, ensuring that the soil is wet to a depth of 2 to 3 feet.

Q: How frequently should I water my patio plants in containers?

A: Twice-daily watering of potted plants is a must during a desert summer like we have been experiencing. If you are watering by hand or by drip irrigation, early morning and again in early afternoon is recommended. A moisture meter, available at most garden centers, is a good tool to make sure enough water is being applied.

Q: A neighbor tells me that I should put Epsom Salts on my roses to prevent leaves from yellowing. How much and how often should I apply it?

A: Magnesium deficiency is indicated when mature leaves are smaller than usual and begin to turn yellow. To correct this condition, add ¼ cup of dry Epsom Salts (Magnesium sulfate) around each plant two to three times yearly, being sure to water in well.

Q: Can you recommend scented plants for my patio to sweeten the air?

A: Few can ignore the sweetness of chocolate, so Chocolate Flower (Berlandiera lyrata) is a good choice. Another option is Mexican Oregano (Poliomintha Maderensis). Both are low maintenance and produce dense flowers throughout the hot summer.

Mary Kidnocker is a University of Arizona Master Gardener who lives in the Green Valley area. Her articles are featured weekly.