Do cicadas harm plants?

The incessant mating call of male cicadas is nature’s summer theme song. Once mated, the female cicada makes small slits toward the tip of pencil-sized branches (usually mesquite trees) into which she lays her eggs. After approximately six weeks, the eggs hatch and the young cicadas, or nymphs, drop from the branches and burrow underground, where they feed on plant roots until they surface a few years later. The emergent nymphs crawl up a tree or other stationary structure, shed their skin for the last time and continue the cycle. Contrary to suburban legend, adult cicadas do feed on plant juices. Although this may sound like a lot of feeding damage, cicadas are not serious threats to plant health and are even considered beneficial because they help limit the growth of mesquite trees. No treatment is recommended; just sit back and enjoy the music.

Can I plant the living basil I bought at the grocery store in my garden?

Believed to have originated in Central Africa and Southeast Asia, basil thrives in hot, dry and sunny conditions, so the plant you purchased at the grocery store should be fine outdoors. It will have a better chance of success, though, if given an opportunity to ease into its new environment first. Before moving the plant from the relatively dark and climate-controlled kitchen to the hot, bright landscape, place it in a sunny window for a day or two. Then transition it to a shady location outdoors for another day or two before planting into full sun in the garden. Because soil dries more quickly outdoors, be sure to check the ground’s moisture every day and water when it is almost dry. But remember, too much water is as deadly as too little water. Overwatering basil creates an environment favorable to root rot that can kill the plant.

A branch broke off of our eucalyptus tree during a wind storm. Luckily no one was hurt, but I’m worried that other limbs may fall in future storms. The tree provides wonderful shade, and I don’t want to remove it if we don’t have to. What do you suggest?

The tree should be evaluated by an arborist certified by the International Society for Arboriculture to assess the potential hazard it poses to human safety and property. Together, you and the arborist can discuss your options, which may include corrective pruning or removal. Since you value the shade the tree offers, factor into your decision the increased energy costs to cool your home for several summers, until a replacement tree is large enough to provide adequate shade, if it is removed. Visit treesaregood.org/findanarborist to search for a certified arborist in your area.

The man who pruned our Mexican fan palms wore spikes on his shoes, which allowed him to climb the trees to reach the fronds. Now there are ugly gashes along the trunks. How long will it take for the wounds to heal?

The spikes the tree worker wore to climb your palms are called “gaffs.” They give the climber traction. The good news is that palms do not produce bark or form annual growth rings, therefore the gaff wounds will not interfere with the tree’s growth or ability to absorb water and nutrients. However, the wounds may provide an entry point for pests and disease, and they will continue to be visible indefinitely. In the future, consider hiring a certified arborist to prune your palms, and request that he or she use an aerial work platform, sometimes called a “cherry picker,” to safely access the fronds that need to be removed.

When I cut into an apple I recently purchased from the grocery store, I discovered the seeds had started sprouting inside the fruit. Can I plant the seedlings in my garden?

Seeds may germinate while still inside fruit that was harvested after it was already overripe. It can’t hurt to try and nurture the seedlings as a fun experiment, but the odds are against them ever maturing into fruit-bearing trees. Your seedlings are unique genetic individuals and are not likely to bear the same characteristics as the mother tree that produced them. Furthermore, most grocery store apples sold in Arizona come from Washington and are adapted to different soil and climate.

I was told that you shouldn’t put meat into the compost, but my neighbor insists it’s OK. In fact, she puts all her kitchen waste into her pile. Who is correct?

Technically, all organic matter, including animal products, is decomposed by soil microorganisms and therefore compostable. When meat rots, it is being decomposed by microorganisms that produce a terrible smell as a byproduct. Flies are attracted to decaying meat and will lay their eggs on it, which will then hatch into maggots. Most of us are not willing to endure the stench of rotting meat and millions of flies in our gardens. To learn more about backyard composting, download “Small Scale Composting in the Low Desert of Arizona” at extension.arizona.edu.

How can we make our garden attractive to native bees?

The Arizona-Sonora Desert Museum (desertmuseum.org) estimates there are up to 1,000 species of bees in the Sonoran Desert. Most are solitary bees, meaning they do not live in large, social hives, as do honeybees (Apis mellifera). To be a gracious host to as many native bees as possible, offer a wide variety of flora, especially plants that provide pollen and/or nectar, such as desert milkweed, desert lavender, brittle bush, globemallow and desert spoon. Bees also appreciate fresh water, so add a bird bath or other shallow water source. Finally, offer solitary bees a place to call home by building or buying a bee house. This can be something as simple as a block of wood with 2- to 10-millimeter holes drilled into it or a decorative wood-and-bamboo nesting structure that can be purchased at most garden centers.

Our roses have white, powdery spots on the leaves. Could this be a disease? If so, how is it treated?

Your roses may have a fungal disease called powdery mildew, which usually starts as small white spots on the leaves and eventually spreads to the entire leaf and on to stems and flowers. Development of the malady is most common when nights are cool and days are warm and humid. The problem is made worse by crowded plantings that restrict airflow and shade roses and other susceptible plants, such as cantaloupe or penstemon. Preventative practices early in the season that promote airflow and light penetration are more effective than treatment once symptoms have appeared. You can apply foliar fungicides specifically labeled for treating powdery mildew in roses, but avoid using them when temperatures are above 90 degrees, as the product may damage foliage.

Why did our mesquite tree fall over? It looked so healthy and was growing so quickly. What could have happened?

Despite the fact that mesquites survive some of the hottest, driest environments Arizona has to offer, they are not particularly thrifty when given lots of water. When grown in irrigated landscapes, such as lawns, mesquites can get very large, very quickly. Wild, native examples of this tree without supplemental irrigation may never exceed 12 feet in height or spread after 25 years, whereas an excessively irrigated mesquite in a residential landscape may reach that size in just three years. As a result of the rapid growth, the tree’s wood tends to be soft and prone to splitting and failure. When young mesquites are pruned to remove lower branches, the canopy can act like an umbrella, catching strong winds and uprooting the entire plant.