At the end of each year we enjoy looking back on the topics that were of the most interest. Despite another year of uncertainty, people were still interested in home improvement. Regardless of working or schooling at home, things around the house still need fixing, improving and updating.
This week we revisit the two most popular blogs from 2021.
No. 1: Plants
out of control
First appeared July 27, 2016
Be wary of Arizona plants that can take over your yard.
That sounds just like a tree called the Dalbergia sissoo, commonly known as sissoo or Indian rosewood. This is a tree that many homeowners plant because it's very lush and fast-growing.
Sissoos grow to a moderate height of 35 to 40 feet but their vigorous root systems can threaten underground irrigation lines, sidewalks, block walls and even lawns. The invasive roots can take over a yard after only a few years. Some homeowners complain about the many pods and leaves that drop off the tree, but its roots pose the biggest problem. Then when a decision is made to remove the tree, the real headaches begin.
“Although Dalbergia sissoo is not listed as an invasive species,” says John Eisenhower of Integrity SavATree in Phoenix, “it is considered by many horticulturists to be a nuisance tree because of its aggressive rooting and sprouting.”
Homeowners often call our radio program to ask how they can stop the sissoo roots and suckers from spreading in their yards. According to Eisenhower, most of the problems begin when homeowners decide they want to cut down a sissoo.
"Usually when you cut down a tree, it will be gone, but not a sissoo," he said. "After the tree is cut down, it doesn't just send up sprouts from the cut stump like other vigorous trees. It can send up shoots from every root that remains in the soil, creating an unwanted forest of trees, sometimes 100 feet from the stump."
If this happens to you, there are some steps you can take to control the roots and sprouts. According to Eisenhower, start by cutting down the tree and immediately applying a systemic herbicide into holes drilled into the outer sapwood ring on top of the stump.
This will kill the stump as well as roots several feet from the tree. Additional spot spraying of new shoots may be needed over the next several months to achieve full control of sprouting.
Eisenhower added that the chemicals needed for stump, root and sprout treatments are not available over the counter and need to be applied by a licensed applicator with the Arizona Office of Pest Management.
A good word
about sissoos
Despite the risk that aggressive rooting sissoos present, they remain a popular choice for homeowners and commercial properties. If sissoos have adequate room to grow where they don't encroach on surrounding landscape elements, they are beautiful and serviceable shade trees. In fact, in many respects, they are great evergreen trees, just often planted in the wrong place.
Macfadyena
unguis-cati
Another plant that can refuse to die is cat's claw (Macfadyena unguis-cati.) Homeowners often plant this drought-tolerant vine to cover up walls and fences. It's hardy, loves the sun and gets yellow trumpet-shaped flowers in the spring. It can reach 25 feet high and 25 feet wide.
But as I know from personal experience, once you plant it, you might have it forever. In fact, if you want to get rid of it to make it easier to paint your walls or a fence, you should use the same method of killing it as is recommended with the sissoo tree. It's not impossible to get rid of cat's claw. It just takes patience to treat the resprouting for several months after the initial application.
Oleander
Speaking of flowers, the oleander is another popular flowering shrub that has done really well in Arizona. Oleanders are often planted as hedges because they can reach 20 feet in height and be very wide as well — creating a great privacy screen. Sometimes they're even pruned into trees.
But Eisenhower recommends thinking twice about planting oleanders because many of them in the Phoenix area have been infected with bacterial leaf scorch (Xylella fastidiosa) spread by flying insects that feed on their leaves. The pathogen causes the leaves to turn yellow, dry up and drop off, and the entire plant usually dies within a few years.
"In central Phoenix, many neighborhoods have been decimated," he said. "And there's no known treatment available at this time to stop the disease."
If you're looking for a different plant to use as a hedge, try sour orange or Arizona rosewood. Other options include hopseed bush and yellow bells. These last two are more susceptible to frost, so they are not appropriate if you live in an especially cold area. If your oleanders are healthy, consider yourself fortunate. They are evergreen, provide a dense privacy barrier and achieve their landscape purpose quickly.
No. 2: Toughest
stuff to grow
A top 5 article in 2020, 2019 2018, 2017 & 2016. First appeared June 29, 2016.
Over the years we've found that there are several unique plants that many Arizona residents really yearn to have in their yards despite the fact that the odds of success are stacked against them. Again and again these gardeners call our "Rosie on the House" radio program asking if they can grow them or asking why they died.
Jay Harper of Harper's Nursery in Scottsdale, a regular expert on the gardening hour of our show, gave us his list of the six most popular finicky plants and explained why they generally fail to thrive in the Arizona desert.
Avocado trees
If you love guacamole, you may yearn to grow avocados. But these plants fail partly because it's too hot in the summer and too cold in the winter.
Azaleas
One of the most important problems for azaleas as well as for other plants on our list is the extreme alkalinity and saltiness of soil in Arizona.
Papaya, mango
and banana trees
Even though these trees are tropical and seem to love very warm places as are found in our state, they also love the shade. They can also get too cold in winters here and too hot in summer. “People say, ‘Well, they grow in Florida and it’s hot there,’” Harper said. “But it’s hot and humid in Florida, something like a greenhouse. Dehydration is one of the biggest enemies you have in Arizona for your plants.”
On the other hand, citrus does very well in Central Arizona and succeeds to some extent in the southern part of the state. So try an orange or a lemon instead.
Hostas
Hostas are shade-loving, leafy perennials very popular in the Midwest. They don’t require a lot of acid in the soil, but they don’t like strong sun. Long stretches of them are often used as borders or something like ground covers. They’re low maintenance and drought-tolerant. Gardeners in the desert say they grow well at first, but then their leaves curl up and the edges turn brown. You’ll see them sometimes in Prescott, Payson and Flagstaff, but not in Phoenix or Tucson.
Peonies
Some gardeners say peonies like a winter chill, but other people say these luxuriant flowering bushes do not need a heavy cold season. You do see them growing sometimes in Prescott, but they are finicky plants and generally prefer cooler climates. They seem to do pretty well in the northwest United States.
Hydrangeas
Hydrangeas are also fabulous blossoming bushes with immense flowers. They come from Asia and are particularly popular in China, Japan and Korea. The flowers can be white, blue or pink depending on the pH of soil. Those who cultivate them add aluminum sulfate to the soil to make them come out in different colors. But if you don’t live right on the ocean, you might struggle to grow them. That doesn’t mean it can’t be done.
Harper suggests that if you want to plant any shrub or tree in Arizona, you should do some research first and then drive around your neighborhood to see if that plant is growing nearby.
“If you see a lot of them, then you know that plant will do well in your yard, too," he said. "If you don’t see them, you might be taking a chance."
It’s not impossible to grow unusual plants, Harper says; recently someone who visits his nursery brought him a bouquet of hydrangeas.
“Whenever we tell people that they can’t plant one thing or another, someone will send me photographs of a great plant from their yard,” he said. “Some people live in special shady micro-climates, like Arcadia in Phoenix, where they still have flood irrigation. They can often grow things you can’t grow anywhere else in Phoenix.”
Join us next week when we cover the third and fourth most popular blogs of 2021.
