Desert Blooms

Southwest Yard and Garden By Dr. Marisa Thompson   SEE HIGHLIGHTED SECTION BELOW FOR UPDATE FROM March 2024!   A broadleaf mistletoe infects a young ash tree in two different parts of the same canopy on Indian School Road in Albuquerque. The smaller sprout (right) is tiny, but the swollen branch is a likely sign that the infection is deeper than it looks and may be permeating throughout the entire trunk. Photo credits M. Thompson. Question: There’s mixed advice out there on how to control mistletoe. What do you recommend? -           Question submitted via Sandoval County Extension Agent Lynda Garvin Answer: For me, the control approach depends mainly on the kind of tree, how bad the infestation is, and if the mistletoe is reasonably reachable. In a nutshell: there are many species of mistletoe (over 1,500 worldwide) and, for the most part, each one is species-specific. That is, mistletoe on your juniper will never

Southwest Yard and Garden By Dr. Marisa Thompson This six-foot-tall cactus in a Las Cruces yard is likely to be a Sonoran saguaro ( Carnegiea gigantea ), even though it has grown remarkably fast. Photo credit Mike B. Question: Is this a saguaro in my front yard in Las Cruces? I’ve heard that saguaros do not grow well in this area. I planted it in 2012 and it is growing about 1 foot each year. It’s currently close to 6 feet tall.             -Mike B., Las Cruces Answer: Yes, probably, but maybe not. When we talk about saguaros in the Southwest, we’re referring to the Arizona saguaro ( Carnegiea gigantea ) of the Sonoran Desert. But there’s also an Argentine saguaro or cordon grande ( Trichocereus terscheckii , aka Echinopsis terscheckii ) that looks remarkably similar and is known to be one of the cold-hardiest columnar cacti in the world, rated at USDA cold hardiness zone 8 (average annual extreme low temperatures reaching 10–20°F). The Sonoran saguaro is rate

Southwest Yard and Garden By Dr. Marisa Thompson Cone galls on coyote willows just outside Abiquiu on December 1, 2019. Photo credits M. Thompson. Question: What are these beautiful, tiny cones on willow branches near Abiquiu?                                     -Malcolm S., Visiting New Mexico for Thanksgiving Holiday Answer: At first glance, I thought either these aren’t cones or these aren’t willow trees because willows don’t have cones like this, or buds like this either. Full disclosure, the question this week came from my cousin, Malcolm, and I was standing right there next to him. I had noticed the small, multi-trunked trees and assumed they were our native coyote willows ( Salix exigua ). But I hadn’t noticed that many of these small trees lining the dry streambed were covered in miniature cone structures. Had these “cones” been dangling and covered in leaf debris—like a shaggy grey-brown ornament—I would have thought they’re a form of bagworm. The

Southwest Yard and Garden by Dr. Marisa Thompson Reprint from December 2017 In most cases, a few inches of snow doesn’t mean we can skip a winter irrigation event entirely. Two cups of snow scooped up from the front yard at the NMSU Agricultural Science Center at Los Lunas on January 3rd melted down to a little over 1/3 cup of water. Photo credit M. Thompson. Question: I'm wondering what the frequency of winter watering should be and the best time of day or night to have the water come on? -           Rob M., Las Cruces, New Mexico Answer: It seems #itscomplicated is a hashtag I could use every week. Knowing how much water to apply in your landscape is hard enough in the summertime when demands are high, but it can be even more difficult to know the right amount of water needed when many plants are bare, and it can be easy to forget. Most plants need less water in colder months. This is partly because dormant plants are not actively growing. Lower temp

Southwest Yard & Garden By Dr. Marisa Thompson Dormant peach trees in February 2019 at the NMSU Agricultural Science Center at Los Lunas. Late frosts after budbreak nipped almost all of the blooms in these trees this year. Photo credit M. Thompson. Question: I’m trying to decide which fruit tree varieties will produce well in my yard, and many of them list a specific number of required chill hours. Where do I find out how many chill hours we get in Roswell? -           Question submitted via Chaves County Extension Agent Troy Thompson Answer: Many gardeners know that certain seeds need to be cold stratified before they can break dormancy and germinate. This makes sense on a survival level because seeds that drop at the end of the growing season might germinate and grow in the fall or winter and not stand a chance in the cold. Some seeds require other environmental triggers or a combination of factors to break dormancy, like a very specific moisture content within

Southwest Yard and Garden By Dr. Marisa Thompson & Dr. Carol Sutherland Reprint from November 2017 Mesquite girdler. (photo credit: Dr. Salvador Vitanza, previously with TexasAgriLife, El Paso, TX) Question: Our mesquite trees are experiencing what appears to be a girdler bug attack. This is the first time we have experienced this. How harmful are they, and what can be done to rid these pests? -           Jack D., Doña Ana County, NM Answer: In order to answer your question, I enlisted the help of NMSU Extension Horticulture Specialist and NM State Entomologist, Dr. Carol Sutherland. Here is her response: Yep. The culprit here is a type of long-horned beetle known as the “mesquite girdler” ( Oncideres rhodosticta ). Adults are about a half-inch long and are several shades of dark gray, with dots or patches of rusty brown, especially on