Showing posts from September, 2018

What Does Red or Green Really Mean? - Phytochemical Coloration

Southwest Yard & Garden by Dr. Marisa Thompson Question: What’s the difference between different colors on peppers? I’m getting red fruit and purple fruit on the same plant. -Mary S., Santa Fe, NM Answer: The diverse colors on peppers are indicators that they are rich in phytochemicals, whether they be sweet, hot, or sweet and hot. Three main classes of phytochemicals are responsible for these pretty pigments. Chlorophyll is commonly associated with greenness. Carotenoids are the phytochemicals causing the colors to get warmer as they turn from yellow to orange to red. And anthocyanins create those dynamic purple and blackish colors. The relative concentrations of these phytochemicals as they accumulate in the fruit tissue dictates the color. These pigment chemicals also affect the nutrient content and use as natural dyes. CORRECTION NOTE: In original printing of this column, pepper color was also linked to the spiciness of a pepper, but that is not true.  Originating in the Americas,…

Pine Sawyers: Don’t Let These Beetles Saw Down Your Tree

Southwest Yard & Garden by Dr. Marisa Thompson Question: One of my Austrian pines started turning brown at the top this spring, and as can be seen is now 3/4 brown. The trees are drip irrigated and were fertilized lightly for the first 20 years. Today, I found an inch-long bug on the bark. Could these bugs be pine sawyers and, if so, what’s the best approach to control them? -Richard C., Question Submitted via Bernalillo County Horticulture Extension Agent, Sara Moran Answer: Dr. Carol Sutherland, NMSU Extension Entomology Specialist and NMDA State Entomologist, provided a detailed response: “The pictured beetle is indeed the pine sawyer. That would be Coleoptera, Cerambycidae, Monochamus clamator. The beetle in the photo could have come from the trees on this property or elsewhere, too. They are all strong fliers and very alert to finding not only mates but also trees in distress. With drip irrigation, there are always questions about how good that system is for trees: Does it delive…

Livin' on the Sedge: Control of Weedy Nutsedges

Southwest Yard & Garden by Dr. Marisa Thompson Question: This nut grass is taking over my yard. Please help.
-Lori D., Las Cruces, NM Answer: Many of us are familiar with the late, great nutsedge invasion of our garden beds, lawns, fields, and orchards this time of year. NMSU Extension Weed Specialist, Dr. Leslie Beck, explains how to distinguish between sedges and grasses: Sedges look very similar to grasses, but they are in a completely different family (Cyperaceae vs. Poaceae). When you pull away the leaf blades of grass plants, the remaining central stalks (aka culms) are just compressed leaf sheaths. So, a cross-section of a grass culm is hollow. Sedges tend to have solid culms that are distinctly triangle-shaped. This can be easily observed by rolling the base of the stalk back and forth between your thumb and forefinger to see if it feels edgy, like a triangle. Hence the old adage “sedges have edges.”
Yellow nutsedge (Cyperus esculentus), also known as “chufa,” and purple nutse…

There’s an App for That: Identifying Plants with Tech Tools

Southwest Yard & Garden by Dr. Marisa Thompson
Question: What smartphone apps or other tools do you like for plant identification? -Several New Mexican Gardeners Answer: Plant identification is important and fun, but it can also be frustrating and potentially dangerous if done wrong. In the past year, I have downloaded—and subsequently deleted—multiple smartphone apps that were clumsy, slow, or yielded incorrect results. The one I find myself going back to again and again is called Pl@ntNet. According to the app’s credits tab, the Pl@ntNet project is run by a consortium of four French research “organisations” (CIRAD, INRA, INRIA, and IRD) with support from a French botany social network, TelaBotanica, and funded by the Agropolis Foundation. This image sharing and retrieval application for the identification of plants is free and available on both Apple and Android devices; it’s also offered online at The things I like best about this app are tha…

Ornamental Grasses for New Mexico Landscapes

Southwest Yard & Garden by Dr. Marisa Thompson Figure 1. Blue grama (Bouteloua gracilis), the state grass of New Mexico, photographed in November 2017 near Carson National Forest (photo credit M. Thompson).

Question: Do you have recommendations for native grass species for residential landscapes and how to care for them? -Otero County Extension Master Gardeners Answer: Bigger ornamental grasses provide beautiful backdrops, hedgerows, and screens in our landscapes. Smaller species help fill in between broadleaf plants and make great garden borders. Both big and small grasses provide texture, contrast, and grace, all with minimal maintenance and zero fertilizer. In winter, when many of our ornamental plants have shed their leaves, grasses can be delightful, even though they’re dormant and brown. When selecting native grasses for your garden, pay attention to plant height, space needed, and cold hardiness that matches your growing zone. To get you started, here are a few of my faves, or…