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

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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

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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

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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 https://identify.plantnet-project.org/. The things I like best about this app are tha…

Ornamental Grasses for New Mexico Landscapes

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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…

Short Answers to Pressing Questions: Rotting Fruit, Summer Pruning, and Squash Bugs

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Southwest Yard & Garden by Dr. Marisa Thompson This week, when trying to select a question for the column, I looked through the 22-year archive for this gardening column online (http://aces.nmsu.edu/ces/yard/archives/) to find issues that pop up again and again at this time of year. I selected these three columns written in 1996, 1997, and 2000 by my predecessor, Dr. Curtis Smith, retired NMSU Extension Horticulture Specialist.
Question: My watermelon crop had at least a dozen blooms and good-sized melons, but then died due to "brown rot" on the bottom of each melon (not the part that touches the ground, but the end of the fruit). What is causing this and what can we do to prevent the remaining melons from dying before they are fully mature? Answer: You have described the symptoms of blossom end rot. This malady can affect watermelons as well as cucumbers, tomatoes, chiles, squash, and many other fruits produced in the garden. Blossom end rot is due to a calcium deficiency…

Pomegranates Are Bursting Open Too Early

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Southwest Yard & Garden by Dr. Marisa Thompson Question: I have a pomegranate bush, which produced about 30 pomegranates last year. Initially, the pomegranates seemed to be very healthy. However, as the season progressed, prior to ripening, they all began to split open. This year's crop has already started doing the same thing. Is there anything that I can do to prevent all of them from following suit? If not, perhaps you can suggest something that I can do for next season.  -V. Gonzales, Socorro, NM Answer: My first thought was that splitting is a good sign. My dad knew his pomegranates were ripe when they split. He took great pains to grab the newly split fruit before the ants found them. One year, he even rigged a hammock over the driveway to catch ripe fruit that fell while he was at work because the split ones would explode when they hit the ground. Splitting before the fruit ripen is a real problem, though. Over the past year, I’ve gotten this same question from gardeners i…

Grafting Vegetables Isn’t Effortless, but Could be Advantageous

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Southwest Yard & Garden by Dr. Marisa Thompson Question: Other than the novelty, why would a gardener be interested in grafting vegetable plants? -Yours Truly, Los Lunas, NM Answer: I’ve been hearing more and more about vegetable grafting for commercial production and wanted to know more, so I posed this week’s question myself. Grafting, in general, is a common method for propagating plants by carefully joining cut plant parts so they grow together as one plant. Many plants can be propagated from seed or from cuttings that put out new roots. Others—like apples—don’t “grow true’” from seed or root easily from cuttings and must be grafted. Every apple you’ve ever eaten is from a grafted apple tree (unless you’ve eaten crabapples) where a small branch cut from a desirable apple tree was then grafted onto the trunk of an apple variety with desirable roots. “Desirable” means different things depending on if you’re talking about the top portion (scion) of the grafted plant or the bottom (root…

Pick Figs Now, Propagate Cuttings Later

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Southwest Yard & Garden by Dr. Marisa Thompson
Question: What is the best time of year to grow fig trees from cuttings?
-Rod B., Rio Rancho, NM Answer: The short answer: not now. Fig trees (Ficus carica) are one of the relatively few species that propagate easier from hardwood cuttings than softwood. Hardwood just means dormant, older growth. Softwood, by comparison, is the soft, usually green, new season growth. So, the best time to harvest the wood for fig propagation is in the wintertime (January–February). A greater number of woody species are propagated using softwood cuttings, including ginkgo, lilac, redbud, sumac, and wisteria. Others still can be propagated by either method, but there are different tricks for each. I asked Dr. Margaret Pooler, a researcher and woody plant breeder with the USDA U.S. National Arboretum (http://usna.usda.gov), to explain differences between propagation methods for woody plant cuttings. She said that they usually use softwood or semi-hardwood cutti…