Desert Blooms

Southwest Yard & Garden by Dr. Marisa Thompson Compost Spent Coffee Grounds Before Using Them on Your Soil The pH of my morning cup of coffee (not the grounds) while still black (left) and after adding cream and honey (center), and plain filtered tap water (right). Photo credits M. Thompson.   Question: Can I discard spent coffee grounds in my houseplant pots?                                    -        T. Dominguez, Santa Fe   Answer: Sure you can, but I can't exactly recommend it. Putting the grounds directly on houseplant soil might not pose a problem, but it’s hard to be sure. Research on the composition and chemistry of coffee grounds has shown wide variability. Some of this variability stems from differences between species in the Coffea genus grown for commercial production...

  Southwest Yard & Garden by Dr. Marisa Thompson, with the help of Dr. Carol Sutherland! Dwarf umbrella tree (Schefflera arboricola) looks great from afar, but on closer inspection, mealybugs are an issue. Photo credit Tyra Trumble. Question: Can I put peroxide in the soil to kill the mealybugs on our schefflera?                                            -Tyra T., Los Lunas Answer: I don’t recommend it. While hydrogen peroxide is not likely to kill your huge houseplant, it’s not going to kill your mealybugs either. Full disclosure to readers: I worked with Tyra over the summer, and we’ve been discussing ways to handle these mealybugs since she discovered them on her mom’s 12-foot-tall, 20-year-old dwarf umbrella tree ( Schefflera arboricola ) in May. At first Tyra rep...

Southwest Yard & Garden  by Dr. Marisa Thompson Why Frost Damages Some Plants and Not Others Partial reprint from October 2019 This lettuce’s peppery flavor offers a clue as to how the leaves made it through 5.5 inches of snow this week without blinking an eye while other plants turned to mush. Photo credit M. Thompson. We harvested and weighed over 1,100 lb of unripe tomatoes from frost-bitten plants in October 2019 at the NMSU Agricultural Science Center at Los Lunas. Photo credit M. Thompson.   Question: Why did some plants in my garden handle the first freeze just fine, and others died back completely? -           Jane P., Albuquerque Answer: Last year I was in Las Cruces when we got our first two freezes in Los Lunas. Luckily, my poor houseplants on the patio didn’t freeze hard enough—or for long enough—to cause permanent damage. I believe my grandmother would u...

  Southwest Yard & Garden by Dr. Marisa Thompson Reprinted/updated column from October 2018 Happy tomato plants getting ready for planting in the field at the NMSU Los Lunas Agricultural Science Center in May 2018. Photo and enhanced emoji credit M. Thompson. Question: What should I do with all of these green tomatoes? Answer: I first answered this question way back in 2018. And here we are again, with first frosts snapping across the state and gardeners sharing photos of final harvests, many with green tomatoes piled high. The same questions keep coming up: What’s the best way to ripen them, and then what can be done with them? If you’re a seed saver, you may want the fruits to ripen to maturity. The difference between a fruit being mature and one that’s ripe is that “maturity” refers to seed viability and “ripeness” is the most favorable state for consumption or use. Ripeness, then, is partly dependent on personal taste and the intended market. Many fruits, like grapes...

  Southwest Yard & Garden by Dr. Marisa Thompson This purple fountain grass is thriving after a single growing season, but it may not be cold hardy enough to stay alive through the winter. Photo credit Les Bender. Question: We have a lovely purple fountain grass (planted in the spring), and I keep hearing that it will die in the winter and we would have to plant a new one each year. Others say to dig it up, pot it, cut it back, put it in the house near a window, and replant it in spring. Another view is it will be fine in winter; just cut it back in spring and it will flourish! So we are confused. I also considered purchasing a small pop-up greenhouse and putting it around the plant to fight off frost and also allow it to get sun. Any help you could give would be most appreciated.                                    -           L...

Southwest Yard & Garden by Dr. Marisa Thompson,  with Sage Advice from Mora County Extension Agent Suzanne Cole Like many herbs, basil responds well to being cut back frequently (aka “herb cutting”). Photo credit M. Thompson. Our most recent NMSU gardening webinar for the “ Ready, Set, GROW! ” series was on herb gardening in New Mexico. Extension Agents Suzanne Cole of Mora County and John Garlisch of Bernalillo County gave informative presentations that covered distinctions between herbaceous versus woody herbs, growing them both indoors and out, and tips on how to preserve and use them in your kitchen. We received great questions from several of the over 80 attendees. For this week’s column, I’ve selected just a few of the questions and answers that I found interesting. Question: I have heavy clay in my garden, and amending the soil doesn't seem to help. What can you recommend? Answer: Poor drainage is a problem for lots of plants, and herbs are no exception. Clay soi...