Desert Blooms

Southwest Yard & Garden by Dr. Marisa Thompson Tulips and daffodils offer tons of color with remarkably low water requirements. This year at the NMSU Agricultural Science Center at Los Lunas we’ll also be sampling bulb blossoms for presence of beneficial insects. Stay tuned! Photo credits M. Thompson. Reprints from years past. Written by Dr. Curtis Smith, retired NMSU Extension Horticulture Specialist, with additions by Dr. Marisa Thompson.  Question from 1997: What does it mean when they say our soil is calcareous? Answer: The term calcareous refers to the abundance of calcium, or lime, in our soil. This is due to the fact that our dry environment has not resulted in the leaching of calcium and other salts from our soils. Some of these salts, such as sodium, can be toxic to plants at the level found in some New Mexico soils. Calcium, however, is not toxic, but it does alter the pH, or acidity, of the soil, making it difficult for some plants to obtain the nutrient

Southwest Yard & Garden by Dr. Marisa Thompson with guest contributor Dr. Leslie Beck Silverleaf nightshade flowers are beautiful, but these weeds are invasive and parts of the plant are toxic to humans and animals. Photo from NMSU Extension Guide “Silverleaf Nightshade” W-15 . Yellow nutsedge seedhead (photo credit L. Beck). Question : Silverleaf nightshade and nutsedge are taking over parts of my yard! Please help. Organic control options are appreciated. -           Helen B., Las Cruces, NM     Answer : Last week I asked NMSU Extension Weed Specialist, Dr. Leslie Beck, to explain why annual weeds like sandburs and goatheads are so difficult to control and to give us options for managing them without the use of pesticides. Visit  https://nmsudesertblooms.blogspot.com/2019/02/the-early-bird-catches-weed-control-of.html to read that column. The two weeds for this week, silverleaf nightshade ( Solanum elaeagnifolium ) and nutsedge ( Cyperus esculentus a

Southwest Yard & Garden by Dr. Marisa Thompson with guest contributor Dr. Leslie Beck Controlling Annual Weeds: Timing is Everything with Goatheads and Sandburs Both are annual weeds with vengeful, spiny seeds, but sandbur (top) is a grass and goatheads (bottom) are a flowering, broadleaf species. Photos from  https://weeds.nmsu.edu/ . Question : Can you help me battle my weeds organically? I’ve got sandspurs and goatheads. Are there soil conditions weeds hate? -         Helen B., Las Cruces, NM   Answer : Ouchie, that’s a nasty duo of weedy enemies. Most readers can commiserate all too well. Sandbur is a grass of the Cenchrus genus, also commonly referred to as “stickers” or “sandspurs.” Goatheads ( Tribulus terrestris ), also known as “puncturevine,” have tiny yellow flowers; delicate, compound leaves; and spiny seeds that are even meaner and tougher than sandburs. Many people mistakenly call sandburs “goatheads,” and I understand why. Both have spi

Red arrow is pointing to a porcupine munching on tree bark way up in the canopy of a cottonwood at the Albuquerque Botanical Garden in January 2018. Photo credit M. Thompson. Southwest Yard & Garden by Dr. Marisa Thompson   Question : The Texas red oak, live oak, and pecan trees in my yard were looking bad going into the fall, as were my neighbor’s honey locust and maple. When I searched for problems online, I found different possible pests and diseases for each tree. Can you help me narrow down the possibilities? -           Richard V., Hobbs, NM Answer : This is Part II of the column on diagnosing tree problems.  Last week, we learned that water stress and weed whacker injury are the most common tree problems in our landscapes and that the rooting area necessary for large trees to survive and grow is much bigger than most folks realize.  **click here for Part I** We also touched on the reasons why symptoms are rarely sufficient for conclusive diagnosis of a