Desert Blooms

Southwest Yard & Garden by Dr. Marisa Thompson   Peaches harvested from a four-year old ‘Elberta’ peach tree in Las Cruces (photo credit: M. Thompson).   Question: I suspect that my peach tree died of borers a few years ago because when I took it out I found lesions way down low on the trunk, partially buried. I am finally ready to plant a tree and would like to plant a peach, but is it okay to plant in the same spot? -         Wayne B., Los Lunas, NM              Answer: The greater peach tree borer ( Synanthedon exitiosa ) is known for causing oozing trunk wounds found at ground level or just below the soil line on stone fruit trees. The sap is often clear, but sawdust frass produced by the borer can be mixed in, giving it a darker color. Stone fruits are named for the pit, or “stone,” that encloses the seed; they include peaches, nectarines, plums, cherries, almonds, and others. I’m focusing this column on the greater peach tree borer, but peach trees ar

Southwest Yard & Garden by Dr. Marisa Thompson Figure  1 . Damage from improper staking (photo credit Andrew Koeser, International Society of Arboriculture, Bugwood.org) Question: Should I stake the new trees I plant this spring? I heard staking can be bad, but we have a very windy yard. -         Matt C., Clovis, NM                        Answer: You heard right. Staking trees can be bad. You are also right that the spring winds in New Mexico can be extremely strong. The Albuquerque National Weather Service tweeted the high wind reports from March 18, with Curry County in the lead for highest wind speed on that day at 73 mph at Cannon AFB ( @NWSAlbuquerque ). Sustained winds of 74 mph define the lower speed limit for a category 1 hurricane. #nmtrue Staking a newly planted tree may seem like a kind thing to do for a new friend. The reality is that staked trees tend to generate weaker roots after planting, compared with un-staked trees. Trunk movement, like that

Southwest Yard & Garden by Dr. Marisa Thompson   Figure 1. Forsythia in full bloom in 2015 (photo credit M. Renew). Question: I will prune my roses soon, but I’m confused about when is the best time to prune and what are the possible problems if I prune too early or too late? -         Elizabeth T., Ruidoso, NM              Answer: This is a great question, and the full answer includes all kinds of cool rose physiology information that could make a riveting book (nobody steal my idea, please). Unlike many other landscape species, many roses do not go dormant. Dormancy can be defined as a physiological condition in which growth is halted until internal switches are triggered, even if environmental conditions are otherwise perfect for growth. That is why roses may green up and start to grow in January with only a few days of warm temperatures. This is also why pruning too early in the winter can cause more harm than good. I heard that the proper time to pru

Southwest Yard & Garden by Dr. Marisa Thompson   Figure 1 . Afghan pine ( Pinus eldarica ) at the NMSU Agricultural Science Center at Los Lunas (photo credit M. Thompson). Question: When and how should I fertilize the piñon and other pine trees in my landscape? -         Silver City Resident via Grant County Extension Agent, Jessica Swapp                     Answer: Generally, native plants (including piñon, ponderosa, and some other pines) do not need fertilizer in our soils, especially if they have a nice fibrous mulch layer protecting the roots (more on that later). Appropriate irrigation is the best “fertilizer” for them. Several experts I reached out to said that oftentimes plant water stress is incorrectly diagnosed as nutrient stress. If you rarely or never watered your native trees in the past, start irrigating this season! By lowering water stress, you also reduce many pest and disease pressures. Native or nonnative, all trees deserve deep irrigation

Southwest Yard & Garden by Dr. Marisa Thompson     Kindergartener enjoys an apple during a field trip to the Los Lunas Agricultural Science Center (M. Thompson). Question: What am I doing wrong with my apple trees? I have two apple trees in my back yard that I planted a few years ago. They flowered each spring, but only produced a couple fruit per tree. -         Sandra L., Las Cruces, NM             Answer: Fruit production can be very tricky in New Mexico, so you are not alone in feeling like you’re doing something wrong. In fact, there is an NMSU Extension publication entitled “Why Fruit Trees Fail to Bear” ( http://aces.nmsu.edu/pubs/_h/H308/welcome.html ). Let’s click through the ways to encourage better apple yields from your trees, starting with flower pollination. For most apple cultivars (varieties), flowers need to be cross-pollinated with pollen from another apple cultivar in order to have good-quality fruit and good quantity, too. Even pollen f