Fall Garden Dos and Don’ts

By: Ann KissingerDon’t cut back your garden. Wait! Horticulturist and SFMGA instructor David Salman teaches “in your flower beds and landscape plantings, let the perennials and ornamental grasses stand over the winter.” The dormant plants add beauty to the winter garden and also provide habitat to butterflies, moths, and other beneficial insects. Leave seed heads to feed the birds, or come to our SFMGA Seed Weekend in November and learn how to harvest the seeds.Don’t prune shrubs and trees now. Wait until late winter to early spring to prune most woody plants (some, like lilacs, should be pruned later in the spring, after blooming).Don’t plant spring-blooming bulbs until cold nights have brought soil temperatures down to 40 to 50 degrees; in Santa Fe that is generally not before late October or early November. While you do want to give bulbs six weeks or so to root out before the ground freezes, if they are planted too early, warmer temperatures could encourage them to sprout prematurely, which could result in winter damage. If possible, plant tulips, daffodils, and grape hyacinths near drip lines.Do plant perennials, ornamental grasses, shrubs, trees, and evergreens now, beforelate October, to give them time to root. Water deeply twice weekly through the month, or until the ground freezes. Then, if there is no snow or rain and daytime temperatures are over 45 degrees, water once every three weeks.Do remove and dispose of weeds and diseased plants. It is conservative to remove disease-prone tomato, cucumber, and squash plants.Do plant a cover crop in your vegetable garden soon, ideally a month before the first killing frost.Do feed the soil. Anytime from now through late fall, top dress and scratch in organic compost into your raised beds and flower beds. SFMGA instructors Davis Salman and Jeannine Cabossel recommend supplementing your compost with organic amendments, such as slow-release fertilizer/soil food Yum Yum Mix, which feeds the microbes, fungi, and earthworms that help keep your plants healthy. (Don’t use any fertilizer with readily available nitrogen, which would cause unnatural growth just as plants are getting ready to go dormant.)Do mulch. For xeric plants and many natives, Salman recommends one to two inches of pine needles, crushed pecan shells, or crushed gravel. For plants that like more moisture and richer soils, including fruit trees, flowering shrubs, and evergreens, he recommends one to two inches of composted bark, shredded wood, or composted cotton burs. For your vegetable beds use clean straw.Do winterize your drip line and sprinkler system in late October or early November. Shut off the main water supply to the system and drain the system. Drain the back-flow preventer. Open all manual drain valves in the irrigation system. Open all manual valve automatic bleed screws. Turn irrigation controller off. The City of Santa Fe Sustainability Office recommends you have a licensed contractor perform the “blow-out” method.Do turn water supply to exterior faucets off on the inside, if possible, and drain the line by opening the faucet. To minimize risk of freeze damage, if there is no inside valve, use foam insulated covers on your faucets. Disconnect and drain hoses.References:Cabossel, Jannine. Remineralization for Better Vegetable Gardens, giantveggiegardener blogCity of Santa Fe, Winterize Irrigation SystemsSalman, David. Fall Gardening To-Do List, Waterwise Gardening blog