Garden Success with Stephen Brueggerhoff

This month’s Ask the Plant Doctor segment brings host Stephen Brueggerhoff together with Hannah Ayala from the Texas Plant Disease Diagnostic Lab for a season-spanning tour of what’s landing on her bench — canker pathogens on roses and conifers, drought-driven root stress masquerading as disease, and viral infections turning up in watermelon and tomato. Hannah walks through proper sample submission (fresh tissue in a dry Ziploc bag, shipped early in the week, never a wet paper towel) and shares the lab’s full rose virus testing panel. Two listener cases anchor the hour: Kate’s mature bur oak with browning, crunchy leaves turns into a lesson on secondary stress — Hannah and Stephen trace it back to a lush, well-watered lawn effectively drowning the tree’s root system, with a practical how-to on digging and sniff-testing a root sample for rot. A second case, a white oak with marginal leaf cupping and browning, points toward anthracnose, with a broader discussion of fungicide timing (always preventative, ahead of a growing or dormancy period, never after symptoms appear) and Hannah’s own daylily rust story, including its surprising alternate-host lifecycle on plants like gladiolus and cedar. Callers round out the show: Juliana’s oddly patchy, whitish St. Augustine lawn gets narrowed down to possible salt buildup, nutrient deficiency, or chinch bugs (with a soil test recommended either way), and Elizabeth’s brittle, holey yellow lantana leaves get diagnosed as lace bug damage, with guidance on dormant oil timing and why Texas heat makes horticultural oils risky to apply right now. Plus: a reminder about the Trees for Brazos County sapling giveaway on November 7th, and that November 19th is the next Ask the Plant Doctor segment.

This week on Garden Success, host Stephen Brueggerhoff works through a stack of listener emails and photos, starting with Walter’s rental-property crape myrtles — planted too close to the foundation and showing a light infestation of crape myrtle bark scale. Stephen walks through why mature size matters before planting any tree (oaks need 40 feet of clearance; crape myrtles vary wildly by variety, from ground-cover types to 75-footers), and the right-time-of-year strategy for treating bark scale: pressure-washing light infestations now, saving systemic treatment for the spring crawler stage. Listener Georgia, new to the show after Skip Richter retired, asks for replacement tree recommendations after two established oaks (a chinkapin and a Shumard) died at her South College Station home — Stephen runs through cedar elm, Mexican sycamore, and Mexican white oak as alkaline-soil-tolerant alternatives, plus thornless blackberry variety picks (Prime-Ark Freedom and Natchez) for her backyard fruit patch. A separate caller, Ameena, gets a detailed pruning lesson for leggy rosemary bushes — identifying dead wood, why cutting back into old woody growth won’t regenerate, and the “semi-woody tissue” sweet spot for selective pruning (with the same rule applying to lavender), plus a reminder to stop pruning both about six weeks before first frost. Plus: a full slate of upcoming events, including a free Trees and Tree Planting program at the Mounce library (October 17th), the Texas New Fruit Growers Conference in Rosenberg (October 15–16), the Trees for Brazos County sapling giveaway on November 7th (Texas Arbor Day), and College Station’s Trunk or Treat event at Wolf Pen Creek Park later in October.

This week on Garden Success, host Stephen Brueggerhoff opens with a cabbage comparison trial underway at the Brazos County demonstration garden — heirloom varieties Early Jersey Wakefield and Early Flat Dutch going head-to-head with hybrid Red Ball and the supersized Sapporo Giant — before digging into a listener's sweet potato harvest puzzle. Listener George, growing sweet potatoes at a Baylor Scott & White community garden, found long healthy vines but small, underdeveloped roots. Stephen walks through the likely culprits one by one: too much nitrogen favoring foliage over root swelling, the benefits of extra phosphorus and potassium (bone meal and muriate of potash get a mention), inconsistent irrigation during root development, and simply digging too early relative to the variety's 90–120 day maturity window — sharing his own at-home sweet potato experience (11 pounds from one slip last year, a less impressive harvest this year) along the way. From there it's a rundown of what's ready to plant now and what to hold off on — broccoli, cauliflower, and cabbage transplants; Swiss chard and leek seed now; carrots and garlic in a couple more weeks once it cools down; and turnips as a surprisingly good, forgiving cover crop. A walk-in visitor's unidentified yard plant turns into a profile of slender fall aster (Symphyotrichum subulatum), a native annual with modest flowers, a dormant seed bank triggered at 75°F soil temps, and control options that boil down mostly to hand-pulling before it goes to seed. Caller Ryan gets practical advice on seeding a backyard wildflower meadow — including the extra care bluebonnet seed needs due to its hard, scarified seed coat. Plus: upcoming events including the Native Plant Society of Texas Post Oak Chapter meeting tonight at Lick Creek Park, the Texas A&M Horticulture field day rescheduled to October 9th, and a shrub and root ball preparation workshop at Martha's Bloomers (October 2nd).

This week on Garden Success, host Stephen Brueggerhoff tackles the question every Brazos Valley gardener is asking right now: is my browning lawn dead, or just dormant? He walks through the telltale signs — a uniform brown across the whole yard versus irregular patches, whether blades pull free easily from the crown, and checking for green material at the soil line — plus how salt buildup from irrigation water and off-season fertilizer use can compound summer stress on St. Augustine, Bermuda, and zoysia turf. The practical lawn-recovery checklist runs deep: why now's the time to ease off (or skip) mowing, keeping the deck high, holding off on fertilizer until 4–6 weeks before the average first frost (roughly Thanksgiving for Brazos County, at half the spring rate), the soil-temperature window for pre-emergent herbicides and large patch fungicide treatments, and the classic DIY can-and-dish-soap trick for scouting chinch bugs before reaching for a pesticide. Stephen also works through a detailed listener email about a newly planted oak in a narrow street-median strip with a thinning canopy — diagnosing likely water stress (too much or too little) in a tight, clay-heavy root zone, ruling out a discontinued irrigation bubbler as the culprit, and identifying a harmless cosmetic "smooth patch" fungal growth on the bark. Plus a fall-garden pick-me-up: Mexican mint marigold as a heat-tolerant, licorice-flavored stand-in for finicky French tarragon. Plus: upcoming events including the Wings in the Garden pollinator celebration and the Brazos Valley Beekeepers Association's Bee School (both this Saturday, September 26th), and the Native Plant Society of Texas Post Oak Chapter meeting on October 1st.

This month's Ask the Plant Doctor segment brings host Stephen Brueggerhoff back together with Dr. Kevin Ong of the Texas Plant Disease Diagnostic Lab. The two open by tackling one of late summer's most common misdiagnoses: patchy, crispy lawn areas that homeowners assume are disease but are often just hydrophobic dry spots, with practical fixes ranging from soil polymer gels and compost topdressing to core aeration. Kevin shares a milestone for the lab — recent National Plant Diagnostic Network core accreditation, a rigorous standardization process tracing back to a post-2002 federal effort to protect U.S. agriculture from bioterrorism and emerging pathogens — and gives a tour of Texas's three-lab diagnostic network, including the virus-focused Weslaco lab working with USDA APHIS and Border Patrol. The conversation moves into real quarantine stakes close to home: citrus greening and citrus canker restrictions covering the greater Houston area, and lethal bronzing disease now showing up in palms in Galveston and Harris counties, with insect-vector research still very much unsettled. Building on last week's caller conversation, Kevin and Stephen dig deeper into distinguishing chili thrips from spider mites on roses (the classic shake-test-over-white-paper trick), why horticultural oils and soap treatments can backfire into sunburn-like leaf damage in Texas heat, and a fascinating detour into biopesticides — including Kevin's own past work with beneficial nematodes and a mystifying case where doubling a biological treatment's rate made it perform worse, not better. Caller Lynn phones in with details on the Brazos Valley Beekeepers Association's daylong Bee School (September 26th). Plus: a genuinely fun tangent on corn smut as a Mexican culinary delicacy, and a reminder that product labels aren't just guidance — they're the law. Plus: upcoming events including blooming bulbs at the Bryan library (September 19th), Wings in the Garden pollinator event (September 26th), and the next Ask the Plant Doctor segment on October 15th.