Your tomato plants were thriving yesterday—today, they’re sporting ominous brown spots with concentric rings that look like tiny targets. Early blight has arrived, and if you’re reading this, you’re likely watching your harvest dreams crumble faster than an overripe Roma. Take a deep breath. While Alternaria solani is one of the most aggressive fungal pathogens you’ll face, it’s not a death sentence for your 2026 tomato crop if you act strategically.
The game has changed. Climate fluctuations are creating perfect storm conditions for early blight, but our understanding of integrated disease management has evolved dramatically. This isn’t your grandmother’s “spray and pray” approach. We’re talking about a precision rescue plan that combines cutting-edge 2026 horticultural science with battle-tested cultural practices. Whether you’re managing a backyard patio garden or a quarter-acre homestead, this step-by-step protocol will help you suppress the infection, protect uninfected foliage, and—most importantly—salvage a meaningful harvest.
Understanding Early Blight: The 2026 Threat Landscape
The Science Behind Alternaria solani
Early blight isn’t just a single disease—it’s a complex of fungal pathogens, primarily Alternaria solani, that attacks tomatoes, potatoes, and other solanaceous crops. Unlike late blight’s explosive devastation, early blight is a slow-burn assassin, systematically weakening plants through defoliation and stem lesions. The fungus overwinters in soil and plant debris, producing spores that splash onto lower leaves during rain or irrigation. In 2026’s increasingly erratic weather patterns, these infection events are becoming more frequent and severe.
The fungus produces distinctive “bullseye” lesions with dark concentric rings and a yellow halo. These lesions expand, causing leaves to yellow, wither, and die from the bottom up. Left unchecked, early blight can defoliate entire plants, exposing developing fruit to sunscald and drastically reducing yields. The key to 2026 management lies in understanding that this pathogen thrives in warm (75-85°F), humid conditions with extended leaf wetness periods—exactly what climate data suggests many regions will experience this growing season.
Why 2026 Growing Conditions Matter
This year’s weather forecasts indicate prolonged periods of elevated humidity across many tomato-growing regions, coupled with temperature swings that stress plants and compromise their natural defenses. These stressed plants release chemical signals that essentially invite fungal spores to attack. Additionally, 2026 brings heightened awareness of fungicide resistance—overreliance on single-mode-of-action products has rendered some traditional treatments less effective.
The modern approach requires treating early blight as a manageable chronic condition rather than an acute emergency. Your goal isn’t necessarily eradication (that’s nearly impossible once established), but suppression to levels where your plants can outgrow the damage and produce fruit before the fungus wins. This mindset shift is crucial for 2026 success.
Step 1: Early Blight Identification Masterclass
Spotting the Telltale Bullseye Lesions
Early detection separates successful rescues from total losses. Begin daily inspections the moment nighttime temperatures consistently exceed 60°F. Focus on the lowest, oldest leaves first—these are the fungus’s primary entry point. Look for small, dark brown spots no larger than a pencil eraser. Within 48-72 hours, these develop into the classic target pattern: concentric rings of dark and light tissue with a distinctive yellow chlorotic halo.
Use your smartphone’s macro lens to photograph suspicious spots. Compare them daily—if the lesion diameter increases more than 2mm per day, you’re dealing with active early blight, not a benign leaf spot. Check stems for dark, sunken lesions at the soil line and leaf axils. These cankers girdle stems, cutting off nutrient flow and causing entire branches to wilt dramatically. Fruit can also develop leathery, dark lesions, typically starting at the stem end.
Differentiating Early Blight from Common Look-Alikes
Septoria leaf spot appears similar but lacks the concentric rings and tends to produce more numerous, smaller spots with tiny black fruiting bodies in the center. Bacterial spot lacks the yellow halo and often appears greasy. Nutrient deficiency—particularly potassium—can cause yellowing but never produces the dark necrotic centers.
The definitive test: early blight lesions feel slightly raised and rough when you run a fingertip over them. This textural difference, caused by fungal mycelium growth, is your best field diagnostic tool. In 2026, consider investing in affordable lateral flow test strips that detect Alternaria antigens—these provide lab-quality confirmation in 10 minutes without sending samples to extension services.
Step 2: Immediate Quarantine and Sanitation Protocols
The 24-Hour Contamination Window
The moment you confirm early blight, treat your garden like a biohazard zone. Fungal spores spread through water splash, wind, and contact. Stop all irrigation immediately and switch to hand-watering only the base of plants. Place temporary barriers—old shower curtains, landscape fabric, even cardboard—between infected and healthy plants to prevent splash dispersal.
Remove visibly infected leaves using sterilized pruners, but never remove more than 25% of a plant’s foliage at once—this stresses the plant further. Place removed leaves directly into a sealed plastic bag, not your compost pile. The fungus survives home composting temperatures and will reinfect next year’s crop. For small gardens, consider a complete 48-hour “garden lockdown” where you avoid working with plants during wet conditions when spores are most mobile.
Tool Sterilization Techniques That Work
Bleach solutions corrode tools and harm soil microbiology. Instead, opt for 70% isopropyl alcohol in a spray bottle—spray tools before and after each cut. For maximum efficacy, follow the alcohol wipe with a heat treatment: pass pruner blades through a propane torch flame for 3-5 seconds. This two-step approach kills 99.9% of fungal spores and bacterial contaminants.
Invest in color-coded tool sets: one for healthy plants, one for diseased areas. This simple system prevents cross-contamination during busy gardening sessions. At season’s end, disassemble pruners and soak all metal parts in a solution of hot water and trisodium phosphate (TSP) for 20 minutes to remove organic debris where spores hide.
Step 3: Strategic Pruning for Airflow Optimization
The 12-Inch Ground Clearance Rule
Early blight spores splash up from soil, so your first defensive line is vertical distance. Prune all lower leaves to create a minimum 12-inch bare stem zone above the mulch line. This single action reduces infection rates by up to 60% according to 2025 university trials. Use clean, sharp bypass pruners and make cuts at a 45-degree angle just above leaf nodes to promote rapid healing.
For indeterminate varieties, continue this “lifting” process weekly, removing any leaf that droops within the 12-inch zone. Determinate varieties require a more conservative approach—remove only the lowest two leaf branches to avoid reducing yield potential. The goal is creating a “fungal dead zone” where spores can’t reach viable leaf tissue.
Timing Your Pruning for Maximum Impact
Never prune during wet weather or when rain is forecast within 24 hours. Fresh pruning wounds are infection highways. The optimal pruning window is mid-morning on a sunny, breezy day—wounds dry quickly and plant defenses are at their peak. Follow every pruning session with an approved fungicide application within 2 hours to protect the fresh wounds.
In 2026’s volatile weather, use predictive tools like leaf wetness sensors or local agricultural weather networks to identify 48-hour dry periods. Some advanced gardeners are using battery-powered leaf blowers on low setting to rapidly dry foliage after morning dew, effectively reducing leaf wetness duration below the 6-hour infection threshold.
Step 4: Watering Regimen Overhaul
The Morning Watering Mandate
Switch to pre-dawn watering—between 4 AM and 6 AM. This timing allows foliage to dry completely before evening, denying the fungus the extended wetness it needs. Never water after 10 AM; wet leaves during the warm midday period create a fungal paradise. Use a soil moisture meter to water only when the top 2 inches of soil are dry, typically every 3-4 days rather than daily.
Implement the “deep and infrequent” philosophy: water until the top 6 inches of soil is moistened, then wait. This encourages deep root growth, making plants more resilient to both disease and drought stress. Stressed plants emit ethylene and other compounds that signal vulnerability to pathogens.
Drip Irrigation vs. Soaker Hoses: A 2026 Perspective
Drip tape with pressure-compensating emitters every 6 inches delivers water directly to the root zone with zero foliar contact. This represents the gold standard for early blight management. Soaker hoses, while better than overhead watering, still create a wet soil surface that promotes spore splash. If you must use soaker hoses, bury them 2 inches deep and cover with a thick mulch barrier.
For container tomatoes, consider self-watering pots with wicking systems that maintain consistent moisture without surface wetting. The 2026 innovation: moisture sensors that trigger irrigation only when needed, preventing the overwatering that weakens plants and fuels fungal growth.
Step 5: Mulch Magic - Creating a Fungal Barrier
Choosing the Right Mulch Material
Straw mulch is the traditional choice, but 2026 research favors wood chip mulch (1-2 inch diameter) for superior splash suppression. The irregular surface dissipates raindrop energy more effectively than flat straw blades. Avoid fine mulches like shredded leaves or grass clippings—they retain too much moisture and can harbor fungal spores.
For maximum efficacy, consider living mulch: low-growing, non-solanaceous plants like white clover between tomato rows. Their canopy intercepts splashing water while fixing nitrogen. Just ensure you plant them 3-4 weeks before tomatoes to establish a dense mat. Whatever material you choose, the key feature is creating a physical barrier between soil-borne spores and lower leaves.
Application Depth and Techniques
Apply mulch to a depth of 3-4 inches after soil has warmed to 65°F and plants are 12 inches tall. Premature mulching keeps soil cool, slowing growth. Keep mulch 2 inches away from main stems to prevent collar rot and allow air circulation. For plastic mulch (effective but less sustainable), choose reflective silver mulch that repels spore-carrying insects and reduces soil temperature, making conditions less favorable for fungal development.
In wet climates, consider a double-mulch system: a 2-inch layer of compost covered by 2 inches of wood chips. The compost layer hosts beneficial microbes that outcompete Alternaria, while the wood chip layer provides splash protection. This approach reduced early blight severity by 43% in 2025 Pacific Northwest trials.
Step 6: Soil Health Rehabilitation
pH Balancing for Blight Resistance
Early blight thrives in acidic soils (pH below 6.0) where calcium becomes less available. Test your soil pH immediately—tomatoes prefer 6.2-6.8. If your pH is low, apply pelletized limestone at a rate of 5-10 pounds per 100 square feet, working it into the top 3 inches of soil. The calcium itself strengthens cell walls, making them more resistant to fungal penetration.
For quick adjustment during the growing season, apply liquid calcium chloride as a soil drench (1 tablespoon per gallon of water) every 14 days. This provides immediately available calcium while gradually shifting pH. Avoid over-liming, which can lock up micronutrients and create new stress factors.
Beneficial Microbe Activation Strategies
Suppressive soils—those naturally resistant to pathogens—contain high populations of Trichoderma and Bacillus species. Activate these allies by applying high-quality compost tea brewed for 24-36 hours with active aeration. The key is applying it to foliage as a spray in late afternoon, allowing microbes to colonize leaf surfaces and outcompete Alternaria.
For 2026, consider adding humic acid (0.5% solution) to your compost tea. Recent research shows humic compounds stimulate beneficial microbe sporulation and enhance root exudates that feed protective soil organisms. Apply this microbial cocktail every 7-10 days as both soil drench and foliar spray for maximum ecosystem support.
Step 7: Organic Fungicide Application Strategy
Copper-Based Options: What to Look For
Copper fungicides remain the organic gold standard, but 2026 formulations have evolved. Look for products with 8-10% metallic copper equivalent (MCE) in a fixed copper formulation (copper hydroxide, copper sulfate, or copper octanoate). These provide 7-10 days of protection when applied correctly. The key is using the lowest effective rate—overapplication leads to copper accumulation in soil and potential phytotoxicity.
Apply at 1-2 tablespoons per gallon of water, ensuring complete leaf coverage including undersides. The spray should run off leaves slightly. Time applications for early morning when stomata are opening, maximizing uptake. Never tank-mix copper with acidic compounds or insecticidal soaps. For enhanced rainfastness, add a spreader-sticker approved for organic production—look for lecithin-based or saponin-based products rather than synthetic surfactants.
Biological Controls and Their Application Timing
Streptomyces lydicus and Bacillus amyloliquefaciens are beneficial bacteria that colonize leaf surfaces and produce antifungal compounds. These work best as preventative treatments, but can suppress active infections if applied intensively. The secret is timing: apply in evening when UV radiation is low and humidity is rising, giving microbes time to establish overnight.
For active blight, apply every 3-5 days for two weeks, then weekly. These organisms require free moisture to activate, so light overhead watering 2 hours after application (or timing before evening dew) dramatically improves efficacy. In 2026 trials, alternating copper and biological controls reduced resistance development and improved overall suppression compared to copper alone.
Step 8: Conventional Fungicide Protocols (When Organic Isn’t Enough)
Understanding FRAC Codes and Resistance Management
If organic methods aren’t controlling spread after 10 days, conventional fungicides may be necessary. The 2026 resistance landscape demands strict rotation. Fungicides are grouped by Fungicide Resistance Action Committee (FRAC) codes—never use the same code more than twice sequentially. For early blight, rotate between:
- FRAC 11 (azoxystrobin, chlorothalonil alternatives)
- FRAC 7 (boscalid, penthiopyrad)
- FRAC 3 (tebuconazole, difenoconazole)
Always tank-mix single-site fungicides (FRAC 11, 7, 3) with a multi-site protectant like chlorothalonil (FRAC M5) to prevent resistance. This strategy ensures that any surviving fungal spores are hit with a different mode of action next application, dramatically slowing resistance development.
Spray Schedule Optimization for 2026
Begin applications when disease first appears, then maintain a strict 7-14 day schedule. In wet, humid conditions, spray every 7 days; in dry conditions, extend to 10-14 days. The 2026 protocol: use a “trigger spray” approach based on leaf wetness sensors rather than calendar dates. When sensors record 6+ hours of continuous leaf wetness, that’s your signal to spray within 24 hours.
Apply at 30-50 psi using hollow-cone nozzles for optimal coverage. Spray to the point of runoff, ensuring both leaf surfaces are coated. Stop spraying 3-5 days before harvest, depending on the product’s pre-harvest interval (PHI). Keep detailed records of applications, rates, and weather conditions—this data becomes invaluable for refining your 2027 strategy.
Step 9: Nutrient Management for Plant Immunity
Calcium and Potassium: The Dynamic Duo
Calcium strengthens cell walls, literally building physical barriers against fungal penetration. Potassium regulates stomatal function and activates over 60 plant enzymes involved in stress response. A deficiency in either nutrient makes tomatoes 3-5 times more susceptible to early blight.
Apply calcium as a foliar spray (calcium chloride at 1 tablespoon per gallon) every 10-14 days, starting at first fruit set. For potassium, use sulfate of potash (0-0-50) rather than muriate of potash (potassium chloride), which can be harsh on soil biology. Side-dress with 1 tablespoon per plant monthly, working it gently into the top inch of soil. The 2026 innovation: potassium silicate supplements that deliver both potassium and silicon, which accumulates in cell walls as a structural barrier.
Foliar Feeding vs. Soil Application
During active early blight infection, foliar feeding provides immediate nutrients to stressed leaves. Use a balanced 10-10-10 fertilizer at quarter-strength weekly, but never within 3 days of fungicide application—nutrients can interfere with fungicide adhesion. Add a teaspoon of molasses per gallon to feed beneficial leaf-surface microbes.
Soil applications build long-term plant health but are slower acting. The 2026 balanced approach: foliar feed for immediate immune support while building soil health for future seasons. Remember, over-fertilization with nitrogen creates lush, tender growth that’s more susceptible—keep nitrogen moderate once fruiting begins.
Step 10: Resistant Variety Selection for Future Seasons
Decoding Disease Resistance Codes
When browsing seed catalogs for 2027, look for these key codes:
- A or AB = Early blight resistance
- V = Verticillium wilt resistance (often co-occurs)
- F = Fusarium wilt resistance
The gold standard: varieties with multiple resistance genes (polygenic resistance) rather than single-gene resistance. These are often labeled “tolerant” rather than “resistant” and show fewer symptoms under heavy pressure. For 2026, note that many heirlooms lack resistance but can still succeed with rigorous management. Hybrids like ‘Defiant’, ‘Mountain Merit’, and ‘Iron Lady’ offer robust early blight packages while maintaining flavor profiles that rival heirlooms.
Heirloom vs. Hybrid: The 2026 Balanced Approach
The heirloom purist vs. hybrid debate is outdated. Smart 2026 gardeners grow both: 60-70% resistant hybrids as insurance, with 30-40% cherished heirlooms in the best-managed, most protected garden sections. This strategy ensures you get some harvest regardless of pressure while still enjoying those Brandywine and Cherokee Purple flavors.
For heirlooms, prioritize those with potato-leaf morphology—thicker cuticles provide some natural resistance. ‘Pruden’s Purple’ and ‘Kellogg’s Breakfast’ show surprising tolerance in field trials. Save seeds only from your healthiest heirloom plants, as this selects for local adaptation over time.
Step 11: Companion Planting for Blight Suppression
Beneficial Plant Partnerships
Certain plants exude compounds that suppress fungal spore germination. Interplant tomatoes with basil (particularly ‘African Blue’ or ‘Spicy Globe’ varieties) at a 1:1 ratio. Basil’s volatile oils inhibit Alternaria spore germination by up to 40% in controlled studies. The key is planting basil 2-3 weeks before tomatoes so it’s established and actively releasing compounds when tomatoes are most vulnerable.
French marigolds (Tagetes patula) produce thiophenes that are toxic to many soil-borne fungi. Plant them as a border around tomato beds, spacing 6 inches apart. For maximum effect, chop and incorporate marigold foliage into the top inch of soil at season’s end—these compounds persist for 30-60 days, protecting fall crops.
Spatial Arrangement Strategies
The 2026 recommendation: wider spacing. Increase row spacing to 4-5 feet and plant spacing to 3 feet for indeterminate varieties. This improves airflow, reducing leaf wetness duration below the critical 6-hour threshold. Use trellising systems that keep foliage vertical—Florida weave or stake-and-weave methods outperform cages for airflow.
Consider orienting rows north-south to maximize sun exposure and morning dew evaporation on both sides of plants. In windy areas, use permeable windbreaks (snow fencing, tall annual grasses) to reduce physical damage that creates entry points for pathogens while still allowing air movement.
Step 12: Weather Monitoring and Predictive Prevention
Leveraging 2026 Forecasting Technology
Download agricultural weather apps that provide leaf wetness duration forecasts and disease severity index (DSI) calculations. These tools use local weather station data to predict infection periods 48-72 hours in advance. When the DSI exceeds 7 on a 10-point scale, that’s your trigger to apply protective fungicides before symptoms appear.
For serious growers, invest in an on-site weather station with leaf wetness and humidity sensors. The 2026 models integrate with smartphone apps sending push notifications when conditions favor early blight. This allows you to spray preventatively rather than reactively—far more effective and uses 40% less fungicide overall.
The Critical Temperature-Humidity Window
Early blight’s sweet spot is 75-85°F with relative humidity above 85% for 6+ hours. When your weather monitoring shows these conditions approaching, implement emergency protocols: stop overhead watering entirely, increase airflow with portable fans (for greenhouse growers), and apply protective fungicides 24 hours before the event.
The 2026 twist: climate change is expanding this danger zone. Some regions are seeing nighttime temperatures staying above 70°F, allowing continuous fungal growth. In these areas, consider night ventilation strategies or accept that you’ll need weekly protective sprays through peak summer rather than the traditional 10-14 day interval.
Step 13: Post-Harvest Cleanup and Soil Solarization
The Complete Garden Reset Process
Early blight survival in debris means your 2026 battle continues after harvest. Within one week of final harvest, remove all tomato plant material—roots, stems, leaves, fruit. Don’t compost any of it unless you maintain a hot compost system that sustains 140°F+ for 21 consecutive days (most home systems don’t). Instead, bag and dispose with municipal waste or burn where permitted.
Follow plant removal with aggressive soil cultivation—turn the top 6 inches of soil to bury any remaining spores. Then apply soil solarization: cover moistened soil with clear 2-4 mil polyethylene for 6-8 weeks during peak summer heat. This traps solar radiation, raising soil temperatures to 120-140°F at 2-inch depth, killing overwintering fungal structures and weed seeds simultaneously.
Solarization Timing for Your Climate Zone
In Zones 5-7, solarize June through July. In Zones 8-10, solarize July through August—these regions need the most intense sun angle for effective heating. Before laying plastic, incorporate organic matter like chicken manure or alfalfa meal; decomposition generates additional heat. Seal plastic edges with soil to trap heat and moisture.
Post-solarization, don’t disturb the soil. The beneficial microbe community is temporarily depleted. Instead, plant a cover crop of mustard or buckwheat for 30 days to rebuild biology before your next tomato crop. This cover crop also acts as a biofumigant, releasing compounds that further suppress soil pathogens.
Step 14: Record-Keeping for Long-Term Success
What Data to Track in 2026
Create a simple spreadsheet or dedicated garden journal tracking: first disease observation date, daily temperature/humidity highs and lows, rainfall amounts, irrigation timing, fungicide applications (product, rate, date), pruning dates, and weekly disease severity ratings (1=no disease, 10=complete defoliation). Photograph plants weekly from the same angle for visual comparison.
This data reveals patterns: perhaps your infections always follow 3-day rainy periods, or maybe certain varieties show symptoms 10 days later than others. Over 2-3 seasons, this becomes a predictive tool allowing you to time interventions with precision rather than guesswork.
Digital vs. Analog Garden Journaling
Apps like Gardenize and Planta offer photo integration and weather data import, but require consistent data entry. A waterproof field notebook and pencil never crash and allow quick sketches of lesion patterns. The 2026 hybrid approach: use a simple voice-to-text app on your phone for quick field notes, then transcribe weekly into a digital database for analysis.
Whichever method you choose, commit to 5 minutes daily. This small investment pays enormous dividends in understanding your garden’s unique disease pressure patterns and refining your personal early blight management protocol.
Step 15: When to Accept Defeat and Start Fresh
The 50% Rule: Knowing Your Threshold
If early blight has infected over 50% of leaf area and stem cankers are present on main stems, your plant’s photosynthetic capacity is too compromised to support fruit ripening. Continuing aggressive treatment is throwing good resources after bad. At this point, harvest any mature green fruits and remove the plant. Green tomatoes ripen beautifully on a sunny windowsill, often developing better flavor than vine-ripened fruit in late season when plants are stressed.
For plants between 25-50% infection, switch to maintenance mode: stop fungicide applications, remove only leaves that are completely dead, and let the plant pour remaining energy into fruit. You’ll get a smaller harvest, but without further expense or effort. This pragmatic approach frees up time and resources for fall crops.
Salvaging Seeds and Planning Your Comeback
Only save seeds from completely healthy heirloom plants that remained disease-free while neighbors were infected. This selects for genetic resistance. Ferment seeds properly, then treat with hot water (122°F for 25 minutes) to kill surface contaminants without damaging viability.
For 2027, start your rescue plan in January: order resistant varieties, build compost, and plan a 3-year rotation that keeps solanaceous crops away from this year’s infected area. Consider converting infected beds to raised beds with fresh soil mix, effectively resetting the disease timeline. The sting of defeat fades when you’re eating perfect, blight-free tomatoes next summer.
Frequently Asked Questions
How quickly can early blight kill my tomato plants?
Early blight rarely kills plants outright—it typically takes 4-8 weeks to defoliate a mature plant completely. However, severe defoliation exposes fruit to sunscald and stops photosynthesis, making harvest impossible. Act within 48 hours of first symptoms to slow progression dramatically.
Can I eat tomatoes from plants with early blight?
Absolutely. Early blight affects foliage and stems, not fruit directly (unless fruit lesions develop). Wash harvested tomatoes thoroughly. Avoid using leaves as culinary herbs once disease is present, and never compost diseased plant material with edible crops.
Will early blight spread to my peppers and eggplants?
Yes, but less aggressively. Alternaria solani primarily attacks tomatoes and potatoes, but can infect other solanaceous crops. The 2026 protocol: treat peppers and eggplants as sentinel crops—if they show early blight symptoms, your tomato pressure is extreme and requires immediate intensive management.
How do I know if fungicides are working?
Measure lesion expansion rate. Working fungicides should slow lesion growth to less than 1mm per day. Photograph marked lesions weekly with a ruler for scale. If lesions continue expanding 2mm+ daily after 10 days, rotate to a different FRAC code immediately.
Can I reuse tomato cages next year after early blight?
Only after thorough sterilization. Remove all organic debris, then pressure wash at 2000+ PSI. Follow with a 10% bleach solution soak for 30 minutes, rinse thoroughly, and dry in direct sunlight for 48 hours. For extra precaution, flame-sterilize with a propane torch before storage.
What’s the best temperature to apply fungicides?
Apply when temperatures are between 65-80°F. Below 65°F, fungicide uptake is slow; above 85°F, rapid evaporation reduces coverage and plant stress increases phytotoxicity risk. Early morning (6-9 AM) typically provides this window in most climates.
How long do early blight spores survive in soil?
Infected debris protects spores for 1-3 years. Without debris, free spores survive 3-6 months. This is why crop rotation and complete cleanup are non-negotiable. Solarization can reduce survival to weeks by eliminating the debris shelter.
Can I plant tomatoes in the same spot if I use new soil?
Yes, but with caveats. Remove the top 6 inches of native soil and replace with quality potting mix. Install a root barrier to prevent tomato roots from penetrating the contaminated layer below. This “soil replacement” method is expensive but effective for small spaces where rotation isn’t possible.
Are there any homemade sprays that actually work?
Milk sprays (1 part milk to 9 parts water) show modest efficacy by boosting plant defenses, not killing fungus directly. Apply weekly in morning. Baking soda sprays (1 tablespoon per gallon) raise leaf pH temporarily inhibiting spores, but wash off quickly and can cause phytotoxicity. These are supplements, not replacements, for proven fungicides.
How do I prevent early blight in my seed-starting area?
Sterilize all trays, pots, and tools with a 10% bleach solution. Use fresh, sterile seed-starting mix—never garden soil. Provide excellent air circulation with fans running 24/7. Water from below only. If you see damping-off or leaf spots, discard entire flats—it’s not worth risking your entire garden’s introduction of pathogens.