Tomate

Clemson HGIC, 'Tomato Diseases & Disorders', hgic.clemson.edu/factsheet/tomato-diseases-disorders (read 2026-07-11): 'tomatoes and related vegetables, such as potatoes, peppers, and eggplants, should not be planted on the same land more than once in three years.'

NC State Extension, 'Early Blight of Tomato', content.ces.ncsu.edu/early-blight-of-tomato (read 2026-07-11): 'Rotate every 2-3 years.'

NC State Extension, 'Septoria Leaf Spot of Tomato', content.ces.ncsu.edu/septoria-leaf-spot-of-tomato (read 2026-07-11): 'The fungus is known to overwinter on infected tomato debris and solanaceous weed hosts'; 'Rotate away from tomato for 2 or more years.'

NC State Extension, 'Verticillium Wilt of Tomato and Eggplant', content.ces.ncsu.edu/verticillium-wilt-of-tomato-and-eggplant (read 2026-07-11): 'The pathogen can survive in the soil without a host for up to 10 years in the form of structures called microsclerotia'; 'affects more than 300 host families.'

UMass Extension, 'Solanaceous, Verticillium Wilt', umass.edu/agriculture-food-environment/vegetable/fact-sheets/solanaceous-verticillium-wilt (read 2026-07-11): 'Verticillium wilt tends to affect a wide range of hosts and can infect many unrelated plants. Fusarium spp., on the other hand, have very narrow host ranges.'

UMass Extension, 'Late Blight Management for Fall, Winter and Spring', umass.edu/agriculture-food-environment/home-lawn-garden/fact-sheets/late-blight-management-for-fall-winter-spring (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Potato tubers that are infected with late blight and don't freeze or decay during the winter can carry the pathogen over the winter to next spring' - 'Left in the ground at harvest, down several inches in the soil'; 'Disposed of in a compost pile that does not fully decompose and does not freeze'; 'Tomatoes will not carry late blight over the winter, because freezing kills the whole plant'; 'Tomato seed, even from fruit that was infected with late blight, will not carry the pathogen'; 'In the spring (April - June), inspect last year's potato plot and any compost or cull piles for volunteer potato plants that might come up. If you find potato plants, pull them out and put them in the trash or destroy them.'

UMN Extension, 'Late blight of tomato and potato', extension.umn.edu/disease-management/late-blight (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'P. infestans can overwinter in Minnesota if protected in potato cull piles'; 'The host range is typically limited to potato and tomato, but hairy nightshade (Solanum physalifolium) is a closely related weed that can readily become infected'; 'Control volunteer potato plants, as infected plants can grow from infected tubers.'

University of Illinois Extension, 'Time Your Vegetable Plantings by Cold Hardiness' (2018-03-26), extension.illinois.edu/blogs/ilriverhort/2018-03-26-time-your-vegetable-plantings-cold-hardiness: very hardy vegetables 'withstand freezing temperatures and hard frosts without injury' (planted earliest in spring); frost-tolerant vegetables 'can withstand light frosts, but not freezing temperatures' (planted a couple of weeks later). LLM-summarised from a read of the page; it establishes the CATEGORIES but states no week offsets.

Colorado State Univ. Extension, GardenNotes #720, 'Vegetable Planting Guide', extension.colostate.edu/resource/vegetable-planting-guide (read 2026-07-25): hardy vegetables go in 'As early as 2-4 weeks before the date of the average last spring frost'; semi-hardy 'As early as 0-2 weeks before the date of the average last spring frost'; tender from seed 'around the date of the average last spring frost'; very tender 'Typically 2+ weeks after'. This is the source that states the offsets in weeks.

Where this rule sits in that range: hardy at 3 weeks is mid-range of CSU's 2-4. Half-hardy at 2 weeks is the EARLIEST EDGE of CSU's 0-2 - the most aggressive planting CSU sanctions, not the middle of it. The rule is inside published guidance at both ends, but it leans early on the half-hardy side and a gardener following it in a cold spring is taking that boundary.

Do not import an offset from another publication's hardiness scheme without checking the category names: CSU has no 'very hardy' tier, so a '4-6 weeks before frost' figure written against a four-tier scheme does not describe CSU's 'hardy'. Categories are not comparable across sources.

University of Minnesota Extension, 'Starting seeds indoors', extension.umn.edu/planting-and-growing-guides/starting-seeds-indoors: seed-starting chart gives tomato '5-6 weeks' and pepper and eggplant '9 weeks' before the outdoor planting date (warm crops set out after the last frost). Read 2026-07-19 (LLM-summarised); read by the maintainer 2026-07-25, which is the read that promoted this rule. Note what the corpus's per-crop values do with the sources: tomato 6 sits at the top of Minnesota's '5-6 weeks' and inside Illinois's '6-8'; pepper and eggplant 8 sit BELOW Minnesota's '9 weeks' and at the top of Illinois's '6-8'. They are a reconciliation of two published ranges, not a figure either source prints.

University of Illinois Extension, 'When should I start my seeds?' (2023-02-10), extension.illinois.edu/blogs/good-growing/2023-02-10-when-should-i-start-my-seeds: peppers, tomatoes, and eggplant started '6-8 weeks before the last frost'. Read 2026-07-19.

UGA Extension, 'Troubleshooting Cultural Problems in Tomatoes' (C1089), fieldreport.caes.uga.edu/publications/C1089 (read 2026-08-22): 'applying too much nitrogen can cause excessive growth and hinder flowering'; 'Too much nitrogen is also a common problem, and can be identified when the plant is tall and dark green, with excessive growth and no blooming.'

Univ. of Missouri Extension, 'Watering and Fertilizing Tomatoes in a High Tunnel' (G6462), extension.missouri.edu/publications/g6462 (read 2026-08-22): 'Too much nitrogen creates excessive vine growth, twisted foliage, delayed flowering and lower yield.'

UMN Extension, 'Early blight in tomato and potato', extension.umn.edu/disease-management/early-blight-tomato-and-potato (fetched in-container 2026-09-25, read 2026-09-25): 'Larger spots have target-like concentric rings.'; 'The early blight pathogens both overwinter in infected plant debris and soil in Minnesota.'; 'Lower leaves become infected when they come into contact with contaminated soil, either through direct contact or when raindrops splash soil onto the leaves.'; 'Cover the soil under the plants with mulch, such as fabric, straw, plastic mulch, or dried leaves.'; 'Water at the base of each plant, using drip irrigation, a soaker hose, or careful hand watering.'; 'Do not remove more than one-third of the plant's leaves.'; 'Rotate out of tomatoes and related crops for at least two years.'; 'Spores (reproductive structures) can germinate between 47° and 90° F and need free water or relative humidity of 90% or greater.'; 'Fruit spots are leathery and black, with raised concentric ridges.'; 'Staking will also reduce contact between the leaves and spore-contaminated soil.'; 'Remove leaves with leaf spots and bury or burn them.'; 'There are many resistant tomato cultivars available, often designated with an "EB" in seed catalogs.'; 'In the fall, remove or bury infected plants to reduce the likelihood of the pathogen surviving into the following year.'

UW-Madison Extension (Wisconsin Horticulture), 'Troubleshooting Tomato Problems', hort.extension.wisc.edu/troubleshooting-tomato-problems/ (fetched in-container 2026-09-25, read 2026-09-25): 'Early blight and septoria leafspot are fungal leaf diseases infecting tomato plants, especially during wet weather.'; 'Initial symptoms typically appear on the lower foliage of plants, starting as deep brown or blackish spots, followed by yellowing or browning of leaves.'; 'Early blight spots will develop concentric rings and a target-like appearance, often with a yellow halo. Septoria spots typically have whitish centers and dark borders.'; 'Tomato leaves may also show yellowing from lack of nitrogen. This is especially common in containers, due to frequent watering and low soil fertility.'; 'Adding nitrogen fertilizer will help alleviate this problem but be careful not to over-apply.'; 'Removing infected leaves, or even entire plants, might help reduce spreading of disease.'; 'Mulching will help reduce soil splashing onto lower foliage, which often includes fungal spores.'; 'Improve air circulation around tomato plants by avoiding closely spaced plantings, using cages, or staking.'; 'In future years, practice crop rotation and choose early blight- and septoria-resistant tomato cultivars.'