Where our data comes from

“Native to your area”

• This is flagged at the state level - matched to your zip code's state - not down to your specific county. A plant native to one part of a large state may not actually occur naturally near you.
• The base source is BONAP (Biota of North America Program), which distinguishes truly native populations from “adventive” ones - a plant that's native to North America somewhere, but was introduced and has spread into a state outside its original range. We only flag the former as native. BONAP also has county-level detail for about 36 states so far; where that's available it's a good next step for finer-grained checking than we currently show.
• Where BONAP's data is incomplete for a plant, or a result looks genuinely unclear, we research it against other reputable sources (state Cooperative Extension guides, native plant society databases) rather than guessing or leaving it blank. That's our standing process for every plant we add, not a one-time cleanup.
• A few cultivated garden varieties (like zucchini or bell pepper) are close relatives of a wild native plant, but the variety you're actually growing is a domesticated selection quite different from that wild ancestor.

❄️ Frost dates

• Sourced from NOAA's official 1991-2020 Climate Normals - 30 years of real weather station data, not a live forecast.
• We show a range (a “safe” and a “typical” date) instead of one single date, because frost timing is genuinely a probability, not a fixed day on the calendar.
• Your zip code is matched to the nearest weather station with a solid, reliable data record - not always literally the closest station, if a closer one has a weak or incomplete history.

“Might struggle in your area”

Two independent checks against your zip code - a plant can trip neither, either, or both. They flag different kinds of problem, so they get different badges.

• Zone fit - your zip's USDA Plant Hardiness Zone falls outside the plant's documented zone range. This is a real climate limitation, not something you can work around: too cold means it likely won't survive winter, too warm can mean it won't get the cold it needs or won't tolerate the heat. Hardiness zone data comes from the official 2023 USDA Plant Hardiness Zone Map (published by PRISM Climate Group at Oregon State University, the organization that builds the map for USDA) - see prism.oregonstate.edu/phzm.
• Validated against real zip codes, not just trusted as-is - before this data went live, we spot-checked it against 18 zip codes covering both major metro cores and small rural towns nationwide, all matching their independently documented zone. Along the way we caught a set of “corrected” zone values (sourced from a quick Google search rather than the actual USDA map) that were themselves wrong for three of those zips - two used the outdated pre-2023 map, one had no real source at all. It's the same lesson as everywhere else in our data: a search-result summary is not a substitute for reading the actual source.
• Season length - your zip's frost-free growing season (last frost to first frost, from the same NOAA data behind our frost dates above) is shorter than the plant's days to maturity. Unlike a zone mismatch, this one is usually fixable - starting the plant indoors, using row cover to extend the season, or choosing a shorter-season variety can all help it fit.
• This badge uses your typical growing season - the same “typical last frost / first frost” dates shown elsewhere on the page, not the more conservative ones. We don't want to badge or hide a plant that would work for you in a normal year just because an unusually cold one might trip it up.
• A separate, lighter note covers the cold-year case - if a plant fits your typical season but wouldn't fit a particularly cold one (a late last frost or an early first frost), its page shows a blue informational note explaining that, instead of the amber/red badge. It's not part of the “Hide plants that don't fit my area” filter below, and it doesn't appear in search results - it's only meant as a heads-up on the plant's own page, not a reason to exclude it.
• This check doesn't apply to every plant - multi-year perennials like asparagus and fruit trees, and fall-planted crops like garlic, use their days-to-maturity figure differently (a multi-year establishment period, or a span that crosses winter into next year) rather than a single season's countdown, so comparing it against your frost-free window wouldn't mean anything. Those plants never show a season badge, regardless of how long they take - that's expected, not a gap.
• Blank is a real answer here too - a plant with no hardiness zone researched yet, or a zip code we don't have hardiness-zone or frost data for, never shows either badge. That's “no check possible,” not “we checked and it's fine.” Hardiness zone research is an ongoing pass across our plant list, the same as sun needs and pollinator flagging.
• The “Hide plants that don't fit my area” filter on Add Plants excludes anything flagged by either check.

Sun & shade

• Full Sun - needs 6+ hours of direct sun a day to perform well.
• Part Sun / Part Shade - does well with roughly 3-6 hours of direct sun, or a full day of dappled, filtered light.
• Full Shade - can grow with less than 3 hours of direct sun.
• This rating is the most shade a plant can tolerate, not necessarily its single best condition - check a plant's own notes for whether it merely tolerates shade or truly prefers it.

💧 Water needs

• Low - drought-tolerant once established; let the soil dry out between waterings.
• Moderate - water regularly, keeping soil evenly moist but not soggy.
• High - keep soil consistently moist, especially in hot weather.
• These are relative to a typical garden plant, not an exact schedule - actual needs vary with your soil, climate, and whether it's in a container or in the ground.

Pollinator-friendly

A plant is only marked pollinator-friendly when a Xerces Society plant list or a Cooperative Extension publication names it. Every rated plant shows its source line.

• What counts - the plant is documented as a nectar or pollen source that draws pollinators, or as a host plant that caterpillars feed on. We list which groups the source names: bees, butterflies, hummingbirds, moths, flies, wasps, or beetles.
• Species, not just genus - a rating for one species doesn't automatically carry to a relative. Where a source states genus-, crop-, or family-level scope itself (“Rubus species,” “cucurbit crops”), we use it and say so on the plant's page.
• Not rated isn't the same as no - many heavily bred bedding and cut-flower ornamentals simply haven't been rated by anyone we'd cite. Those plants say “no pollinator rating yet” rather than being quietly marked unfriendly. A handful of plants are marked “not a pollinator plant” - but only when a source says so, not because we couldn't find one.
• Cultivars and timing matter - pollen-less sunflowers bred for cut flowers feed nothing, doubled flowers can be hard for a bee to work, and a herb or leafy green only feeds anything if you let it bloom. Where that applies, it's on the plant's page.

🧪 Edible, toxic, & traditional use

This holds a higher sourcing bar than the rest of our plant data, since getting it wrong is a real safety issue, not just a UX gap. Each plant's page shows a short source line; this is the fuller explanation of what stands behind it.

• Per-part, not one flattened line. A plant can have several different parts, each with its own edible, traditional-use, and/or toxic entry - Sunflower, for example, has seeds, petals, and buds independently marked edible, plus a separate traditional-use note and a separate toxicity note. This is a category-by-category rewrite of an older, flatter version of this data (flowers first) - a plant showing only the older single-line style just hasn't been through the rewrite yet, not a sign it was skipped.
• Edible and toxic parts - sourced from university Cooperative Extension offices and established toxicology references, cross-checked against peer-reviewed literature where the topic warrants it (a specific compound, mechanism, or dose). Framed plainly: which parts are eaten, which aren't, and why - including prep requirements where a source states them (e.g. cooking, or removing a specific part before eating).
• Traditional use - deliberately not called “medicinal.” We only note that a plant part has a documented history of traditional or folk use, phrased as “traditionally used for...” - never as a health claim, never implying a plant treats, cures, or benefits any condition, and never dosing or other directive language telling you to use it that way. We'd rather leave this blank than include something thinly sourced - tomato, for example, has no entry here, even though folk-medicine claims about it exist online, because what we could find traced back to alternative-medicine marketing rather than a source we'd trust for this.
• Pet toxicity - dogs and cats specifically, sourced only from the ASPCA's published toxic and non-toxic plant list, including their exact wording on the toxic principle and clinical signs where a plant is listed as toxic.
• None of this is ever general knowledge or a guess - if we can't point to one of the source types above for a specific plant part, we leave that field blank rather than fill it in.
• Every plant currently in our database has been through this review. As we add new plants, each one gets the same research and sourcing bar - but that work doesn't always land in the same update as the plant itself, so a newly-added plant may briefly show less here than an established one. Absence of a warning is not the same as confirmed safety; it may just mean the research hasn't caught up yet.
• This is informational only, not medical or veterinary advice. Always verify independently before consuming any plant or trying any traditional use. If you suspect a poisoning, contact Poison Control (1-800-222-1222) for humans or the ASPCA Animal Poison Control Center (1-888-426-4435) for pets.

❓ When a field is blank

This applies to everything on this page, not just one badge. A blank field almost always means no source we'd cite has published on it - not that we checked and found the answer to be no. Two causes account for most of the blanks:

• Naming and taxonomy mismatches - a source lists a close relative rather than the plant you're looking at, or the same common name attaches to a different species. Beach plum isn't covered by a page about garden plums; the “hyssop” on pollinator lists is usually anise hyssop, a different plant entirely. We don't carry a rating across that gap.
• Bred ornamentals - pollinator and native-plant research concentrates on wild species, so the bedding and cut-flower plants filling most gardens are simply understudied.

Where we can explain a specific blank, the plant's own page says why. We'd rather show you a gap than fill it with a guess.

🔄 Crop rotation

• Every plant in our database carries its botanical family (Solanaceae, Brassicaceae, and so on), which is a fixed taxonomic fact rather than something we had to research plant-by-plant.
• The guidance itself only shows up on vegetables and herbs. Crop rotation is a practice for annual beds that get replanted every year - most flowers and fruit are perennial plantings that don't get “rotated” the same way, even when they happen to share a family with a vegetable.
• Every family a vegetable or herb belongs to gets a sentence explaining what to do about it, not just a bare family name. About a dozen - nightshades, brassicas, cucurbits, legumes, the carrot family, the beet family, alliums, the lettuce/aster family, corn, sweet potato, and okra - are the classic groups gardeners actively plan a rotation around, with a specific cycle length. The rest get a sentence explaining why a rotation plan isn't really the concern - either it's a single minor crop with no documented shared soilborne disease or pest pressure, or (like most Lamiaceae herbs - rosemary, sage, thyme, oregano - and a handful of others like asparagus and rhubarb) it's usually planted once and harvested from the same spot for years rather than replanted bed to bed. Basil is the one Lamiaceae exception worth calling out specifically, since unlike its perennial relatives it's replanted fresh every year.
• This is general horticultural guidance, not a per-plant sourced citation the way our safety and pollinator data is - think of it as similar to a seed-packet planting note.

📅 Monthly task list

• My Garden's Tasks view has two kinds of content. Planting and harvest/bloom windows are the same sourced timing data used everywhere else in the calendar, just regrouped by month. Fertilizer and pest guidance is general horticultural content, not a per-plant sourced citation - the same “seed-packet planting note” treatment as crop rotation above, not our safety or pollinator data's sourcing bar.
• Fertilizer and pest guidance only covers vegetables, herbs, and fruit - not flowers, which don't have an established “feeder type” convention to classify against. Fertilizer guidance is keyed by nutrient-demand bucket (heavy/moderate/light) crossed with botanical family, since some families need a fundamentally different approach than their feeder type alone would suggest - legumes fix their own nitrogen despite fruiting, grapes want less nitrogen despite being a vigorous vine, and so on. Pest guidance is family-level, covering the common, nameable pests for the families with real patterns worth flagging - not every family in our database has an entry.
• Where an NPK ratio is genuinely standard for the kind of feeding called for, we name one (e.g. a balanced 10-10-10, or a low-nitrogen 5-10-10 for fruiting/flowering-stage feeding). Where it isn't - a “phosphorus-rich starter” blend varies too much by product and by whether the target is an annual transplant or a woody perennial, for instance - we describe the type of formulation instead of inventing a number. Same “blank is a real answer” rule the rest of this database follows, applied to editorial content instead of a sourced field.
• The Tasks view itself shows only a short summary per plant - a ratio-type label for fertilizing, or just the pest name(s) to watch for. The full explanation (exact wording, establishment-vs-mature detail, pest identification and control) lives on each plant's own page, under “Fertilizing & pest watch” - tap a plant name in the task list to get there.
• Where a pest is common enough on a family that a specific proactive step is worth taking before it shows up - row covers ahead of an egg-laying moth, wrapping a squash vine's base before borer season, clearing debris after harvest to deny next year's overwintering site - that shows as a “Prevent” line, both in the Tasks view and on the plant's own page. Where it isn't (aphids, and most pests that only announce themselves after the fact, like a borer's wilted cane), the honest guidance is to watch and treat if you see it, not a preventative step we'd be inventing to fill the space.
• Watering isn't included here on purpose - each plant's own page already covers its water needs.
• A fertilizer or pest task shows up in every month of a plant's active growing season for a short season, or a handful of evenly-spaced check-in months for a long one (a fall-planted crop, or a perennial establishing over several years) - this is a rough guide to when to check in, not an exact feeding schedule tracked to the week.

🗺️ State guide

• Each state's guide - soil, common pests, climate character, garden prep, and urban/vertical gardening - is sourced from that state's own Cooperative Extension System publications (the land-grant university Extension service for your state), read directly rather than taken from a search-result summary. The guide page itself shows a brief, org-level credit at the bottom (e.g. “UAEX”); the full, individually-verifiable citation list for every publication used is below, inFull source list.
• It's matched to you at the state level, the same way native-plant flagging is - not down to your county or exact microclimate. Large states with real internal variation (coastal vs. inland, north vs. south) say so in the guide itself rather than forcing one answer.
• All 50 states plus DC now have a written guide. As we cover new geographies in the future, they'll go through the same research and sourcing process - but that may not happen the moment we expand there. As with everything else on this page, a blank section within a guide means no Extension publication we'd cite covers that topic for that state, not that we checked and found nothing.

🌻 Companion planting

Grouped from standard, widely-used companion-planting guidance, not controlled scientific studies. See each plant's page for its specific companions.

Pest control

Some plants' Companion Plants section also lists pests they're documented or traditionally believed to repel, protecting nearby plants. Each claim carries one of two tiers:

• Research-backed - a citable source (a Cooperative Extension publication, the Xerces Society, the Royal Horticultural Society, or peer-reviewed literature) documents the effect. The plant page shows a brief org-level credit; the underlying claim was checked against the actual publication, not a search-result summary.
• Folklore (Not citable) - a claim widely repeated in companion-planting tradition that we checked for a citable source and didn't find one at that bar. This includes claims a study has directly tested and found untrue - we still list those, since they're part of real gardening tradition, but the tier tells you no research backs it. There is deliberately no source shown for this tier.

A few things worth knowing that apply broadly rather than to any one plant:

• Many research-backed findings come from a lab test of extracted essential oil, or a trial measuring a specific effect (like reduced pest counts, not full elimination) - not simply “growing this plant nearby.” Where that distinction changes what the claim actually means, it's noted next to the entry.
• Some claims describe trap-cropping (the pest prefers the companion plant and is drawn away from your crop) rather than true repellency (the pest is deterred by scent). We still record these as “repels” since that's how the tradition describes them, even though the mechanism differs.
• A finding for one species is never assumed to apply to a closely related species or ornamental cultivar unless a source specifically tested that one - catnip's mosquito research, for example, doesn't carry over to ornamental catmint.
• This isn't researched for every plant yet. A plant with no pest-control entry means nothing was found that cleared either bar - the same “blank is a real answer” rule as everywhere else on this page, not a claim that it repels nothing.