Gaia

Sources

Every figure in the almanac names the bulletin it came from on its own entry. This page is the same citations gathered in one place, read from the database when the site is built: 40 of 49 crops carry a source for their growing figures, 33 published calendars supply the planting windows, and 41 documents supply the tips. A figure whose source has not been found is marked unverified on its entry and listed below.

Where two bulletins disagree by more than a fifth, the entry shows both and says so; nothing is averaged. Years ago are used for dates older than the written record.

Growing figures: spacing, depth, days, germination, yield

Filed under the first bulletin each entry names; open an institution to read every citation as the entry prints it.

University of Arizona Cooperative Extension2 crops +
  • Basil · also UF/IFAS Extension (Florida), Texas A&M AgriLife Extension, Utah State University Extension, Penn State Extension
    Days: 60-75 from seed, 30 from transplant (Univ. of Arizona AZ1005, 2018; UF/IFAS Leon County guide (n.d.) 60-90). First cut at 6-8 leaves (Utah State, Basil in the Garden, rev. May 2020). Spacing DISAGREES over 20%: thin to 3-4 (Utah State) vs 12 (Texas A&M EHT-079, 2014) vs 12-18 (Penn State Extension, Apr 2026); range stored. Depth DISAGREES: one eighth in (Utah State) vs one quarter in (Penn State); one eighth stored. Seed germinates in 1-2 weeks (Penn State). Root zone not found in a primary source.
  • Garlic · also Utah State University Extension
    Spacing DISAGREES over 20%: 3-4 in, rows 6-10 (Utah State, Garlic in the Garden, May 2020) vs 4-6 in, rows 6-12 (Univ. of Maine Bulletin 2063, 2022); range stored, 4 used for layout. Depth 2-3 in (Utah State) and 2-4 in to the clove point (Maine); 2 stored. Days: 5-7 months in the low desert (Univ. of Arizona AZ1005, 2018); fall-planted northern garlic runs about 9 months to a July harvest. Root zone not found in a primary source; Utah State calls it shallow and waters to 12 in. No fresh federal price series.
University of Georgia Extension23 crops +
  • Beans (Pole) · also University of Nebraska-Lincoln Extension, Michigan State University Extension
    Pole beans. Days/spacing/depth: UGA Bulletin 577 (2022) (MSU P3616 (n.d.) gives 55-65 d and 4-12 in, within 20%). Depth 1 to 1.5 in; 1 stored. Root zone: UNL G2189 (2013).
  • Beet · also Oklahoma State University Extension, University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022) (Oklahoma State (n.d.) 50-70 d). Root zone: UNL G2189 (2013).
  • Broccoli · also Oklahoma State University Extension, University of Nebraska-Lincoln Extension
    Days DISAGREE over 20%: 60-80 (UGA Bulletin 577 (2022)) vs 80-90 (Oklahoma State (n.d.)); full range stored. Spacing: UGA Bulletin 577 (2022). Transplanted; days from setting out. Root zone: UNL G2189 (2013).
  • Cabbage · also Oklahoma State University Extension, University of Nebraska-Lincoln Extension
    Days/spacing: UGA Bulletin 577 (2022) (Oklahoma State (n.d.) 60-90). Transplanted; days count from setting out. Root zone: UNL G2189 (2013).
  • Cantaloupe / Muskmelon · also University of Nebraska-Lincoln Extension
    Cantaloupe. Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013) melons row.
  • Carrot · also Oklahoma State University Extension, University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022) (Oklahoma State (n.d.) 70-90 d, within 20%). Root zone: UNL G2189 (2013).
  • Chile Pepper · also University of Nebraska-Lincoln Extension
    Days/spacing: UGA Bulletin 577 (2022) pepper row, which does not separate chile from bell. Days count from transplant. Root zone: UNL G2189 (2013).
  • Corn · also University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013).
  • Cucumber · also University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013).
  • Kale · also University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013).
  • Lettuce · also Oklahoma State University Extension, University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022) (Oklahoma State (n.d.) 60-90 head). Root zone: UNL G2189 (2013).
  • Okra · also University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013).
  • Onion · also University of Nebraska-Lincoln Extension
    Bulb onion. Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013) onions, dry.
  • Peas · also University of Nebraska-Lincoln Extension
    Garden peas. Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013).
  • Potato · also University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013).
  • Radish · also University of Nebraska-Lincoln Extension
    Days/spacing/depth: UGA Bulletin 577 (2022). Root zone: UNL G2189 (2013).
  • Spinach · also University of Nebraska-Lincoln Extension, Michigan State University Extension
    Days: UGA Bulletin 577 (2022) (MSU P3616 (n.d.) 35-45). Spacing DISAGREES over 20%: 1-2 (UGA Bulletin 577 (2022)) vs 4 (MSU P3616 (n.d.)); range stored. Depth 0.75 (UGA Bulletin 577 (2022)) vs 0.5 (MSU P3616 (n.d.)); 0.75 stored. Root zone: UNL G2189 (2013).
  • Squash (Summer) · also University of Nebraska-Lincoln Extension, Michigan State University Extension
    Days: UGA Bulletin 577 (2022). Spacing DISAGREES over 20%: 24 in (UGA Bulletin 577 (2022)) vs 36 in (MSU P3616 (n.d.)); range stored. Depth 1.5 to 2 in (UGA Bulletin 577 (2022)) vs 1 in (MSU P3616 (n.d.)); 1.5 stored. Root zone: UNL G2189 (2013).
  • Squash (Winter) · also University of Nebraska-Lincoln Extension, Michigan State University Extension
    Days: UGA Bulletin 577 (2022) (MSU P3616 (n.d.) 90). Spacing DISAGREES over 20%: 36 (UGA Bulletin 577 (2022)) vs 48 (MSU P3616 (n.d.)); range stored. Depth 1.5 to 2 (UGA Bulletin 577 (2022)) vs 1 (MSU P3616 (n.d.)); 1.5 stored. Root zone: UNL G2189 (2013).
  • Strawberry · also UF/IFAS Extension (Florida), University of Nebraska-Lincoln Extension, Oregon State University Extension
    Days DISAGREE over 20%: 30-60 from transplant to first harvest (UF/IFAS SP103 Table 1, 2025) vs 90-110 from planting (UF/IFAS Baker County, 2018, and Pasco County, 2026); SP103 stored, both named. Full production in year 2 in perennial culture (Oregon State EC 1307, 2020). Spacing: SP103 12-16 (its HTML flattens the spacing columns), Baker County 10-18, OSU 15. Root zone: UNL G2189 (2013).
  • Sweet Potato · also University of Nebraska-Lincoln Extension
    Days/spacing: UGA Bulletin 577 (2022); planted as slips, days count from setting out. Root zone: UNL G2189 (2013).
  • Tomato · also University of Nebraska-Lincoln Extension, Michigan State University Extension
    Days: UGA Bulletin 577 (2022) 70-85 from transplant (MSU P3616 (n.d.) 60-70). Spacing DISAGREES over 20%: 30-36 (UGA Bulletin 577 (2022)) vs 18-36 (MSU P3616 (n.d.)); range stored. Root zone: UNL G2189 (2013).
  • Watermelon · also University of Nebraska-Lincoln Extension, Michigan State University Extension
    Days: UGA Bulletin 577 (2022) (MSU P3616 (n.d.) 70-85). Spacing DISAGREES, large: 96-120 (UGA Bulletin 577 (2022)) vs 48-72 (MSU P3616 (n.d.)); full range stored, both named. Depth 1.5 (both). Root zone: UNL G2189 (2013).
UF/IFAS Extension (Florida)1 crop +
  • Amaranth
    Leaf harvest about 30 days (UF/IFAS HS1407, c. 2024); grain days not found in a primary source. Spacing and depth: UF/IFAS HS1407 (thin to 6 in; one eighth to one quarter in). Root zone not found in a primary source.
Clemson Cooperative Extension (HGIC)2 crops +
  • Fig Tree
    Partly verified: a mature fig reaches 15-30 ft in height and spread (Clemson HGIC 1353, Oct 2025), so the 15 ft stored is the closest two trees should stand; Clemson gives no explicit spacing. Years to fruit, depth and root zone not found in a primary source.
  • Pomegranate · also University of California ANR
    Partly verified: a mature pomegranate reaches 12-20 ft in height and spread (Clemson HGIC 1359, Oct 2025), so spacing is raised from 10 to 12 ft, the closest two should stand; Clemson gives no explicit spacing. Years to bearing (2-3, UC ANR Napa Master Gardeners, n.d.) and root zone not found in a primary source.
Texas A&M AgriLife Extension9 crops +
  • Blackberry · also University of Nebraska-Lincoln Extension
    Spacing: Texas A&M AgriLife Blackberries (2015). Primocane types crop lightly in year 1, floricane types in year 2. Root zone: UNL G2189 (2013) cane fruits.
  • Chamomile
    Spacing: Texas A&M EHT-079 (2014). Days, depth and root zone not found in a primary source.
  • Cilantro / Coriander · also Utah State University Extension, LSU AgCenter
    Spacing: Texas A&M EHT-079 (2014). Depth: one quarter to one half in (Utah State, Cilantro/Coriander in the Garden, Aug 2018; LSU AgCenter Pub. 3424 agrees at one half). Seed takes about 21 days to germinate (Utah State); harvest when leaves are 4-6 in tall. Days to harvest and root zone not found in a primary source.
  • Lavender
    Spacing: Texas A&M EHT-079 (2014). Days, depth and root zone not found in a primary source.
  • Mint
    Spacing: Texas A&M EHT-079 (2014). Days, depth and root zone not found in a primary source.
  • Oregano
    Spacing: Texas A&M EHT-079 (2014). Days, depth and root zone not found in a primary source.
  • Rosemary
    Spacing: Texas A&M EHT-079 (2014). Days: about 3 months from a nursery plant and 15 months from seed, which germinates at only about 15 percent (Texas A&M AgriLife E-623, Easy Gardening: Rosemary, 2010); nearly always grown from cuttings, which root in 4-8 weeks (EHT-079). Depth and root zone not found in a primary source.
  • Sage · also Alabama / Auburn Extension
    Spacing: Texas A&M EHT-079 (2014). Depth: one eighth in, started indoors 6-8 weeks before planting out (Alabama Cooperative Extension, Grow More Sage, rev. Sep 2025); EHT-079 says seed germinates slowly and most sage is grown from cuttings. Days and root zone not found in a primary source.
  • Thyme
    Spacing: Texas A&M EHT-079 (2014). Days, depth and root zone not found in a primary source.
Oklahoma State University Extension1 crop +
  • Grape · also University of Nebraska-Lincoln Extension, University of Maryland Extension
    Spacing: Oklahoma State HLA-6246 (n.d.) 72-96; Univ. of Maryland Extension (n.d.) 96. First crop about year 3. Root zone: UNL G2189 (2013).
University of California ANR1 crop +
  • Nopal (Prickly Pear)
    Prickly pear. Not verified: 3-4 years from seed to fruit (UC ANR Small Farms, n.d.); pad depth and non-hedge spacing not found in a primary source.
University of Missouri Extension1 crop +
  • Sunflower (Mammoth)
    Days to bloom, spacing (6 in for 2-5 ft varieties, 12 for over 5 ft, 24 for giants) and depth (1 in or less): Univ. of Missouri Extension YM102 (n.d.). Root zone not found in a primary source.

Planting calendars behind the windows

  • Univ. of Arizona AZ1005, Vegetable Planting Calendar for Maricopa County (2018) — 24 crops
  • Univ. of Arizona AZ1435 (2015) — 23 crops
  • UF/IFAS SP103, Florida Vegetable Gardening Guide (2025) — 22 crops
  • UGA Bulletin 577 (2022) — 21 crops
  • University of Minnesota Extension — 21 crops
  • After soil reaches 65°F — 1 crops
  • Block plant 4x4 minimum for pollination — 1 crops
  • Needs shade screen by June in zone 8+ — 1 crops
  • Needs shade by July in 8+ — 1 crops
  • MUST have shade screen by June — 1 crops
  • Also Aug for fall crop. Mid-summer sun kills them. — 1 crops
  • 30-day crop. Tuck between slower plants. — 1 crops
  • Fall crop best in hot zones — 1 crops
  • Needs loose soil 12"+ deep. Not raw caliche. — 1 crops
  • Fall crop — 1 crops
  • Fall is best in hot zones — 1 crops
  • Cool season ONLY in hot zones. Bolts in heat. — 1 crops
  • Cool season ONLY. Bolts in any heat. — 1 crops
  • Fall only in desert — 1 crops
  • Fall crop only — 1 crops
  • Fall/winter only in desert. Bolts in heat. — 1 crops
  • 90+ days to harvest. Needs heat. — 1 crops
  • Fall/winter only — bolts in heat — 1 crops
  • Any time. Stick pad 1/3 in soil. — 1 crops
  • Plant dormant season. 15ft from foundation. — 1 crops
  • Zone 8a borderline — may need winter protection — 1 crops
  • 2-3 seeds per hole. 2yr old seeds OK. — 1 crops
  • Fall planting in desert — 1 crops
  • Short-day varieties for southern zones — 1 crops
  • Plant in fall for spring harvest — 1 crops
  • University of Maine Bulletin 2063 (2022) — 1 crops
  • Fall crop only in desert — 1 crops
  • Needs 80+ days of heat — 1 crops

Tips, with the document each one is drawn from

Polycultures and their evidence

  • Three Sisters · empirical — Mt.Pleasant and Burt, Journal of Ethnobiology 30(1) (2010): the polyculture yielded a land equivalent ratio of 1.08-1.30 against the three crops grown alone in New York trials, with bean yield down 88-95% in the mix. Ebel et al., Terra Latinoamericana 35(2) (2017), one highland-Mexico season, found bean per-plant yield equal to monoculture and maize 1.2x; the two trials DISAGREE on whether the beans hold their yield, and both are kept. Archaeology dates the three grown together in the Northeast to after about AD 1300.
  • Desert PHI Guild · design — A composition for this tool: the five share full sun and warm-season timing in the extension calendars (UGA 577, AZ1005). The pest-repelling claims for chile and basil are traditional; the basil-whitefly trials were on tomato, not okra.
  • Kitchen Door Garden · design — A composition for this tool. Basil wants more water than the three perennials; give it the downhill side or its own pot. Spacing per Texas A&M EHT-079 (2014).
  • Mediterranean Circle · design — A composition for this tool from five Mediterranean-basin natives that share soil, water and sun needs (Texas A&M EHT-079, 2014). They are grown together across the Mediterranean, but no trial of the five as a set was found.
  • Salad Bowl · design — A composition for this tool; the succession logic is standard cool-season practice (radish 25-30 d, lettuce 60-85 d, beet 55-65 d, carrot 70-80 d, UGA Bulletin 577, 2022). The Fibonacci day counts are a mnemonic, not the measured intervals.
  • Desert Food Forest Starter · design — A composition for this tool on the forest-garden layer model (Hart, Forest Gardening, 1991; Jacke and Toensmeier, Edible Forest Gardens, 2005). Moringa is frost-tender and dies back below about 25 F; in zone 8 it is a cut-back perennial at best.
  • Aztec Milpa · documented — The milpa (maize, beans, squash, with chile and other plants in the same field) is a living Mesoamerican system described in the 16th-century sources (Sahagun, Florentine Codex, Book 11) and still practised. The five together have not been trialled as a set; the maize-bean-squash core carries the Three Sisters evidence.
  • Corn with Cowpea, Relay-Sown · empirical — Sumarni and Anggoro, Jurnal Agronomi Indonesia 52(2) (2024), East Java, one season: land equivalent ratio 1.96 with cowpea sown 21 days after sweet corn; sowings at 0, 7, 14, 28 and 35 days gave less. A tropical trial; no Florida or Gulf trial with an LER was found.
  • Strawberries with Garlic Between · empirical — Ciência Rural 49(12) (2019), Paraná, Brazil, planted 2015: strawberry yield unchanged (377-454 g per plant open-field), LER increased; the pest reduction is from cited prior work (Experimental and Applied Acarology 69:311, 2016), not this trial. Strawberry with onion specifically: not found in a primary source.
  • Chinampa Bed · documented — FAO Globally Important Agricultural Heritage System, Xochimilco-Tlahuac-Milpa Alta (designated 2017): "grown up to 5 times a year"; earliest securely dated fields Middle Postclassic, 1150-1350 (Parsons, Calnek, Armillas, via the secondary literature). No yield figure on the record; crop list is the milpa complex plus amaranth.
  • Oasis Understory · documented — FAO GIAHS, Gafsa Oases (designated 2011): three levels, 98 date varieties over olive, apricot and pomegranate over cereals and vegetables, 700 ha. Date palms were under cultivation in southern Mesopotamia by the 4th millennium BC (Besseiche et al., Peer Community Journal 2025); the layered system itself has no located early attestation. No per-hectare LER exists for an oasis.

Still unverified

The growing figures for Cowpea / Black-Eyed Pea, Chives, Epazote, Mulberry Tree, Moringa, Nasturtium, Marigold, Jujube (Chinese Date), Tomatillo have not yet been matched to a primary source. They are marked unverified on their entries and will be replaced or confirmed as bulletins are found; the search is in progress.

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