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Garlic

When to start, transplant and harvest garlic, as 6 university extension services put it, and what that means in each zone.

Type
Bulb
Rules
6
Last reviewed
Garden experts do not always agree, so I show every rule side by side.

Five digits. The calendar is computed on your device.

Fall timing, source by source

Fall rules count from the first fall frost.

  1. MinnesotaPlant for fall
  2. WisconsinPlant for fall
  3. Texas A&M (E-502)Plant for fall
  • Plant outdoors
Figure 1. How each extension source times garlic in fall, in weeks before or after the first frost. Rules written for warm states sit weeks earlier than those for cold ones.
Table 1. Planting rules for garlic, as published.
SourceWritten forWhatWhen
Minnesota6MNPlant for fall1-2 weeks after first frost
Wisconsin4WIPlant for fall1-2 weeks after first frost
Texas A&M (E-502)1TXPlant for fall4-6 weeks before first frost

Garlic by hardiness zone

Applied to the frost records of every ZIP in each zone. The zone median is a starting point; your own station can be weeks earlier or later.

Table 2. Fall planting for garlic by zone, using the Wisconsin rule. Linked zones have their own page.
ZoneWhatZone medianAcross most of the zone
4aPlant for fallOct 5 – Oct 12Sep 27 – Oct 18
4bPlant for fallOct 8 – Oct 15Sep 29 – Oct 22
5aPlant for fallOct 12 – Oct 19Oct 3 – Oct 27
5bPlant for fallOct 18 – Oct 25Oct 8 – Nov 2
6aPlant for fallOct 24 – Oct 31Oct 12 – Nov 7
6bPlant for fallOct 29 – Nov 5Oct 17 – Nov 12
7aPlant for fallNov 1 – Nov 8Oct 23 – Nov 16
7bPlant for fallNov 8 – Nov 15Oct 31 – Nov 28
8aPlant for fallNov 13 – Nov 20Nov 7 – Nov 28
8bPlant for fallNov 20 – Nov 27Nov 11 – Dec 7
9aPlant for fallDec 3 – Dec 10Nov 23 – Dec 23

Growing facts

Table 3. Each value as one source states it. Sources measure differently, so values are not averaged.
FactValueSource
Days to maturity140-150 days from plantingTexas A&M (E-502)1
Spacing4-5 in in the row, rows 15-18 in apartIllinois2
Spacing4-8 in in the rowPenn State3
Spacing6 in in the rowWisconsin4
Spacing2-4 in in the row, rows 14-24 in apartTexas A&M (E-502)1
Spacing3-5 in in the row, rows 12-24 in apartClemson5

Companions, and how sure anyone is

  • Beans · Avoid together Traditional pairing7

  • Peas · Avoid together Traditional pairing7

    The chart says "onion family"; garlic is an onion-family (Allium) crop.

  • Tomatoes · Helps Traditional pairing7

    The chart says "onion family"; garlic is an onion-family (Allium) crop.

  • Lettuce · Helps Traditional pairing7

    The chart says "onion family"; garlic is an onion-family (Allium) crop.

  • Carrots · Helps Traditional pairing7

    The chart says "onion family"; garlic is an onion-family (Allium) crop. The carrot fly study tested onions, not garlic.

Traditional pairings come from a UC Master Gardener chart that traces to the UC Davis Edible Landscaping Handbook and ATTRA. The chart gives no reasons, and we found no trial of these pairs; treat them as garden lore.

All garlic companions, with sources · The full companion chart

Sources

  1. Texas AgriLife Extension Service, The Texas A&M System, Texas Home Vegetable Gardening Guide (E-502), 2/09. Retrieved 2026-11-02.
  2. University of Illinois Extension, Planting and Growing Garlic (infosheet), Updated September 2020. Retrieved 2026-11-02.
  3. Penn State Extension, Growing Garlic - Fall Planting, Updated September 9, 2026. Retrieved 2026-11-02.
  4. University of Wisconsin–Madison Division of Extension, Wisconsin Horticulture, Garlic, Allium sativum, Rev: 10/2023. Retrieved 2026-11-02.
  5. Clemson Cooperative Extension, Home & Garden Information Center, Onion, Leek, Shallot, & Garlic (HGIC 1314), Updated: Jan 20, 2023. Retrieved 2026-11-02.
  6. University of Minnesota Extension, Fruit and Vegetable News blog, Tips for garlic planting season, Page shows October 15, 2026; URL path says 2021/10 (unresolved). Retrieved 2026-11-02.
  7. University of California Agriculture and Natural Resources (UCCE Master Gardener Program), Companion Planting Chart: Companion planting in the vegetable garden, File dated 2023-09 in URL path; no date printed. Retrieved 2026-11-02.