How to grow lime (key lime)
Family Rutaceae. Hardy to USDA hardiness zone 9b+ (U.S. Department of Agriculture). Full sun. Ready in 2-3 years to bearing (perennial tree).
Sun
Full sun
Spacing
8-12 ft (or a large container)
Days to harvest
2-3 years to bearing (perennial tree)
Hardiness
Zone 9b+
What growers actually recorded
Loading zone 7b results…
When to plant lime (key lime)
- Transplant out: ~2 weeks after last frost.
Companion plants for lime (key lime)
Plant with: Marigold, Basil.
Common pests & problems
Citrus leafminer, scale, citrus greening where present.
Grower's tip
More cold-sensitive than lemon or orange; container culture with winter protection is the only realistic option outside zone 10.
When to plant lime (key lime) in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for lime (key lime)
Soil & pH
6.0-7.0: near neutral
Loose, well-drained loam with 3-5% organic matter.
Compost 2 in worked into the top 6 in of soil each spring.
Watering
1 in / week
Deep drip at the base twice a week beats a daily shallow sprinkle.
Consistent moisture prevents most crop problems.
Knowing when to harvest
- Most limes are picked green and firm; full ripeness (yellowing) exists but reduces the characteristic tartness prized in cooking.
- Fruit should feel heavy for its size, a sign of juice content.
- Clip rather than pull; thin-skinned limes tear easily at the stem.
Storing & keeping
Counter for about a week, fridge crisper for 2-4 weeks. Juice and zest both freeze well for months.
What to expect
Per plant: 50-100+ limes from a mature tree, bearing by year 2-3, sooner for grafted trees
Lime is among the least cold-tolerant citrus, damaged near 30-32°F; strictly a zone 10-11 outdoor tree or a container-and-shelter crop elsewhere.
Troubleshooting lime (key lime)
Tree defoliates or dies back after a mild cold snap
Likely cause: Lime has the lowest cold tolerance of the common citrus
What to do: Grow in a container that can be moved indoors well before frost in any marginal climate.
Thorny, vigorous growth from the base overtaking the graft
Likely cause: Rootstock suckering below the graft union
What to do: Remove rootstock suckers as soon as they appear, cutting flush at the base.
Varieties worth growing
Bearss (Persian)
Seedless, the common grocery-store lime, relatively more cold-tolerant than Key lime.
Key lime (Mexican)
Smaller, more aromatic and tart, but noticeably more cold- and wind-sensitive.
Growing lime (key lime) in containers
Viable and common in a 10-15 gallon pot; the practical way to grow lime nearly everywhere outside zones 10-11, with reliable winter shelter.
Nutrition
A meaningful source of vitamins, minerals, and fiber when eaten fresh.
Common questions
Why did my lime tree die after a light frost that my orange survived?
Lime has the least cold tolerance among common citrus and is damaged at temperatures oranges and even lemons can shrug off.
Does lime need a pollinizer?
No, lime is self-fertile.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.