Lima Beans reward good timing in a Zone 8 garden: sow at the right moment and the harvest is heavy; sow wrong and it disappoints. This guide answers when to plant lima beans zone 8 in full: sowing, transplant and harvest windows for USDA Zone 8, plus spacing, soil, water, companions, pests and storage.
Zone 8 covers areas with average annual minimum temperatures of 10 to 20°F, across the southern United States and the Pacific coast. The average last spring frost falls in the Mar 1–15 range and the average first autumn frost in the Nov 15–Dec 1 range. These are USDA zone averages, not exact dates for any one garden — check your local extension service and the forecast before planting tender crops outside. The frost-free season runs roughly eight months, from mid-March into mid-November, which is one of the longest in the country.
When to plant lima beans in Zone 8
Lima Beans are tender, so frost is the limiting factor in Zone 8. The long, warm season from mid-March to mid-November suits them well, but they must not go outside until the last frost has passed and the soil has warmed. A single cold night can check growth for weeks, so patience in spring pays for itself many times over. Lima Beans take 60–90 days to reach maturity, so work backwards from the frost dates to place each stage of the season.
The table below puts the whole season on one page, worked back from the Zone 8 frost averages (Mar 1–15 last frost, Nov 15–Dec 1 first frost) and 60–90 days to maturity. Use the frost date calculator to check the averages for your own area, and confirm them with your local extension service.
| Stage | Zone 8 window | Notes |
|---|---|---|
| Direct sow outdoors | Apr–Jun, once the soil is warm | Sow into moist, prepared soil |
| First harvest | Jul–Sep, 60–90 days after sowing | 60–90 days to maturity |
| Second sowing | Sow by early Jul for a late-summer crop | Count back from the first frost |
Starting and planting
Lima Beans are direct-sown where they will grow — they do not transplant well, and there is no need to start them indoors. Sow seed directly in warm soil from April to June. Lima beans are fussier about cold soil than other beans, so wait until the soil feels genuinely warm — cold, wet soil rots the seed. Bush types need no support; pole types need a sturdy trellis.
Fork the bed over, remove weeds and stones, and dig in well-rotted compost before sowing. Lima Beans grow best at a soil pH of 6.0–7.0 — test your soil through your local extension service before amending it. Henderson Bush is a reliable bush lima; pole types need a tall trellis. Plan the bed with the Harvest Date Calculator so each sowing lands in its window.
Spacing, sun and soil
Space plants 4–6 inches apart. Crowded plants stay small and invite disease through poor airflow, so thin seedlings to the final spacing once established.
This crop needs full sun — at least six hours of direct sun a day, and more is better. In Zone 8, a south-facing bed or an open spot away from trees and fences gives the strongest growth and the best flavour. Soil should be deep, fertile and free-draining, with a pH of 6.0–7.0; heavy clay improves with compost, and raised beds help where drainage is poor.
Watering
Water needs are moderate: aim for steady, even moisture rather than feast-and-famine watering. About an inch of water a week from rain or irrigation is a useful guide in most Zone 8 summers, more in hot, dry spells. Water at the base in the morning and mulch to hold moisture.
Companion planting
Good companions for lima beans include marigolds, basil, onions, lettuce. Planting companions nearby can help with pest confusion, pollination and making the most of bed space. The companion planting finder can suggest combinations for your whole bed. Rotate crops each season, and avoid planting lima beans where others of the same family (Fabaceae) grew last year.
Common pests and problems
Watch for aphids, bean beetles, slugs, cutworms.
- Aphids — inspect weekly; hand-pick or wash off with water, and encourage natural predators.
- Bean Beetles — inspect weekly; hand-pick or wash off with water, and encourage natural predators.
- Slugs — inspect weekly; hand-pick or wash off with water, and encourage natural predators.
- Cutworms — inspect weekly; hand-pick or wash off with water, and encourage natural predators.
Beyond pests, the main problems are weather-related: a late frost, drought at a critical stage, or waterlogged soil after heavy rain. Cover tender plants with frost cloth if a late frost threatens, and mulch to even out soil moisture.
Harvest and storage
Pick pods when they feel plump and the beans inside have filled out, usually July to September. Shell fresh limas promptly, or let pods dry on the plant for dried beans.
The classic Zone 8 mistake with lima beans is sowing in cold soil. Lima seed rots fast in cold, wet ground — wait until late April at the earliest, and later still after a wet spring.
For storage, pick in the morning when plants are crisp and cool, and handle the harvest gently.
Frequently asked questions
When should I plant lima beans in Zone 8?
Work from the table above, using the average last frost (Mar 1–15) and first frost (Nov 15–Dec 1), with 60–90 days to maturity. These are averages, not exact dates — check your local extension service before planting.
How much sun do lima beans need in Zone 8?
Full Sun — at least six hours of direct sun a day. Give them the sunniest spot you have.
What soil pH do lima beans prefer?
A pH of 6.0–7.0. Test your soil before amending it, and add compost to improve structure whatever the pH.
What pests attack lima beans in Zone 8?
The most common are aphids, bean beetles, slugs, cutworms. Inspect weekly, hand-pick larger pests, wash small ones off with water, and keep the bed clean and well spaced.
Do lima beans need a trellis in Zone 8?
Bush varieties do not; pole varieties do, and they climb 6 feet or more. In Zone 8's long season, pole limas can be very productive if given a tall, sturdy support.
Browse the full planting calendar. For the same crop in a colder zone, see when to plant lima beans in Zone 7, and for a related crop, when to plant edamame in Zone 8.