Growing lima beans in USDA Zone 9 means gardening in one of the warmest zones in the country: average winter lows of 20 to 30°F, an average last spring frost of Jan 30–Feb 15 and an average first autumn frost of Dec 1–15, giving a frost-free window of roughly 290–320 days. Frost dates vary by microclimate, elevation and year — check your local extension service.
Lima beans are a warm-season legume that does well in Zone 9's long summer, and they reward the gardener twice: as a soil-improving legume while they grow, and as a protein-rich harvest of buttery beans. They need warm soil to germinate properly, so patience in spring pays off — seed sown into cold soil can rot, while seed sown a week or two later into warm soil catches up quickly.
When to plant lima beans in Zone 9
In Zone 9, March to May, once the soil is warm; a second sowing in August gives an autumn crop.
The table below puts the whole season on one page, worked back from the Zone 9 frost averages and the crop's published days to maturity (60–90 days). Use the frost date calculator to check the averages for your own area.
| Stage | Zone 9 window | Notes |
|---|---|---|
| Start indoors | Not needed — direct sow | Germination takes 7–14 days |
| Direct sow outdoors | March to May, once the soil is warm; a second sowing in August gives an autumn crop | — |
| Transplant outdoors | Not applicable — direct-sown | — |
| Days to maturity | 60–90 days | — |
| Cold tolerance | tender | — |
Starting and planting
Lima beans are direct-sown in Zone 9 after the average last frost, once the soil has warmed. Sow seeds about an inch deep, keep the seedbed evenly moist until germination, and thin to the final spacing once seedlings are up. Bush types stay compact and need no support; pole types need a trellis, fence or poles to climb, and will keep producing over a longer period. Give pole types a sturdy support from the start — a trellis put up after the vines are tangled is a frustrating job.
Spacing, sun and soil
Space plants 4–6 inches apart. Crowded plants compete for light, water and nutrients, stay small, and invite disease through poor airflow, so thin seedlings to the final spacing once they are established. Use the plant spacing calculator to work out how many plants fit in your bed at that spacing before you sow.
This crop needs full sun — at least six hours of direct sun a day where possible. In Zone 9, a south-facing bed or an open spot away from trees and fences gives the strongest growth; part-shade types do better with morning sun and afternoon shade.
Soil should be deep, fertile and free-draining, with a pH of 6.0–7.0. Test your soil through your local extension service before amending it, and dig in plenty of compost, which improves drainage in heavy soil and holds moisture in light soil.
Watering
Water needs are moderate: aim for steady, even moisture rather than feast-and-famine watering. Lima beans like even moisture, especially while pods are filling, but they dislike waterlogged soil, so a well-drained bed matters in Zone 9's occasional heavy rain. Water at the base and mulch to hold moisture steady through hot spells. In a dry spell, water deeply rather than sprinkling a little each day.
Companion planting
Good companions for lima beans include marigolds, basil, onions and lettuce. The companion planting finder can suggest combinations for your whole bed. Avoid planting lima beans where others of the same family (Fabaceae) grew last year: rotate crops each season to reduce soil-borne disease and pest build-up.
Common pests and problems
Watch for aphids, bean beetles, slugs and cutworms. Inspect plants weekly — look under leaves, where small pests hide, and at the base of stems. Hand-pick larger pests, wash aphids off with a strong jet of water, and remove badly affected leaves rather than leaving them to spread a problem. Beyond pests, the main problems are weather-related: bolting in a hot spell, slow growth in cold soil, and damping off in seedlings kept too wet.
Harvest and storage
Harvest timing follows the maturity range of 60–90 days, but judge by the pods, not the calendar: pods should feel full and plump, with the beans inside clearly swollen. For fresh use, pick pods while the beans are still tender; for dried beans, leave pods on the plant until they are dry and papery, then shell them. Harvest in the morning when plants are cool, and pick regularly — regular picking encourages the plant to keep setting pods.
The August sowing is worth trying in Zone 9: beans set in late summer mature in the cooler autumn, and pole types in particular keep producing until the first frost in December.
Frequently asked questions
When should I plant lima beans in Zone 9?
Sow or transplant according to the table above, working from the average last frost of Jan 30–Feb 15 and the average first frost of Dec 1–15. These are zone averages — check your local extension service before planting out.
Can lima beans survive a frost in Zone 9?
Cold tolerance for this crop is listed as tender. Hardy crops can take a light frost, frost-tolerant crops can take a light frost once established, and tender crops are killed or badly damaged by frost, so use row cover on cold nights.
How long do lima beans take to grow in Zone 9?
Germination takes 7–14 days and maturity takes 60–90 days from sowing or transplanting, according to standard published ranges.
Do lima beans need a trellis in Zone 9?
It depends on the type. Bush lima beans stay compact and need no support, while pole lima beans climb and need a trellis, fence or poles — and they repay the effort with a longer harvest. Check the seed packet before you buy, and put the support in place at sowing time so you are not wrestling vines later.
See the April planting guide for Zone 9 for what else to sow that month, and when to plant edamame in Zone 9 for a related crop.