South Dakota planting calendar

When to plant rhubarb in South Dakota — sow, transplant & harvest dates

South Dakota is mostly USDA zone 4b (range 3b-5a). Dates below are derived from rhubarb's frost tolerance and South Dakota's frost window — not generic national averages.

Rhubarb planting timetable for South Dakota

Stage	When in South Dakota	Anchor
Direct-sow outside	late April (April 24)	21 days before the last frost (mid-May)
First harvest (estimate)	late October (October 23)	~547 days from direct sow

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why South Dakota's climate shifts the rhubarb dates

South Dakota's last spring frost averages mid-May and first fall frost late September, which sets the whole planting clock. South Dakota is a cold, windy, short-season plains state. Fast-maturing, cold-hardy varieties are the rule statewide. Wait for warm soil — rhubarb stall in cold ground even after the air warms, so don't rush them out.

Rhubarb is planted as divisions or crowns in early spring while the soil is still cool, 2-3 weeks before the last frost; it is extremely cold-hardy and actually requires winter chilling to break dormancy (reliably hardy to zone 3, marginal in zones 9-10 where inadequate chilling reduces vigour). Do not harvest in year one; take only 2-3 stalks per plant in year two; harvest freely from year three onward, always leaving at least 3-4 strong stalks per crown. Never eat the leaves — rhubarb foliage contains toxic oxalates at harmful concentrations.

Frost-risk note

Don't plant before mid-May — a hard freeze can still set young plants back. In the northern plains near North Dakota (zone 3b) the safe date runs a week or two later.

Regional variation within South Dakota

the northern plains near North Dakota (zone 3b) runs roughly 1-2 weeks behind the state average; the southeast around Sioux Falls and the Black Hills foothills (zone 5a) can plant 1-2 weeks earlier.

Sioux Falls — USDA zone 5a
Rapid City — USDA zone 5a
Aberdeen — USDA zone 4a
Pierre — USDA zone 4b

What else to plant in South Dakota around then

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Quick-grow guide

Sun: Full sun — 6+ hours direct (tolerates light afternoon shade in hot zones).
Soil temperature for germination: Soil 4-10 °C (40-50 °F) at crown planting.
Spacing: 36-48 inches (90-120 cm) between plants.
Days to harvest: ~547 days from planting out.

Frequently asked questions

When is the best time to plant rhubarb in South Dakota?

In South Dakota (mostly USDA zone 4b), direct-sow rhubarb late April (before the last frost, mid-May), and harvest from late October. Rhubarb are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

What USDA zone is South Dakota?

Most of South Dakota sits in USDA hardiness zone 4b, with the state spanning roughly 3b-5a from the northern plains near North Dakota (zone 3b) to the southeast around Sioux Falls and the Black Hills foothills (zone 5a). The last spring frost averages mid-May and the first fall frost late September.

Can you grow rhubarb in South Dakota?

Yes. South Dakota's dominant zone 4b supports rhubarb — the key is timing. Rhubarb are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

Does the planting date change across South Dakota?

the northern plains near North Dakota (zone 3b) runs roughly 1-2 weeks behind the state average; the southeast around Sioux Falls and the Black Hills foothills (zone 5a) can plant 1-2 weeks earlier.

What else can I plant in South Dakota around the same time?

Pair the post-frost slot with other warm-season crops — peppers, beans, squash, and cucumbers.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.