Rutabagas are mostly a fall crop. They need about 3 to 4 months to mature (NC State) and taste best after frost, so sow them in summer and count back from your first fall frost. Illinois Extension's rule is to plant about 100 days before the first frost. In regions with a long, mild spring you can also sow 4 to 6 weeks before your last spring frost (NC State).
Rutabaga (Brassica napus) is a cross between turnip and cabbage, with a larger, denser, yellow-fleshed root. Illinois Extension says rutabagas take about 4 weeks longer than turnips to mature, which is why they are best grown as a fall crop: the roots finish in cool weather instead of summer heat. Clemson notes that roots left in the ground in hot weather turn pithy and strong-flavored. For turnips, see when to plant beets, radishes and turnips.
Fall planting dates by first frost
The middle column applies Illinois Extension's 100-day rule. The window around it is GardenPal's estimate, based on NC State's variety range of 90 to 120 days: sow toward the earlier end for slower varieties such as 'Laurentian', and the later end for faster types.
| Average first fall frost | Sow seed (about 100 days before) | Sowing window (GardenPal estimate) |
|---|---|---|
| Sep 15 | Jun 7 | May 28 – Jun 17 |
| Oct 1 | Jun 23 | Jun 13 – Jul 3 |
| Oct 15 | Jul 7 | Jun 27 – Jul 17 |
| Nov 1 | Jul 24 | Jul 14 – Aug 3 |
| Nov 15 | Aug 7 | Jul 28 – Aug 17 |
| Dec 1 | Aug 23 | Aug 13 – Sep 2 |
Extension dates by region
| Region | Fall crop | Spring crop |
|---|---|---|
| Minnesota | Sow late May to early June; harvest September, October or later (University of Minnesota) | Not recommended; rutabagas are planted in summer for a fall crop |
| Central Maryland | Sow seed directly in July (University of Maryland) | — |
| South Carolina Piedmont | July 15 to September 30 (Clemson) | March 15 to April 30 (Clemson) |
| South Carolina Coastal Plain | August 15 to October 15 (Clemson) | February 1 to March 31 (Clemson) |
Minnesota's early start reflects its short season: the crop needs the summer to size up, then stays in the ground well into fall. In mild-winter areas, Illinois Extension says large rutabagas can hold in the garden well into winter.
Spring planting
NC State says rutabagas can be sown 4 to 6 weeks before the last frost. The catch is timing at the other end: the roots need 3 to 4 months, so a spring crop matures in early summer heat. Only try it where spring is long and cool, and pick the roots as soon as they reach size. The harvest column is GardenPal's estimate from NC State's 90-to-120-day range.
| Average last spring frost | Sow seed outdoors | Roots ready (approx.) |
|---|---|---|
| Mar 1 | Jan 18 – Feb 1 | Apr 18 – Jun 1 |
| Mar 15 | Feb 1 – Feb 15 | May 2 – Jun 15 |
| Apr 1 | Feb 18 – Mar 4 | May 19 – Jul 2 |
| Apr 15 | Mar 4 – Mar 18 | Jun 2 – Jul 16 |
| May 1 | Mar 20 – Apr 3 | Jun 18 – Aug 1 |
| May 15 | Apr 3 – Apr 17 | Jul 2 – Aug 15 |
| Jun 1 | Apr 20 – May 4 | Jul 19 – Sep 1 |
Planting and spacing
| Step | What extension sources say |
|---|---|
| Depth | ¼ to ½ inch (Clemson); ½ inch (Illinois Extension) |
| Spacing | Thin to 6 inches when seedlings are 2 inches tall (Illinois Extension) or to 8 inches (University of Minnesota); rows 14 to 18 inches (Clemson) or 18 to 30 inches (University of Minnesota) apart |
| Germination | Seedlings appear after about 10 days (University of Minnesota); water lightly and often so a crust doesn't block them (Clemson) |
| Soil | Well-drained and loosened; pH 6 to 7 (University of Minnesota) or 6.0 to 6.5 (Clemson) |
| Water | About 1 inch a week; drought makes roots bitter or woody (University of Minnesota, NC State) |
| Feeding | Side-dress about a month after planting (University of Minnesota); too much nitrogen can reduce root formation (Clemson) |
Rotate and protect
Rutabagas share pests and diseases with cabbage, broccoli and kale. University of Minnesota recommends planting where no cabbage-family crop has grown for four years, and NC State says to avoid a spot for at least 6 years if clubroot shows up. Flea beetles chew small holes in young leaves and root maggots tunnel into roots (University of Minnesota); NC State suggests row cover to protect the plants. See what to plant with cabbage for companions that suit the whole family.
Harvest and storage
Start harvesting at 3 to 4 inches across (Clemson); NC State says roots are best at 3 to 5 inches and can turn tough beyond 5. Dig them with a spading fork rather than pulling (University of Minnesota). In a root cellar at 32 to 40°F and 95% humidity, University of Minnesota says rutabagas keep up to five months; in a refrigerator they may sprout or dry out after a few weeks.
Frequently asked questions
When should I plant rutabagas?
Mainly in summer for a fall crop. Illinois Extension says to plant about 100 days before your first fall frost. NC State also allows a spring sowing 4 to 6 weeks before the last frost.
Can you plant rutabagas in spring?
Yes, 4 to 6 weeks before the last frost (NC State), but the roots take 3 to 4 months and can turn pithy and strong in hot weather (Clemson), so fall is usually better.
When do you plant rutabagas in Minnesota?
Late May to early June, for a harvest in September, October or later (University of Minnesota).
How long do rutabagas take to grow?
About 3 to 4 months (NC State); common varieties take 90 to 120 days.
Does frost make rutabagas sweeter?
University of Minnesota says frost improves their flavor, and many gardeners wait for a hard frost before digging. Clemson advises harvesting ready roots before a hard freeze in South Carolina.
How far apart should rutabagas be?
Thin to 6 inches (Illinois Extension) or 8 inches (University of Minnesota) apart.
How big should rutabagas be when harvested?
About 3 to 4 inches across (Clemson); NC State says 3 to 5 inches, and larger roots can be tough.
Enter your frost dates to see your fall cool-season crops alongside the rest of your planting calendar.
Open itSources
- Virginia Cooperative Extension, "Companion Planting in Gardening" (SPES-620P)
- University of Maryland Extension, "Vegetable Succession and Companion Planting"
- Oregon State University Extension, "Companion Planting"
- Penn State Extension, "Herbs Make Good Plant Partners and Companions"
- University of Minnesota Extension, "Planting the vegetable garden"
- USDA Plant Hardiness Zone Map
- NOAA NCEI U.S. Climate Normals (frost/freeze data)
- University of Illinois Extension, "Turnip" (home vegetable gardening)
- University of Minnesota Extension, "Growing turnips and rutabagas"
- Clemson HGIC, "Turnips & Rutabagas"
- NC State Extension Gardener Plant Toolbox, "Brassica napus (Napobrassica Group)" (rutabaga)
- University of Maryland Extension, "When to Plant Vegetables"
Pairings are summarized in our own words from extension-service guidance. Research support for many companion effects is limited, so treat them as good habits, not guarantees.