Brassicas ·Growing Guide
Purple Top Turnip
Brassica rapa subsp. rapa
Purple Top TurnipBrassicasVery Low Maintenance
Two crops in one—Purple Top Turnip produces both high-protein leafy tops (15-20% crude protein) and energy-rich bulbs (10-12% crude protein, high in digestible energy) on the same plant. Livestock graze the tops first, then dig and consume the bulbs as the tops are depleted. Deer managers plant turnips because whitetails learn to paw u...
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About Purple Top Turnip
Purple Top Turnip (Brassica rapa) is the dual-purpose workhorse of brassica plantings. The leafy tops provide immediate high-protein forage while the bulb stores energy-rich carbohydrates underground, available for grazing or harvest through fall and into early winter.
For livestock, turnips extend the grazing season 4-8 weeks beyond the normal grass growing season. After frost kills grass growth, turnip tops remain green and palatable, and the bulbs persist in the ground until hard freeze. Cattle, sheep, goats, and deer all readily consume turnips.
For wildlife food plots, turnips are the most popular brassica because deer learn to eat the bulbs. After the first hard frost converts starches to sugars (sweetening the bulbs), deer activity on turnip plots intensifies dramatically. This makes turnips the centerpiece of late-season deer food plots across the northeast.
The Purple Top variety is the standard—recognizable by its purple crown above the soil line and white flesh below. It's the most widely planted turnip variety for forage and food plot use.
For livestock, turnips extend the grazing season 4-8 weeks beyond the normal grass growing season. After frost kills grass growth, turnip tops remain green and palatable, and the bulbs persist in the ground until hard freeze. Cattle, sheep, goats, and deer all readily consume turnips.
For wildlife food plots, turnips are the most popular brassica because deer learn to eat the bulbs. After the first hard frost converts starches to sugars (sweetening the bulbs), deer activity on turnip plots intensifies dramatically. This makes turnips the centerpiece of late-season deer food plots across the northeast.
The Purple Top variety is the standard—recognizable by its purple crown above the soil line and white flesh below. It's the most widely planted turnip variety for forage and food plot use.
Fit
Where It Shines
Best for
- Wildlife food plots (deer, turkey)
- Late-season livestock grazing extension
- Dual-purpose forage (tops + bulbs)
- Quick brassica cover crop (60-90 day maturity)
- Fall planting after early crop harvest
- Homestead animal feeding (chickens, goats, pigs love turnips)
- Nitrogen scavenging after summer crops
- Food plot mixes with clover and chicory
Not ideal for
- Lawns or turf
- Permanent ground cover (annual)
- Biofumigation (lower glucosinolate than mustard)
- Dry conditions without moisture for bulb development
- Waterlogged soils (bulbs rot)
- Horse pastures as a sole feed source (introduce gradually)
From Seed to Stand
Establishment & Growth
Germination
Days 3-5: First seedlings emerge. Days 5-7: True leaves develop rapidly. Very fast germination and establishment. Bulb formation begins within 30-40 days.
Growth Habit
Annual. Produces leafy rosette (12-18 inches) above ground and enlarged bulb (3-6 inches diameter) below ground. Both tops and bulbs are edible and grazeable.
Establishment Timeline
Emergence: 3-5 days. Grazing tops: 45-60 days. Mature bulbs: 60-90 days. Winter-kill: varies by severity (bulbs survive moderate frost).
Rates & Care
Seeding & Maintenance
| Seeding rate (new) | 3-5 lbs per acre (forage/food plot); 0.1 lbs per 1,000 sq ft |
|---|---|
| Overseeding rate | 2-3 lbs per acre |
| Soil temp to germinate | 40°F |
| Mowing height | Not mowed; grazed or harvested whole |
| Minimum mow height | Not applicable |
| First mow | Graze when tops reach 12-15 inches (typically 60-90 days from planting) |
| Soil pH | 6.0-7.0 |
| Soil preference | Well-drained loam to sandy loam preferred for clean bulb development. Tolerates heavier soils but bulbs may be misshapen in heavy clay. |
| Nitrogen needs | 50-80 lbs N per acre (brassicas are heavy nitrogen users) |
Conditions
Tolerances
SunFull sun to partial shade (4-8 hours)
ShadeModerate
DroughtModerate
TrafficLow
ColdGood (tops tolerate light frost; bulbs tolerate harder frost and improve in flavor after frost)
HeatModerate (bolts in prolonged heat; best as fall crop)
Hardiness ZonesAnnual in all zones
Step by Step
How to Sow
1
Step 1: Prep
Plant 60-90 days before frost; apply 50-80 lbs N
2
Step 2: Fertilize
No specific fertilizer requirement
3
Step 3: Sow
Broadcast at 3-5 lbs/acre (do not plant deep)
4
Step 4: Contact
Lightly rake or press into surface
5
Step 5: Water
Water if dry
6
Step 6: Mow/Establish
Graze tops in 45-60 days; allow frost to sweeten
Feeding & Timing
Fertilizing & Season
Fertilizer Recommendation
Apply 50-80 lbs N per acre at planting. Brassicas are heavy nitrogen users—adequate N is critical for both top growth and bulb development. Phosphorus and potassium based on soil test. Recommended: Wicked Growth balanced formula at planting.
Find the right Wicked fertilizer →Seasonal Planting
Late summer planting (July-August) is the primary window for northern zones—timed so that bulbs mature as hunting season opens and livestock grazing season extends. Spring planting (April-May) possible for summer forage but turnips perform best as a fall crop when cool temperatures prevent bolting and frost improves palatability.
In Context
How It Compares
Turnip vs. Tillage Radish: Turnip produces an edible/grazeable bulb plus leafy tops; Radish focuses on deep compaction breaking (12-24 inches). Turnip vs. Kale: Turnip matures faster (60-90 days vs. 90-120 for kale) and produces a bulb; Kale produces more leaf biomass and is more cold-hardy. Turnip vs. Rape: Turnip offers dual-purpose (tops + bulbs); Rape produces leafy forage only but with higher protein tops. Turnip is the best all-around brassica for food plots.
Answers
Frequently Asked Questions
What is purple top turnip and what is it used for?
Purple top turnip (Brassica rapa) is a fast-growing brassica planted for livestock forage, deer food plots, and cover crop applications. It produces both nutritious leafy tops (12-16% crude protein) and a large root bulb (10-14% crude protein) that provides high-energy forage through late fall and early winter. Turnips mature in 60-90 days and can withstand light frost, making them one of the best late-season forage options for extending the grazing season.
What soil pH does turnip need to grow well?
Purple top turnips grow best in soil pH 5.5-7.0, with 6.0-6.5 being optimal. They are more acid-tolerant than many brassicas and perform adequately at pH 5.5 where other crops struggle. Turnips prefer well-drained loam but tolerate clay and sandy soils. Adequate phosphorus and potassium promote bulb development—a soil test before planting helps ensure proper fertility. Boron deficiency causes hollow, brown bulbs, so apply 1-2 lbs boron per acre on deficient soils.
When should I plant turnips for deer food plots?
Plant turnips for deer food plots in late summer—mid-July through mid-August in USDA zones 4-6, or August through September in zones 7-8. This timing allows 60-90 days of growth before hard frost, producing mature bulbs and lush tops when natural forage quality declines in fall. Deer typically begin feeding on turnip tops first and switch to bulbs after several hard frosts sweeten the roots. Spring planting is possible but produces lower-quality forage during summer heat.
What is the seeding rate for purple top turnip?
Seed turnips at 3-5 lbs per acre broadcast, or 1-2 lbs per acre drilled in rows. For food plots, 4-5 lbs per acre broadcast provides dense forage. For small plots, use approximately 0.1 lbs (1.5 oz) per 1,000 sq ft. Plant 0.25-0.5 inches deep. Turnip seed is small and benefits from a firm, smooth seedbed. When mixed with other brassicas or cover crops, reduce to 1-2 lbs per acre as part of the blend.
How long does it take for turnips to mature?
Purple top turnips reach harvestable size in 60-90 days from planting. Tops are grazeable within 45-60 days. Full bulb development (3-6 inch diameter) takes 75-90 days under good growing conditions. Turnips grow fastest in cool weather (60-70°F) and slow significantly in summer heat above 80°F. For maximum bulb size, plant early enough to get 60+ days of growth during cool temperatures.
Can livestock graze turnips and how should grazing be managed?
Yes—cattle, sheep, goats, and deer readily graze turnips. Introduce livestock to turnips gradually over 7-10 days to prevent digestive upset (rapid diet change from dry hay to high-moisture brassica forage can cause scouring). Strip-grazing with temporary fencing maximizes utilization. Limit turnip forage to 30-50% of total diet; provide dry hay or grass alongside turnips. Turnip tops contain 85-90% moisture, so animals on turnip-heavy diets may need less water but more dry fiber.
Do turnips survive frost and can they be grazed into winter?
Purple top turnips tolerate light to moderate frost (down to 20-25°F) and actually improve in palatability after frost—cold temperatures convert starches to sugars, sweetening the roots. In zones 5-7, turnips provide grazing through November-December. Hard freezes below 15°F will eventually kill the tops and freeze bulbs solid. Bulbs insulated by snow cover can remain grazeable longer. Turnips will not overwinter or regrow in spring—they are a single-season crop.
