Carrot and Parsnip

Introduction

Carrot (Daucus carota) and parsnip (Pastinaca sativa) both belong to the Umbelliferae (Apiaceae) family, along with several other crops including celery, fennel, dill, cilantro, and parsley. Best production of these root crops is obtained from deep, well-drained sandy loam soils. Raised beds tend to increase the depth of tilled soil and can help provide good root shape. Some growers chisel plow before forming beds to loosen the soil and enhance root development. Do not destroy soil structure by overworking soils or working them while wet. Some growers rototill to obtain a deep, friable soil. Hilling soil over the shoulders of the roots at the last cultivation can help reduce greening.

Types and Varieties

Carrot and Parsnip Varieties
Roadside Market Carrot Specialty Carrot
Bolero - nantes/imperator, A, C Yellowstone - yellow
Mokum - nantes, A White Satin - white
Ya Ya - nantes, A Purple Haze - purple
Napoli - nantes Rainbow - assorted colors
  Atlas - small round parisian type
Wholesale Market Carrot  
Maverick - imperator, A Parsnip 
Sugar Snax 54 - imperator, A, C Harris Model
  Javelin
  Albion
Resistant or tolerant to: A: Alternaria, C: Cercospora

Soil Fertility

Apply lime according to soil test recommendation to maintain soil pH at 6.5-6.8. Calcium levels should be maintained at a high level to avoid cavity spot. Calcium should be 60%-85% base saturation.

Less nitrogen fertilizer will be needed if legume sod was plowed down or if manure was applied (see Table 1 and Table 7). Application of high amounts of nitrogen to parsnips can cause excessive top growth, increasing their susceptibility to diseases. Using urea as a source of nitrogen for sidedressing may increase the incidence of cavity spot. Fresh manure or urea as nitrogen source can result in branched roots. Manure may also create a food safety issue, so plan on at least 120 days between application of manure and harvest. If large amounts of potassium are needed or if soils are highly leachable, some of the potassium can be applied with the first nitrogen sidedressing application. Carrots and parsnips have relatively high requirements for potassium, but excessive applications can inhibit calcium uptake and thus increase the incidence of cavity spot. 

Suggested rates of nitrogen, phosphorus and potassium are based on high yield expectations of 20-25 tons per acre for carrots. If soil type or other factors limit potential to a lower yield, reduce fertilizer application accordingly.

PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR CARROT AND PARSNIPS
CARROT AND PARSNIPS NITROGEN (N)* LBS PER ACRE PHOSPHORUS (P) LBS P2O5 PER ACRE POTASSIUM (K) LBS K2O PER ACRE
SOIL TEST RESULTS   VERY LOW LOW OPTIMUM ABOVE OPTIMUM VERY LOW LOW OPTIMUM ABOVE OPTIMUM
Broadcast and Incorporate 50 150 100 50 0 300 200 75-100 0
Sidedress 4-6 weeks after planting 30-50 0 0 0 0 0 0 0 0
Sidedress when Roots are 1/2" in Diameter* 30-50 0 0 0 0 0 0 0 0
TOTAL RECOMMENDED 110-150 150 100 50 0 300 200 75-100 0
* IF EXPECTED YIELDS WILL BE LESS THAN 20 TONS/A, THE SECOND SIDEDRESSING CAN BE OMITTED.

Planting

Carrots should be planted to a stand of 15 plants per foot of row, which requires 2-3 lb of seed/A (about 0.0625 oz per 100 feet of single row). Parsnips should be planted to a stand at 8-10 plants per foot of  row, which requires 4-5 lb of seed/A (about 0.5 oz per 100 feet of single row). Parsnip seeds have a short life and lose viability quickly during storage; parsnip seeds should be purchased new each year.

Sow 0.5-0.75 in. deep with row spacing 12-18 in. with 3 or 4 rows per bed. Seeds should be scattered uniformly in a 3-4 in. band when seeding with non-precision seeders. A more uniform stand may be obtained using pelleted seed and precision seeders to seed in bands of 3 rows, 1.5 in. apart.

These crops are slow to germinate; an adequate and constant moisture supply is necessary during this period. Parsnips require a long growing season (110-130 days) and should be seeded as early in the spring as practical. 

Harvest and Storage

Carrots and parsnips must be topped before storage. Mature roots can be kept in good condition for 4-5 months at temperatures near 32°F if not allowed to freeze. Avoid relative humidity higher than 95%, which cause condensation and dripping. Carrots that are not fully mature can be stored only 4-6 weeks. Parsnips should not be harvested until fully mature for good quality. Parsnips can be left in the ground over winter but should be harvested before growth starts in the spring (this is risky because poor spring weather may prevent timely harvesting). Do not store these crops in a building with apples, pears or other ethylene-producing fruits since bitterness can result.