Crop Program · Carrots

Feed the whole season, without feeding the groundwater.

An organic carrot program built on CDFA FREP and UC Davis research: a Phyta-Grow® Leafy Green Special base at planting and post-cultivation, then in-season Phytamin® matched to the crop’s steady mid-season uptake — supplying the nitrogen carrots need while keeping nitrate out of the water table.

Why timing matters

Carrots take up nitrogen slowly, then steadily.

Carrot nitrogen uptake is slow for roughly the first 40 days, then climbs steadily as the tops grow, before plateauing as top growth slows (UC Davis / CDFA FREP). A mature crop removes about 3 lb N per ton of root, and full-season demand typically runs 150–200 lb N/acre. Because carrots are grown on light, sandy soils where nitrate leaches easily, the FREP research is clear: nitrogen should be applied close to planting and matched to uptake through the season, not front-loaded where it can move below the root zone. This program places a base at planting and post-cultivation, then delivers immediately available Phytamin® nitrogen during the steady mid-season uptake window.

An organic-system program. These rates account for most of the crop’s nitrogen demand, but your soil also contributes through organic matter, compost, and any cover crop. Start from a soil nitrate test and adjust: where residual nitrate or irrigation-water nitrate is high, reduce the applied rate. Building the full budget from all sources keeps nitrogen efficient and out of groundwater.

The program

A dry base at planting, then in-season liquid.

Timing	Product	Rate	N supplied
Pre-plant Near planting	Phyta-Grow® Leafy Green Special 7-1-2 Dry, incorporated	1,500–2,000 lb/acre	105–140 lb N/acre
Post-cultivating	Phyta-Grow® Leafy Green Special 7-1-2 Dry, side-dress	500–800 lb/acre	35–56 lb N/acre
~60 days Steady uptake	Phytamin® Pure 5-0-0 or Phytamin® Jumpstart 4-1-1 Through irrigation	20–30 gal/acre	~8–12 lb N/acre
Base program nitrogen from COFI products			~148–208 lb N/acre

TimingPre-plant
Near planting

ProductPhyta-Grow® Leafy Green Special 7-1-2
Dry, incorporated

Rate1,500–2,000 lb/acre

N supplied105–140 lb N/acre

TimingPost-cultivating

ProductPhyta-Grow® Leafy Green Special 7-1-2
Dry, side-dress

Rate500–800 lb/acre

N supplied35–56 lb N/acre

Timing~60 days
Steady uptake

ProductPhytamin® Pure 5-0-0
or
Phytamin® Jumpstart 4-1-1
Through irrigation

Rate20–30 gal/acre

N supplied~8–12 lb N/acre

Base program nitrogen from COFI products: ~148–208 lb N/acre

Additional applications as required. Further in-season Phytamin® Pure or Jumpstart applications may be made based on field data — leaf tissue tests, soil nitrate, and crop stage. Adjust rate and number of applications to your yield target and season length with your PCA.

Application timing

Placed against the uptake curve.

STEADY UPTAKE · TOPS GROWING

PRE-PLANTLeafy Green Special
1,500–2,000 lb

POST-CULTIVATINGLeafy Green Special
500–800 lb

~60 DAYSPure or Jumpstart
20–30 gal

PlantDay 20Day 40Day 60Day 80Day 100Harvest

The two Phyta-Grow® Leafy Green Special applications build the nitrogen base through the slow early period and into rapid top growth. The in-season Phytamin® application delivers immediately available nitrogen at around 60 days, during the steady uptake window — with additional liquid applied as the crop and tissue tests indicate.

Sources

Carrot nitrogen uptake, timing, and removal: CDFA FREP & UC Davis California Crop Fertilization Guidelines (Carrot Nitrogen Uptake and Partitioning; ~3 lb N/ton root; ~20 lb N per 100 cwt). Nitrogen and irrigation management on sandy soils: Montazar, UC ANR, Enhancing Nitrogen and Water Use Efficiency in California Carrot Production (Imperial & Kern Counties, tested 140–235 lb N/acre). Leaching and residual-nitrate accounting: CDFA FREP field-specific nitrogen adjustments. Product rates and densities: Phytamin® and Phyta-Grow® CDFA-registered labels, California Organic Fertilizers.

This program is a starting point, not a prescription. Set actual nitrogen rates for each field using its yield target, soil type, soil nitrate test, nitrogen in irrigation water, and cover crop or compost contributions. Carrots are grown on leaching-prone sandy soils — apply nitrogen close to demand and avoid over-application, which wastes nitrogen and risks groundwater. Finalize your program with your PCA or Certified Crop Adviser. Talk to a COFI agronomist

DOWNLOAD CARROTS CROP PROGRAM PDF

THE ORGANIC AGRONOMIST

Growing Organic Carrots: Managing the Root Zone for Marketable Yield

Explore how nitrogen timing, soil conditions, irrigation, and healthy root development work together to produce uniform, marketable organic carrots.

Read the Carrot Article

Illustration showing how soil conditions and root development influence the shape and marketable quality of organic carrots.