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Carrots in the Home Garden — 2004

Garden Help > Vegetables > Carrots

Introduction

The carrot study consisted of growing 14 varieties of carrots in three different soil textures and compositions. There were several objectives for the study:

  1. Determine the best germination method for planting seeds.
  2. Determine the effect of soil texture on carrot growth.
  3. Determine the effect of soil composition on carrot flavor.
  4. Determine the effect of soil composition on carrot shape.
  5. Determine the effect of soil composition on carrot production.

Study Design

A raised bed was built in which to plant the carrots. The bed was 32 feet long, 4 feet wide and 1 foot high. The soil was removed 6 inches below ground level and replaced with the planting mixture, giving the carrots 16 inches of soil mixture in which to grow. The bed was divided into three equal sections, 10 2/3 feet in length. Each section was filled with a different planting mixture as shown below:

Mix 1 Mix 2 Mix 3
1/3 compost 1/3 compost 1/3 compost
1/3 soil 1/3 soil 1/3 soil
1/3 sand 1/3 perlite 1/3 soil

 

Fourteen varieties of carrots were planted in 5 feet long rows in each section of the raised bed. The varieties selected can easily be found in local stores, nurseries or on-line. The varieties and seed source were:

Variety Packet Description Seed Source
Danvers Half Long "Board shouldered, almost coreless, good taste, rich orange" Heritage Seeds
Danvers 126 "Strong top and tapered root pull up easily, crisp, sweet taste" NK Lawn and Garden
Early Nantes 2 "Uniform blunt end roots, outstanding flavor" Mr. Fothergill's Seeds
Scarlet Nantes "Dependable sweet flavor, crisp texture and bright orange color" NK Lawn and Garden
Bolero Nantes "Slender cylinder w. blunt tips, deep orange, sweet, brittle texture" Renee's Garden
Babette Harvest mini or full size, "full sweet flavor, uniform deep orange" Renee's Garden
Tendersweet "Tapered long with strong tops, sweet, tender" NK Lawn and Garden
Chantenay Red Cored "Short, thick, crunchy sweet flavor" NK Lawn and Garden
King Midas "Large, tapered, sweet, deep orange flesh" Renee’s Garden
Cartago F1 Harvest as mini or full size, "intense orange
and sweet flavor"
Mr. Fothergill's Seeds
New Kurodo Wide at top, long, "one of sweetest, deep orange" Botanical Interests
Gold Pak "Long, smooth, delicious, red orange, almost coreless" Heirloom Seeds
Oxheart "Short, thick root, excellent keeper with great taste" Heirloom Seeds
St. Valery "Smooth uniform roots, thick, sweet, tender flesh" Heirloom Seeds


carrot

carrot1

carrot2

The rows were spaced 7 inches apart with the two outer rows planted 3 inches from the side of the bed, as shown in Table 1.

carrot6

An irrigation system was installed using 1/4 inch soaker hose and 1/2 inch poly-propylene hose. The 1/2 inch hose was placed horizontally across the bed between the two sets of 7 rows. The 1/4 inch soaker hose was connected to the 1/2 inch hose, running next to the side of the bed and between each row. Before germination, the soaker hose was placed directly on soil above the seeds and then moved to a midpoint between the rows after germination. The soaker hose should be checked for water flow since older hose can shrink and cause less water to flow.

A separate study was conducted to determine the germination rate for carrots using three planting methods. Carrot seeds were planted in three one foot rows and then each row was covered with different materials. The materials used were sand, soil, and vermiculite.

Study Timing

The raised bed was constructed and filled in February. The germination study was done at this time. In late March, the 14 varieties of carrots were planted. A shade cloth was placed over the bed for about one month or until the carrot tops were 4 inches tall. A taste test of the carrots was done the first week of July and all of the carrots were harvested the next week.

carrot3

carrot4

carrot5

Study Results

Germination Experiment

Twenty-three seeds were planted approximately 3/4 inch apart in each of the compartments of a 9-inch by 13.5-inch plastic container with 2 inches of top soil. Each seed section was covered with 1/4 inch of either top soil, sand or vermiculite and watered regularly and equally with a fine spray. The first seedling appeared on the 9th day. On about day 21, some seedlings in both the vermiculite and the sand began to droop or die. This could be from over or under watering. Thinning of the seedlings was then performed by cutting with scissors. X in the table below denotes dates on which the seedlings were not counted.

Germination Data

Table 2 shows the germination rates for the seed coverings. The best results were achieved with the vermiculite covering. This covering was used for all 14 varieties in this study.

 Table 2: Germination Experimental Results
 
  Day
9
Day
10
Day
11
Day
12
Day
13
Day
14
Day
15
Day
16
Day
17
Day
18
Day
19
Day
20
Day
21

Seedlings
thinned to:

Soil
Covered
0 0 0 X 2 2 6 X X 6 6 7 7

No Thinning

Sand
Covered
1 4 6 X 9 13 13 X X 15 18 18 17 5
Vermiculite
Covered
5 14 16 X 19 19 19 X X 21 21 22 19 7
 
  

Taste

Table 3 and 3A is a summary of the taste testing. The taste was very subjective and varied among the tasters. The results are relative and even the carrots which received negative comments had excellent taste. The results indicated that there is no one best soil texture in which to grow carrot for taste. Mix 3 (soil/compost) had the highest rating. Mix 1 (sand/soil/compost) had the lowest ratings. The best soil mixture and taste seems to depend upon the variety being grown.

 Table 3: Taste Test Results for First Seven Varieties of Carrots

 
  Babette Tendersweet Chantenay
Red Cored
King Midas Cartago F1 Danvers
Half Long
Danvers
126
Mix 1
Sand, Compost
and Soil
2 2 3 3 1 3 3
Mix 2
Perlite,
Compost and Soil
1 3 1 2 2 2 1
Mix 3
Soil and
Compost
3 1 2 1 3 1 2
Comments Bitter in
Mix 3
Very sweet in Mix 3 Tender Crisp
Greater flavor in Mix 3
Green Taste, Grainy Sweet, Great taste  
Ranking 1 = best tasting

 

Table 3A: Taste Test Results for Second Seven Varieties of Carrots

  Early Nantes 2 Scarlet Nantes Bolero Nantes New Kurodo Gold Pak Oxheart St. Valery
Mix 1
Sand, Compost
and Soil
3 3 3 2 3 2 1
Mix 2
Perlite,
Compost and Soil
1 1 2 3 2 3 2
Mix 3
Soil and
Compost
2 2 1 1 1 1 3
Comments   Bland Good
variety,
succulent
Nice flavor Bland Better
flavor in
Mix 3
 
Ranking 1 = best tasting

 

Production and Shape

Carrots grown in the Mix 3 (soil/compost) were heavier and, in general, longer. Those grown in the Mix 2 (perlite/soil/compost) mixture grew almost as well. The Mix 1 (sand/soil/compost) carrots seemed significantly lighter in weight. These results can be seen by comparing average weight per carrot in Table 4, 4A and 4B. The difference in the total number of carrots in the data is due to thinning. A spacing of at least 1 inch between the carrots was maintained. Because the carrots in the Mix 3 (soil/compost) had larger diameters, it was necessary to remove more carrots to obtain the 1-inch spacing.

A general shape of the carrot can be obtained by calculating the ratio of the top diameter and length for the average carrot for the different varieties. These ratios for carrots grown in the Mix 3 (soil/compost) and the Mix 2 (perlite/soil/compost) mixtures were quite similar, while those grown in the Mix 1 (sand/soil/compost) differed.

Table 4: Soil Type: 1/3 Sand, 1/3 Soil, 1/3 Compost (July 13, 2004)

Variety

Longest Carrot

Average Carrot

Shortest Carrot

Total
Weight (lbs)
Total No. Average
Weight per
Carrot
Length (in.) Diameter Length (in.) Diameter Length (in.) Diameter
Top Bottom Top Bottom Top Bottom
Danvers Half Long 4.75 0.75 0.38 3.00 0.75 0.50 1.50 0.38 0.13 1.00 37 0.03
Danvers 126 7.00 2.00 0.25 5.25 1.13 0.13 1.50 0.50 0.25 3.0 30 0.10
Early Nantes 2 6.38 0.63 0.25 4.50 0.50 0.38 1.25 0.25 0.06 1.25 35 0.04
Scarlet Nantes 6.50 1.00 0.25 3.50 0.75 0.06 2.06 0.38 0.13 1.75 37 0.05
Bolero Nantes 5.25 1.00 0.25 4.75 0.75 0.25 2.75 0.25 0.06 2.75 41 0.07
Babette 4.50 0.50 0.25 4.25 0.50 0.25 1.00 0.38 0.06 0.75 38 0.02
Tendersweet 8.75 1.00 0.63 5.00 0.75 0.25 2.00 0.13 0.06 3.25 58 0.06
Chantenay Red Cored 5.50 1.25 0.13 4.25 0.75 0.25 3.00 0.38 0.03 2.00 39 0.05
King Midas 4.75 1.75 1.75 3.00 0.75 0.50 1.75 0.38 0.38 1.50 46 0.03
Cartago F1 6.50 0.75 0.25 6.00 0.50 0.06 3.50 0.25 0.06 0.75 29 0.03
New Kurodo 5.25 1.75 1.50 4.00 1.50 0.75 1.75 0.75 0.50 3.50 43 0.08
Gold Pak 6.50 0.50 0.06 5.00 0.25 0.06 1.50 0.06 0.03 0.75 51 0.01
Oxheart 4.00 2.00 0.75 3.00 1.75 1.00 1.00 1.50 0.25 6.25 30 0.21
St. Valery 7.00 1.50 0.38 6.50 0.50 0.13 3.13 0.63 0.25 2.00 33 0.06

 

Variety Shape/Comments Variety Shape/Comments
Danvers Half Long Wide at top, long Chantenay Red Cored Look healthy, fat, tapers
Danvers 126 Malformed, some are split or have 2 tails King Midas Short, cylinders
Early Nantes 2 Narrow, some very short, 1 yellow Cartago F1 Long, narrow
Scarlet Nantes Short, cylinders New Kurodo Wide at top, tapers, 3 are flaccid, rubbery
Bolero Nantes Nice carrot shapes, some with 2 tails Gold Pak Long, very narrow
Babette Short, cylinders Oxheart Heart shape
Tendersweet Long, narrow St. Valery Wide at top, tapers to bottom, flowering carrot is yellow, very rigid

 

Table 4A: Carrot Production and Shape, Soil Type: 1/3 Perlite, 1/3 Soil, 1/3 Compost (July 13, 2004)

Variety

Longest Carrot

Average Carrot

Shortest Carrot

Total
Weight (lbs)
Total No. Average
Weight per
Carrot
Length (in.) Diameter Length (in.) Diameter Length (in.) Diameter
Top Bottom Top Bottom Top Bottom
Danvers Half Long 6.25 1.25 0.25 5.50 1.00 0.13 1.75 0.50 0.06 2.25 38 0.06
Danvers 126 6.25 1.50 0.13 3.50 1.00 0.50 1.75 0.50 0.13 1.75 26 0.07
Early Nantes 2 6.25 1.00 0.25 4.00 0.75 0.25 0.75 0.13 0.06 2.00 50 0.04
Scarlet Nantes 6.00 0.88 0.25 4.00 0.75 0.13 1.50 0.13 0.06 1.25 30 0.04
Bolero Nantes 6.25 0.75 0.38 5.75 1.00 0.38 2.25 0.50 0.25 3.25 38 0.09
Babette 4.75 0.50 0.25 4.50 0.75 0.25 1.75 0.25 0.06 1.5 35 0.04
Tendersweet 8.25 0.75 0.25 5.75 0.50 0.13 2.75 0.50 0.13 2.00 36 0.06
Chantenay Red Cored 6.50 1.50 0.19 5.50 1.00 0.75 2.00 0.75 0.13 4.75 35 0.14
King Midas 4.25 0.50 0.25 3.50 0.50 0.25 2.50 0.38 0.25 1.00 25 0.04
Cartago F1 7.75 1.00 0.75 5.00 0.75 0.13 3.50 0.25 0.13 2.13 30 0.07
New Kurodo 6.00 1.25 0.25 4.50 0.75 0.50 2.25 0.25 0.13 1.75 30 0.06
Gold Pak 9.50 0.75 0.13 5.50 0.50 0.13 1.25 0.25 0.06 1.63 32 0.05
Oxheart 3.75 3.00 1.00 3.00 1.50 0.75 1.00 0.25 0.13 3.00 28 0.11
St. Valery 8.50 1.75 0.25 6.00 1.25 1.50 1.50 0.25 0.19 4.50 34 0.13

 

Variety Shape/Comments Variety Shape/Comments
Danvers Half Long Wide at top, long Chantenay Red Cored Look healthy, fat, tapers
Danvers 126 Malformed, some are split or have 2 tails King Midas Short, cylinders
Early Nantes 2 Narrow, some very short, 1 yellow Cartago F1 Long, narrow
Scarlet Nantes Short, cylinders New Kurodo Wide at top, tapers, 3 are flaccid, rubbery
Bolero Nantes Nice carrot shapes, some with 2 tails Gold Pak Long, very narrow
Babette Short, cylinders Oxheart Heart shape
Tendersweet Long, narrow St. Valery Wide at top, tapers to bottom, flowering carrot is yellow, very rigid

 

Table 4B: Carrot Production and Shape,  Soil Type: 2/3 Soil, 1/3 Compost (July 13, 2004)

Variety

Longest Carrot

Average Carrot

Shortest Carrot

Total
Weight (lbs)
Total No. Average
Weight per
Carrot
Length (in.) Diameter Length (in.) Diameter Length (in.) Diameter
Top Bottom Top Bottom Top Bottom
Danvers Half Long 9.00 3.00 0.25 6.50 1.25 0.25 0.75 0.13 0.06 3.00 29 0.10
Danvers 126 7.25 2.00 0.25 5.50 1.38 0.25 1.50 0.63 0.25 6.25 33 0.19
Early Nantes 2 7.00 1.38 0.25 4.25 1.00 0.50 1.50 0.38 0.13 2.00 29 0.07
Scarlet Nantes 7.00 1.13 0.63 5.75 1.00 0.63 2.25 0.50 0.25 6.25 35 0.18
Bolero Nantes 6.75 1.00 0.50 6.00 1.00 0.25 1.50 0.50 0.25 3.25 36 0.09
Babette 4.75 1.13 0.63 4.25 0.75 0.50 2.00 0.38 0.25 2.00 31 0.06
Tendersweet 7.75 0.88 0.25 7.00 1.00 0.25 1.75 0.38 0.25 2.50 27 0.09
Chantenay Red Cored 5.50 2.00 0.38 5.25 1.75 0.25 2.75 0.50 0.13 7.00 32 0.22
King Midas 4.50 0.50 0.50 4.25 0.50 0.38 2.25 0.50 0.38 0.75 15 0.05
Cartago F1 8.00 0.63 0.25 6.25 0.88 0.38 2.75 0.25 0.13 3.75 26 0.14
New Kurodo 6.50 1.50 0.50 4.63 1.38 0.25 2.75 0.63 0.25 2.50 18 0.14
Gold Pak 8.00 1.00 0.25 6.25 0.75 0.25 2.25 0.50 0.25 2.25 27 0.08
Oxheart 4.50 2.00 0.50 3.25 2.13 0.38 2.50 1.25 0.50 4.00 20 0.20
St. Valery 5.00 1.25 0.25 5.00 1.00 0.25 3.00 0.63 0.13 3.13 24 0.13

 

Variety Shape/Comments Variety Shape/Comments
Danvers Half Long Wide at top, long, rough skin Chantenay Red Cored Wide at top, some tapering
Danvers 126 Wide at top, some malformed King Midas Short, cylinders
Early Nantes 2 Some long, some very short Cartago F1 Long, narrow
Scarlet Nantes Some long, some short cylinders New Kurodo Wide at top, tapers, 1 yellow carrot
Bolero Nantes Long cylinders Gold Pak Long, narrow
Babette Cylinders Oxheart Heart shape
Tendersweet Long, narrow St. Valery Malformed, many with 2 tails

 

by Jackye Churchill and Ken Witthaus

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