Tag: soil thermometer

It’s carrot planting time for many of us from spring to late summer, and many growers are searching my site for information. Here are quick links to all of my many carrot posts over the years. Inevitably there is some overlap.

After these links there are seasonal details on planting carrots.

• Carrot Seed Viability: you may be wondering if you can still use the seeds leftover from last year. Carrot seeds are generally good for 3 or 4 years if you have stored them carefully. Click the link above to read Factors influencing seed viability and Seed germination testing
• See my slideshow on Succession Planting. We sow carrots from mid-February to August. Here’s Video of me presenting Succession Planting for Continuous Vegetable Harvests ten years ago at New Country Organics (I’ve updated the presentation since then);
• Sowing carrots: Surprisingly to me, I have not written much about sowing carrots in spring. From Root Crops in February: Carrots do very poorly with competition from weeds or too many other carrots. You can make use of the Stale Seedbed Technique, preparing the bed ahead of time, and flaming or hoeing one or more flushes of weeds as they germinate.

Carrots are small seeds, needing a fine tilth (small soil particle size and good texture – not likely to crust or blow away).  Good information on crop spacing for maximum yields, or biggest vegetables is in an out-of-print book, The Complete Know and Grow Vegetables by JKA Bleasdale, PJ Salter, and others. Buy it used.

For maximum total yield of carrots, they recommend 1.5” x 6” (4 x 15cm). You get medium-sized carrots. For early carrots go with 4 x 6” (10 x 15cm) to minimize competition and get rapid growth. If you want to have rows more than 6” (15cm) apart, calculate the area of these optimum spacings, then divide by your chosen row space. For example, if your rows are 12” (30cm) apart, the carrots can be as close as 0.75” (2cm) if total yield is more important than individual size, or 2” (5cm) for fast early carrots. We do five rows in a 4’ (1.2m) bed, so the rows are about 10” (25cm) apart, with the outer rows 4” (10cm) from the bed edge.

From Root Crops in March:

Spring Carrot Start-up Plan

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  We aim to spread compost 4-6 weeks before planting, rototill 2-4 weeks before planting, and prep the bed a week or two before. This is more time than we allow later in the year, but in early spring it’s good to seize the opportunities that arise and not take the weather for granted.

• This means in January we compost and till beds for our first two beds of carrots, to be sown February 14 and February 28.
• In the first half of February we till and spread compost for more carrots (planting dates March 9 to 15).
• In the second half of February, we compost the third carrot bed and till the ones we already composted.
• Once we get to March, day length has improved and temperatures are starting to climb. There is a noticeable increase in the rate of germination and growth (unlike our February sowings, which are rooted in faith and optimism!).
• In early March we till the third carrot bed.
• All being well with the weather, we sow carrots #3 in mid-March
• In late March, we sow carrots #4

There’s also a full chapter on carrots with all my information in my book Sustainable Market Farming, 2^nd edition. It includes info on varieties, and which types are better for which soils, pests and diseases, crop rotations, cover crops before and after carrots, and more.

Preparing for Carrot Sowing

• • Planning for a continuous supply; see my slideshow on Succession Planting. Carrots have a much longer window for harvesting than most carefully planned successions, so you can be a lot looser in your planting dates. Mainly, just grow enough! After the spring start-up plan, we sow carrots once a month in April and May. If we need to, we sow once a month in June and July, although summer-grown carrots do not taste as sweet as those grown in cooler weather. We finish with a big sowing at the end of July or early August, 10–12 weeks before the usual first frost, to be harvested in November and stored for winter eating.
  • Decide how many to plant. Yield: 100 lb/100′ (150 kg/100 m), 30,000 lb/acre (34,000 kg/ha)
  • Calculate the amount of seed required; Carrot seeds are 175,000–600,000 (avg. 288,000)/lb, 18,000 seeds/oz, 625 seeds/g. 3,000 seeds (0.2 oz, 6 g)/100′ (30 m), 1 seed/cm. 625 cm/g, 600’/oz, 9,600’/lb, 2.5 lb/acre (at 30 seeds/ft in rows 24″ (60cm) apart). 720,000 seeds/acre.

Success with Planting Carrots

• • Before you plant, understand soil temperature requirements: Use a soil thermometer! Flag its location so you don’t lose track of it! Measure at 4″ (10 cm) deep at 9am. Carrot emergence takes3 days at 50°F (10°C), 10.1 days at 59°F (15°C), 6.9 days at 68°F (20°C), 6.2days at 77°F (25°C), 6 days at 86°F (30°C)and 8.6 days at 95°F (35°C).

    

  • Old books warn against using manure before sowing carrots as it will make them fork. This refers to uncomposted manure, not compost. Compost will increase yields and even reduce the culls with some varieties (research by Dan Brainard and Corey Noyes, at Michigan State University). Compost not only increases the organic matter in the soil but also suppresses some diseases and nematodes (which can cause forked carrots)
  • Seed spacing and depth: for carrots, aim to sow 30 seeds/ft (1/cm), only 0.25″–0.5″ (0.6–1.2 cm) deep. Close the furrows and tamp down the rows with the back of a hoe or rake. The goal is to get good contact between the seed and the soil. Keep the soil surface damp until the seedlings start to emerge.
  • We sow a few Indicator Beets at the beginning of the bed. Beets germinate

    

    one day sooner than carrots at almost any temperature. When we see the red loops of the beet stems emerging, we know it’s the day to flame weed the carrots. (From Workhorse Crops for March)

  • Carrots do very poorly with competition, so try to start early carrots in a bed that had only light weeds the year before. Later sowings can make use of the stale seedbed technique, where the bed is prepared ahead of time and one or more flushes of weeds are germinated and flamed or hoed off.

    

Growing Great Carrots: Thinning and Weeding

• • Remember to thin carrots as soon as you can see them well enough to do so. We usually hoe between the rows first, then crawl along thinning and weeding. It does take time! But you won’t get good carrots without thinning, unless you either have a precision-seeder that drops one seed per inch, or pelleted seed which you can sow at one per inch.
  • Precision seeders like the Jang are expensive, but worthwhile if you need to use it every week. Pelleted seed costs more than raw seed, and its big advantage is traded off for two other disadvantages: The soil has to be kept well-watered until germination or else the clay coating will imprison the seed forever, and the seed does not store for long – don’t keep any over for next year.
  • It pays to sow in parallel rows an even distance apart. This makes for fast and effective hoeing with fewer mistakes.

    

Harvesting carrots

• • November harvesting
  • Late November harvesting and bagging
  • 41 bags of carrots
  • Hasty July harvest
  • Storage Vegetables slide show
  • Here’s Storage Vegetables on SlideShare, where you can increase the size for easier viewing.