Always great to look through seed catalogs and see carrot varieties which are pencil-straight and 10" to 12" long. Most can only dream of getting anything near that and yet I can grow them 18" long. It's never going to happen in most gardens unless you rare using a trenching shovel to work the soil that deep. Part of the secret is growing them in pots or containers at least 15" deep. Second is an organic medium. I have been using 100% old horse manure aged to the point where it looks like soil. Third is to select varieties which do not have shoulders. The deep pots allow the carrots to grow even beyond the advertised. The horse manure has ample nutrients, and that combination allows the carrots to grow almost solid. Favorite varieties are Candysnax, Sugarsnax, and Rainbow. All three are capable of growing to the bottom of a 15" pot and making a 90º turn for another 3 or 4 inches. The seeds are sown as if sowing grass seed. Unlike in a garden row, they self-thin in containers as only the biggest survive.

This also shows how organic matter is recycled in Nature. If the pot starts out with 7 gallons of pure manure, there is only 3½ gallons after the carrots are done with it. They convert it to food for us! This next season I will not have access to that manure. Instead, I was able to get somewhat aged manure. Pots are already set up with 50/50 mix of that new manure with used stuff from the past season. Also all pots are at least 18" deep meaning that there will possibly be 20" carrots.

Martin

In our raised bed my wife grew Nantes this past year. We have a cattle watering tank as the pot with logs as a filler and 24 inches of compost (none of it manure) and 12 inches of soilless mix. Best year ever for carrots. Long, solid, great tasting and very little thinning necessary. Most got cut up and frozen for vegetable stew this winter. The container is 7 foot diameter and the seeds were sprinkled into the area reserved for carrots.

I remember my Dad's instructions to prep the carrot bed. Dig down a foot and a half and remove every rock you can find down to the size of a pea or less. That was a job. although it did produce very nice carrots. Starting with rock-free material is a better plan. Love that rainbow carrot. We normally grow chantenays here which are shaped to do better in the ground.

If there is a mere pebble encountered during early growth, the carrot will bend. The same applies to any bits of wood or other solids in compost. That's why I prefer pure composted manure. There is nothing to divert the root from its downward course. There used to be a canning company in the next town which canned carrots. The fields that they were grown in were formerly peat marshes. Walking on them after harvest was like walking in deep snow.

Martin

If anyone feels like wasting some time on the web, look up "exhibition carrots" and the like. The current world record length is 20 feet 5.86 inches. It almost sounds impossible, until you see the picture.

I was thinking vertical pvc pipe...but of course someone else already had that idea:
http://www.allotment-diary.co.uk/Exhibi ... arrot.html

Sounds like a pipe dream!