Green (Living) Review: Growing carrots in containers

by Michael Smith (Veshengro)

Most people believe that carrots, potatoes and other root crops (as well as cabbages) cannot be grown in containers and need large beds of one kind or another. That, however, it not true.

It is easy to grow carrots (and other vegetables) in containers, be those large “flower” pots or other tubs. In fact, as far as container types are concerned the sky – or better your imagination – is the limit. Do NOT, however, plant any vegetables whatsoever in tires unless they did have inner tubes. The steel radial belted tires are not suitable as they leach cadmium into the soil which is taken up by the plants and is harmful to health. In fact, my advice is to leave tires well alone and use only, if you want to, for the growing of flowers, cut or other, but not for food. That means also no nasturtiums in tires as you may want to use the leaves and flowers as they are edible.

In order to grow carrots – and other veg – in containers all you have to do is get the container you want, and this can even be an old bathtub, fill with compost and this can be compost you have bought in or made yourself (or use the lasagna gardening method (and no, you won't be harvesting lasagna, however nice this would be), and then sow the carrots, or other veg. Or you can use plugs you have grown yourself from seed or bought. Do not, however, do this with carrots or their relations as they do not like to be moved.

If you use a round tub you can sow, I tend to do, in a circular fashion and don't fall for the instructions that you have to thin them out. You don't have to.

As I have said, the containers that you use are basically irrelevant. Just ensure there is enough depths of soil.

I have very successfully grown carrots in shopping carts converted to planters and, in fact, this year has me using a cart for this again where last year there had been pole beans growing in them.

Container vegetable growing with carrots has a lot going for it as the environment is so easy to manage, and this goes for about every kind of vegetable imaginable. It is the easiest way I know for how to grow carrots and any other vegetables. I also grow successfully potatoes in containers of various kinds and sizes and,, another word of wisdom from myself: You do not have to use seed potatoes either. Just use any that have sprouted, even supermarket bought ones.

Carrots in containers are target for the dreaded carrot (root) fly in the same way as those that are grown in beds. However, when the planters are about waist height off the ground the problem seems to be reduced to averted, as I found with the ones grown previously in a shopping cart.

If any roots of the carrots begin to show above soil level earth them up to cover the them in order to lessen the chances of a carrot fly attack. The fly is apparently attracted by the carrot smell and also you do not want the tops to green off.

Talking about greens. The greens of the carrots are also edible and make good soup so do not discard the leaves but use them instead. Waste not want not was the old adage of my grandparents and has seen them well through the lean years.

Sowing your carrot seed

Sown over the months from mid-February to July you can be eating carrots from early June to October. Storing this vegetable correctly can increase that period even longer. Below is a list of the average sowing and harvesting dates that will act as a rough guide on how to grow carrots at the correct times in the British Isles. They will vary in other areas, such as the USA, mainland Europe, and especially Down Under.

Sow mid February and protect with a cloche. Grow an early variety which you can harvest in early June.
Sow March and protect with a cloche. Grow an early variety which you can harvest in June/July.
Sow April - no protection necessary. If you grow an early variety expect to harvest July/August. A main crop variety will be ready August.
Sow May. Grow a main crop variety and harvest in August.
Sow June. Grow a main crop variety and harvest in September.
Sow July. Grow a main crop variety and harvest in October.

Remember that for container the spacing does not apply and, as said already, do not worry, necessarily, about thinning them. All too often you end up pulling those that you do not want to pull out with those you aim for.

Caring for your carrot plants

As you are growing them in a container using a hoe, with the exception of a small wire hoe, such as the Agralan Threadhoe, is not possible and thus you will have to remove any weeds by hand.

Water enough to keep the ground damp as splitting of the root can occur if the watering is too irregular. Also water with a liquid feed on a regular basis. They respond well to this.

Carrot pest control

The carrot fly is the carrots' worst enemy. It is a small black fly which lays its eggs in the soil at the base of the plant and it is the small maggot that hatches from those egg that causes the damage. The tell-tale signs of carrot fly infestation are reddish leaves which droop in sunny weather.

As the maggot eats out the carrot root the foliage turns yellow and the root is liable to rot. Needless to say seedlings are shown no mercy and are soon killed. The fly tends to be most common in May.

There is no known treatment against the carrot fly, even if one of the other chemical claims so and thus preventive measures are the only safeguard that you can undertake. It is essential to learning how to grow carrots and indeed any vegetable that you get to know your enemy.

Cover seedlings with a plant fleece in spring.
Destroy thinnigs immediately - bury, burn or trash can.
If carrot fly infestation is bad in your area then harvest early varieties no later than August and do not sow main crop varieties until June.
Infestation seems worst on dry soils so keep the ground damp at all times. This also prevents root splitting.

One thing to remember in learning how to grow carrots is that the carrot root fly's 'flight path' is low and in a straight line. It is for that reason that I said about placing the containers above ground at about waist height. Also makes it easier for your back in dealing with the plants.

If you grow at ground level then try erecting a low 'fence' around your carrot growing rows – about 30 cm (12") high. It could be made from fleece, fine netting or similar.

Harvesting your carrots

You can start harvesting the earlier varieties sown from about June onwards. Careful, even if grown in tubs, loosen the soil around the plants – you won't be able to use a garden fork, not even a border one, but a hand one will work – if necessary.

If you intend to store some of your crop of carrots for over winter then October is the best month for doing this. Lift the main crop varieties, clean off any soil – use only undamaged carrot roots – and cut the foliage back to about 12 mm (1/2") above the crown of the root.

Using a stout box place the roots on layers of sand – ensuring that the carrots do not touch each other and then store this box with the carrots in the sand in a dry place and inspect regularly to remove any that may have started to rot. This way they should keep until March.

Canning your carrots in a variety of ways is another great option and thus learning the skills of canning is also a good idea.