Pests and Diseases


Mangold growers need to be keenly aware of the various pests that may attack and destroy the crop.  Here we list the ones most likely to be encountered, and helpfully suggest measures which may be taken to deter them.

1. The Blackfly Aphid  Aphis fabae

Blackfly aphid

These versatile creatures may be found on many vegetables including the mangold, although their favourite is the bean. You will find them on the underside of mangold leaves in late Spring.

To destroy them, simply spray with a solution of 1 (one) teaspoonful of Fairy Liquid to one (1) litre of water. Because they have no lungs and breathe through their skins, the detergent will suffocate them.  In addition, your mangold foliage will acquire a lemony freshness.

2. The Mangold Fly Pegomya hyoscyami

Mangold fly eggs

Mangold fly eggs under a leaf. To take this picture the photographer had to lie on the ground with the camera pointing upwards, which must have been quite difficult.

The mangold fly is drawn to the mangold wurzel just as the fruit bat is drawn to fruit or the peacock to peas.  The fly lays its eggs in neat rows on the underside of the leaves, then flies off to do something else. 

The eggs take 3-7 days to hatch, which is quicker than chicken eggs, and emerging from the eggs we find not chicks but the horrible mangold fly larvae. These are known as Beet Leaf Miners because they use their jaws to cut a path through the mangold leaves, eating the juicy bits and leaving the unjuicy bits.

When they have quite finished, the larvae burrow into the soil and pupate, eventually to hatch into more mangold flies. This is known as the Circle of Life and may be represented in a diagram.

To eradicate the mangold fly it is necessary to remove the eggs from the leaves with tweezers and place them in boiling water. This process is humane and quite painless unless you are careless enough to splash yourself.

3. The Turnip Gall Weevil  Ceuthorhynchus pleurostigma

Turnip gall weevil and galled turnip

As one might imagine, the turnip gall weevil is usually associated with turnips and other brassicas, but this is no excuse for being complacent so look out for lumpy mangolds.

The best way to get rid of this weevil is simply to stamp on it. It is only 2.5mm in length (max) and will not damage a normal shoe.

4. The Rabbit  Oryctolagus cuniculus


Above: a rabbit [rab-bit].

The rabbit is by far the worst predator of the mangold.  In the course of a single evening a family of rabbits can destroy up to one (2) hectares (acres) of mangolds and still have room for pudding.

The only effective method of dealing with rabbits is to surround your mangold patch with a rabbit fence. These may be obtained from agricultural merchants worldwide.

Right: Inspecting the rabbit fence for damage. Rabbits are very crafty and sometimes persuade other animals to make holes in the fence for them so they can get in.

Checking the rabbit fence

5. The Pig Sus scrofa scrofa

Sus scrofa scrofa (The Pig)

The mangold wurzel is the pig’s favourite food, so once a pig gets onto your mangold patch you might as well give up the whole idea of growing mangolds.

Thankfully, most of the pigs in the United Kingdom are domesticated and living in secure accommodation. There are few if any wild pigs to worry about.


The mangold wurzel is resistant to most of the familiar diseases such as influenza and toothache. There are however some diseases which can spell disaster for the mangold unless treated according to the instructions below.

1. Boron Deficiency

Boron deficiency

The first signs of boron deficiency are wilting and discolouration of the leaves.  This then spreads to the root, causing it to rot from the top down.

It is imperative that you react quickly to this disease by obtaining extra supplies of boron.  The chemistry lab at your local school or college is often the best source, and they will probably let you have some free of charge if you explain the situation calmly and politely.

Remember: “Don’t be a Boron Moron!”
(This slogan is copyright © The Mangold Hurling Association 2007.)

2. Phosphorous Deficiency

A mangold wurzel exhibiting a worrying deficiency of phosphorous

Phosphorous deficiency is characterised by reddening and splitting of the foliage in young plants, and the failure of the root to form.

The solution is to apply supplementary phosphorous.  Like boron, phosphorous may be obtained from a school laboratory, but it might be best not to ask the same school that you got the boron from. The science teacher may feel that he or she is being taken advantage of.

When going to collect your phosphorous, don’t forget to take a carrier bag to put it in.

3. Non-Specific Beet Wilt

Scientists have yet to identify the cause of non-specific beet wilt, let alone the treatment, which is pretty pathetic considering they can put a man on the moon. They probably sit around all day drinking cups of tea instead of doing experiments.

All we know is that the disease looks like this (left) and is 100% terminal in all cases.

Beet Wilt (non-specific)

Right: These scientists are doing some research into Beet Wilt instead of drinking tea.  Makes a change! 

4. Too Much Fertiliser

Excessive growth

Over-zealous application of fertiliser can have undesirable effects. If you let things get really out of hand, as shown in this photograph, you will almost certainly receive complaints from your neighbours and your Local Authority.  You may even end up in court.