Common Leek Pests and Problems


Generally, leeks grow unhampered by pests and diseases.  This herb of the Allium family is hardy and not very sensitive to the soil where they are grown.

It does, however, get attacked by some pests and diseases from time to time.  One of the most common problems encountered by gardeners is leek rust.

Leek rust is an infection caused by the fungus Puccinia allii.  You would know your crops are infected by this disease when orange or brown powdery spots are on the leaves of your leeks.

Typically, mild infections do not do a lot of damage.  However, acute infections can kill your crops.  Spreading of the fungus is easy as it spores can be carried by the wind and infect other plants of the same family.

Leek rust can be avoided in a number of ways.  Once you see a few infected leeks, remove them immediately to prevent the fungus from spreading.  Any dried leaves must not be composted but instead be thrown away.

Too much nitrogen will also make your crops susceptible to leek rust infection so avoid using it on your leeks.  Instead, you may use potassium like seaweed dressing and mix it with the soil.

Onion flies also occasionally attack leeks.  This pest looks similar to a grey housefly.  It lays its eggs at the base of the leek plant, on the leaves and in the soil.  Maggots have a white color that’s about half an inch in size when fully mature.

The manifested symptoms of this pest include yellowed and drooping leaves.

To get rid of onion flies, remove infected plants.  Make sure no maggots are left in the soil to stop its life cycle.  Avoid using fresh manure on your soil so as not to attract flies and help them proliferate.

Other problems that can affect leeks also include leek moth, white rot and white tips.