Problems Growing Garlic
Garlic is largely pest and disease free, but sometimes ‘rust’, a fungal disease of the foliage, can be damaging. If this happens, then grow garlic in a different part of the garden in future years and destroy all of the infected leaves. White rot disease is present in some soils and attacks the roots. If this happens grow garlic in tubs of soil-based potting media, such as John Innes No3 compost
Onion white rot:
This fungus causes the leaves to wilt and turn yellow. Under wet conditions, the plants may not wilt but will become loose in the soil. If you lift them, you will see a white fluffy growth on the bulbs.
Remedy: Throw out any infected bulbs, and don’t grow leeks, onions or garlic in that spot again for at least eight years. This is a very persistent fungus that survives in the soil for a long time. There is no chemical control.
This is a fungal disease causing bright yellow spots on the leaves. It is often worse in long, wet spells.
Remedy: Mild attacks of rust won’t affect the plant, but serious infections may cause leaves to shrivel and affect yield. There is no control for rust once you have the infection. Make sure you don’t crowd plants as this increases both humidity and the likelihood of infection. Dispose of any badly affected plant material, and don’t grow garlic, leeks or onions in the same spot for three years.
Click Here for more information on leek rust
Growing Garlic: Flower Stalks
Hardneck garlic cultivars readily produce flower stalks. The developing flowers should be removed as soon as they appear and can be used for stir fries. Softneck cultivars occasionally produce flower stalk if exposed to adverse growing conditions such as high temperatures or drought.
These can be a problem, pulling the shallow-rooting plants out of the ground.
Remedy: Place chicken wire, fleece or plastic netting over plants to keep the birds off. They are usually not such a problem when the plants are older and growing strongly.
Two leaf mining pests that can cause damage to the foliage of garlic and other members of the Allium family are the allium leaf-mining fly and leek moth.