The horrible little allium leaf miner flies are still active through November, so it is a good idea to protect crops like leeks and autumn planted garlic and onions with fine mesh, as recommended by the RHS.

Community Gardening in North-West Leeds
Cover leeks, onions, garlic through November.
The horrible little allium leaf miner flies are still active through November, so it is a good idea to protect crops like leeks and autumn planted garlic and onions with fine mesh, as recommended by the RHS.