How to grow garlic on the allotment

Garlic, like onions, is a member of the allium family. It is renowned for its strong flavour and is an essential ingredient in Mediterranean and Indian recipes in particular. Garlic is also said to have health benefits. There are many varieties available and these fall into two general categories known as hardneck and softneck.

Hardneck garlic varieties usually produce about ten large cloves per bulb. They have intense flavour. Ready to harvest from May to July, they will usually keep for three to six months from harvest.

Softneck garlic varieties produce up to twenty smaller cloves per bulb. They are milder in flavour. Ready to harvest from June to August, they will store for up to nine months from harvest.

Garlic prefers a well drained site in a sunny location. Try growing in raised beds, pots or planters if you are on heavy soil.

Planting Garlic

Garlic can be planted from autumn until early spring depending on the variety you choose. They need a period of cold weather to encourage the bulb to split into separate cloves. For that reason it is beneficial to choose an autumn planting variety. Garlic planted in the autumn will usually produce the best crops.

Garlic grows best in free-draining soil in a sunny spot. My allotment is on heavy clay, but I have reasonable success on my slightly raised, no-dig beds. It will do well in pots or planters too. Plant 2 or 3 bulbs in a 15cm pot, 6 to 8 in a 20cm pot or 8 to 10 in a 30cm pot. Pots should be at least 6 inches deep to allow good roots to form. Take extra care with watering and feeding as pots can dry out quickly and compost does not have sufficient nutrients to develop the bulbs.

Carefully split your garlic cloves into separate cloves. Note that the flatter end where the cloves are joined together is where the roots will form so remember to plant pointy end up!

Plant each clove separately so that the tip of the clove is about 3cms below the soil and the cloves are 15cms apart. Rows should be 30cms apart.

Garlic can be started in modules or small pots for planting out once established. This is beneficial on heavier soils as the growing plants are less likely to rot. The rooted cloves are more difficult for birds to pull out too.

It is generally accepted that larger cloves form larger bulbs so smaller ones can be discarded. I tend to plant them all though!

Grow Garlic

Keep your garlic bed weed free to ensure that the plants benefit fully from the sunshine and are not competing for nutrients. To avoid damaging your crop it si best to weed by hand. Water in dry periods. Avoid overwatering as this can cause rotting. Garlic will benefit from occasional feeding. You can buy specialist garlic fertilisers but any general purpose fertilizer will do.

Remove any flower spikes (known as scapes) that appear as these take energy from the plant reducing growth of the bulb.

Harvest Garlic

When the foliage is thoroughly dried it can be removed and the bulbs stored in a cool, dry place. Alternatively leave the foliage on and tie in bunches. You could also try the traditional method of plaiting. Here’s a video of how to do it.

Garlic Problems

Although usually a trouble free crop, as part of the allium family they may be affected by similar problems to onions.

Bolting. Unfavourable growing conditions such as drought can cause garlic to bolt. This is when the plant produces a flower spike. If left it can reduce growth of the bulb. Hardneck varieties bolt more easily than softnecks. Remove any flower spikes that appear.

White Rot. This is a fungal disease that causes the onions foliage to wilt and a mildew-like growth around the roots of the onions. The bulbs will not keep. There is no known treatment for this disease. It is a soil bourne disease so try not to allow it to spread on tools or boots. It can stay in the soil for many years so don’t plant in the same place again for as long as possible. Try growing your garlic in containers of fresh compost if your plot is badly affected.

Onion Rust. Another fungal disease. It causes yellow spots to appear on the leaves and affects yield. Remove affected foliage and the plants may survive.

Do not compost any diseased material, it should be burned or taken to a municipal recycling centre where the heat created by the volume of composted material will kill the fungus.