Sowing & Harvesting Garlic


My gardening great grandfather George Cook swore that garlic was the key to a long life (and he lived to 108), he may have been on to something; garlic contains vitamins C and B6, manganese and antioxidants like allicin and selenium. Throughout the ages garlic has been used to prevent almost every ailment known to man and woman, from circulatory disorders to cancer.

MrsGrow is part Italian so we eat our fair share of Italian dishes all of which require garlic. I would say that garlic is one of the most cost-beneficial crops that I grow at the allotment. My preferred variety for planting is ‘Cristo’ which I find does well on clay, has both a wonderful flavour and odour, and stores through until the following year after harvesting.

When to Sow Garlic

A Garlic Clove Ready for Covering

A Garlic Clove Ready for Covering

Sow garlic in the Autumn before it gets too cold, this gives the garlic bulbs a chance to take root before the depths of winter set in. I have sown garlic as early as October and late as mid-December – in all instances the garlic has grown successfully so it can be worth waiting until the garden centres add heavy discounts if you have not stored some bulbs from a previous garlic harvest. The main deadline you’re up against is nature / cold weather; garlic needs a prolonged spell of low temperatures (and ideally a frost or two) in order to trigger the bulb to split into multiple cloves for harvest time. Bulbs should be sown just below the surface of the soil.

Tricking Garlic
It’s possible to keep garlic in the fridge for a couple of weeks to simulate a cold spell prior to planting in order to trick the clove into separating later. MrsGrow is known to put left over garlic cloves in the fridge and I occasionally find a clove sprouting in there when she hasn’t used it quickly enough. It’s not something I’ve tested myself but potentially worth a go if you’re already into February or March and don’t mind a later harvest (August).

Where to Sow Garlic

Choose a location that receives full sun, I sow garlic in recently manured raised beds (well-rotted manure) to give them all the nutrients they might need. It is important that the beds are free draining which is why I use raised beds (I have heavy clay soil at my allotment). In theory sandy soil is better than clay for garlic growing but it hasn’t caused me any issues, the main aim is a soil ph of between 6.0 and 7.5.

You could just as easily use pots or containers to grow garlic in but I would be very wary of frost damage based on my experience of growing ornamental Alliums in pots (Alliums are in the same family as garlic). Be prepared to relocate pots to a shed or a greenhouse during extremely cold spells.

I tend not to plant garlic in rows instead preferring to sow into the corners of raised beds (which I rotate row by row each year). There are two reasons why I prefer this technique:

  1. Space – the corners of my beds are often empty, sowing into the corners doesn’t prevent me getting started with main crops in Spring the following year. (The garlic will be gone in early summer anyway if main crops expand to edges and corners).
  2. Pests & Diseases – planting one crop variety in a single location makes it easier for pests and diseases to spread throughout. I like to make life more difficult for rust or wire worm (which aren’t just a potato issue for me). The odour of garlic is also known to deter some pests (including slugs and snails) consequently my logic is that spreading the plants out also spreads the odour to dissuade a visit to a courgette plant or lettuce later in the Spring and Summer.


Early Planting Bird Damage

At my allotment birds like to peck garlic or onion bulbs out of their beds and then leave them abandoned on my plot after finding them inedible. I usually pop them back into the soil and they grow on but there are a couple of options if this is a problem for you:

  1. Netting (unless you’re using my corner bed planting method – rows only).
  2. Start the bulbs in trays in the greenhouse and plant out the module when the roots are well developed, this makes it harder for birds to pull up a bulb. I use this method for all my onions as I find the bulbs develop more quickly anyway. I shall be using it for garlic sowing as well from Autumn 2017.

When to Harvest Garlic

Yellow Leaves - Harvest Indicators

Yellow Leaves – Harvest Indicators

Garlic doesn’t need much attention after sowing (perhaps one liquid compost feed in late Spring) and is generally ready for harvesting when the leaves begin to turn yellow or brown and dry out. If you have sown garlic in the previous Autumn then June is typically the best time for harvesting in the South of England. There isn’t an exact harvest time indicator just keep in mind that if you leave the garlic until all the leaves have turned yellow then the cloves may not keep as well.  If the plants are still quite green with only a hint of yellow on the tips it may be too early.

Garlic Bulbs

Garlic Bulbs

If in doubt ‘below ground investigation’ is the best method – have a little dig down around a bulb with your fingers to look at the sides and determine whether it is good to harvest. For the past three years I have harvested garlic around the 5th or 6th of June. This year a sudden cold spell and continued heavy downpours persuaded me to harvest yellowing plants – I didn’t want to risk white rot developing on the bulbs.



Storing Garlic

Dried Garlic in our Kitchen

Dried Garlic in our Kitchen

Once harvested lay garlic bulbs with their stems intact on their sides somewhere warm and dark – typically I choose a warm garden shed rather than the greenhouse (which can accidentally bake the garlic!). As a rule I tilt the garlic bulb stems slightly downwards at a 10 degree angle raising the bulbs above the stems so that the bulbs dry out and any liquid is drained away from them. After a fortnight the stems are dried out, at which point I cut, tidy and tie them together for location in the kitchen. Easy access for MrsGrow to use in Italian meatballs or Spaghetti!




About Author

Matt Peskett is GrowLikeGrandad (if you want to know why read 'About the Editor). He has a 'heavy clay' allotment and is a member of the Dorking Allotment Holders Association (DAHA). Matt also has a medium sized 'sandy soil' hillside garden (Italian terrace designed) and enjoys photography - especially nature. Matt takes inspiration from gardens like Hidcote, Great Dixter and Sissinghurst and enjoys watching anything on TV with Monty Don in it.

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