Growing Garlic in Ireland
Growing garlic in Ireland
Garlic is one of the most rewarding crops you can grow in an Irish garden. Get the timing right, choose the right variety for our conditions, and the rest largely takes care of itself.
Most garlic sold in supermarkets was not grown for Irish conditions. It looks the part but it was not bred for Irish soil or Irish weather, and it can carry disease into your ground. The answer is straightforward: buy certified seed garlic suited to northern European conditions, plant it in autumn, and let the cold Irish winter do the work.
Peter Dowdall, Irish horticulturist and broadcaster, explains how to grow garlic successfully in Irish conditions, including when to plant, which varieties perform best in Irish soil and weather, and how to prepare the ground for a reliable harvest.
Garlic is well suited to Irish conditions in a way that surprises most people. It comes originally from the mountain regions of Central Asia, where temperatures swing hard between cold and warm. Irish winters, with their sustained cold and wet, actually give garlic exactly what it needs: a cold period of at least four to six weeks at low temperatures is what triggers a single clove to divide into a full bulb. Plant in autumn, and the Irish winter does that work for you.
The mistake most gardeners make is planting too late, or planting varieties that were never intended for this climate. Autumn planting, from October into early December, produces the largest, most reliable bulbs. Spring planting is possible but the bulbs will be smaller and the harvest later. If you are starting out, plant in autumn and give yourself the best possible result.
The other thing worth understanding before you start is drainage. Garlic will rot in waterlogged ground over winter. If your soil holds water, or if you have clay, growing garlic in a raised bed is not just a preference. It is the practical answer for Irish conditions. See the full guidance on growing in raised beds in Ireland if that applies to your garden.
When to plant garlic in Ireland
The timing question is the one that matters most. Get this wrong and everything else becomes harder. Garlic needs cold to form properly, and autumn planting gives it the longest exposure to those conditions before the warmth of spring triggers bulbing.
Irish garlic planting calendar
The cold requirement is not negotiable. Garlic needs four to eight weeks at temperatures between 0 and 10 degrees Celsius for the clove to divide and form a full bulb. In Ireland, autumn-planted garlic gets this naturally. If planted too late in spring, when soil temperatures have already risen, you risk the clove growing as a single large mass rather than dividing into individual cloves at all.
Which garlic varieties work in Ireland
There are two main types of garlic: hardneck and softneck. Both grow well in Ireland, but they behave differently, and knowing the difference helps you choose the right one for your situation.
Do not plant supermarket garlic. It is almost always grown in warmer climates, not adapted to Irish conditions, and can carry disease into your soil. Buy certified seed garlic from a reputable Irish or UK supplier each season.
Hardneck garlic
The better choice for Irish gardens. Hardneck varieties are cold-tolerant, produce strong flavour and are better suited to the sustained cold of an Irish winter. They produce a flower stalk called a scape in early summer. Cut the scape off when it curls, before it straightens. This redirects energy into the bulb and gives you a bonus harvest from the scapes themselves, which have a mild garlic flavour.
Good varieties for Ireland include Carcassonne Wight, Picardy Wight and Mikulov Wight. Flavour is generally more complex than softneck.
- Best for Irish climate and flavour
- Stores for four to six months
- Produces edible scapes in early summer
- Cloves arranged around a central stem
Softneck garlic
Softneck varieties produce larger bulbs with more cloves per bulb and store considerably longer than hardneck, sometimes up to twelve months in the right conditions. They do not produce scapes. If you want garlic that keeps well into spring and beyond, a softneck variety is worth considering alongside a hardneck.
Solent Wight and Provence Wight are reliable softneck varieties for Irish conditions. They suit spring planting better than hardneck varieties if you miss the autumn window.
- Longer storage life, up to twelve months
- Larger bulbs with more cloves
- No scapes
- Better suited to spring planting
Soil preparation for garlic in Ireland
Garlic is not demanding in terms of fertility, but it will not tolerate waterlogged ground. The priority for Irish gardens is drainage first, fertility second.
Choose a sunny, open position. Work the soil thoroughly so it is loose and crumbly. If you have heavy clay or a site that holds water in winter, grow in a raised bed. The drainage advantage of a raised bed is significant in Irish conditions and the difference in bulb quality at harvest can be considerable. See the full guidance on raised beds in Ireland for how to set one up properly.
Garlic prefers a soil pH of 6.0 to 7.0. It does not want freshly added manure at planting time, as this can encourage rot. Well-rotted compost worked in a few weeks before planting is the right approach. If the soil is biologically tired, which is common in Irish gardens that have been intensively grown or neglected, improving the underlying soil structure will make a real difference to how the cloves establish and how the bulbs develop.
Improve your soil before you plant
NutriChar is a certified organic biochar plant food made using a patented process that locks nutrients into biochar structure rather than allowing them to wash away. It improves soil structure and supports the biological activity that helps garlic establish strongly. Work it into the bed before planting rather than as a surface feed afterwards.
Do not fertilise once the bulbs have begun to form in late spring and early summer. Feeding at this point is counterproductive and can reduce bulb quality. The work of feeding the crop happens in autumn at planting and in early spring when growth resumes.
How to plant garlic
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1
Break the bulb into individual cloves
Do this shortly before planting, not weeks ahead. Keep the papery skin on each clove intact. Use only the outer, larger cloves for planting. Smaller inner cloves can go into the kitchen.
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2
Plant pointed end up, flat base down
Push each clove so the tip sits about 2.5cm below the soil surface. On light, free-draining soils you can plant slightly deeper. On heavier soils, keep to the shallower depth to avoid rot.
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3
Space at 15cm within the row, 30cm between rows
Garlic has shallow roots and does not like competition. Good spacing helps air circulate between plants and reduces the risk of fungal problems in Irish conditions.
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4
Water in and then leave it alone
Water once after planting to settle the soil around the cloves. After that, garlic needs very little water over winter. Soggy soil is the enemy. Resume light watering in spring only if there is a dry spell.
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5
Mulch lightly in late autumn
A light layer of straw or compost over the bed helps protect the cloves from the worst frost and keeps the soil from compacting over winter. Keep it light, not thick, so air can still move through.
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6
Keep it weed-free
Garlic is a poor competitor. Weeds, particularly in spring when growth is rapid, will suppress the crop noticeably. Keep the bed clear throughout the growing season. Hoe carefully to avoid disturbing the shallow roots.
Harvesting and storing garlic
Harvest timing is something many gardeners get wrong. The instinct is to wait until the plant has completely died back, but by then the bulb has often split and the individual cloves have started to separate. Split bulbs will not store well.
The right moment to harvest is when the lower four to six leaves have browned and dried but the upper leaves are still green. Typically this falls between June and August for autumn-planted garlic, depending on the variety and the season. Watch the plant, not the calendar.
Loosen the soil with a fork before lifting. Do not pull by the stem. Lift carefully to avoid bruising the bulbs. Bruised garlic will not keep.
Curing garlic for storage
Freshly lifted garlic needs to be cured before it will store properly. Lay the bulbs in a single layer in a warm, dry, well-ventilated space, out of direct rain, for two to three weeks. A shed, greenhouse or covered porch works well. Turn them occasionally. The outer skin will dry and become papery, which is exactly what you want.
Once cured, store in a cool, dark, well-ventilated place. Hardneck varieties will keep for four to six months. Softneck varieties can keep considerably longer when conditions are right. Never store in a sealed container or in the refrigerator, as moisture will cause rot.
Keep back the best of your harvest as seed garlic for next year. Choose the largest, healthiest-looking bulbs. Over several seasons, garlic that has been grown in your own conditions adapts to them, and the performance improves.
Questions gardeners ask about growing garlic in Ireland
Can I plant supermarket garlic?
Technically yes, but it is not recommended. Supermarket garlic is almost always grown in warmer climates and is not adapted to Irish conditions. More importantly, it can carry disease, including white rot, into your soil. White rot is a serious problem: once it is in the ground it persists for ten years or more, and you will not be able to grow any alliums, including onions and leeks, in that area for a decade. Buy certified seed garlic from a reliable Irish or UK supplier.
My garlic did not form proper bulbs. What went wrong?
The most common cause is planting too late in spring, when soil temperatures have already risen. Garlic needs a cold period to divide from a single clove into a bulb of multiple cloves. If it misses that cold period, it may grow as a single round bulb with no division. The solution is to plant in autumn next time. If you did plant in autumn and still had the problem, the variety may not have been suitable for your conditions, or the soil may have been waterlogged, which suppresses root development.
Do I need to remove the flower stalks?
Only from hardneck varieties, which produce a stiff flower stalk called a scape in early summer. If you leave the scape to develop fully, the plant puts energy into flowering rather than bulbing, and the bulb will be smaller as a result. Snap or cut the scape when it has curled into a loop but before it straightens. The scapes themselves are excellent in cooking, with a mild garlic flavour. Softneck varieties do not produce scapes.
My garlic has rust on the leaves. Is the crop ruined?
Garlic rust, which shows as orange or brown spots on the leaves, is common in Ireland given our damp conditions. It is frustrating to see but it does not necessarily mean the crop is lost. The bulbs usually develop reasonably well even when the foliage is affected, as long as the rust does not appear too early in the season. Avoid wetting the foliage when watering, ensure good spacing for air circulation, and rotate your garlic to a different part of the plot each year.
Can I grow garlic in pots or containers?
Yes. Garlic grows reasonably well in pots and containers, which is a practical option if you have heavy soil or limited space. Use a deep container, at least 20cm, with good drainage holes. Fill with a well-draining compost mix. The results will generally be slightly smaller than ground-grown garlic, but the timing and care are the same. Containers dry out faster than ground soil, so watch watering more carefully in spring.
That is the general picture
But your garden has its own soil, its own drainage and its own microclimate. Tell Ask Peter about your specific situation and get advice tailored to what you are actually dealing with.
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