Garlic

Allium sativum

Vegetable gardenFamily: Amaryllidaceae (Amaryllidacées)Difficulty: EasyToxicity: see below

Garlic (Allium sativum) is one of the easiest vegetables in a Belgian kitchen garden, provided you grasp two things. You don’t sow it: you plant the cloves, separated from a head, point facing up. And white and purple garlic are planted in autumn, because they need to go through the cold of winter to form good, well-divided heads. The real trap here is not frost but moisture: in heavy, waterlogged soil, garlic rots.

Light and exposure

Garlic wants full sun, no compromise. Give it the most open and sunny bed in the garden, away from tall vegetables that would cast shade. The less light it gets, the smaller the heads stay.

Avoid the low corners of the garden where water sits and air circulates poorly after rain. A spot on a slight slope, or a raised, well-aired bed, always gives better results in our climate than a damp bottom of the garden.

Watering

This is one of the most frugal crops in the vegetable garden. Once the cloves are in place in autumn, Belgian rainfall is more than enough, and most of the time you will have nothing to water all winter or spring. Too much water does far more damage than too little.

Only water in the event of a real prolonged drought in spring, when the foliage is growing strongly. As soon as the leaves start to yellow, in June, stop all watering: the heads finish ripening in dry conditions, and waterlogged soil at this stage makes them rot in the ground.

Soil and repotting

Drainage is the point that decides everything. Garlic demands a light, loose and above all well-drained soil; it hates heavy, waterlogged ground, where it rots before bulking up. In clay soil, plant on a small ridge ten to fifteen centimetres high so the water drains away and the cloves never sit in water.

When planting, push each clove point up, five centimetres deep, spaced ten to fifteen centimetres apart, in rows thirty centimetres apart. Never add fresh manure: it makes garlic rot and encourages disease. Simply loosened soil, with no fresh manure, suits it very well.

Temperature and humidity

Garlic is perfectly hardy and overwinters outdoors without protection in the Herve area. Cold is not an enemy, quite the opposite: white and purple garlic need a period of winter cold, vernalisation, to divide properly and form a head with several cloves. Without that cold spell, you often harvest a single bulb, with no cloves.

The real danger here is not the temperature, it is the moisture in the soil during the cold months. Heavy soil that stays waterlogged all winter makes the cloves rot before they even get going. The ridge in clay soil and full sun are your best insurance against this risk.

Pruning and upkeep

There is no pruning as such, but one useful task on autumn garlic. In spring, some varieties send up a rigid flower stalk in the centre, the scape. Cut it as soon as it appears: the plant stops feeding the flower and concentrates its energy in the head, which bulks up all the more. These scapes, tender, are actually very good to cook.

Weed regularly around the plants, as garlic tolerates competition from weeds poorly. A light hoeing now and then keeps the soil aerated. Watch the foliage in spring: it is what will warn you of the first signs of disease.

Pests and diseases

Garlic rust is the most common enemy under our mild, damp springs. You spot it by small, bright orange pustules that speckle the leaves. It weakens the plant and reduces head size. You limit it by spacing the plants well so air circulates, avoiding any excess nitrogen and never wetting the foliage.

White rot, a soil fungus, is more serious because it persists in the ground for years. It makes the plants yellow then rot, with a white felting at the base. The only real defence is a long rotation: never replant garlic, onion or leek in the same spot for four to five years. In soil that is too wet, clove rot is also a threat, hence the importance of drainage.

Propagation

Garlic is propagated only by its cloves, there is no sowing. Take a healthy head, detach the cloves one by one just before planting, and keep the largest ones from the outside: those are the ones that will give the finest heads. Each clove planted becomes a whole head.

Always use healthy seed cloves, bought at a garden centre or saved from your own harvest. Avoid supermarket garlic: it is often treated so it won’t sprout, sometimes carries disease, and is poorly suited to our climate. A good Belgian garlic, replanted year after year from your finest heads, adapts and improves.

Toxicity

Harmless to humans, it is an everyday seasoning. Garlic, however, is toxic to dogs and cats: it destroys their red blood cells and can cause anaemia. Don’t leave peelings or heads within their reach, and never slip any into their bowl.

Local know-how

In Belgium (Herve climate, zone 8a)

In the Herve area, garlic is an autumn affair. Plant white and purple garlic between October and early December: that way they get the winter cold they absolutely need to form good, well-divided heads. Pink garlic, on the other hand, is planted rather in late winter, in February or March, as soon as the soil has drained. In both cases, the harvest falls in June or July, when the foliage yellows and bends over.

Drainage is the crux of the matter here. Our winters are wet and many plots in the region are clayey and heavy: it is the ideal scenario for rotting the cloves before they get going. If your soil holds water, always plant on a ridge ten to fifteen centimetres high, in full sun, and banish any fresh manure. In spring, keep an eye on the leaves: the orange pustules of rust arrive quickly with our mild, damp springs.

After lifting, don’t bring the heads in straight away. Let them dry for one to two weeks in the air, sheltered from rain, in a ventilated spot, before storing them dry. And remember rotation: don’t replant garlic or any of its onion and leek cousins in the same spot for four to five years, to avoid white rot in the soil.

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Month-by-month care calendar

JanuaryAutumn garlic lies dormant in the ground, nothing to do. This is the time to order healthy seed cloves for spring planting or the following autumn.
FebruaryPink garlic can be planted as soon as the soil has drained and is workable. Push the cloves point up, five centimetres deep, on a ridge in heavy soil.
MarchLast window to plant pink garlic. Autumn garlic restarts its growth. Weed around the plants without damaging them.
AprilThe foliage grows fast. Watch for the appearance of rust, those orange pustules on the leaves, in mild, damp weather. Hoe lightly.
MayFull growth. Cut the flower scapes as soon as they rise so the energy goes into the heads. Only water in the event of real drought.
JuneThe foliage starts to yellow. Stop all watering. First harvests of autumn garlic when half the leaves have yellowed.
JulyFull harvest. Lift in dry weather when the foliage is yellowed and bent over. Let the heads dry off in the sun for a few hours.
AugustEnd of air drying, one to two weeks sheltered from rain in a ventilated spot. Plait or store the well-dried heads in a dry place.
SeptemberPrepare the bed for autumn garlic: loosened, well-drained soil, no fresh manure. Choose a spot where no allium has grown for four years.
OctoberStart of planting white and purple garlic. Separate the cloves from a healthy head, plant point up, on a ridge if the soil is heavy.
NovemberContinue autumn planting. The cloves take root before the hard frosts and will benefit from winter vernalisation.
DecemberFinal deadline to plant autumn garlic. After that, let the cold do its work: it is necessary for head formation.

Green Hub tips

  • Plant white and purple garlic in autumn, never in spring: without winter cold, it won’t form true heads with several cloves.
  • In clayey, damp soil, always plant on a ridge ten to fifteen centimetres high. Garlic rots as soon as it sits in water, that is the number one risk here.
  • Stop all watering as soon as the foliage yellows in June. The heads finish ripening in the dry; waterlogged soil would make them rot.
  • Never replant garlic in the same spot for four to five years, nor onion or leek: white rot settles into the soil for years.