Gadenin日本語Get the appSplit the bulb the day you plant, not before
Garlic is grown from cloves, not seed. Break the bulb apart on the day you plant and leave the papery skin on each clove. A clove separated a fortnight early starts drying at the basal plate, the flat disc of root tissue at the bottom, and a dried basal plate roots slowly or not at all.
Plant only the outer cloves. A bulb has six to twelve outer cloves and often a few small inner ones tucked against the stem, and those small ones give you small bulbs. Set aside anything narrower than about half an inch (12 mm) across and use it in the kitchen instead.
- Break the bulb by hand Press down on the neck with your thumbs and the bulb splits along its natural lines. Do not use a knife, which cuts through basal plates.
- Keep the skin on each clove The papery wrapper protects the clove from soil fungi for the first few weeks. Peeled cloves rot far more often than unpeeled ones.
- Grade the cloves by size Sort into large, medium and reject. Plant the large ones in your best ground, the medium ones at the end of the row, and eat the rest.
- Reject any that are soft Squeeze each clove. If it gives under your thumb, or if the basal plate has gone brown and crumbly, it is already rotting. Throw it out.
Clove weight is the single strongest predictor of bulb weight. Planting a clove twice as heavy typically gives you a bulb around a third larger, on the same soil and the same feeding.
Plant in autumn, six to eight weeks before the ground freezes
Garlic needs a long cold period to divide into cloves rather than growing as a single round bulb. Plant in mid to late autumn, roughly six to eight weeks before your soil freezes hard, so the clove makes a solid mass of roots but only two or three inches (five to eight cm) of top growth before winter shuts it down.
Too early and the plant makes a tall green top that gets burned back by frost and wastes the clove's reserves. Too late and it goes into winter with almost no roots, then heaves out of the ground as the soil freezes and thaws. In mild winter regions where the soil never freezes, plant at the same point in autumn and give the bulbs a cold period by chilling the cloves at about 40F (4C) for four weeks first.
| Planting timing | Top growth by midwinter | What you get |
|---|---|---|
| Late summer | 8 inches (20 cm) or more | Frost-burnt leaves, weakened clove |
| Mid autumn | 2 to 3 inches (5 to 8 cm) | The target. Strong roots, small top |
| Late autumn | Just breaking the surface | Acceptable. Mulch heavily |
| Once the ground is cold | None | Frost heave, small bulbs, gaps in the row |
Depth and spacing decide the size of the bulb
Set each clove pointed end up, flat basal plate down, with the tip two inches (five cm) below the surface. In a cold garden go to three inches (eight cm), which buys real protection against frost heave. Planted shallower than an inch (2.5 cm) the bulb pushes itself out of the soil in spring and the outer wrappers split.
Space cloves six inches (15 cm) apart with eight to ten inches (20 to 25 cm) between rows. That spacing is not about light, it is about the volume of soil each bulb can draw on in late spring when it is sizing up. At four inches (10 cm) apart you will get a full row of small bulbs, which is the most common reason a home garlic crop disappoints.
- Mark the row before you start Lay a cane along the bed and mark every six inches (15 cm). Garlic rows are planted blind and stay in the ground for eight months, so getting the spacing right now saves regret later.
- Make the hole with a dibber Push a dibber or a thick stick in to make a clean hole rather than shoving the clove into the soil. Forcing a clove down damages the basal plate.
- Check which way is up The pointed end is the shoot, the flat rough end is the root. A clove planted upside down still grows, but it comes up crooked and the bulb ends up misshapen.
- Firm and water once Cover, press the soil down with your palm, and water the row once. After that autumn rain is normally enough until spring.
Loose, well-drained ground with the feed already in it
Garlic sits in the same ground for eight months, and it will not tolerate waterlogging for any part of that. Dig the bed at least a spade deep and break up any pan you find. On heavy clay or in a wet garden, plant into a raised bed or a ridge four inches (10 cm) proud of the path, because rotting basal plates over winter are almost always a drainage problem.
Work in a bucket of well-rotted compost per square yard (square meter) plus a balanced granular fertilizer a week or two before planting. Fresh manure is the wrong choice here: it burns the basal plate and encourages the soft rots. Aim for a pH between 6.0 and 7.0, and lime in autumn if you are more acidic than that.
| Soil condition | Problem it causes | What to do before planting |
|---|---|---|
| Heavy, wet clay | Basal plate rot over winter | Raise the bed 4 inches (10 cm), add grit and compost |
| Compacted layer at a spade's depth | Shallow roots, small bulbs | Fork through the pan, do not just turn the top |
| Acidic below pH 6.0 | Poor uptake, weak spring growth | Lime in early autumn, ahead of planting |
| Grew onions or garlic last year | White rot and nematode build-up | Move the bed. Allow at least four years |
Write down what you planted and where
Garlic is in the ground for eight months and looks identical to itself the whole way through, so memory is not good enough. Before you cover the row, note the planting date, the number of cloves, the spacing you used, and which end of the row got the biggest cloves. Sketch the bed position too, because you need to keep garlic and onions off that ground for four years.
Next summer, weigh the bulbs from each end of the row and compare them against those notes. Two seasons of records will tell you more about your own garden than any general guide can: whether you plant a fortnight too late, whether your six inch spacing is generous or tight for your soil, and which of your own bulbs to hold back for replanting.
- Record the planting date and the source Note whether the cloves came from a bought bulb or from your own crop, and the average clove size. This is the number you will compare harvests against.
- Map the bed Sketch which bed and which end. Garlic needs a four year gap before it returns to the same ground, and by then you will not remember.
- Mark the row physically Put a stake at each end. Nothing shows above ground for weeks and it is easy to plant something else straight over the top of it.