Gadenin日本語Get the appThe hull tells you when, and nothing else does
An almond is not a nut in the way the shops present it. On the tree it is a small green fruit like a hard flat peach, with a leathery outer hull, a shell inside that, and the kernel you eat inside the shell. Through the summer the hull is tight and green and the whole thing looks like an inedible little fruit.
When the kernel is full and mature, the hull dries and splits along the seam, opening to show the shell inside. That split is the signal, and it is the only reliable one. There is no color change on the outside to judge, no softening to feel, and cutting one open early tells you very little because a kernel that looks full may still be soft and papery.
The split starts on the highest and sunniest parts of the tree and works its way down and inwards over two to four weeks. Do not pick the first ones and assume the tree is ready. Wait until roughly three quarters of the hulls on the whole tree have opened, then take the crop in one go, because a tree standing with open hulls is exposed to rain, birds and the insects that lay into split hulls.
| Stage | What you see | What to do |
|---|---|---|
| Midsummer | Hulls tight, green, fuzzy and closed | Nothing; keep watering evenly and keep the ground clear |
| Hull split begins, top of the tree | A crack opening along the seam of the highest hulls | Stop watering or cut right back; taper off so the hulls dry rather than rot |
| Split spreading down and inwards | Half the hulls open, shells visible | Get sheets, ladders and drying trays ready; watch the forecast for rain |
| About three quarters of hulls open | Most hulls gaping, some starting to drop | Harvest the whole tree now; shake it down and clear the ground |
| Hulls open for weeks in wet weather | Mold inside the hull, dark stained shells | Too late; take what is sound, discard stained nuts and harvest earlier next season |
Shake it down, do not pick it off
Almonds are harvested by shaking, not by hand-picking, and the difference is not just speed. A nut that comes off when the tree is shaken is a nut that was ready to come off. One that has to be pulled is not finished, and pulling also tears off the spur it was growing on, which is next year's crop from that point.
Lay old sheets, tarpaulins or netting on the ground under the whole canopy first. Almonds falling onto bare soil pick up dirt and moisture and are much harder to find; falling into long grass, half of them simply vanish. Overlap the sheets and run them out past the drip line, because a shaken nut travels further than you expect.
- Pick a dry day after a dry spell Hulls and shells that are already dry come off cleanly and go into storage without a soaking. Harvesting after rain means every nut carries moisture into the drying stage, which is where mold starts.
- Cover the ground completely Sheets or tarpaulins from the trunk out past the edge of the canopy, overlapped at the joins and weighted at the corners. This is the step people skip and then spend an hour on their knees in the grass.
- Shake limb by limb Take hold of each main limb and give it several sharp shakes rather than one slow pull. For high branches use a padded pole to knock the limb, not to beat the shoots. Work round the tree so every limb gets done.
- Go back for the stubborn ones Anything still hanging after a second shaking is either not ready or has stuck in the fork of a branch. Pick off the ones you can reach by hand and leave the rest for a second harvest in a few days rather than fighting the tree.
- Gather up the sheets and sort Draw the sheets together and tip the crop into buckets. Sort as you go: discard nuts with moldy or blackened hulls, holes in the shell, or a fine sawdust-like frass at the split, all of which mean something has been living inside.
- Clear everything left on the ground and the tree Any nut left lying under the tree or hanging on it over winter is where next year's pests and rots overwinter. Sweep the ground and strip the last stragglers off the branches; it is the single most effective sanitation job of the year.
Stop or sharply reduce watering as soon as hull split begins. Water at that stage keeps the hulls soft and green, delays the split, and is the direct cause of hull rot, where the hull decays on the tree and the shoot behind it dies back. Dry weather from hull split to harvest is exactly what an almond wants.
Hull it the same day, then dry it properly
The hull comes off on the day of harvest, not later. Once separated from the tree the hull holds moisture against the shell, and a bucket of unhulled almonds left in a shed for a week comes out stained and musty. On a properly ripe nut the split hull pulls away in two halves with thumb pressure; anything that grips hard is not fully mature and should be set aside and dealt with separately.
Drying is what turns a harvested almond into one you can keep. Spread the hulled nuts, still in their shells, one layer deep on trays, racks or mesh in a warm airy place out of direct sun. Direct sun makes the kernels rancid and can scorch them. Turn them every day or two and give them one to two weeks depending on the weather.
The test is simple and worth doing rather than guessing. Crack a few nuts from different trays. A dry kernel snaps cleanly when you bend it and the inside is uniformly pale and firm. A kernel that bends rubbery and shows a slightly darker, softer center needs another few days. Storing under-dried almonds is how a whole harvest turns moldy in a sealed jar.
Once they snap, store them in their shells if you can, in a sealed container somewhere cool and dark. In shell and cool they keep for a year or more. Shelled they keep for a few months at room temperature, longer in a refrigerator and about a year frozen, because the oil in the kernel is what eventually goes rancid.
What goes wrong between split and storage
Almost every harvest problem happens in the fortnight around hull split, and almost all of them come down to moisture or delay. An open hull is an open door, and every day the crop hangs on the tree with split hulls is another day for something to get in.
Rain during hull split is the worst of it. Water sits inside the open hull, the hull rots against the shell, and the kernel is stained and off-flavored even where it is not actually moldy. If heavy rain is forecast and half your hulls are open, harvest early rather than waiting for the rest. A slightly early crop that is sound beats a fully ripe crop that has been rained into.
The other loss is to the insects that lay eggs into split hulls, and to birds and squirrels that find the crop the moment the shells show. Both are arguments for taking the tree in one operation once three quarters of the hulls are open.
The dates that make next year easier
Write down four things every year: the date you first saw a hull split, the date you judged three quarters of the tree open, the date you harvested, and how long the nuts took to reach the snap test. Add a weight or a rough count, and one line on quality.
The gap between first split and full split is remarkably consistent for a given tree in a given garden, usually two to four weeks. Once you know your tree's figure, the first split becomes a countdown: you know when to stop watering, when to get the sheets out, and when you will be committed, instead of watching the forecast and hoping.
Note which parts of the tree split first as well. That is a map of where the light and heat actually fall, and it tells you which side to open up when you prune after harvest. Record what proportion of nuts you threw away for mold, holes or staining; three seasons of that shows whether the problem is a pest that needs sanitation or simply harvesting a week too late.