When to harvest black walnut 'sparks 147'

Hulls splitting or nuts dropping naturally, typically late summer to autumn. Black Walnut 'Sparks 147' is harvested for its nuts, which ripen inside a hull that splits or drops when ready. The tree tells you when: hulls open, and nuts start to fall on their own. Gather promptly — nuts left on wet ground mould within days.

Shake or knock branches over a sheet and gather what falls, or pick hulls that have already split. Remove the hull straight away and dry the nuts in a single layer somewhere warm and airy for a week or two before storing.

Fully dried nuts keep for months in a cool, dry, dark place in a mesh or paper bag. Shelled kernels are best frozen.

Storing before the nuts are properly dry. Damp kernels mould from the inside, and by the time it shows the batch is lost.