How to grow currants

There is a reason currants are everywhere in British gardens and almost nowhere in American ones, and it is not climate or taste. It is white pine blister rust.

The fungus needs two hosts to complete its life cycle: a five-needled pine, and a Ribes — a currant or gooseberry. It arrived in North America early in the twentieth century and threatened the eastern white pine, then one of the most valuable timber trees on the continent.

The federal response was drastic. From 1911 onwards, programmes to eradicate Ribes were organised across the pine states, and a federal ban on growing currants followed. Crews pulled wild and cultivated bushes out by hand across whole regions. An ordinary garden fruit was removed from American life by policy.

The federal prohibition was lifted in 1966 and control passed to the states. Some lifted their restrictions entirely; others kept them, and several still restrict or prohibit planting Ribes, sometimes only for blackcurrants, sometimes county by county.

So this is the one crop on this site where the first question is legal rather than horticultural. Check your state's current rules before you buy, and if there is a restriction, look for certified rust-immune cultivars — several were bred precisely to satisfy it.

The lasting effect is a whole generation of American gardeners who have never tasted a blackcurrant, growing up in a country that removed it deliberately. Read Roe's 1881 chapters on currants against that: he is writing about a completely standard fruit, thirty years before it became contraband.

They look like the same plant and they are not. Redcurrants and whitecurrants fruit on old wood, at the base of last year's shoots and on short permanent spurs. Blackcurrants fruit on young wood — shoots produced the previous season.

That single difference reverses the pruning entirely, and it is the mistake that costs people a crop.

Redcurrants and whitecurrants are pruned like a miniature apple tree. Build a permanent framework of eight to ten main branches on a short leg, then each winter shorten the side shoots back to one or two buds. The structure persists for years and the fruit comes off it.

Blackcurrants are pruned like a raspberry. Cut roughly a quarter to a third of the oldest stems right down to the ground each winter and leave the young ones alone. There is no permanent framework; the bush is continually replacing itself from the base.

Prune a blackcurrant like a redcurrant — trimming the tips and keeping the old wood — and you get a thicket of ageing stems and very little fruit. It is the same class of error as pruning an autumn raspberry as though it were a summer one, and it fails just as quietly.

Currants are among the very few fruits that give a real crop in part shade. A redcurrant will fruit usefully on a north-facing wall or under the edge of a tree canopy, where a strawberry or an apple would sulk.

That makes them the answer to a specific garden problem: the shaded corner nothing wants. They will crop more heavily in sun, but unlike most fruit the shaded version is still worth having, and the fruit hangs longer without going over.

They are hardy well beyond anything the maritime Northwest offers, tolerate a wide range of soils, and want only reasonable drainage and a mulch. They are also self-fertile — one bush crops perfectly well alone, which none of the tree fruit does.

The one thing to plan around is birds. Redcurrants in particular are taken the moment they colour, and they colour weeks before they are sweet. A fruit cage or netting on a frame is the difference between a crop and a nice display for the blackbirds.

Pick whole strigs rather than individual berries, and strip them from the stalk afterwards — a table fork run down the strig does it in seconds.

Currants are high in pectin and high in acid, which is precisely why they are a preserving fruit rather than a dessert one. Redcurrant jelly sets without help from anything, and a handful of redcurrants thrown into a low-pectin jam will set that too.

Blackcurrants are the strongest-flavoured fruit most gardens can grow, and unusually high in vitamin C — the reason Britain planted them intensively during the Second World War when citrus imports stopped, and the origin of the cordial that is still sold there.

Whitecurrants are a redcurrant without the pigment: milder, sweeter, and the one currant genuinely pleasant to eat raw off the bush.

All of them freeze well without any preparation beyond removing the stalks, and all of them are better cooked than they are fresh — which is the opposite of every other fruit on this site and worth knowing before you plant six bushes.