How to grow strawberries

Three types, and they behave so differently that advice written for one is misleading for another.

Junebearing plants set flower buds in the short days of autumn and give one heavy crop in early summer. That concentrated harvest is what you want if you intend to make jam or freeze a year's supply, and the plants make runners freely. This is the traditional type and still the heaviest cropper.

Everbearing gives two smaller flushes, roughly early summer and again in autumn. Day-neutral plants ignore day length altogether and fruit steadily from summer to frost, with the smallest berries of the three and the fewest runners.

For a household that wants strawberries on cereal from June to October, day-neutral is right. For anyone who wants to preserve, junebearing is right. Most disappointment with strawberries is somebody who bought one and wanted the other.

Whichever you plant, pinch off every flower in the first year on junebearers — and for the first six weeks on the others. It feels wrong and it is the difference between a bed that crops for four years and one that exhausts itself in two.

A strawberry propagates itself by throwing out runners — horizontal stems that root where they touch soil and make a new plant, genetically identical to the parent. This is both the crop's great convenience and the reason beds decline.

Left alone, a bed becomes a crowded mat. Crowded plants make small fruit, hold damp air, and get grey mould. Meanwhile the original crowns age: a strawberry plant is most productive in its second and third years, and by the fourth it is worth little.

So the discipline is a rolling replacement. Each year, let a few runners root into pots or into a clear strip of ground, and each year pull out the oldest plants. After three seasons you have replaced the bed entirely without ever losing a harvest.

The alternative — start a new bed on fresh ground every three or four years — is better still where you have the space, because it breaks the soil-borne disease cycle that builds up under strawberries.

Roe, in 1881, describes selecting the single best plant in a bed and letting only that one propagate, then repeating the selection from its offspring. That is clonal selection, and it is exactly what a modern grower does when they mark the best plant with a cane before letting it run.

The plant is thoroughly hardy — it survives winters that kill far tougher-looking things. The flower is not.

An open strawberry blossom is damaged at about 30°F and killed a little below that, and the damage is unmistakable: the centre of the flower turns black. Growers call it black eye. A flower with a black centre will not make a fruit, and there is no recovering it.

This is where your own frost dates matter more than any published month. The gap between the date frost *usually* finishes and the date it is *safely* finished is exactly the window in which strawberry blossom is at risk, and it differs by weeks between two towns.

The protection is simple and works: throw fleece or even an old sheet over the bed on any clear, still night when frost is forecast and flowers are open. Take it off in the morning so pollinators can reach them. A few nights of that saves the crop.

Straw mulch — which is very likely where the name comes from — does a second job here beyond keeping fruit clean: it moderates soil temperature and slightly delays flowering, which in a frost-prone garden is a feature rather than a cost.

Edward Payson Roe gave up a pulpit to grow small fruit commercially on the Hudson, and published Success with Small Fruits in 1881. It is on our shelf, it is free, and it contains the best sentence about growing anything that we have found in any of these books.

Writing about strawberries, he reports Charles Downing's remark that no other fruit was so affected by varying soils and climates — and then draws the conclusion himself: “soil, locality, and climate make such vast differences that unless these variations are carefully studied and indicated, books will mislead more people than they help.”

That is, almost word for word, the argument this whole site is built on. A gardening book that prints one date and one variety list for an unnamed climate is not merely incomplete; it is actively misleading to most of the people reading it. Roe knew that in 1881 and said so in his own book, which takes some nerve.

It is also why the strawberry is the right crop to open our fruit section with. Of everything we grow, it is the one where local conditions most overwhelm general advice — and the one where we can do something about it, because we already know your frost dates.

Pick when the whole berry is red, including the shoulders under the leaves, and pick with a short stem rather than pulling the fruit off its cap — a strawberry pulled off bruises where your fingers were and goes over within hours.

Pick in the morning while they are cool, and pick every day or two in warm weather. A ripe strawberry left one extra day is a grey mould infection waiting to spread to the fruit next to it.

Birds will take the crop, and there is no half measure that works. Netting is the answer, held clear of the fruit on hoops so blackbirds cannot simply perch and reach through, and tucked in at the edges so nothing gets underneath and trapped.

Slugs take the underside of any berry resting on soil, which is what the straw is for. Grey mould is the main disease and is largely a spacing and airflow problem — plants a foot or more apart in rows dry out after rain, plants in a crowded mat do not.

One thing not to do: fresh manure or a nitrogen-heavy feed, which produces enormous leaves and very little fruit. Feed after cropping, not before it.