Raspberries: Varieties, Pruning, and the Whole Business with Suckers

Getting to know the raspberry: a rewarding plant with a clear blueprint

Few berries reward you as reliably as the raspberry. Give it a sunny or lightly shaded spot, loose soil, and a drink of water in the dry weeks, and it more or less grows itself. That easygoing nature has a flip side, though: leave it to its own devices and it spreads by root suckers, quickly turning into a thicket. Once you understand how the plant is built, you'll keep it in check for years.

Botanically, the raspberry (Rubus idaeus) belongs to the rose family, so it's a cousin of the rose, the apple, and the blackberry. It's a perennial subshrub: the rootstock below ground lives on and sends up fresh growth year after year. That rootstock is the living heart of the plant, and it can stay put for decades.

The individual canes, on the other hand, live for just two years. That's the one principle everything else rests on.

In the first year the plant pushes up a green new cane, the primocane. It grows, turns woody, and overwinters.

In the second year that same cane becomes the fruiting cane, the floricane: it flowers, bears berries, and then dies right back.

While one cane dies off up top, the rootstock is already pushing the next new cane up from below. Hold that two-year rhythm in your head and the difference between summer and autumn raspberries, and all the pruning that comes later, pretty much explains itself.

Summer or autumn raspberry: the one difference that decides everything

If there's one thing to understand about raspberries, it's this: there are two types, and they fruit on completely different wood. Everything hangs on that, the harvest time, the pruning, even whether you find grubs in your berries.

The summer raspberry (single-cropping, a floricane type in the jargon) fruits on two-year-old wood. A cane that grows this year overwinters and only bears fruit the following year. You pick roughly from late June into July, often on into August (around CW 26 to 32). This is the classic, aromatic raspberry flavour, and each cane carries a heavy crop. The trade-off: you need a decent trellis and careful pruning, because the young and the spent canes have to be kept neatly apart.

The autumn raspberry (everbearing, a primocane type) does it the other way round. The canes that come up out of the ground in spring flower and fruit that very same year. The harvest runs from late summer to the first frost, roughly August to October (around CW 34 to 42).

Its big advantage is the pruning: in late winter you simply cut everything down to the ground. No sorting, hardly any cane diseases. And because it doesn't flower until July, the main harvest falls after the raspberry beetle has laid its eggs (May to June). That grub that spoils your summer raspberries is the beetle's larva, and in autumn raspberries it's almost entirely absent.

Tried-and-tested varieties for the home garden

Raspberries fall into two camps: summer raspberries fruit on last year's canes and give their main harvest from June to July, while autumn raspberries fruit on this year's canes from August until the first frost. For a long picking season, it pays to grow both side by side.

Among the red summer raspberries, 'Glen Ample' is the dependable one: thornless, very high-yielding, with large, sweet and aromatic berries (ready around CW 26 to 30). Those thornless canes make picking child's play. 'Meeker' scores with firm berries that store well and a mid-to-late season, 'Malling Promise' is the early variety for your first taste from June on, and 'Schönemann' fruits late and has a name for being tough and tasty. Summer raspberries reach a good 1.5 to 2 m and need a wire framework or trellis.

Among the autumn raspberries, 'Autumn Bliss' is the aromatic classic, early and cropping over several weeks. 'Polka' delivers very high yields with large fruit, 'Himbo-Top' stands out for its big, sturdy berries that come away cleanly (ripe from late August), and 'Aroma Queen' has a fine wild-raspberry flavour and bears into October. These varieties stay a touch more compact at around 1.5 to 1.8 m, though a light support still keeps them upright under a full load of fruit.

If you like a bit of variety, try the yellow sorts. 'Fallgold' and 'Golden Everest' are autumn-fruiting, mild and sweet with little acidity, perfect for children and for grazing straight off the cane. The red 'Sugana' plays a special role: it crops twice, on the two-year-old canes from June and on the one-year-old canes from August, giving you two harvests from a single plant.

When you buy, be sure to get certified, virus-free stock. Raspberries pass viral diseases around easily, and a healthy start saves you a lot of grief in the bed later on.

Site, soil, planting, and care

The raspberry will thank you for a sunny to lightly shaded spot with plenty of air. A sheltered but airy corner is ideal: where the canes dry off quickly after rain, fungi get little foothold. A draughty, exposed spot, on the other hand, wears the plant down.

About soil, the raspberry is fussy. It likes it loose, rich in humus, and evenly moist, but never waterlogged. Ideally the pH sits slightly acidic, around 5.5 to 6.5. Heavy, chalky soils are worth improving before planting with mature compost and a little composted bark. Where water tends to sit, a raised ridge or a raised bed helps, so the roots are never left sitting in the wet.

The best time to plant is autumn (October to November, CW 40 to 46), or else early spring. Planted in autumn, the canes root in strongly before they break into growth. Within the row, leave about 40 to 50 cm between plants and at least 1.5 m between rows. Don't plant too deep: the crown belongs just below the soil surface, otherwise the new shoots rot.

To keep the canes standing upright, you'll want a support. A wire trellis or a T-shaped frame about 1.8 m high holds the growth in shape, keeps the fruit clean, and makes picking comfortable.

With watering, steadiness is what counts, especially while the fruit is forming in summer. With feeding, go easy: raspberries are moderate feeders with a healthy appetite for potassium, but they react badly to too much nitrogen. In spring, give them a dose of compost and a little organic berry fertiliser, nitrogen-forward in spring and only sparingly in high summer. Too much of it forces soft, disease-prone growth. If the leaves turn yellow between the veins, chlorosis is often behind it, an iron deficiency on soil that's too chalky. Then it's worth checking the pH, because too much lime locks up the plant's uptake of iron.

Pruning: where the theory meets the shears

Summer and autumn raspberries fruit on different wood, and that's exactly what all the pruning hangs on. Once you've got the difference clear in your head, the shears more or less guide themselves.

Summer raspberry: tidy up after the harvest

Right after the harvest, usually July to August, cut the spent, two-year-old canes out at ground level. They've done their job and will never fruit again. The young canes from this year that have grown up alongside them stay put. They're next year's harvest.

Of those young canes, keep the 8 to 12 strongest per running metre and take out everything thin and weak. Less crowding means more light and drier foliage, which keeps fungi at bay. In late winter, trim the tips back lightly and tie the canes in to the trellis.

Autumn raspberry: one cut, and you're done

Here's where the big advantage lies. In late winter, around February in CW 6 to 8 and still before growth starts, cut every cane right down to the ground. No sorting, no thinning. The new young canes grow up from the root and fruit that same year.

This drastic cut rejuvenates the whole planting every year and breaks the disease and raspberry-beetle cycles: the beetle lays its eggs in the flowers in May, but the autumn raspberry doesn't flower until mid-July. By then he's long finished, and your berries stay grub-free.

The most common mistake is to treat the autumn raspberry like a summer one and leave the old canes standing. You can do it, and it does give you an early and a late harvest off the same plant, but it costs you flavour and plant health. For the home garden, it's rarely worth it.

A word on tools: cut clean and sharp, a smooth cut heals faster than a crushed one. Disinfect the blade between diseased plants, and diseased cane material belongs in the household waste, not on the compost.

How the raspberry wanders: understanding and steering root suckers

The raspberry doesn't stay where you planted it. Below ground it sends out horizontal runners in every direction, what gardeners call root suckers. Along these shallow-lying roots sit buds, and some distance from the mother plant new canes push up out of them. That's the plant cloning itself.

That's why a well-established row never really holds still. It travels a good few centimetres a year, often 50 cm to well over a metre. By the third year, the first canes suddenly turn up in the middle of the lawn, in the vegetable bed, or over the fence in the neighbour's garden.

Left unchecked, the row turns into a thicket. The canes stand too close, compete for light and water, don't air through properly, and the crop per cane drops off. Suckers that have once got themselves deep into the lawn or in among the carrots are a real chore to get out again.

The most reliable way to contain it is right at planting time: a rhizome barrier, also called a root barrier. Sink a root-proof HDPE sheet vertically into the ground about 40 to 60 cm deep, and let it stand a few centimetres proud of the soil so no sucker can creep over the top. Next to a lawn or a bed especially, this is the safest solution.

Without a barrier, discipline does the job. Mark out a strip about 40 to 50 cm wide and hold that line firmly. Anything that shoots up outside it, slice off young with the spade, at least about 30 cm deep. The important bit: slice it off, don't just cut it, because a topped sucker will simply reshoot from the root that's left behind. Check two or three times a season, ideally in spring and early summer, while the suckers are still young and shallow-rooted. For very small gardens or the balcony, growing in a pot works too, in a 60-litre mortar tub that pens the roots in by its very nature.

One special case: autumn raspberries get cut right down to the ground in late winter. After that drastic fresh start, they come back especially thick in spring and throw suckers with real enthusiasm. This is exactly where a rhizome barrier pays off most clearly.

Diseases and pests: prevent rather than spray

The best plant protection there is is a strong plant in the right place. An airy spot, clean pruning, and consistent hygiene pull the rug out from under most problems before they start. Buy virus-free stock, and if a spot keeps ailing year after year, move the planting elsewhere.

The classic one is the raspberry beetle (Byturus tomentosus), or more precisely its whitish grub inside the ripe fruit. The beetle flies at the flowering of the summer raspberry, usually May to June (CW 19 to 25), and lays its eggs in the open blossom. The nicest counter-move is horticultural, not chemical: autumn raspberries carry their main harvest only after the flight period, and so stay largely grub-free. It also helps to loosen the top of the soil in winter (the beetles overwinter down there), to set out white bowl traps at flowering time, and to clear away any infested dropped fruit thoroughly.

Autumn raspberries have an edge against cane disease too: the hard cut to the ground in winter clears away all the wood the fungus would overwinter in.

Grey mould (Botrytis cinerea) coats the fruit in a grey fuzz in wet weather. Pick often then, let nothing hang on overripe, and keep the planting airy so the berries dry off quickly after rain.

Worth a quick note, since they're rarer: the raspberry cane midge lays its eggs in cracks in the bark and weakens the cane, while spider mites show up in dry heat as a fine speckling on the leaves. On well-tended plants with plenty of air around them, both usually stay within bounds.

Harvesting, storing, using

A raspberry is ripe when it comes away from the white core with a gentle tug. The core stays on the cane, and the fruit keeps that hollow it's known for. That's the big difference from the blackberry, where the core comes away with the fruit. If you have to tug or pull, give it another day.

Pick regularly, in full flush every 2 to 3 days, or fruit will go overripe on the cane and draw in wasps. Harvest dry if you can, in the late morning once the dew has burned off. Wet berries mould faster and lose flavour.

For the store cupboard, I freeze them in portions. Lay the dry berries out singly on a tray in the freezer first, and only tip them into the bag once they're frozen. That way they trickle out one by one later instead of sticking together in a clump. Frozen, they'll keep about six months.

Whatever's left over turns into jam, jelly, or cordial. Drying is worth it too, for tea, and the young leaves make a mild raspberry-leaf brew. A well-kept row bears generously over many years, often more than one household can get through fresh. That's exactly what the freezer is for.

And there it stands, year after year, bearing fruit. The raspberry isn't a project for a single season but one that grows along with you. In time you come to know which cane carried the sweetest fruit last year and which variety the children liked best, and there's something lovely about a garden that remembers such things with you over the years.