Life & Style
Of all the juicy berry bombs that summer produces, raspberries are touted by many as the irrefutable kings.
They're delicious, definitely healthy (chock full of antioxidants) and they're super easy to grow. And now's the time to plant them. Head to your local garden centre and you'll find a bevy of berry plants waiting for a new home.
Raspberries are either summer-bearing or autumn-bearing. It's important to recognise which type you have because if you prune at the wrong time for the type of raspberry you have, your fruit bowl come summer will be empty.
Autumn-bearing raspberries are easy. Each winter, these types can be cut right down to the ground, and the new canes that grow will fruit the following autumn.
However, for summer-bearing types only, the canes that fruited should be cut out. This is done immediately after fruiting. The smaller canes that didn't fruit need to be retained because the berries will grow on these the next summer. Sarah Frater, of Edible Garden in Palmerston North, explains it more technically.
"Raspberries produce two types of canes: primocanes are vegetative canes in their first summer of growth and turn into floricanes in their second year of growth and have the flowers and fruiting wood. The two stages of canes are growing at the same time. Once the floricanes have fruited, these are removed in the autumn and winter, and the other primocanes left to come away and fruit the following summer.”
As raspberries spread from suckers, you need to be a bit ruthless and leave only four to five strong shoots per plant to fruit the following season, says Sarah.
How many bushes you plant depends on how much you like raspberries. Sarah suggests two plants per person. So for a family of four, plant eight plants. Each bush should produce between two and three kilograms per season.
Raspberries like a sunny spot, but in warm northern areas, provide some sort of protection from the afternoon sun. Provide some shelter, too, because fruiting laterals and berries may be damaged by strong winds.
Soil must be free-draining because raspberries won't tolerate wet feet. They like sandy loam soils rich in organic matter. Dig in plenty of compost before planting.
To avoid disease, don't plant them in the same spot where tomatoes, potatoes, capsicums and eggplants have grown in the past four years.
Because raspberries sucker, you'll need to contain or manage your plants carefully.
"To stop suckers spreading you can grow raspberries in isolation with a grass mowing strip," says Sarah. "Anything that pops up can just be mown off. Or lay weed mat along the row and cut slits in it to plant the raspberries. This allows the suckers to come up in the row and be removed but not sucker all over the place.”
Before planting, remove any weeds, because the raspberries won't like the competition. Plant at the same level as the plant was in the container.
“In the late summer of the first season's growth, the plants multiply from two to three canes to a clump of about five to 10 growths,” says Sarah. “If small, don't prune, and only allow six strong canes to fruit. Top the remaining canes to stimulate the growth of buds lower down the cane. To allow easy harvesting. top the canes at two metres."
The fruit ripens over a four or five-week period and should be picked regularly. Eat immediately or process for jam because the fruit is very perishable. It will keep in the refrigerator for only one to two days.
“As soon as possible after fruiting those canes that have fruited should be cut out at ground level,” says Sarah. “Then in autumn go through and take out weak, damaged or overcrowded canes at ground level. Remaining cane spacing should be at 100 to 150 millimetres, and keeping four to eight canes per stool.”
There are several varieties to choose from. Heritage and Waiau both produce a small crop in summer but have their main crop in autumn. “My favourite variety would be Heritage as it can all be pruned off at ground level and then becomes an autumn fruiting variety (March-May),” says Sarah.
“You then don't need to remember which canes fruited and which ones didn't at pruning time. But it's also important not to let more than four or five strong canes come away from each clump otherwise you will get a million canes and no raspberries.”
Some of my favourites include the red raspberry Skeena, which ripens in early summer on almost thornless canes. It's bred to have good resistance to fruit rot.
Waiau was bred in New Zealand and does not require a cold winter chill for fruit set to occur. It fruits late December to early January and is suited to all areas of the country.
Southland is grown commercially, as it's considered to be the sweetest and tastiest of all raspberries. It is a strong grower and produces heavy crops of large, firm, roundish fruit which are borne late December. This variety does best in cooler areas.
There are also black and gold raspberries, the former touted as a great antioxidant bearer and the latter one that the birds tend to leave alone.
Sarah sells a variety that's simply known as Black. "It ripens December-January and is very free-fruiting. It's delicious."
Availability: Edible Garden (ediblegarden.co.nz) offers mail order to all areas of the country.
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