How and When to Prune Raspberries & Blackberries
Why Prune Raspberries at All?
Raspberry plants spread by suckers. This means raspberries like to grow and will spread out far and wide if you let them. But large, unpruned raspberry bushes won’t yield more berries and can lead to problems and even early die out of the raspberry bushes. Pruning raspberry plants does more than just keep your plants under control. Raspberries can be prone to disease and pruning inhibits the spread of disease throughout your patch.
To insure that light and air can get inside the plants and to facilitate pruning, keep your raspberry plants controlled in a row. Keep the base of the bushes within a 12 – 18 inch footprint by pruning out any suckers that poke up outside the 12 -18 inch footprint. Don’t worry, the bushes will be much larger on top
What Kind of Raspberry are Your Pruning?
There are 2 bearing categories for raspberry plants:
Summer Bearing (floricane) Raspberries will provide 1 large harvest, usually in late summer or early fall. Summer bearing raspberries bear fruit on 2 year old canes, the canes that sprouted last season. Summer bearing raspberries can be further categorized as early season, mid-season and late season. The harvest period lasts about 4 -5 weeks.
Everbearing (primocane) Raspberries aren’t really everbearing, but they do generally have 2 harvests per season; one in mid-late summer and one in the fall. They fall crop will probably be a bit lighter and is on 1 year old canes of the current season. Many fall bearing raspberries bear so late in the fall that they are not practical for gardeners in short season climates.
How and When to Prune Raspberries
A Word of Caution: Wear thick gloves; raspberries have serious thorns. And use clean, sharp tools.
LATE WINTER / EARLY SPRING – (Before Bud Break)
Prune all canes that bore fruit last year; they won’t fruit again. These will have grayish, peeling bark.
Remove any canes that have grown outside the 12 – 18 inch designated row footprint.
Remove any spindly or short canes.
Thin so that there is about 4-5 of the healthiest, tallest and fattest canes left per foot along the length of the row.
Tie remaining canes to your fencing.
To force your everbearing raspberries to produce only one crop in the fall, prune back the entire raspberry bush in early spring. As the canes grow back in the summer, remove outside suckers and thin the canes to about 6 inches apart. Keep the sturdiest canes. This technique will give you a larger fall harvest and is good if you also have summer bearing raspberry bushes and you want to stagger the harvests.
Prune dead, broken or diseased canes.
Prune any canes that poke up outside your designated row area.
Of course, you can prune broken, dead, diseased or infested canes at any time of the year, the sooner the better.