Our 3 Kinds of Raspberries: Their Stories

The Garden has planted 3 different kinds of raspberries on the west border: 2 red raspberries: Latham, Heritage  and a Black Raspberry.  In general, raspberries bear large succulent fruits when ripening during sunny, hot weather after a good rain.  If not well-watered during hot weather when fruiting, the berries may be small and even pithy.

LATHAM bear June-July & sometimes a 2nd bearing in Fall
Our largest crop comes from the Latham canes and bears in later June through July.  The berries fruit on last year's growth, so care must be taken not to prune them out in the Fall.  Latham have no significant pests in our Garden.  The dying woody canes from this summer's crop can be pruned before new canes emerge after harvest for next year's crop.

HERITAGE bear Aug-Oct

This cultivar bears in late summer on this year's growth and in some years will even bear until Thanksgiving depending on the weather.  Heritage has two pests that plague it in our Garden:

Wilted raspberry tip from cuts
made by the Cane Borer Beetle

• The Raspberry Cane Borer (Oberea bimaculata Oliver) is a half inch black longhorned beetle with yellow stripes on the wing covers and antennae as long as the body.  It attacks by inserting its eggs into the canes, usually at the tender tip growth. The tips wilt because the beetle makes 2 girdles of punctures about an inch apart and inserts its eggs in between.  To manage this problem, interrupt the life cycle by cutting off the tip below the lowest set of punctures and placing in the trash.
• The Two-spotted Fruit Fly, (Drosophila suzukii) a recent newcomer to this country, inserts its eggs into the raspberry fruit, causing it to become inedible.   When you pick a nice ripe berry and look inside to see it liquified, you know the larvae have been at work.  You may even see the small, white, wriggly, wormy larvae themselves!

BLACK RASPBERRIES bear in July
The Black Raspberries are planted in the SW corner of the patch inside the fence.  It is a small patch, planted much later than the reds.  The flavor is distinctly different from the red raspberries.  In harvesting, the trick is to wait until they are black and almost ready to fall off the cane.  When red, these berries are unripe and hard & unpalatable.  We have not noticed any pests amongst these berries. For summertime pruning (waist high at the Fourth of July) see Summertime Pruning of Black Raspberries (July 4)  How to Prune and Grow Black Raspberries is a 21 min video of general black raspberry care. To learn about best pruning practices after fruiting is over check out Pruning Black Raspberries in Late Winter.

Raspberry Cane Borer Beetle
Laying Eggs on a Cane
Photo credit - Mark Longstroth, MSU Ext

RASPBERRY PESTS & HOW TO TREAT THEM

Monitor the Heritage canes for the Cane Borer once the new growth appears, especially in late June. Look for wilted tips and cut them off at least 1 inch below the lowest girdling.  If there appears to be a burrow in the cane where the cutting occurred, cut further down.  The larva may have already started its inside journey down the cane.  Doing this faithfully each season seems to keep the population down and each season there are fewer wilted tips.

Vinegar Trap for Two-Spotted Fruit Fly

For the Two-spotted Fruit Fly, being proactive is the best.  Prior to the fruits appearing in late July on the Heritage, hang vinegar traps on the fence.  Replenish the vinegar if rain dilutes it too much.  The vinegar attracts the flies when they first appear and lures them into the cup where they can't emerge and often drown.  This helps crash the fruit fly population and the damage it does to the berries.

July 25, 2016 The last Latham berry is harvested.  Most of the old Latham canes have been removed to give breathing space to new growth and cut back on insect predation.