Hello Sally,

Thank you for including a photo of your raspberries. It looks like you may have a few problems going on.

The discoloration or whitening of the berries is most likely sunscald or white drupelet disorder. Your raspberries should still be edible even if they’re not very attractive. We have had very hot, dry weather for the last few weeks, and it has no doubt taken a toll on your raspberries.

Also, summer bearing raspberries do have some hardiness problems in our area which may explain your smaller fruit. To help them along, be sure to give them adequate water, not only in winter when the ground is not frozen, but also during the summer when they usually require up to 1” of water every week. Fertilizing with a 20-0-0 fertilizer in the spring and also in June will also go a long way toward strengthening your raspberries for the fruiting season. Mulching will help retain moisture during these hot days of summer.

In looking at your photograph it appears that you may have a problem with sawfly larvae chewing on the leaves. Diatomaceous earth should be an effective tool in protecting against the sawfly in addition to grasshoppers. It can be mixed with water and sprayed on your raspberry leaves. Be sure to wear a protective mask when applying it.

One last thought. If your raspberries are 10-15 years old, it may be time to replace them. This could also be a factor in your disappointing harvest.

For more information, please refer to this fact sheet: https://cmg.extension.colostate.edu/Gardennotes/761.pdf

Thanks!!