raspberry die off problem
over the years in my Bonny Slope (NW portland) garden, i've lost a variety of raspberry plants, from the original delicious variety that were here when i bought my house in 1981, to some current plants which are shown in the photos.
i can't figure out the problem, and would love some help in determining the cause, so i can correct it. the die off seems to be on new canes.
thank you for any help you can provide!
Thank you for attaching the images. The most common problem with raspberries here in the northwest is root rot. The typical story is the berries thrive for a number of years and, then one or several plants decline and die. The worst part is that the problem gradually destroys most of the plants.
You can determine if your plants have root rot by checking the following:
- A healthy raspberry should be difficult to pull out of the ground; one with root rot comes out much more easily plus the roots are dark–colored, shortened, and with a mushy or rotted surface.
- Check the lower stem of an affected floricane (fruiting stem) by scraping it vertically to remove the bark; then look for a color change just underneath the bark. Root rot is present if you see a distinctive reddish-brown color on the stem with creamy-white above; unfortunately, this isn’t always true for raspberries.
- The primocanes (those stems that will fruit next year) will typically look healthy.
If the problem is root rot, the only remedy is to build a new, open-sided raised bed in a different area with clean soil and, then, plant fresh, new healthy plants obtained next spring. Even if some of the existing plants appear to be free of root rot, I suggest you start over.
Unfortunately, no chemical treatment is available for use either before or after planting.
Caution: Don’t move soil or what appear to be healthy plants from the old bed because doing so will contaminate the new bed with the disease organism. And don't be tempted to accept plants from friends or neighbors; instead, always obtain certified plants from a local garden center,
Ratings for root rot:
- Very susceptible to root rot: ‘Canby,' 'Comox,' 'Qualicum,' 'Malahat' and 'Skeena'
- Susceptible: 'Amity,' 'Chilcotin,' 'Nootka,' and 'Willamette'
- Moderately resistant: 'Chilliwack,' 'Meeker,' 'Sumner,' and 'Summit' (Young 'Meeker' plants are very susceptible but mature plants seem to have some field tolerance.)
- Resistant: ‘Cascade Delight’ has some tolerance; ‘Cascade Bounty’ has excellent resistance.
Resources for you:
- “Growing Raspberries in Your Home Garden” https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec1306.pdf
- “Raspberry Cultivars for Oregon” https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/pnw655.pdf
thank you so much for the useful and informative reply! i will check for root rot, and will proceed from there. i posted your reply on a Pacific NW Tree Growers page on facebook where someone was asking a similar question about their raspberries. so this will benefit many besides me.
with appreciation and all best,