I have a lot of raspberry bushes on the east side of my house. I have lived in this house for over 6 years and the bushes have never produced a single berry. They grow like crazy and get quite large, and they produce the beginnings of a flower but these always die off before they become berries. I've tried fertilizer, I've tried cutting them down to the ground in the fall, but without results. I love raspberries! Any ideas?
Mike writes: Raspberries are heavy feeders, but you may be overdoing it if you've got them planted in good organic soil. The consensus of a quick poll of local growers: Don't fertilize more than once a year (June).
Your pruning may also be too aggressive: You want to cut canes that bore fruit last year to the ground, but canes that were new last year will bear for the first time this year. If you cut those prepubescent canes to the ground, the plants will channel energy into growing canes (again) instead of bearing fruit.
Once you've cut out spent canes, thin the remaining ones so you have 4-5 per foot. My colleague Mike Dunham sez: Pick out the best younger stalks and give each about a 9"-12" radius all to itself. Make it easy to bush out, and the plant will figure "this is easy. What a sweet life. I'm going to make babies."
Some growers say you should move raspberries about every five years because they exhaust the soil; others say that's nonsense if you renew the compost in the soil they are planted in.
Another thought from Mr. Dunham: If they're right against the house, the roots may be picking up something they don't like from whatever was used to seal the foundation. That could affect their growth. Dig up a few and move them elsewhere, as far as you can get them from a structure, then see what happens.
But you may just be trying too hard.
"Of course, one doesn't grow raspberries," Jeff Lowenfels wrote in the Anchorage Daily News back in 1995. "Raspberries grow themselves. You only have to provide cool temperatures and ample moisture. After that, they grow themselves, which is why I have to laugh to myself every time someone brags to me how wonderful their raspberries are. This only means that we are having a particularly rainy summer."
Some varieties recommended by the extension service for growing here in Anchorage:
* Red raspberries: Latham, Boyne, Chief, Trent, Indian Summer, Kiska, Canby, Willamette, Reveille, Newburgh, Heritage, Redwing.
* Gold raspberries: Amber.
* Purple raspberries (marginally hardy in some Anchorage locations): Brandywine, Royalty.