How to grow big blueberries and raspberries

Credit: Flickr / audreyjm529

Q: I grow raspberries and blueberries in a 12′ x 4′ raised bed.
The berries have been getting smaller each year, and I’m wondering what are the most important re-furbishing things I could do to go back to those gorgeous, large-sized berries I loved to pick each morning for the first few years.

Because they’ve been in the same container for a while, your plants have eaten up the nutrients that they need. These will need replacing. It’s like withdrawing from your bank account over and over, and never putting any money in!

Small fruits like raspberries and blueberries can stay in the same spot for quite a long time, but – especially when grown in containers – need a little organic matter added regularly, as well as some form of good organic fertilizer – kelp- or fish-based.

Now – another “problem” (sorry) is that you are growing blueberries and raspberries in the same spot. Blueberries prefer acid soil (regular soil on the wet coast); raspberries like the soil a little more alkaline, making this not an ideal pairing. My recommendation is that you put the blueberries in another spot or their own pots. Amend with leaf compost or just lots of chopped up leaves or a bit of “new” topsoil. Add a little peat moss or bark mulch (acid).

Raspberries don’t need much fertilizer, but appreciate an occasional (annual) application of organic material like compost or manure. They love kelp too. Not too much fertilizing or they’ll make all leaves and no fruit! It sounds complicated but it is not. Give it a try, and best of luck.