We have some raspberry canes growing in a space in our yard and while doing some work this summer I removed some thorn bushes and stunted trees that were taking up sun, which was great for the raspberries since they flourished in the past two months. With the space we ended up putting some blueberry bushes since I had the space, and its fairly sunny, but now I am wondering if the raspberry bushes will be ok. Our soil is slightly acidic so I figure the raspberries can handle it, but if I am watering the blueberries will any acidic fertilizer I give them cause problems for the raspberries?
Yes, in short. These fruiting plants are not natural bedfellows: Raspberries prefer alkaline soil conditions, so the acidity required to grow blueberries successfully will not suit them. You could plant Blackberries instead of blueberries, they will thrive where raspberries do, and plant the blueberry elsewhere.
Yes. I wouldn't plant them on top of each other, but they can be planted next to each other. I routinely have blackberry popping up like weeds in my blueberry stand.
There is a lot of misinformation concerning blueberries. Blueberries don't like Nitrates, as in Ammonium Nitrate. Blueberries prefer the Ammonium, but the Nitrate can kill fine roots. Blueberries should always be fertilized with Ammonium Sulfate. Many garden supply shops will recommend Aluminum Sulphate because it makes the soil acid. Do NOT use Aluminum anything on anything you want to live! Especially blueberries, which are sensitive to all sort of things (salt, moisture levels, ph due to iron availability).
Read http://pubs.cas.psu.edu/freepubs/pdfs/AGRS097h.pdf for more info.
Here is another article I thought applicable:
Ph is an indication of a proper nutrient balance, not the cause of it. There is only one proper nutrient combination, but there are many ways to change soil ph.
The main difference between raspberries and blueberries (nutritionally) is that blueberries prefer a little more magnesium in relation to potassium than raspberries. Otherwise, the N, P, Ca levels are the same between the two. If you should happen to splash some epsom salt or ammonium sulfate mix onto the raspberries, I'm sure it wouldn't hurt them.
Now if you start asking about pear and blueberry combinations, then we'll have a problem. Pear requires significantly more Ca than blueberry and the two just wouldn't get along. Your pears would taste like cardboard. Even the deer wouldn't eat them. And the pear trees would be very unhealthy, possibly having fire blight. Ask me how I know this :)
The two plants can be placed near each other, but you may want to place some barrier underground to keep the raspberries from expanding.
I have blueberries growing about 3 feet from my raspberries, with a small patch of grass between them. Both plants seem to be doing fine, but I regularly need to pull out little raspberry shoots that come up right next to blueberries.