Return to the Fruit & Orchards Forum | Post a Follow-Up

ammonium sulfate concentration for watering blueberries?

Posted by oldryder (4), MN (My Page) on
Thu, Jul 19, 12 at 11:40

Is one tablespoon of ammonium sulfate per 2.5 gallons of water sound right for watering established blueberry plants?

should the amount be adjusted for 7.5 ph well water?

(I noted this last year but could not find the original thread. I believe it was from "fruitnut" but not sure.)

Follow-Up Postings:

RE: ammonium sulfate concentration for watering blueberries?

Yes, the ratio is correct, but I only apply that once per week establishing plants, not at every watering. And I used it from April thru June. I'm not fertilizing now anymore except for what little of the CRF is left in the soil from the spring. I add approx 2 tablespoons of white vinegar per gallon of my approx 8.0 pH tapwater for each watering. I have five 2 y.o. plants, and two 5 y.o. plants. They are growing very well.

RE: ammonium sulfate concentration for watering blueberries?

It's usually recommended to shake crystals around the drip line on top of a thick layer mulch rather then water it in directly. This helps it release more slowly, and needs to be done less often. I usually only add ammonium sulphate twice per year, in spring and in June, no later.

As far as pHing water, it depends on your soil and the water itself. If the soil is on the low side of pH, no need to lower. If it's already high, then add acid to lower the pH of the water. If your soil is just right, go by the ppm of your water. If the ppm is high, adjust the pH. If the ppm (amount of carbonates) is low, no need to adjust. Rainwater, due to it's low ppm usually doesn't need to be adjusted. Low ppm's usually means your water doesn't buffer pH much, and soil will overcome it. If you don't have a ppm meter, the amount of acid you use to correct the pH tells you the buffering capability. If you need a lot of acid to lower it, then you will likely need to use it.

RE: ammonium sulfate concentration for watering blueberries?

thx for replies. I think my soil is OK, started with 1/2 peat and 1/2 7.2 Ph native soil in fall 2010.

plants were started spring 2011 and are heavily mulched with wood chips with bottom layer starting to rot noticably.

sprinkled ammonium sulphate this spring.

overall plants seem to be doing well. based on your advice seems like I'm doing this right.

RE: ammonium sulfate concentration for watering blueberries?

I wouldn't be surprised if your soil still has a high pH. Usually with alkaline soil and peat, you often also need to add sulphur to get it just right. The rotting mulch will also tend to raise pH as it breaks down. I would suggest you measure the pH now, and regularly to establish the trend so you can fix it before it does start to show on your plants.

RE: ammonium sulfate concentration for watering blueberries?

Oops, sorry. I thought you said for establishing plants. My bad. You said "established." Here's a link for a good thread on the subject. Instead of once per week, it might be only once per month. Also, I grow mine in containers. The routine is different for plants in the ground. Hope this helps.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Fruit & Orchards Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here