How much aluminum sulfate should i feed my hydrangeas to turn them to blue?10points!?

Question

right now there are pink but want them blue. Shoul i mix 1/4 oz of aluminium sulfate to a gallon of water or 1/2 oz? And how much should i had i know that to much will burn the roots but how much is too much? By the way they are plated on the ground right next to each other there are close to each other about 2 ft from each other. so how much do i really add to like each plant? thank you in advance and 10points for best answer!

Answer 1

here's the link http://www.hydrangeashydrangeas.com/colo...

the first answer is a quote from that site i think

Answer 2

To obtain a blue hydrangea, aluminum must be present in the soil. To ensure that aluminum is present, aluminum sulfate may be added to the soil around the hydrangeas.

Authorities recommend that a solution of 1/2 oz (1 Tbsp) aluminum sulfate per gallon of water be applied to plants (which are at least 2-3 years old) throughout the growing season. Important: Water plants well in advance of application and put solution on cautiously, as too much can burn the roots.

To make the aluminum available to the plant, the pH of the soil should be low (5.2-5.5). Adding aluminum sulfate will tend to lower the pH of the soil. Another method for lowering the pH is to add organic matter to the soil such as coffee grounds, fruit and vegetable peels, grass clippings etc.

:)