Can you add any kind of fertilizer that will make Plumbago flowers a deeper blue?

I use Miracle Gro and my flowers are very bright blue. They are not going to change color blue, but may get more intense.

Can you add any kind of fertilizer that will make Plumbago flowers a deeper blue?
No
Reply:Aluminum sulphate will make some hydrangea cultivars bluer, also works on blue spruce, you could try a small handful around the plumbago.You can buy it at a garden center.
Reply:I am not sure that Plumbagos respond in the same way Hydrangeas do - in fact I am thinking that they do not.


If the variety is white, it is white, blue it is blue and so on......





However, you might try the "Hydrangea treatment" and lower the Ph of the soil. You can buy a soluable product at your garden centre that will lower the Ph. for more blue.


The way you remember this is:


Pink flower for girls = sweet soil


Blue flowers for boys = sour


Try it and let us know next year.
Reply:Check the soil PH and adjust accordingly.