You should only use fertilizer when needed. Are the perennials displaying issues that might lead you to assume they should be fertilized? Do you mulch? Have you had a soil test done?

I use Milorganite in my flower beds and around my shrubs a couple of times a year. My plants love it. Cannas and elephant ears thrive and my annuals do well also. Not only a solid fertilizer but in my zone it is a deer deterrent.

plants are not really like children ... they do not need to be fed all the time .. nor clothed.. nor educated ...

as noted above.. add fert if you get any inclination that such is needed by how your plants are growing ...otherwise.. save your money to buy more plants ...

imo ,. and many of us.. you would be better off building your soil by adding compost .... to add nutrients.. and improve your soil.. rather than spreading fert around ... and leaving your soil lacking ...

this stuff is rather benign intensity-wise ... so no matter what you decide.. it probably wont be doing any harm ..

and btw ... as with any garden product.. use according to the label instructions... and i would be surprised if the answer to your question.. isnt on the label/bag

ken

I agree for the most part about not needing to fertilize perennials and shrubs, but there are some exceptions. Lillies and roses are the first two that pop into my mind -- both are heavy feeders and benefit from fertilization. So targeted feeding = yes, broadcast fertilizing = no.