Answer: Generally speaking, you would fertilize in early spring, possibly again in early summer, using a complete fertilizer such as 10-10-10 in a slow release form per the label directions. For more specific recommendations on how much to use and what to use, you would look at what types of perennials you are growing and run some basic soil tests so you could fertilize based on the test results. If you top dress spring and fall with compost and also use an organic mulch year round, your plants might do fine with little or no additional fertilizer. If in doubt, it is better to underfertilize than over fertilize. I hope this helps.
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