Click below to listen to my Garden Bite radio show: Fertilizing annuals and perennials
Yes, there’s a difference. Because annuals live their entire life cycle in one season, they do well with more fertilizer treatments. Also, if they’re in containers, the fertilizer runs out much quicker. Perennials have the advantage of establishing their roots deeper in the soil and the fertilizer lingers longer.
Always follow package directions OR use less! Never use more. For great blooms, use a 10-20-10 fertilizer. The middle number is phosphorus and is responsible for fruits, blooms and roots.
N = Nitrogen – foliage
P = Phosphorus – blooms/fruits and roots
K = Potassium – overall plant health
If it’s fantastic foliage then go for a 20-10-10 fertilizer. You can rarely go wrong with an all-purpose fertilizer such as 10-10-10. Perennials could use a little power boost each Spring. If it’s really hot, DON’T fertilize. You can always top dress your plants as well. Adding compost right on top of the soil works for water retention and gives them some macro and micro nutrients.
If you’re perennials look pooped they may just need some fertilizer. They could be overcrowded too. Typically MOST perennials need to be divided every 3 years.
NOTE: the WAVE petunias and pansies could do with a little more fertilizer because they grow so fast, and to such beautiful lengths. Plant them with slow release fertilizer and give them an extra boost every couple of weeks, especially if they’re in containers.