To get those stunning, lush blooms and strong stems we all love, your Phlox needs a little more than just a drink of water—it needs the right nutrients. But be careful: when it comes to feeding these beauties, you can definitely have too much of a good thing. Here’s the lowdown on how to fertilize your garden phlox the right way.
When should you fertilize Phlox?
The “when” and “how often” really depends on which type of Phlox you’re growing. You’ll want to treat your plants differently based on whether they are:
- Perennial Phlox or
- Annual Phlox (Drummond phlox).
For the perennials that come back year after year, a single good feeding in the early spring is usually all they need to get moving. Annuals, on the other hand, are heavy feeders because they put all their energy into one season; you’ll want to give them a boost about every two weeks.
What’s the best fertilizer for Phlox?
Again, your choice of “plant food” depends on the variety. For your perennial Phlox, try working one of these into the soil in the spring:
- A balanced organic fertilizer or
- Some well-aged compost.
If you’re growing annuals, a liquid fertilizer works wonders. Look for a blend that is high in phosphorus but low in nitrogen—this combo keeps the plants healthy and focuses their energy on flowers rather than just leaves. Pro tip: Adding a layer of mulch around the base of your plants is a game-changer. It helps lock in moisture and keeps those pesky weeds from crashing the party.
What happens if you overdo it (or underfeed)?
If you’re too stingy with the fertilizer, your Phlox might look a bit stunted and produce fewer flowers than you’d like. However, over-fertilizing is actually a bigger risk. Phlox is particularly sensitive to high nitrogen levels, which can make the plant weak and much more prone to diseases. Too much fertilizer can also mess with the blooming cycle—in the worst-case scenario, your Phlox might not bloom at all.
Your best bet is to always follow the instructions on the fertilizer package. If you’re growing annuals and realize you missed a feeding, don’t sweat it! Just jump back into your two-week routine. Whatever you do, don’t double the dose to “make up” for the missed one.
