Fertilizing Astilbe

The astilbe is a great plant that can grow alongside a diverse range of shrubs and perennials and can do very well in the shade of a deciduous tree. Native to the far east, these perennials are a hugely popular choice amongst American gardeners. This may be because of their high level of versatility, elegant appearance, and beginner friendliness. 

Although astilbe perennials do not require much maintenance to grow healthily, taking advantage of quality fertilizers can give your plant the edge it needs to truly thrive. If you have a newly planted astilbe, you can utilize a fertilizer that is rich in phosphorus to help promote its growth. You can sprinkle a small amount of fertilizer into the soil after it has been planted.

Once your plant is established, you can fertilize it once per spring when the soil is moist – not dry. Additionally, you can opt for a high-nitrogen fertilizer for use during autumn time.


How to Fertilize Astilbe

Using fertilizer for your astilbe is not only beneficial but very easy to do. After picking up a good fertilizer, be sure to pay attention to the directions on the packaging and follow them as closely as possible. Astilbe prefers soil with an acidic pH that ranges between the high 5’s and low 6’s.

Once again, it’s important to avoid fertilizing when the soil is dry. Water the soil generously while being mindful not to accidentally overwater it. When the soil is moist, the fertilizer will be able to dissolve easily and reach your astilbe’s roots. 

Best Time To Fertilize Astilbe

Most astilbe perennials will respond excellently to yearly fertilizer. Applying a phosphorus-rich fertilizer during spring will be enough to achieve desirable results.

At the absolute maximum, you can fertilize twice per year. Use a phosphorus-rich fertilizer in springtime to help the plant use and store energy and then a nitrogen-rich fertilizer during the fall. Fertilizing it more frequently can do more harm than good to your plant so make sure not to overdo it.


Best Fertilizer For Astilbe

The ideal fertilizer for an astilbe plant will be a slow-release, granule-based organic formula with an NPK ratio of 5-10-5 or 10-10-10. It’s important to use the recommended type because others may not have the nutrients your astilbe needs to properly flourish. 

Astilbe Fertilizing Tips

  • Make sure your astilbe’s soil is moist
  • Apply a phosphorus-rich fertilizer once per year during spring
  • Use a nitrogen-rich fertilizer once per year during autumn (optional)


-Always wear protective gloves and a face mask when handling chemical fertilizers.

-Closely follow all directions and storage guidelines that are on the fertilizer label.

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Author Chris Link - Published 07-06-2022