How to Fertilize Dahlias

Are you looking for information about fertilizing dahlias? We can help! 

There are three main things to know about properly fertilizing dahlias:

    • Use a balanced fertilizer toward the beginning of the season. 

    • Switch to a lower nitrogen fertilizer later in the season.

    • Fertilize throughout the season.

Early Season Fertilizing

We plant with granulated organic chicken manure fertilizer (5-3-2 + micronutrients!) in our beds, and top dress with more balanced fertilizer about 4-6 weeks later (or about 3 weeks after sprouts emerge). We recommend using a fertilizer that is heavier on Nitrogen at planting, and then switching to a fertilizer with less Nitrogen mid-season. (If you’d like to know what the fertilizer numbers mean, check out this blog post.)

Mid-Season Fertilizing

As your dahlias start to grow, you’ll want to fertilize them again every 3-4 weeks through the season. We recommend a low nitrogen fertilizer for mid-season fertilization because too much nitrogen at this point will cause your plants to have lots of lovely green foliage, but they’ll produce fewer blooms. A 5-10-10 fertilizer is a good ratio for mid-season fertilization. 

How often should I fertilize my dahlias?

We recommend fertilizing every 3-4 weeks throughout the season. This should keep your dahlias blooming and growing all summer long!