Fertilizing Ornamental Grasses

In general, ornamental grasses need little fertilizer. As plants that focus most of their energy into foliage instead of flowers or fruit, their nutrition needs are low to manageable. In fact, overfertilizing an ornamental grass could cause its growth to burst too rapidly and the blades to become lanky or flop over.


Still, a little fertilizer can help an ornamental grass flourish, especially if a mature plant is a few years old and the soil lacks fertility. This is common when growing the grasses in containers, since the nutrients present in the original potting mix fade with time.

How to Fertilize Ornamental Grass

Most ornamental grasses grow best in neutral soil, around pH 5 to 7, but they can tolerate a range of soil pH. Primarily, the soil needs to drain well, so heavy, compacted soil can lead to soggy roots or too little air reaching roots. Having enough organic matter in the soil or potting mix can help the soil retain some water without staying soggy. In general, avoid overwatering or overfertilizing ornamental grasses. When fertilizing, avoid applying the formula to the foliage. Just sprinkle the dry fertilizer around the root zone of the plant, work it in gently, and water. Or use a liquid formula in place of a regular watering.

Young plants typically need no fertilizer, just healthy potting mix or ground soil with some organic matter such as compost. After fertilizing a grass, watch its health and growth, so you can reduce the amount used if the plant grew too fast or lanky.

Best Time To Fertilize Ornamental Grass

If you want to ensure healthy, colorful foliage and good growth, you can apply an all-purpose fertilizer each spring. Be sure to follow package directions and avoid adding too much fertilizer to the area around your ornamental grass.

The best time to fertilize ornamental grasses is once in spring, just as new growth begins to appear. Choosing a slow-release fertilizer can feed your ornamental grass through summer. Avoid fertilizing in fall, winter, or on hot summer days. Wait to fertilize a new ornamental grass until the next spring if possible.

Best Fertilizer For Ornamental Grass

Begin with just ensuring your ornamental grass is planted in a good potting mix or in ground soil with some organic matter. You can add compost each year around the base of the plant, especially one grown in a container. If you want to fertilize ornamental grass, use a balanced, slow-release fertilizer like Osmocote 14-14-14. You can avoid fertilizers designed to encourage flowering.

Ornamental Grass Fertilizing Tips

  • Ornamental grasses need little fertilizing.
  • Avoid fertilizing in fall, winter, or on hot summer days.
  • Apply fertilizer in spring when new growth appears.
  • Use a balanced, slow-release fertilizer.

-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.
-Avoid over-fertilizing ornamental grasses.

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 Author Teresa Odle - Published 11-14-2020