Best Fertilizers for Hydrangeas

Using the appropriate fertilizer is important for success when growing hydrangeas. Are you using the right ones?

Fertilizers make all the difference when you are trying to grow healthy hydrangeas. It can be challenging to select the right one because there are so many choices out there and it’s hard to see the effects of the product that you use until many weeks later. I’ve done the testing and compiled a list of the best fertilizers for hydrangeas for you. Keep reading to see our top recommendations.

Best fertilizers will produce full looking and beautiful blue hydrangeas as seen here. In the background are purple hydrangeas

Osmocote Outdoor Smart Release

  • N-P-K Ratio: 14-14-14
  • Type: Granules
  • Amount: 8 lbs

For both indoor and outdoor plants, follow the directions and fertilize all of your acid-loving plants. Don’t mix, work into the top area of soil. It works with all types of plants. Eleven essential nutrients are included in this product. With a no-burn pledge when applied as instructed, one feeding lasts six months. Get the biggest blue blooms on your hydrangeas.

Jack’s Classic Hydrangea Fertilizer

  • N-P-K Ratio: 7-3-3
  • Type: Water mix
  • Amount: 1.5 lbs​

Use this for the bluest of blooms. This water-soluble food contains aluminum sulfate, the ingredient that makes the flowers bluer. Mix at one tablespoon per gallon and feed every two weeks for the first month. Apply onto damp soil. This product makes hydrangeas healthier and blooms may be larger and last longer. Acidity in the soil makes the blooms blue and this really perks up the color.

Down To Earth Acid Mix

  • N-P-K Ratio: 4-3-6
  • Type: Granules
  • Amount: 5 lb

This is a soil additive, mix shallowly into the soil at the drip line of the shrub, not the base. Mix in about three inches down. Apply when foliage appears. When using this product, water following the application. A slow-release food of this type is easiest to use on hydrangeas and other acid-loving plants, like blueberries. Expect larger blooms when using this all-natural brand. A second application may be used when blooms finish but is often not needed.

Purple, yellow, and pink hydrangeas that have received proper nutrients.

Miracle-Gro Water Soluble Miracid

  • N-P-K Ratio: 30-10-10
  • Type: Water mix
  • Amount: 1 lb

Specially formulated for acid-loving plants, like hydrangeas, simply mix the appropriate amount in a gallon of water. This product begins working immediately, with double action feeding. It can be used as a spray while also feeding through to the roots. Be sure to water before feeding or apply following rain. Feeding dry ground can cause fertilizer burn. Seal the product well before storing it. Apply twice yearly, when foliage sprouts and when blooming ceases.

Jobe’s Spikes

  • N-P-K Ratio: 9-8-7
  • Fertilizer type: Spikes
  • Amount: 30 Spikes

Jobe’s Tree and Shrub Spikes are perhaps the easiest way to feed your hydrangeas as well as Azaleas, Camellias & Rhododendrons. Simply place them in the ground around the root system in spring as the foliage begins to appear. If the ground is dry, moisten it before inserting them. The soil hould remain moist most of the time for optimal performance. These tree and shrub spikes provide a steady supply of nutrients to your shrubs.

Epsoma Holly Tone

  • N-P-K Ratio: 4-3-4
  • Type: Granules
  • Amount: 18 lbs

Specifically Formulated for acid-loving plants, mix this into the soil at the drip-line of the bush. Long-lasting, organic, often used by professional growers. A 4-3-4 NPK contains ingredients to makes the root system grow larger, leaves get greener and blooms grow larger and last longer. Available in a large bag for those with many acid-loving specimens. Consider this product if you have a heavy clay soil.

Hydrangeas that are purple and blue in front of a cement wall

How to Produce Beautiful Flower Blooms

Many of us grow hydrangeas and expect a lush and vibrant bush, full of summertime blooms. Proper fertilization can ensure your plants will develop magnificent flowers. Grow these plants in rich, well-draining soil. Let’s look at a couple factors that you may want to look into when making an educated decision on deciding on what to buy.

N-P-K Ratio

Generally, hydrangeas prefer products with an NPK ratio of roughly 1-1-1. Make sure to check out further details of what NPK ratio means in my other article.

Slow release nitrogen

Slow release forms of nitrogen provide a good form of nutrients. Just make sure that if you are using granules that you actually cover the granules with soil otherwise they will not release properly.

Beautiful pink, purple, and blue hydrangeas

Follow product instructions

Make sure to follow the product instruction because over-fertilizing can create just as many issues as under-fertilizing. If you give your hydrangea too much nutrients it will get something called leaf burn, where you will start to see the leaves looking like they are scorched. This is only a symptom of the deeper problem that the roots are being damaged.

Wrapping it up

I hope you have found this useful. You cannot go wrong with any of the fertilizers above. Make sure to choose based on your needs rather than on price alone.

Carley Miller
Carley Miller is a horticultural expert at Bustling Nest. She previously owned a landscaping business for 25 years and worked at a local garden center for 10 years.
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