Horizon Distributors - Irrigation & Landscape Supply toggle menu

Horizon stores are open for business during this crisis and can take orders online, by phone, fax or text. Saturday hours may change - call your local store.

Learn More

The Different Types Of Tree And Shrub Fertilizer

Fertilizers designed for trees and shrubs are often very similar in the ratio of NPK, so it's important to take a further look at the bag to see what the fertilizer actually contains and how it will affect your plantings.

In this FAQ, Christina Burton, Horizon's Maintenance Channel Manager, shows you what to watch for when reading a bag to avoid excessive quick growth, tender shoots, and insect damage.

Breaking Down Tree And Shrub Fertilizers - Video Transcript

Spring is a great time in a lot of areas to fertilize your landscape ornamentals. So your trees, shrubs, flowers, ground covers. Those type of things.

And typically, compared to a turf fertilizer, landscape ornamental fertilizer will be a lot higher in these 2nd and 3rd numbers. The phosphorus and the potassium.

And the important thing to really examine when you're looking for a fertilizer for your landscape plantings is that a lot of products can look very similar just in the ratio of NPK. These are both 1:1:1 products. 15-15-15 and a 14-14-14.

You might think, "What's the difference?"

But they're very different in what all is in the bag and that's very important for landscape ornamentals in particular.

So there can be something as basic as a 15-15-15, and really all that's in this product is some quick release fertilizer, quick release nitrogen, and phosphorus and potassium. And the downside, the major downside of using quick release fertilizer on your trees and shrubs is that it causes very quick growth. And with that you end up with very tender shoots. And what happens is those tender shoots are very prone to insect damage.

So if you notice in some of your properties that you have a lot of repeated problems with aphids, with white flies, a lot of times that's a sign you're using too much quick release fertilizer.

14-14-14, and again this doesn't mean it's these exact ratios, but it's just saying look a little closer on the bag. This could be a product that rather than just quick release nitrogen, it contains slow release and a good portion of it. 60% plus. And that's really getting you sustained feeding, slow growth. Not getting the tender shoots over the entire season.

In addition, usually really good products for trees and shrubs contain micronutrients. So iron, manganese, zinc. And those are again just very important, more so than for turf, for landscape ornamentals. It has to do with flowering and their colors.

So again, just pay close attention to the label and make sure you're choosing the right product for those landscape plantings.