What is the shelf life of Osmocote®?
What is the best time to apply Osmocote?
Will Osmocote react with other fertilizers or plant products?
Does Osmocote stain?
How should Osmocote be stored?
Should the plant be watered before or after application?
Is Osmocote harmful to animals?
How does Osmocote differ from other slow-release plant foods?
What are the yellow and white shells leftover after application?
Do plants receive nutrients right away after application, or does it take longer for feeding to begin?
Which product should I use?
Is there any difference between ‘consumer’ Osmocote and the Osmocote product used by professionals?
Does Osmocote have an odor?
Is Osmocote expensive?

 

What is the shelf life of Osmocote?

As long as the product is stored properly, it can last for over eight (8) years.  Proper storage means being in a relatively cool but dry place.  Sunlight or its absence is not a factor.  However, should granules come into contact with moisture or high temperatures, they may begin to release some of their nutrients and the remaining product may become less effective when it is finally applied. 

What is the best time to apply Osmocote?

One of the nice characteristics about Osmocote is that it can be applied just about anytime.   Early spring is a good time to start feeding perennials, trees and shrubs as long as the ground is not frozen.   It’s best to work product into the top 1-3 inches of soil or mulch, but even when that’s not possible, the melting of late snow and/or early spring rains will work the granules into the soil.  As ambient temperatures begin to climb, so will soil temperatures, eventually.  The release of nutrients from the Osmocote granules will track the steady rise in soil temperatures thus ensuring that the right amount of nutrition is available when plants are able to use it.  The ideal soil temperature for nutrient release is between 50◦F – 70◦F.  When feeding annuals, it’s best to apply in-the-hole as plants are transferred from flats to pots or mother Earth.   A second feeding may be appropriate four months later.  Fall is also a good to time to feed perennials.  Many plants have another burst of growth at this time of year.  Soil temperatures drop to friendlier levels and often this is accompanied by an increase in rainfall.  The result is ideal growing conditions.  And, don’t worry about an early frost.  Remember, it’s soil temperatures that matter.  Plants keep right on feeding until the temperature of the soil drops below 45◦F.

How does Osmocote react with other fertilizers or plant food products?

Professional growers frequently use a water-soluble fertilizer in addition to Osmocote.  Water-soluble fertilizer is absorbed partially through the leaves (foliar feeding).  This compliments the root-feeding properties of Osmocote.  When using a water-soluble product with Osmocote, be sure to follow the recommended rate on its package but then cut that amount by half.  Typically, a water-soluble fertilizer has a roughly two-week impact on the plant, but meanwhile, Osmocote goes right on feeding for up to four months!

Does Osmocote stain?

Osmocote does not contain staining agents. 

How should Osmocote be stored?

The product should be stored in a cool, dry place.  When the product is exposed to moisture or high temperatures, nutrient release could begin making the product less effective when eventually applied. 

Should Osmocote be used with water?

It’s important that Osmocote be applied dry.  Do not pre-mix the product with water before applying.  Further, it’s not necessary to water plants immediately after Osmocote is applied in order to reduce the potential for chemical “burn.”  Osmocote has a resin coating that encapsulates the nutrients.  Direct contact by the product with plants is not a problem.

Is Osmocote harmful to animals?

Osmocote is not harmful to animals when used as directed.

How does Osmocote differ from other slow-release plant foods?

Compared to most other slow-release plant foods, Osmocote contains 2-3 times as much slow-release nitrogen per pound of product.  Since nitrogen is an important element for plant growth, this makes Osmocote more effective and significantly increases its value to the consumer.   Osmocote granules are nearly perfect spheres.  This ensures that nutrient release works the same way with each granule.  Osmocote granules are also uniform in size, contributing to the consistency of the nutrient release.  Osmocote has a resin coating, a characteristic of that’s somewhat elastic.  This reduces the risk of granules cracking, then initiating the release of nutrients during the packaging process and while the product is transiting to the retail store. 

What are the yellow and white shells that are leftover after application?

Sometimes the spent shells are mistaken for product that failed to activate and release nutrients.  These shells are actually empty and just residual material.  After osmosis occurs and all of the nutrients are released, the remaining granule is empty.  These shells will eventually disintegrate into the soil.

Do plants receive nutrients immediately after application?

Nutrients are released shortly after the granule is inflated with moisture.  Of course, this depends upon the amount of moisture in the soil.   Because of the special properties of the Osmocote coating, granules hold a fixed amount of moisture and no more, even if submerged in standing water.  The temperature of the soil controls the rate at which nutrients are released.  The warmer the soil, the faster nutrients are released.  Conversely, when soil temperatures drop, so does the release of nutrients.  Most North American plants cease to feed when soil temperatures drop below 45◦F.  The osmosis process that releases nutrients into the soil stops working at approximately the same temperature.  

Which Osmocote formula should I use?

Osmocote is available in three formulations:

Indoor & Outdoor (Analysis 19-6-12)

• Ideal for pots, window boxes, hanging baskets, anything in a container
• Annuals
• Indoor plants
• Plants in raised beds

Vegetable & Bedding (Analysis 14-14-14)

• Tomatoes, garden vegetables, melons, berries
• Perennials
• Trees and shrubs
• Most anything in mother Earth

ACR with Soil Acidifiers (Analysis 9-6-6)

• Aster
• Azalea
• Begonia
• Birch
• Camellia
• Dogwood
• Evergreen
• Gardenia
• Holly
• Hydrangea
• Impatiens
• Marigold
• Magnolia
• Oak
• Pansy
• Petunia
• Pine
• Rhododendron
• Spruce

Is there any difference between ‘consumer’ Osmocote and the Osmocote product used by professionals?

Osmocote for consumers and Osmocote for professional growers utilize the same technology.  Both products use the same prills (spheres) and the same unique resin coating.  In fact, these products are manufactured in the same plant in Charleston, South Carolina.  While the consumer product is available in just three formulas, the professional product is produced in nearly 50 formulas because professionals require a broader range of NPK analysis depending upon the crop they are growing and local growing conditions. Osmocote for consumers is available in three sizes, 1.25 lb. and 3 lb. bottles and 10 lb. bags. Osmocote for professionals is packaged in 50 lb. sacks.  

Does Osmocote have an odor?

Because of it’s unique resin coating, Osmocote does not have an offensive odor.

Is Osmocote expensive?

Not really.  What consumers are buying is slow-release nitrogen.  The amount of slow-release nitrogen is critical to plant food performance (it almost always drives plant growth).  On a price per pound for slow-release nitrogen basis, Osmocote is competitively priced.  In other words, you get what you pay for!