Planting Hole Placement (PHP) Technology

With our focus on superior quality, Reforestation Technologies International (RTI) is always looking for new ways to further enhance the performance and safety of our products. RTI’s new PHP teabag fertilizer products are one more example of that commitment.

How do the new PHP products work?

Each nutrient within the teabag is coated with a high-performance polymer coating that precisely controls the speed of nutrient release over a set period of time.

As a result of that high degree of control, foresters can safely place the teabags in the same hole as the seedling without fear of killing it.


Just like our coatings in the past, our new PHP products break the feast or famine cycle associated with conventional and inferior slow-release technologies. This ensures that the nutrients remain available to the seedling and are not leached into the environment.

How Does the Polymer Coating Work?

The polymer coating is activated by moisture and the speed of release is affected by soil temperatures. As the soil temperatures rise, osmatic pressure builds within the polymer coating, opening channels and releasing the fertilizer into the soil through reverse osmosis. The warmer the temperature, the greater the osmotic pressure that develops within the coating, creating a quicker release. As the soil temperatures cool, the osmotic pressure decreases and the release of nutrients through the polymer coating slows down.

In fact, if temperatures are too cold for roots to grow, the membrane will close, holding the nutrients in place until conditions are again favorable.

Also of note, is that the rate of nutrient release by the polymer is not significantly affected by soil moisture, soil type, soil pH or microbial activity. For instance, if soil temperatures are consistent, the rate of release will essentially be the same whether soils are saturated or they have minimal moisture levels for plants to grow. If soils are entirely dry (i.e. plants will wilt because they can no longer access moisture) the nutrients will stay put until moisture becomes available again.

Sounds good, but I have heard that placing fertilizer in the same hole kills trees?
How does RTI know PHP products will not damage trees?

That is a fair question and given we are in the business of helping you succeed, we would never recommend anything unless we were confident that it works. Over the past 3 years, up until the end of the 2015 planting season, over 3.5 million RTI PHP teabags have been utilized on the BC Coast and throughout the BC Interior in a number of different ecosystems with numerous species. To date, RTI has not received any complaints of seedlings being burned by any of our PHP teabags. We are confident that they will work for you!

Still not ready to believe?
Look at this incredible example to the right!

One of our clients wanted to know whether the product’s claims were accurate, so he went beyond our placement recommendations and “tested to fail” by placing the PHP teabags right against the seedling plug. After one growing season, he found healthy, vigorous seedlings that benefited from the fertilizer. No sign of burning!

What are the advantages to converting to the new PHP products?

SIMPLICITY — Tree planters will be happier with a simplified process, leading to greater efficiency at time of planting. The less time they take to plant the trees, the lower the cost in labor. Therefore that extra time can now be allocated elsewhere.

MORE CONSISTENT PERFORMANCE — You will benefit a from more consistent result as the teabag will always be placed in the right spot, close to the seedling. How many times have you gone out to the field to check the planters and couldn’t find the teabag? It may be because they put it too far away fearing that they would burn the tree with the fertilizer. Being able to place the teabag in the same hole ensures that you get the full benefit of the fertilizer you are paying for.

ENHANCED SAFETY — Product safety is always on our minds given the concern of tree planters handling teabag fertilizer. We want to do our best to address their concerns and to assure planters that what they are handling is safe. Not only are the levels of heavy metals lower in the fully coated paks than the regular version, but the polymer coating provides an additional layer of protection to prevent contact between the tree planter and the nutrient contents.

For more information regarding the RTI PHP advantage, please contact Darius Bucher, RPF, Integral Forest Management Ltd. At 250-318-8861 or by e-mail at