How do I use the Primerus Spot-Spitter for container irrigation?

To use the Spot-Spitter for nursery irrigation, cut a piece of 1/8” Spaghetti Tubing at 90° and place it over the top peg. Cut the other end at 45°, poke a hole in your poly lateral and insert the Spaghetti Tube without using a barb. Place the Spitter in your container, point the spray direction toward your plant, and pressurize your system to 15-25 psi.

For detailed information, see our tutorial at How to use the Spot-Spitter.

Where do I place the Spot-Spitter in my Container?

Place the Spot-Spitter near the edge of your container (1-3” from edge depending on container size) and direct the spray toward the plant. The spray head should be 1-1.5” above the soil surface, although it can be higher when using the Spot-Spitter Tall.

The Spot-Spitter’s 160° pattern is designed to provide good coverage without overspray when placed near the edge of a round pot of square box. If two Spitters are used, place them on opposite sides of the container. If multiple Spitters are used in a large container or box, space them equally around the circumference of the container.

How do I design a Spot-Spitter System?

Design a Spot-Spitter system from the emitter backward. Start by selecting the right Spitter for each container. Next, select poly laterals for each row with large enough diameter to supply all of the Spitters in the row. Size zones to stay within the capacity of your water supply and, finally, choose submains big enough to feed all of the rows attached to them. See  How to Design a Spot-Spitter System for more detailed information.

We will be publishing an article in the near future with more details on how to do this.

How long should I run my Spot-Spitter for?

The right amount of water to apply with each irrigation cycle depends on your container size, media type, and irrigation frequency. In most cases, adding an amount of water equal to about 25% of the container size fully wets the soil profile (this number can vary depending on media type). If you allow the plant to consume 25% of its available water between irrigations, it will take an amount of water equal to ¼ of 25%, or 6.25% of the entire container size to refill the profile between irrigations.

Example: A 65-gallon container filled with media and roots can hold about 25% x 65 = 16.25 gallons of water. To refill the container after 25% depletion requires about 6.25% x 65 = 4 gallons of water. If the container is irrigated by two black Spitters at 20 PSI, each Spitter applies .25 GPM so the container receives .5 GPM. Run your system for 8 minutes to apply 4 gallons.

Is the Primerus Spot-Spitter the same as the Roberts Spitter?

Yes. The Spot-Spitter was developed by Jim Roberts and introduced by Roberts Irrigation Products, Inc. in 1971. John Deere (Deere & Co.) acquired Roberts Irrigation in 2006 and acquired the Spot-Spitter along with it. In 2012, Primerus Products acquired the Spot-Spitter from Deere.

The Primers Spot-Spitter is made using the same injection molds and the same high-quality acetal material as the original Roberts Spitter. The leadership of Primerus was part of the original Roberts team and has over 25 years of experience in manufacturing and using the Spitter.

Is drip better than overhead sprinklers for a nursery?

The answer depends on the specifics of your nursery. Overhead can apply water very uniformly at a low application rate that is good for plants. Overhead is also very simple to install and maintain. However, if the spacing between containers is significant, Spray stakes (often referred to as “nursery drip”) save water by only putting it in the container and avoid putting water in the spaces between containers.

See the article Container Irrigation Basics for more information.

What is the filtration requirement for the Spot-Spitter?

The filtration requirement for the Spot-Spitter is 120 mesh. If the water contains organic matter (often the case in surface water such as lakes and streams), disk filters or media filters should be used. When well water or municipal water is used a screen filter is usually sufficient.

Can I apply fertilizer through my Spot-Spitters?

Yes. The ability to fertigate is a big advantage of the Spot-Spitter. Since water only goes in the container, so does the fertilizer. Always use filters downstream of the fertilizer injection point when fertigating, use only liquid or soluble fertilizers, and perform a “jar test” first when mixing fertilizers.