If you are going to be spraying tall trees then you will need a specific type of sprayer. Hand pump sprayers, backpack sprayers, and even 12-volt spot sprayers won’t do it. Reaching spray heights above 30ft will require more flow and pressure than these sprayers provide.
In order to effectively spray tall trees, you need a sprayer that uses a positive displacement pump like a high-pressure diaphragm pump to generate the volume and pressure necessary to reach the spray heights required for trees. Along with the correct sprayer pump, you will also need other components designed for tree spraying. This includes the right size tank, spray gun, and hose.
While many of the components of a tree sprayer are similar to those used in lawn and turf spraying, there are some significant differences that must be acknowledged. A tree sprayer needs the right combination of flow and pressure, let’s take a closer look at the specific components and why they are needed for tree spraying.
Components of a Tree Sprayer
The main aspects of tree sprayers are the pump, spray gun, tank, and hose. There are many options that will work but they do need to have certain attributes.
Tree Sprayer Pump
The pump is the centerpiece of a tree sprayer. It is vitally important to use the right type of pump. Centrifugal pumps, 12-volt pumps, and roller pumps are not going to provide the combination of flow (GPM) and pressure to develop a stream to reach the branches in taller trees. Especially anything over 40 ft tall.
What is the Best Pump for Tree Spraying?
In general, the best pump to use for tree spraying is a medium-pressure diaphragm pump. These pumps generate the required pressure and flow to achieve spray heights of 50 feet or more. There are several different models available that vary in the flow rate they can achieve but they all produce between 500-600 psi. There may be some scenarios when you need a high-pressure diaphragm pump, but these require a lot more horsepower and are more expensive.
Pump For Spraying 40 ft Trees: Udor Kappa 43 (Requires 5.5 hp Engine)
Pump for Spraying trees about 50 ft Tall: Kappa 55 with Honda Engine
For more information about maintaining and operating a diaphragm pump, you can view my article on diaphragm pump troubleshooting and repair.
Tree Sprayer Tank
Another key for tree spraying is the tank size. While this doesn’t have any effect on the spray distance your rig is capable of, it does affect how efficient you are. If you were spraying at 7-8 gallons per minute then a 100-gallon tank would be nearly empty in 10-15 minutes. That’s not a lot of spray time.
200-300 gallon tanks are ideal for 10 GPM pumps. The cost difference between a 100-gallon tank and a 200-gallon tank is not significant compared to the overall cost of a tree spray rig. Especially considering how it will allow you to be more productive.
In general bigger is better when it comes to tank size, but you should consider the weight of the loaded tank. Larger tanks may not work in the back of a UTV or small pickup. 300 gallons or large may require you to use a large truck or trailer for transportation.
Tree Spraying Gun
To get the spray height needed for trees, you need a sprayer gun that will accommodate the flow and pressure of the pump. The critical aspect of any sprayer gun is the nozzle on the end. The nozzle is the restricting point that regulates flow and the spray pattern. A flat fan or cone tip used for weeds or pesticides will likely be too small. Your spray gun will need a nozzle that allows a flow of at least 10 GPM at 500 psi to get about 45 feet vertically.
The spray pattern is also important. A tree spray gun must generate a solid stream of liquid that travels through the air without turning into a mist. This page will give you a good idea of the kind of sprayer gun you need, as well as information on the spray nozzle size needed to achieve various spray heights.
Tree Sprayer Hose & Plumbing
Knowing that the flow and pressure are crucial in order to achieve the spray height necessary for trees, hose size becomes extremely important as well. The hose is a restriction on the output of the sprayer. For each additional foot of hose, you will have pressure loss due to friction. We can minimize the pressure loss by ensuring the inside diameter of our sprayer hose is adequately sized.
⅜ inch sprayer hose is common on lawn and turf sprayers but this is too small. Tree sprayers should have ¾ inch inside diameter hose to allow for adequate flow. The length of the hose should also be kept to a minimum. 300 ft is a long length of hose and even if it is a ¾-inch ID hose, you may lose 60 psi if you are trying to push 10 GPM through it. When trying to spray tall trees, you want to make sure you can reduce any restrictions on your flow and pressure.
In addition to allowing enough flow, the hose, sprayer gun, pipe fittings, and other components on the discharge side of the pump need to be rated to handle the high operating pressure of your unit. The plumbing on the inlet side of the pump should be no smaller than the pump inlet, and it is better if it can be larger. This will reduce the chances of your pump being “starved” of fluid which can cause damage.
Can I Use a Power Washer to Spray Trees?
Simply put, no. Power washers are not designed to spray trees. They will produce too much pressure that you will not maintain a stream that will reach the needed height. They are also generally supplied with nozzles that don’t allow for enough flow. Additionally, power washers typically do not have pumps, hoses, or spray guns that are compatible with the chemicals used in tree spraying.
Having said all that, power washers come in lots of sizes and it is possible that a pressure washer with a large enough nozzle size and low enough operating pressure may be suitable. Power washers are usually over 1000 psi and 1-4 GPM. If you have a larger nozzle size of 6-10 GPM and can operate your power washer at lower psi with that nozzle it may work. However, it is best to use the right equipment for the job and avoid any damage to trees, or unintended drift from the fine spray mist high pressures can produce.
How Much Does A Tree Sprayer Cost?
If you are in the market for a new tree sprayer that can spray trees 40-50 ft tall you should expect to pay at least $4000 for a quality skid unit. Depending on features like tank size, pump type, engine hp, and spray gun, you can easily spend over $8000.
Spray rigs that are built to spray trees 70+ feet can cost $15,000-20,000 depending on the pump, engine/drive type, tank size, etc.
Cost to Build Your Own Tree Sprayer
You can potentially save money by repurposing equipment and building your own tree sprayer. If you already have a sprayer for turf use, you may be able to convert your existing equipment to spray trees as well as lawns. If you have a 100-gallon tank or larger this might be a good option.
The main component to switch is the pump. If you have a 12-volt pump, centrifugal pump, roller, or small diaphragm pump you will need to switch to a higher GPM diaphragm pump as discussed above. 10 GPM and 500 psi will get you to spray heights of 40-45 ft. 15 GPM and 500 psi will get you 50 ft.
The new pump will likely require that you change your plumbing. The outlet in the tank that supplies the pump inlet should be at least as big as the pump inlet. Same for the hose. If your tank outlet is too small for your pump inlet don’t worry. It is not difficult to change this in a poly tank. Using a hole size and a tank bung, you can install a larger tank outlet and ensure your pump is properly fed with water. Polypropylene bulkhead fittings like this work great. Generally, a 1-1/4 inch or larger tank opening will be needed for tree-spraying diaphragm pumps.
Remember, as discussed earlier, that a larger hose and a long-range spray gun will also be needed when spraying trees.
- New Pump – Hypro D503, Kappa 43, or Simlar: $1000-1500
- New Engine – Honda GX270 or equivalent: $800-900
- ¾ hose – $3-4/foot
- Long Range Spray Gun: $250-350
Assuming you do not need a new tank, you should be able to add the necessary tree-spraying components to your sprayer for $3000-3500.
DIY Tree Sprayer Parts List
Building your own tree sprayer can be a cost-effective option that allows you to customize the sprayer to meet your specific needs. However, before diving into this DIY project, you will want to make sure you have all the components required for an effective tree sprayer.
Below is a comprehensive list of all the items you will need to build a tree sprayer yourself. There are different ways to build a sprayer and lots of options when it comes to the individual components, but this list is a good guide to help ensure you do not miss anything.
Main Tree Sprayer Components
- Discharge/Spray Hose
- Suction Hose
- Connecting hose
- From regulating valve to hose reel
- from regulating valve to agitation
- Bypass hose from relief valve
- Tank Valve
- Hose barbs rated to 1000 psi
- Suction plumbing barbs and fittings
- Barbs for strainer
- Tank outlet barb
- Hose Clamps
Other Things to Remember About Tree Sprayers
The high pressures needed for tree spraying make it very important to properly plumb and operate your machine. Be sure to use equipment rated for your PSI and that bypass valves are in working order. The pump should also be maintained and inspected periodically to avoid unnecessary downtime.
I hope that knowing what makes a sprayer capable of spraying tall trees will help you identify the right sprayer for your operation.