So, what is the best backpack/knapsack sprayer for your spraying job?
Here in the UK, the main sorts of manual spraying jobs where a backpack sprayer (also known as a knapsack sprayer) are used include: weed control, lawn spraying – against lawn moss or somesuch – and spraying plants, flowers and vegetables against various types of fly and insect infestations. They are also extremely useful for cleaning and disinfection jobs.
In terms of which backpack sprayer is best for your needs, it rather depends on the size of the job and how long you are going to be using the knapsack sprayer for. Is it for commercial and professional spraying jobs or are you using it in and around your own property or garden? Are you going to be spending hours with it on your back and do you need a variety of accessories to enable you to do a variety of jobs? Answers to these questions can help guide you towards the equipment that is best for you.
Finding the best backpack sprayer UK
As well as our Guarany sprayers, there are many, many others and you can find one which exactly fits your needs and budget. It goes without saying, however, that you get what you pay for. You can easily pick up a sprayer very cheaply on Amazon or at your local DIY shop and that is fine if you are just misting your house plants with water but, when you are spraying products such as agrochemicals, it is probably best to steer away from the very cheap models; they won’t last and there is a risk you could end up with some not-very-nice weed killer or smelly fertiliser product over you, your clothes or home and garden accessories.
Scroll down to see the top three brands we think are worth a look.
What is the difference between a backpack sprayer with a diaphragm pump and one with a piston pump?
You may also want to consider which type of pump is best for your needs: a piston pump or a diaphragm pump. The main difference between a piston pump and diaphragm pump on a backpack sprayer is the way they create pressure and move liquid through the sprayer.
Diaphragm sprayers work by using a flexible diaphragm to pump liquid out of the sprayer tank and through a nozzle for spraying. The diaphragm is typically made of rubber or other flexible material and is located inside the pump chamber of the sprayer.
When the pump handle is activated, it causes the diaphragm to move up and down, creating pressure and suction inside the pump chamber. As the diaphragm moves down, it creates suction that draws liquid up from the tank and into the pump chamber. When the diaphragm moves up, it creates pressure that forces the liquid out of the pump chamber and through the nozzle.
The spraying pressure and flow rate can be controlled by adjusting the stroke length of the pump handle or by using pressure regulator valves. Diaphragm sprayers are commonly used for applying pesticides, herbicides, fertilizers, and other liquid chemicals to crops or plants.
Some advantages of diaphragm sprayers include their ability to handle a wide range of chemicals and their consistent spraying pressure even when the tank is partially empty. However, they can be more complex and require more maintenance than other types of sprayers.
Piston pumps work by using a piston or plunger to pressurize liquid and push it through a spray nozzle. The piston is typically housed inside a cylinder, and when the pump handle or motor is activated, the piston moves back and forth inside the cylinder.
As the piston moves backward, it creates a vacuum that draws liquid into the cylinder through an inlet valve. When the piston moves forward, it pressurises the liquid, forcing it out of the cylinder and through a discharge valve and spray nozzle.
Piston pumps can be powered by hand, electricity, or an internal combustion engine. They are commonly used for agricultural and industrial applications, such as spraying pesticides, herbicides, fertilisers, and other liquid chemicals, as well as for pressure washing and other cleaning tasks.
Some advantages of piston pumps include their high pressure output, which allows for efficient and effective spraying, as well as their durability and ability to handle a wide range of liquids. However, they can be more expensive and require more maintenance than other types of pumps.
Knapsack sprayer sizes and what do they weigh?
Backpack sprayers tend to range in size from 10L to 20L. With a litre of water weighing approximately 1kg, a 20L sprayer is going to weigh around 25kg (the weight of the water plus the weight of the sprayer itself).
So, which knapsack sprayer brands should you consider?
Stihl have a long and impressive history in handheld power equipment. Founded in Germany in 1926, the company initially designed and manufactured electric chainsaws which had a revolutionary impact on the forestry industry. Today, the company’s product range includes equipment such as brushcutters, hedge trimmers, blowers, sweepers, shredders and pressure washers in addition to robotic lawn mowers and mist blowers.
Stihl offers a good variety of high quality backpack and handheld sprayers for home and professional use.
These include (prices as of Spring 2023):
The 18L SG 71 Sprayer which retails for around £118.
The 12L SG 51 which is around £98
There is also a 17L cordless sprayer, the SGA 85, which retails for £576.
There are a few accessories such as extension and telescopic tubes and a range of different nozzles.
Warranties appear to be 2-3 years for domestic use and 1-2 years for personal use but check with your supplier/retailer as this information is not immediately obvious.
Stihl equipment is robust, light and comfortable and is readily available in the UK through online stores and physical dealerships.
View the range here
For Stihl UK customer service, click here
Solo are another German company, Solo – or Solo Kleinmotoren GmbH to give it its full name – offers an extensive range of quality sprayers, misters and blowers.
The sprayer range includes manual sprayers, pressure sprayers, trolley sprayers, backpack sprayers, battery sprayers, power backpack sprayer and accessories
Solo backpack sprayers are some of the more expensive on the market and they come in Classic (described as entry level for some sprayers), Comfort and Professional lines so you can find a quality product for your budget/needs but you will pay more for Comfort and, with the Professional version, for details such as Viton seals.
425 Classic 15L 145 €
425 Comfort 15L 172 €
425 PRO 15L 220 €
475 Classic 15L 150 €
475 Comfort 15L 190 €
Nova 424 Classic 16L 104 €
435 Classic 20L 166 €
473 D Classic 10L 120 €
Also of note is the 417 18L Battery-operated Sprayer for around 300 € and the 433 20L High Pressure Sprayer for 853 €
Solo offer a good array of accessories including a flexible double spray head (36 €)
Solo sprayers are covered by a one year warranty.
Solo equipment is widely sold online and at garden machinery dealers.
To see the full range, click here
For customer service or parts and spares, contact the retailer where you bought your sprayer.
Cooper Pegler was founded in 1894. In 1995, it became part of France’s Hardi Group and in 2007 part of Exel Industries, one of the world’s largest manufacturers of crop care equipment.
The products are widely available in the UK from garden machinery dealers and online.
The range appears to be divided into three lines: Classic, Comfort and Evolution and they have diaphragm and piston models. On the CP website, there are seven products listed. It is not entirely clear what the differences are between the different model types beyond them being diaphragm or piston pumps and many retailers offer them for very similar prices. As such, we have not specified the different model prices below. If you visit this online retailer for example, all models are around the same £179 price. Confusing!
The CP range of knapsack sprayers includes:
CP 15 Classic
CP15 Evolution Comfort
CP3 Classic 20L
CP3 Evolution 20L
Pump Sprayer CP15 2000
CP 3 2000 20L
Cooper Pegler Accessories
There is not a huge range of accessories.
The CP backpack sprayers have a 3 year warranty.
See the Cooper Pegler range here
For Cooper Pegler Customer Service, click here
As you can tell from the above, there is really not much to choose between these best knapsack sprayer brands in terms of reliability, comfort, accessories and prices. Which you prefer may come down to whether the brand is sold at a physical dealership near you so you know you can get advice and spares if you need them.