Garden tools are essential for effective digging, transplanting, and weeding, but without proper care, they can quickly rust and break, leading to costly replacements.

Rust is a common issue for gardeners, compromising tools’ aesthetic appeal and structural integrity by corroding metal surfaces and hindering their functionality.

Understanding why tools rust and implementing preventative measures is key to prolonging their lifespan and ensuring they remain effective.

Understanding Rust Formation

Rust primarily forms due to a chemical oxidation process involving iron or steel components, oxygen, and moisture. This interaction leads to the formation of iron oxide, commonly known as rust. Several factors can accelerate this process:

• Moisture and Oxygen are the primary drivers. Rain, dew, irrigation water, and high humidity facilitate oxidation.
• Temperature can expedite rust formation, with warmer temperatures increasing moisture levels in the air. Fluctuating temperatures can also create condensation, which promotes rust.
• Salinity in saltwater or salty environments increases the rate of rust by accelerating the breakdown of the metal’s protective oxide layer.
• pH Levels, particularly acidic conditions from rainwater, soil, or corrosive plant saps, can corrode metal surfaces more rapidly.
• Surface Damage like scratches or dents provides entry points for moisture and oxygen. Power tools, with their many cracks and crevices, are particularly prone to pitting.
• Atmospheric Pollutants such as sulfur dioxide and nitrogen oxides can react with moisture to form acidic compounds, accelerating rust.
• Biological Factors like plant debris or animal waste can trap moisture against metal surfaces.
• Galvanic Corrosion occurs when two dissimilar metals come into contact in the presence of moisture, leading to accelerated corrosion of the less noble metal.

Metal tools, including spades, hoes, trowels, pruning shears, hedge clippers, and lawn mower blades, are highly susceptible due to their iron or steel composition and frequent exposure to damp soil, plant residue, and precipitation.

While stainless steel tools are highly resistant, they are not entirely immune and still require proper maintenance.

Proper Maintenance: Cleaning and Sterilization

Regular cleaning and maintenance are crucial for keeping tools efficient, safe, and long-lasting. It also helps control the spread of plant diseases and viruses.

• After Every Use: Ideally, garden tools should be cleaned after each use.
• Cultivation Tools (spades, hoes, forks, rakes, trowels):
  • Use a stiff scrubbing brush to remove soil from the blade and shaft.
  • Extremely muddy tools may need a hose wash, followed by drying with an old towel. Drying prevents wooden handles from swelling and metal from rusting.
• Cutting Tools (secateurs, knives, loppers, pruning saws, shears):
  • Blades often get gummed up with sap, which affects performance and can be corrosive. Remove sap and plant residue immediately.
  • Clean off dried-on sap with a nylon pan scourer or wire wool. A penetrating oil like WD-40 can help loosen grime. For heavy buildup, use alcohol, mineral spirits, or foaming bathroom cleaner, followed by fine steel wool.
  • Once the metal is clear, wipe off any remaining spray with a clean cloth.
  • Tighten any loose parts and add oil to the central pivot point, opening and closing the tool to work the oil in.
• General Cleaning Tips:
  • Keep a brush and an old towel near your tool storage for convenience.
  • If rust is present, clean it away with a wire brush and/or sandpaper. Soaking tools in vinegar (2-3 cups plus 2 tbsp salt for 24 hours) can help remove rust, followed by a water and baking soda rinse to neutralize the vinegar.
• Sterilization for Disease Prevention:
  • To prevent the spread of plant diseases like Phytophthora or bacterial canker, it’s important to clean and sterilize tools that have contacted contaminated soil or plant material.
  • Brush cultivation tools at the site to prevent soil transfer.
  • Apply a suitable disinfectant, such as Jeyes fluid, Citrox, or Propellar, to all used blades. Leave for 15-20 minutes to kill pathogens before wiping off.
  • Dry the tool with an old towel, and then oil it. Remember to also disinfect the brush or cloth used.
  • Don’t forget to remove contaminated soil from and disinfect the soles of your boots.

Rust Prevention: Oiling and Protective Coatings

After cleaning, applying a protective layer is crucial to prevent rust by creating a barrier between the metal surface and the air.

• General Oiling: Wipe all metal surfaces with a lightly oiled rag.
  • Frequency: It is advisable to oil tools after each gardening session, or at least once a month.
• Types of Protective Agents:
  • Mineral oil is recommended for cutting tools and those used on food plants, as it is non-toxic and won’t go rancid.
  • General purpose oil or lightweight motor oil can also be used. Some sources suggest using used motor oil, but it contains carcinogens.
  • Silicone lubricant spray is excellent for tools as it lubricates, reduces friction, drives out moisture, and helps waterproof parts. It’s also good for wooden tools as it prevents drying out and splintering. However, dirt and dust can stick to it, so use sparingly in dirty environments or use a “dry” version.
  • Paste wax creates a hard-wearing and long-lasting buffable coating that works well on metal or wood. You can make your own paste wax by melting beeswax and mixing with mineral oil, turpentine, or mineral spirits.
  • Fluid Film is a lanolin-based product highly recommended for rust prevention.
  • Boeshield T9 is a wax solution mixed in an oil/solvent that leaves a protective wax coating after the solvent evaporates. It offers good, longer-lasting protection than WD-40, but it’s not a “one-time spray” product for surfaces that experience abrasion.
  • WD-40 is excellent for cleaning tools, removing sap, and displacing water. However, it is not a long-lasting lubricant as it tends to dry out quickly or remove existing oils. It should be used with care on food plants. If used, it’s advised to follow up with a better lubricating oil.
  • Other options include 3-in-1 oil, Ballistol, CorrosionX, PB Blasters Surface Shield, and Frog Lube CLP.
• The Sand and Oil Bucket Method:
  • This is an old-school, effective, and cheap way to clean, prevent rust, and even slightly sharpen tools.
  • Setup: Use a 5-gallon bucket filled 80% with construction sand (not play sand). Mix in mineral oil in layers (about 1 cup per half bucket of sand). Mineral oil is preferred as it’s non-toxic and won’t go rancid.
  • Usage: After removing excess dirt, plunge the business end of the tool into the sand and move it around. The abrasive sand scrapes off dirt and surface rust, and the oil lightly coats the metal.
  • Benefits: Keeps tools clean and oiled, helps prevent rust, and is useful for storing tools blade-down.
  • Considerations: This method may dull cutting edges and can scratch smooth or painted surfaces.

Proper Storage Techniques

Storing tools in a clean, dry place is paramount to preventing rust.

• Avoid Storing Tools When Wet: This is an easy mistake that causes significant damage. Wet tools will quickly rust, and moisture can damage wooden handles. Always wipe tools dry after use.
• Keep Tools Off the Ground: Dropping tools on the floor creates clutter, can be a health risk (e.g., stepping on a rake), and causes tools to collect moisture and rust faster. Instead, install wall-mounted storage like pegboards or hooks to keep tools accessible, off the ground, and away from rust.
• Use Blade Protection: For tools like pruners, saws, and hedge shears, blade covers are vital for safety and protecting against rust and moisture. They prevent damage if tools fall and protect against injury.
• Store Batteries Indoors: Power tool batteries, especially lithium ones, should not be left in unheated sheds, garages, or greenhouses. Cold temperatures kill lithium batteries by causing them to lose capacity. Keep them in warmer indoor temperatures to ensure longevity.
• Avoid Leaning Tools Against Walls: This leads to clutter, is unsafe as tools can fall, and can damage tools by inviting moisture to blades and dulling them on rough surfaces. Mounting tools on walls or hanging them from hooks ensures a clutter-free and safe storage space.
• Use Non-Rusty Hooks: Hanging tools on old, rusty nails or hooks can scratch the tool and introduce corrosion, as “rust is a disease, and it spreads”. Rusty nails can also come loose. Use new plastic or rubber-coated metal hooks that are less likely to rust.
• Toolbox Storage: Storing tools in a toolbox, especially a hard case, can minimize rust by protecting them from dings and dents. Store toolboxes in a cool, dry area on a higher shelf, avoiding places with dramatic temperature fluctuations that can create condensation. For added protection, slip in a Zerust toolbox drawer liner, Plastab, VCI vapor capsules, or an appropriate size Multipurpose VCI Poly Bag.
• Shed vs. Garage for Power Tools:
  • The primary consideration is maintaining a stable temperature to prevent condensation.
  • A garage with stable temperatures can be ideal, though garages are often alternately heated and cooled.
  • Sheds, while seemingly more stable in temperature, are typically not airtight and can allow humid air to pass through, risking rust. For this reason, some experts recommend garage storage over sheds.
  • In both cases, using VCI (Vapor Corrosion Inhibitor) technology products from brands like Zerust can provide excellent rust prevention, covering tools or filling enclosed spaces with protective vapors.
• Humidity Control for Humid Climates:
  • For very humid environments, a dehumidifier in the tool room or garage can be the most reliable solution to prevent rust.
  • Placing silica gel packs in toolboxes can also help absorb moisture. These packs can be reactivated by heating them in an oven.
  • A gasket-sealed toolbox also provides a dry storage environment.