Gardeners, lumbermen, and tree fallers have something in common. They often find their hands, hair, and clothing sticky from the sap from bushes, trees, and other plants. Trying to remove the sap by using the conventional soap and water doesn’t work well, partly because sap tends to be waterproof to one degree or another. There is a simple and easy way to remove the sap, though.
Why plant sap is sticky
It is helpful to understand why pitch and sap are sticky.
The sap or juices of plant tends to be sticky and it is more so in some plants than in others, but it isn’t exactly for the reason many people think. The culprit most often cited as causing the sap to stick to almost anything is sugar. Indeed, nearly all plants produce sugar.
Sugar, in a fluid form, is indeed sticky. However, it is also water-soluble. That means that if the problem was entirely because of the sugars in the plant juices, it would wash off with just water.
Most people who have tried to remove the resin have found that water usually doesn’t work. Even adding soap isn’t very helpful. The fact is that for centuries, tree sap, particularly that from pines and firs, has been used in shipbuilding to make the hull of the ship waterproof.
The reason this works is that the sugars, which are sticky, are suspended in a thick liquid that is full of long-chain proteins. Many of the proteins aren’t soluble in water, so the pitch is waterproof. The fact that it remains sticky is good for the shipbuilders since the pitch sticks to the timbers of the boat or ship and resists water.
Nature provides an easy answer
As is often the case, if something isn’t water soluble, it will still dissolve in something else; an acid like lemon juice or vinegar, oil, or some other liquid. That is the case of plant sap. The long-chain proteins that resist dissolving in water easily bind with oil. This is the basis for turpentine, in fact.
Oils and fats are usually easy to remove with soap and water since soaps are normally oil based. The problem of removing sticky pitch has thus been solved by nature.
If you have pitch or sap on your hands, hair or clothing, simply work some oil into the pitch to bind it, then use soap and water to remove the oil. The pitch is removed with the oil.
People are sometimes surprised that I keep the oil-based lubricant WD-40 in my gardening supplies and have another can with my chainsaw and wood splitting tools. This commercial lubricant does no good in lubricating a chainsaw and very little good in doing the same with garden tools since it will hurt many plants. However, spraying a little on the pitch that I get on my skin makes it very easy to remove the pitch.
If you don’t have any WD-40 handy, don’t despair. Cooking oil such as vegetable or olive oil can be used. It may just take more than one application because WD-40 is a more powerful solvent for the pitch. However, olive oil or vegetable oil are also good moisturizers for the skin.
In fact, oil is also good for removing pitch and sap from pruning shears and the like, as long as the shears are washed with soap and water immediately.
Next time you get plant sap or pitch on your hands, in your hair or on your clothing, try using oil, followed by washing with soap and water, to remove the pitch. You might be surprised at how well it works. It even works on creosote based road tar, though it can take several applications since the creosote is concentrated.