Tree swings are funny things. They don’t travel far, but they can carry us way back to simpler times. Even when we’re not the riders, swings take us back to our childhoods. And we want our children to know that such simple joys exist. But for them to be carefree, we need to worry a little for them, to let them experience the small scrapes while protecting them from the big ones. A tree swing is a joy, but it requires care and thought as much as it needs rope and a strong limb. Here’s what I know about hanging one.
Pick the right tree
The right tree for a swing is a straight, strong, mature, and healthy hardwood. Some species are better than others. Good prospects include beech, oak, and maple. Others, like black willow, poplar and birch, are relatively weak and brittle.
A healthy tree will have no signs of rot or fungus; no cracks, hollows, or wood boring insects. It will have green, unspotted, and properly shaped leaves; a balanced, even distribution of limbs; and a minimum of dead or broken branches. Thump the tree with something solid and listen for the hollow sound of decay.
While you’re evaluating, check overhead for any broken limbs hung up in the branches, called widowmakers by loggers, or any other threats from above over any portion of the play area. These will have to be removed to make the site safe.
Choose the right limb
The perfect limb for a tree swing depends, in part, on the type of swing you’re hanging. For a traditional two-rope swing, it’s important that the limb be horizontal. For a single-rope disc swing, the limb need not be level. Look for a limb at least 8” in diameter.
The limb must be healthy. As with the tree as a whole, symptoms of compromise might include cracks or holes, fungus, missing bark, dead or broken branches or limb tips, and sick or missing leaves. Pay particular attention to the union of the limb and trunk for cracks or signs of weak attachment, including crowding by other limbs. Even after the swing is hung, keep an eye on the tree and limb for changes in their health.
Higher is better, within reason. A limb 20 feet up will create a swing with a longer arc and a better rhythm than a limb only 10 feet off the ground. Of course, this objective needs to be tempered by the imperative to work safely, with confidence, and within your own abilities. Something in between will work just fine. Hiring a tree specialist is always an option.
If a limb looks good from the ground, then inspect it up close and from above.
Consider the landing zone
The landing zone for a tree swing should be clear of hazards and relatively soft. Natural surfaces usually provide sufficient cushion. But rocks, stumps, and exposed roots could pose risks. Intruding branches should be trimmed, and the landing area cleared, both behind and well ahead of the swing’s maximum travel.
Sloping ground can present its own problems. As grade drops away, the potential fall height from the swing also increases. So does the chance the rider will stumble on dismount or tumble after a fall. Level is safer.
In general, you want to hang the swing as close as possible to the trunk without creating a collision hazard with the tree. The limb is a long lever. The further from the trunk you place the swing, the greater the stress you place on the limb union. Typically, you will want the swing 3 feet to 5 feet from the trunk. A two-rope swing is a large pendulum, with a regular path, which means it can be hung nearer the tree, at the lower end of the range. A single-rope swing has more freedom of movement, which means you will need more distance from the trunk.
Select the right type of rope
Safe swings require strong rope. Many types are suitable, but a few stand out. Here’s how the four most common rope varieties stack up:
Polyester. From a performance standpoint, polyester is probably the all-around best rope for a tree swing. It is one of the strongest, at more than twice the strength of natural manila. It stretches very little, has excellent natural UV and weather resistance, is supple, and holds knots well. It is commonly available in white or black, but if you look, you can find it from boat rope suppliers in manila tan.
Manila. Natural manila rope works for a tree swing but has some significant downsides. Manila is soft in the hand, holds knots extremely well, stretches little, has a great traditional look, is reasonably priced and, being made from plant fibre, is biodegradable. But it is only moderately strong, a third less than polypropylene and less than half as strong as polyester. And cycles of wetting and drying will cause it to shrink some.
Moreover, because it is a natural product, it is not unusual to have some variability in diameter from rope to rope. You may find a 1” manila rope may not fit in a 1” hole. (Ask me how I know.) But easily its biggest liability is the rate at which it decays. If you use it, understand that it will degrade and lose strength fairly quickly when exposed to sunlight and weather. You will need to inspect and replace it regularly, perhaps at the beginning of each swinging season. A smaller inconvenience has to do with fraying. All ropes need some sort of intervention to prevent the ends from unravelling. But whereas the ends of synthetic rope are easily fused with heat, natural rope generally requires string wrappings, called whipping. As a traditional craft, whippings are fun to learn and practice, and they look great, but they also take work.
Polypropylene. The most common general purpose rope — found in waterski tow ropes and the like — polypropylene is inexpensive and stronger than natural manila. If you purchased a tree swing, odds are this is the rope it came with. It is not as strong as polyester or nylon, but plenty strong for a tree swing. It is a little stiffer than other synthetics, which means it is harder to knot well and less pleasing in the hand. Unlike polyester, it is not naturally resistant to ultraviolet radiation; therefore it requires additives during manufacture to boost its UV resistance. If you use a polypropylene rope, make sure it is the UV resistant type. On the plus side, it’s easy to find polypropylene rope with the look of manila.
Nylon. The strongest common rope, nylon has many of the attributes that make polyester a great material for a tree swing, with one notable exception: It is very stretchy. This means, for one thing, the empty swing will need to hang higher, which may make it harder to board safely. It also is slightly less UV resistant than polyester, and loses some strength when wet. For me, the elasticity is the deal breaker.
Choose the right rope size
Usually, swing ropes will range from 5/8” to just over 1”. For a two-rope swing, 5/8” synthetic ropes might be plenty. If using natural rope, which is weaker, you may find 3/4” more suitable. Likewise, for a single-rope swing, you may want a 3/4” synthetic rope or a 1” manila rope. For me, 3/4” twisted polyester, which has a safe working load north of 1,000 pounds, is the ideal all-around swing rope.
Strength is not the only factor in choosing a rope diameter. Thicker ropes provide a better grip and are usually more comfortable than thin ropes. For the same reason, twisted ropes usually work better for rope swings than braided ropes. And unlike braided ropes, twisted ropes can be spliced, if you have the skills, which is a great way to make strong eyes and loops. Owing in part to the simplicity of manufacture, twisted ropes are less expensive.
Attach the swing in a way that protects the tree and rider
When it comes to hanging your swing, you have several options. Here’s what you don’t want to do: Tie a swing rope tightly around a limb. Tree limbs need room to grow. A tight rope around the limb will eventually strangle it. In the meantime, abrasion opens the tree to disease and infestation.
If you hire an arborist to hang your tree swing, odds are they will use eye bolts through the limb. Although this sounds destructive, the tree will heal around the bolts. There are simpler methods, but this one certainly avoids the issues of direct rope attachment.
Here’s how the eye bolt method works:
For each rope you are hanging, you’ll need one galvanized or stainless steel shouldered eye bolt, 5/8” in diameter or larger, one matching dock or fender washer, and two nuts. The bolts need to be long enough to protrude through the top of the limb and accommodate one thick washer and both nuts. To install, you bore a hole for a one-rope swing, or holes, properly spaced for your two-rope swing, through the limb. Then slide a bolt into place from underneath. Add a washer on top, and tighten a nut against it. Tighten the second nut on top of the first. This locks the nuts together and prevents them from working loose. Repeat as necessary. As an alternative, you can use a single nut on each bolt, with a liquid thread locker to keep it in place.
A properly rated locking carabiner, or lifting rated quick link, is added to each eye. And the swing rope attaches to the carabiner. The right way to do this is to splice an eye in the end of the rope and add a stainless steel or galvanized rope eye to prevent wear to the rope. If you have the means and the skills, no commitment issues, and want a truly lasting installation, the bolt method might be for you.
On the other end of the spectrum, some people tie the swing rope directly to the limb, but employ a loop made with a secure slip knot like a running bowline. Under load, the loop chokes up, but when the swing is empty, the loop relaxes. Because the loop can open freely, it will never girdle the branch. It’s the right idea, with a few potential flaws. One is that the rope is still relatively thin, which means the load and friction are concentrated. Over time, it might still cut into the bark and damage the delicate tissue underneath. Likewise, while the rope is abrading the tree, the tree is returning the favour. It will be hard to tell from the ground how fast the rope is wearing. As time passes, you may need to get up in the tree to inspect it. You can improve this system by using a short split length of hose around the rope where it passes over the limb. Despite some drawbacks, the slip-knot method is simple and economical.
The third method is fairly simple and the one I favour. It uses straps looped around the limb, which are wide enough to keep from cutting into the bark but also free to open as the limb grows. It’s not an original idea. Commercial swing straps are available online.
I prefer to buy round lifting slings, with an eye in each end, from companies that supply industries involved in rigging, hauling and heavy lifting. The quality of these continuous slings is top notch; they are available in a variety of lengths; I can get them in polyester, which I prefer; and I can usually find them in green, which blends nicely with the foliage. Nominally, they are 2” straps, but their scuff resistant covers make them closer to 3” wide. As used here, each sling is rated to support more than 4,000 pounds.
Generally, you’ll want to choose either a 3’ or 4’ length. An 8” diameter limb is about 25” around, which gives you about the right margin with a 3’ strap. A 10” limb is about 31” in circumference, so 4’ is a better fit, with plenty of room to grow.
The sling encircles the limb in what is called a choker configuration, that is with one eye through the other. It tightens when the swing has a passenger, and loosens when the swing is empty. As the limb grows, the loop opens.
Attach the swing rope to the eye with a secure knot. I use a figure 8 follow through knot, which has a backup knot tight against it. If you’ve ever done any climbing, you’ll know the knot, sometimes by the name trace-eight. If not, you can look it up on any of the many excellent knot tying websites. Practice before you need to execute it at height.
The same figure 8 follow through is just as good for tying the loops that attach the seat of the two-rope swing. Another good loop knot for the seat is the double bowline, again with some sort of stopper knot as insurance. I prefer to tie the seat knots first and make all length adjustments from the tree.
For a single-rope swing, the disc seat sits on a bulky stopper knot. One that works is a double overhand, which is level across the top and super easy to tie.
Consider the height of the rider
How high should you hang the swing? The right height for a tree swing depends on the size of the person or people who will be using it most.
The swing sits higher when it is empty. It also sits higher when the rope is new, before everything has stretched out and tightened up. In general, about 24” is a good starting point for an unloaded swing, and a good target ground clearance when the swing is under load is about half of that. Adjust from there. The swing should be easy to climb on and step off. It helps to have the primary swingers on hand when you’re hanging it. It also helps to have assistance on the ground. This way, one person can measure the swing height, and for a two-rope swing use a level, while the other adjusts the rope or ropes from the tree.
Working at height carries substantial risks. For many do it yourselfers, the obvious answer for reaching a tall limb is a big extension ladder. It’s one of the more hazardous ways to do the job. Now, that doesn’t mean you can’t. But if you go this route, know the risks and take extra care.
Make sure that the ladder has four solid contact points, and that the ladder extends several feet past the limb you will work on. Set it at the proper angle, 75 degrees, often depicted on the side of the ladder. Take pains to ensure it is stable. Sometimes you can drive stakes, like sections of rebar, into the ground by the feet and lash the legs to them so they can’t move. Similarly, you can lash the top of the ladder to the limb. Make sure that there is nothing in the tree above you that can shake loose and knock you off.
If professional tree care workers ever use ladders to get into a tree, they tend to be sectional ladders, chained to the trunk, with stand offs between trunk and ladder to provide toe room. Lighter, less expensive versions are made for hunters to climb into their tree stands.
Even with a stable ladder, falls can happen. A safety line is worth considering, as is a climbing helmet. A basic fall arrest system might include a safety line with a rope grab. The rope grab slides along the rope as you climb but will engage to stop you if you fall. It is attached via a short lanyard to the back D ring of an appropriate safety harness. It won’t help much as you climb a ladder, but it might at height. Once in the tree, it also is easy to flip a sling around a sturdy nearby branch and tether to it. There are many options. No time spent learning about safety equipment and how to use it is wasted.
One way to get a rope into a tree is to use a throw line. It consists of a long thin line with a weighted bag on the end. The line is tossed over a strong limb or crotch above the highest point you’ll be working. Then the rope is tied to the line and pulled over. Tie one end of the rope securely around the tree. The other must be long enough to reach over the anchor point and all the way to the ground. Clip onto it and you’re off.
The best, safest way to climb into a tree is the way professionals do. With rope. If you’ve done any climbing, even at the gym, you’ve probably got the basic skills and maybe even the equipment for a simple operation like hanging a tree swing. They are fun, useful skills to learn and have. Today, innovations like foot ascenders let you use your leg muscles to zip up the rope, while braking descenders let you glide back down to earth. Arborist harnesses are extra stout and built so that you can hang and work comfortably.
After you’ve hung your swing, test everything. Start cautiously, but make sure you give everything a rigorous workout. Pull hard on the ropes in all directions. Press down on the swing. Sit on it. Check your knots. Take a test drive. Watch how the limb reacts. Listen as well. If you notice significant bowing of the limb when the swing is in use, or unusual shaking, you may need to move the anchor point closer to the trunk or select a new limb. Make sure the swing has all the clearance from the tree you expected. Think about the dumb things you did on a swing as a kid, and assume the worst about today’s children. Check the knots again for any signs of slippage. When everything checks out, it’s play time. Call the kids over. Or maybe not.