If you pop down to the comments you’ll find that Amber made a brilliant suggestion on another way to build the planter. I’m going to go ahead and leave this set of instructions the way it is for people that want to do it this way, but her method is actually much superior. I have written a 2.0 post on this topic using her idea and photographs of how to do it.
Okay, once again I am not claiming ownership of this idea. I saw it on This Instructable and decided to try it myself. I have loads of 2L bottles on hand all the time so I wanted to put them to use. After a bit of trial and error I’ve come up with some tips and tricks that might help some people interested in doing the same thing themselves, and – to be brutally honest – I like my “How To” articles better than most other people’s. But hey, I’m biased. (About this)
Supplies you need:
A 2L bottle
Potting soil or other kind of dirt appropriate for growing things in
Enough decently thick cloth to cover a 2L entirely
Some twine or similarly hefty string
Some gravel or similar rocky material (optional)
Coffee filter or paper (optional)
Tools you need:
Hairdryer or heat gun
First, clean your bottle inside and out, and get the label off. Set the cap aside – you won’t need it when you’re done, but you’ll want it for one step later on.
Okay, start off by sitting on the floor. Yeah, I’m serious. It’s just easier – you’ll see why in a bit. Take your hairdryer, set it for as hot as it goes, and low fan speed. (You may need to make adjustments since hairdryers can vary a bit. My wife’s hairdryer works best on those settings.) If your fingers aren’t fireproof you may want to use a pair of pliers to grip the nozzle as shown here. Begin heating the bottle and turning it slowly, watching for the plastic to deform as you heat it. You want to heat the entire “cone” – the curved part between the nozzle and the straight sides. It will cave in slightly as you go. (See below.)
Note: I haven’t used a heat gun to do this, as I don’t have one. The hairdryer works fine. If you use a heat gun just be careful and start slow at a low heat. Don’t melt it.
Here you can see the dent on the right side caused by heating the plastic. The goal is to get it pliable, and to begin to invert the curve. Be careful not to heat the nozzle itself, as if you deform this the cap won’t form an airtight seal later. Everything between the straight sides and the nozzle needs to be heated enough that it deforms slightly. Once you’ve done that, try to get as much of the cone warm as you can at once, then begin pressing down on the nozzle.
Here you can see the cone being gently forced downward and some creases beginning to form. Once you reach this point, set the hairdryer aside for a moment and begin pinching the crease all the way around. You want to create as neat and straight a fold as possible all the way around the point where the cone and the straight side meet. Due to the bottle being clear, this is hard to really show in a photograph, but you can see basically what I’m talking about below.
The planter is beginning to take shape here, but we’ve got a bit more refining to do. First up, we want to force the nozzle down as much as possible so that the cone is elongated. You’ve made one fold at the point where the sides and cone meet, but we want the reverse fold to happen right at the bottom of the nozzle, not partway up the cone like it is here. To do that, put the cap on (so that the nozzle will keep its shape) and start heating the area around the nozzle as hot as you can get it without melting anything. If your fingers aren’t fireproof, grab the hotpad and quickly press down on the cap as hard as you can without smashing the whole thing in. I usually have to do this in a series of steps, squeezing the bottle to pop things back out, re-creasing the outer fold, and working the shape until I’ve got it where I want it.
Above you can see it nearly through that process. The cap is nearly flush with the outer fold and the cone has been almost completely reversed. This is good enough the way it is (and I actually stopped at this point with this one – my later efforts are a bit more refined.) Now we want to “mushroom” the top. The space inside the bottle between the sides and the cone is where water will collect and keep the soil from drying out too much. We invert the cone partly to give the roots something to work into and hold onto for later when the plant gets heavy, and partly to keep all the water from running right out the nozzle. This way the water can only run out when it’s deeper than the inverted cone. A little gets caught and keeps the plant happier for longer.
We want to maximize that area by expanding the cone as close to the cap as possible. Luckily this is pretty easy. First, remove the cap and make sure the bottle is as inflated as you can get it. Then put the cap back on the bottle.
This is why you’re sitting on the floor. Put the bottle between your knees or thighs, cross your ankles, and get ready to squeeze the bottle like you’re a wrestler. Point the hairdryer straight down and start heating.
This does two things: makes the plastic pliable, and heats the air inside. Air expands when heated, which tries to further inflate the bottle. Of course 2L bottles don’t exactly “inflate” nicely, but the pliable part will tend to expand inward toward the nozzle. Squeeze the bottle with your legs as necessary to help this process. It may be helpful to periodically remove the cap to allow more air into the bottle, but keep in mind it will probably be very hot. Continue until you’ve created a nice mushroom effect all around the outer fold. It will no longer resemble a “fold”.
See how the fold has been expanded into a billowy, pillowy “mushroom” that surrounds the nozzle? If you managed to fully invert the cone – which this example is a bit short of doing – your nozzle will actually be so buried in this mushroom it may be hard to even grip the cap to remove it. If so, use the pliers to get it started. Once you’ve got about a quarter turn loosened it should come off easily.
Simply chop the bottom off, punch 4 evenly-spaced holes around the edges, and string up some twine to hang it from.
Now it’s time to prepare you plant. Use a small one. The one here is a bit too big, but I managed. Wash all the dirt off the roots (or at least as much as you can). Do at least as well as I have.
Now this isn’t a full-sized dinner plate. This is a standard Corelle desert plate. I washed the roots by simply using running water to gradually work the dirt loose as I basically “massaged” the root ball. It takes time. It’s worth taking the time to reduce the overall damage done to the roots. You’re going to hurt them a little just by doing this, but you don’t want to do more damage than absolutely necessary.
Now start threading the rootball through the nozzle. It may seem possible to go the other way (sticking the plant through from the inside) but you’re guaranteed to do a lot more damage that way unless it’s a seedling. (In fact, I plan to experiment with actually growing a seedling in a Jiffy starter, then putting it in the planter right-side up until it’s bigger, then inverting and hanging the whole thing.) The key word here is “gentle”. Be gentle, go slow, and try not to harm the roots.
Here’s another view of the process. If you haven’t roughed up the interior of the nozzle with the pliers when you were heating the bottle, you can use a bit of a twisting motion to work things along. If you did rough it up, you’ll want to avoid that since it will do extra damage to the roots.
Whatever the case, it’s far easier to do this with a smaller plant than is pictured here.
This behemoth is almost there…
Finished! I got the entire rootball through the nozzle with very little damage. It did, however, take many minutes to accomplish that.
It was the smallest Roma plant I could find at the store, though. And I was really set on getting a Roma.
I have a lot more hydroton than I need, so I decided to use some here as the “gravel” bits for the bottom of the planter. Cradling the stalk and holding the bottom of the planter with one hand, carefully feed your rocky stuff into the top and make sure it gets past the roots and into the bottom. Fill it up to just past the nozzle.
Note: if you want to use the planter indoors, it’s highly advisable to put a coffee filter in first. Cut a slit in it and then slip the filter past the roots and work the slit around the stalk. Then put your rocky stuff in, trapping the filter between the bottle and the rocks and making it much, much harder for dirt to get out the nozzle. Outdoor planters can still benefit from this, but dirt loss is minor.
Fill up the planter with dirt, leaving a bit of room at the top. (You’ll water from the top, so you want some room for water to gather while it soaks in without spilling dirt and water over the top.) Be careful with this step, as you’re still messing with delicate roots. You want to try to keep the roots away from the sides, since they don’t like light, and get the dirt as firm as you can without actually hurting the roots. It’s a bit of a Catch-22, but there’s a middle ground to be had. Once you’re done the plant should be reasonably secure. If it feels like it could fall out, try again.
After the roots have started growing again, it will latch onto the rocks and dirt quite securely.
A quick “test hang” shows everything nicely in place. Now for the “decorative” part. If the planter will be inside this is less important, but UV light from the sun will still change the plastic and make it more brittle. We need to protect it against that, since our plant depends on this planter. We need a cover.
I had recently turned a pair of cargo pants into shorts, and because I save everything I’d saved the extra bit of cloth. A pants leg is perfect for this application. (If you’ve got old pants you may want to chop the legs up and make many planters. They’re awesome gifts.)
Pants leg and twine. Stab some holes in the top and bottom with whatever stabby thing is handy. You want to be able to thread the twine through the holes as shown below.
Basically we’ve made a drawstring here. If you look closely at the middle you can see that both ends come out of holes right next to each other, and when pulled on will cinch the bottom up tight.
Now for the top. This part is kind of cool – put one arm through the pant leg from top to bottom. Then, with that hand, pick up the planter by the top. With your other hand, pull the pant leg down off your arm and onto the planter. In one, easy motion you’ve wrapped the planter without molesting the plant.
Here I just did a very simple process of looping the twine through the holes and wrapping it around the twine used to hang the planter. Here I have the planter hanging from a handy nail to make this easy to do. Looking closely you can see that this planter uses a rather small hole cut into the bottom. This design is less than ideal; the small hole is harder to hit while watering, and prevents you from reaching in from the top when getting the plant into the bottle and filling it with rocks and dirt. My recent designs chop the entire bottom off as close to the bottom as possible. Those bottoms, incidentally, make excellent water trays for Jiffy starters.
This is a shot of the process finished up and tied off. I also have an improvement for this. Instead of tying the cloth to the twine hangers, I suggest doing the next step (cinching the bottom) first. Then pull the cloth snug (basically lift the planter by the cloth) and fold it over the top of the plastic. Pierce through both layers of cloth and the plastic between it as far down as you think is safe (perhaps half an inch or more) and then string the twine through that hole to hang the planter. That way you use the combined strength of the plastic and the cloth to support the planter. If one fails the other should hold long enough for you to notice.
Here’s a shot of the bottom cinched up around the stem of the plant. It’s not important to get this tight, just to make it look nice and make sure the cloth is too narrow for the bottle to fall through. (So the bottle won’t fall if the twine it’s hanging from tears through the plastic. That shouldn’t happen, but it’s better safe than sorry.)
The completed planter with plant.
Obviously this works with more than just tomatoes, but that’s the most popular plant for this application. I’m also planning to do this with a green pepper plant and a cherry tomato plant. Unfortunately for me, my pants have only two legs so I’ll have to scrounge up some fabric from somewhere else. I’ve got an idea for a DIY armored laptop bag, so I may use scraps from that.
It’s interesting to watch the plant adapt to suddenly being upside down. Mine is currently twisty and curved and looks kind of like a bonsai tree. New growth will most certainly be adapted to the new orientation. Keep in mind when you start this that you need somewhere to hang it from as soon as you’re done. It won’t sit on a table or something while you go figure out where to hang it.
Also, don’t hang it higher than you can easily reach to water it.
If you’re using a larger fruit-bearing plant – basically anything heavier than cherry tomatoes, you may want to give it something to support its weight on. A macramé chain or net can be a handy thing not only to hang the planter from, but serve as a support for the branches. If your planter is likely to experience high wind, a ground-based trellis may work better, since the plant could anchor itself more securely that way.
Stay tuned, as I develop these new ideas and test them I’ll post updates.