Windowfarms are indeed a very cool idea. I have a really (really) big front window that is just begging to have some plants in it: it faces south, gets full sun all day, and is behind the couch so if there were plants there they wouldn’t be in anybody’s way and would add some nice visual interest to the room. Plus, I love growing things. And I love eating fresh salad. And I have the gardening bug worse than usual this year.

So … I set about designing a windowfarm that would work in our house. First of all, no pop bottles. It needs to be pretty enough to look at regularly and not upset the rest of the household with my weird experiments. The Widowfarms kits are lovely, but pricey, and anyway, I have room for a lot of plants – the window is seven feet wide. Also suspending things from the top seemed tricky – that’s a long span, and I didn’t want things to be swinging too much (I have rambunctious pets). There are two uprights in the centre that divide the window into 3 panes, so I figured I could attach something there and make horizontal supports for growing trays of some kind. I did a lot of research into hydroponics setups and found that a series of troughs set one above the other with each trough on a slight incline is pretty common: you put water in the top and it runs down each channel into the next and ends up in a reservoir at the bottom, kind of like a marble-run. It’s much like the standard Windowfarm arrangement, but wider and zig-zaggy instead of straight.

So, after several nights lying awake and pondering options, I decided to make a trip to the store and see what I could find that would work.

I was going to use PVC piping, like the Vertical Earth Garden, but the first store I went to was out of the size I needed and the next place had the pipe, but didn’t have enough end caps. Then I remembered that some people use vinyl window gutters instead, so I headed to the lumber aisle and found those. Same price as the PVC, even with the end caps – and this way I wouldn’t have to cut any holes and I would be able to easily clean the troughs when the time comes. The nice man cut the 10’ lengths in half for me, so I had enough materials to build four troughs. And it fit in the back of the van.

I also picked up two metal shelf supports to mount in the space between the window panes: I needed something to hang the troughs on, and though I intended to use the little shelf support things that come with the metal rail, they are too wide for my purposes. I found a different solution, which I will explain below.

Next there is the water: most Windowfarms use a pump to get the water from the reservoir at the bottom back up to the top to make another run. Due to the fact that we have a farm and animals, someone is here every day anyhow, so a manual system is workable (I may add a pump for backup in case of long absences – I started playing with airlift the other day but I need more fiddling time). Since gravity feed is our starting assumption, the growing medium needs to be selected to provide reasonable water retention while not drowning the plant roots. And since I’ve got this hanging, it can’t be too heavy, even when wet. And it can’t clog a recirculating system. I found a hydroponics shop in the city and made a trip there to pick up some Hydroton. I also got some rockwool cubes to start the seedlings in, though I will probably use peat pellets later on. Once they have roots sticking out of the cubes they can be nestled in among the Hydroton pellets but for starters, the seedlings need a bit more coddling.

Okay, I had my supplies and it was time to start the construction. The troughs had to be put together by attaching the end caps to each end of the gutter and sealing with silicone, and then drains added by drilling a hole in the bottom of one end and fixing a piece of tubing in place with more silicone.

At the upper left of the window is the top reservoir, where the nutrient solution (water with fertilizer in it: for starters I bought stuff from the hydroponics store, but come summer I will brew up my own with compost tea – I am not doing that now, as it would stink up the house to brew it indoors and it’ll freeze outside!). The reservoir is a black plastic jug that held protein powder, suspended on a curtain rod hanger mounted inside the window frame.

In the bottom of the jug is the business end of an IV drip set: there are some advantages to living in the same household as an EMT when it comes to drip irrigation systems! I just drilled a hole and poked the tip of the dripset in, then sealed it with silicone. Right now the tube is dripping into the bottom plant tray, because the top two trays are empty of plants. Hint: you can buy dripsets online – that’s all you need, not the bag, not the needle, just the dripset.

The troughs are supported by loops of metal cut from an old venetian blind wired to the shelf brackets. By adjusting the length of the loops a bit of an angle can be created so that the water will drain down and do the marble-run thing.

Until the seedlings get roots long enough to reach the bottom of the tray I will need to give them a bit of water through the top of each pot. The hydroton will wick some of the water from the tray, but it’s not a very deep stream of water and they may get thirsty without some help. That’s no big deal as there are only three seedlings so far (I started these a week ago on the window ledge in some peat and vermiculite and repotted them into hydroton yesterday, rinsing off the soilless mix so as not to clog the system).

The other seedlings are in their rockwool cubes in a turkey roasting pan that my husband picked up at the grocery store, on sale for $1.90, complete with plastic lid! It’s the perfect seedling greenhouse, and because the tray is metal, I can set it on top of my gas stove where the pilot lights give off just a bit of warmth. Once those seedlings are established and have roots sticking out of the cubes, they can be nestled in the trays as well, and then we’ll start the water flowing from the top and doing the full marble-run routine.

The system’s been well flushed now, and I think it’s time to mix up the first batch of nutrient solution and feed those little pea seedlings.

I think once the plants are reasonably well established this will work pretty well – until they have roots that can reach the bottom of the water trough, they’ll need some help, which is a problem the traditional Windowfarm design does not have as it is a top-feed drip system, and I’m doing subirrigation. I’ll let you know how it goes … I’m excited to see the window with greenery in it!

Hello everyone !

The following is a schematic of a WF concept I’m currently testing. It uses no pump, relying instead on gravity for nutrient solution circulation and a manual pump for recharge. The upper tank and the lower tanks have a volume of 1 gallon (3.9 liters). Recharging the upper tank takes less then 3 minutes and it contains enough water for the farm to run for approximatly 24 hours. The growth column is currently host to 3 spinach plants and they appear to be doing quite well, having reached a height of 1 1/2 inch (4cm) in less than 2 weeks. In order to narrow my observations to the physical system of the farm itself, I have decided to use a commercial nutrient solution but I intend on eventually using compost tea.

My flow rate is approximatly 1 drop per second. Can anyone comment on this ? I’ve been wondering if it could become too few when the plants will grow bigger.

Updates to come with pictures of the actual system and updated schematics.

REF – Agrofenêtres, Sys. grav. 1 col. V0.8EN avr-2011GP (English version)

REF- Agrofenêtres, Sys. grav. 1 col. V0.8FR avr-2011GP (Version française)

Your comments are welcome

Hi all,

I just completed my first window farm and wanted to share my experience.  Just as I decided to get one of these together, I had an assignment to create a video about the environmental subject of my choice, and this seemed to fit perfectly. Here’s what I came up with: http://www.youtube.com/watch?v=2fif-hNj47M.  I used several images from this site, so if I used one of yours and you want it removed, then please let me know.

I was particularly impressed with Dave’s Manhattan Window Farm design (http://our.windowfarms.org/2011/01/07/my-manhattan-windowfarm/), and used it as a starting point.  In the interest of simplicity and energy conservation I decided not to use lights or a pump, at least to start.  I don’t live anywhere near a hydroponics supply store, and was unable to find nutrient solution, net cups, clay pellets, or rock wool.  Instead I used Vigoro all purpose soluble plant food diluted for indoor plants, cheap plastic plant containers that I already had and a mixture of vermiculite and pebbles.  I figured that the vermiculite would retain moisture better between manual waterings anyway.  I wanted as large a space for roots as possible, so I used 2L soda bottles, which I regularly use.  I could only find 2″ split ring hangers but they turned out to be just large enough to hold the neck of the bottles and keep them close (but not too close) to the shower curtain rod.

I bought some romaine, arugula, and red leaf lettuce from Lowe’s so I could include actual plants in the video, and for the instant gratification, but in the future I will be using seed, of which I have plenty, to start one with herbs and another one or two with things like beans and peppers.  I waited too long for the first watering and I lost a few leaves because of that and damage sustained during transfer, but otherwise they’re looking good ten days in.  Since, I have been watering with 2-4 cups of solution every 2-3 days.  The red leaf is growing really well, while the romaine seems to be struggling a bit.  The arugula is a little bigger, but has not changed much, although they have all grown.

Here are some pictures:

Day One:

Day Ten:

I would like to thank everyone who has contributed to this project.

04.21.2011 Edit to add:

I lost one (the smallest) of three of the romaine plants to what looks like root rot but the others seem to be doing well-

and unfortunately the arugula looks like it’s going to seed already

Few ! It seems it took me as much time to post this one as to build the real thing. But here it is.  I wanted to make a plastic-free windowfarm that would be appealing to the eye and would blend nicely with our Victorian house, from the inside as well as from the outside. (In French, I like to call it “potager vertical” – vertical vegetable garden).

I wanted a sustainable system, sturdy, easy to handle and that I could easily push away from the window, just like shutters.  At first, I envisioned to pump up the water with an airlift system and maybe l’ll come back to the idea, after all. But having free access to those slow drip tubes made me dream of an electric-free system as well. And how about autonomy : a system that would run by itself or with very few maintenance for up to five or six days ?

Finally, I wanted to nourish my plants with the manure from my earthworm composter.

In the beginnings of my experimentation, my slow-drip system  allowed me 3 to 4 days of autonomy, providing that I readjusted the dripping flow once or twice a day. But then, I discovered that  my plants didn’t need as much water (I have rock wool in my pots as well as clay pellets). So, I’m slowing the flow and closing it off completely during the night. That way, I expect to make my upper reservoirs last for more than seven days before having to refill them (with fresh water and nutrients – the old water will be fed to my ornemental plants, which are planted in soil).

No splashing problems so far : My pots are only 5” to 6” apart, one under the other. Each drop don’t gather enough speed to explode into many droplets and splash everywhere. Also, to direct each drop towards the middle of the pot right under it, I took a Hydroton pellet of just the right size and blocked up the draining hole of the pots with it, making sure that it would protrude outside of (under) the pot. The droplets then gather at the lower part of the clay pellet and are therefore nicely centered before making their dive into the next level of the installation. Eventually, I suspect I will have to introduce a mesh between the clay pellet and the pot’s hole (a short shoe lace should do the thing) to prevent the plants’ foliage from diverting the flow of water outside the pots. We’ll see…

When you click on photos, you have further explanations. After the photos, you’ll find a list of materials and a few more explanations.

The tools I used : hammer, screwdriver, long-nose plier, nail.

Thanks for your suggestions and comments, everybody. I hastily made my reservoirs darker, but will have to address the issue more thoroughly in a near future. I used thick cardboard to make a niche for my upper reservoir and poster cardboard to cap the bottom one. Look at the photos.  Wouldn’t it be wise to cover the tubing as well, inside a sleeve of black fabric, for instance ?

I’m still looking into a sustainable pumpless system. I figure that I can live with the chore of climbing up once every three days to refill my upper reservoir. But I’d like to refine the design. And I thought about capillarity, this capacity of a spongy material to sip water up to a higher level. Still juggling with the idea. I have the habit to leave my plants at school with a very simple but very effective capillarity system to water them during Christmas vacations. By the way, I enrolled my younger daughter in this thinking process.

Meanwhile, I continued my experiments with the slow drip, utilizing the 600mL container, since I like the idea of suspending it directly above the plants. I doubled a simple string of unknown (synthetic) material, made a knot to tie its two ends together and squeezed the fold up into the silicone tubing. To my surprise, this slowed the flow  very significantly. (In my first attempt, using the enteral tubing with the slow drip system built in, the bottle was empty after 3 hours.) This last system lasted 84 hours (3 days and a half) during which it needed no intervention from my part.

But I think I might have been too successful in slowing the whole thing. I’m afraid the plants wouldn’t receive enough water.  So, I thought of coupling two 600mL bottles side by side, and join the two strings together to double the volume of water, which I’ll try out no later than tonight.

Which brings me to my question : does any of you out there can tell me approximately how much water you need to put through your system over a period of 24 hours to sustain your plants’ needs ? What would be your estimate ? And did I understand correctly when I read that people put their air pump on a timer to make it work only 15 minutes at a time ?

Last thing : Somebody gave me 2 swivel curtain rods, a few years ago, which I kept intending to use them for another project. I stumbled on them by chance while looking for something else. And I think they are just perfect for what I have in mind. I want to be able to get the whole window farm to get out of the way when I want to access my window. These rods move just like window shutters and their tubing is square, so we think that they would be strong enough to sustain the weight. I’m posting a photo and will certainly try them. Only need to figure out a way to stabilize the different columns of bottles at the bottom, possibly by tying them to a wooden rod suspended underneath the last row of bottles.

We were having trouble finding the right pump, so we decided to water manually.If the pump makes it cost prohibitive, this could work for you, it costs less than $50.

We give each column about a litre of water every 4 days. It’s only been a few weeks, but the peppers are flowering and everything is growing.

Check out the full blog: http://ebw.evergreen.ca/blog/entry/window-farms/

I’ll post the plans soon.

-Stuart