This has been by far my favorite build to date and is going to completely transform the way I garden moving forward. This Do It Yourself Sub Irrigated (or Self Watering) Raised Cedar Garden Bed is designed to not only be functional but absolutely gorgeous to look at! And who doesn’t love when style and function come together perfectly?
What is a SIP & How Does This Garden Bed Work?
SIP stands for Sub-Irrigated Planter. This is a generic term that covers container gardening where the water is given to your plants from underneath instead of above. This allows your plant to gain their water needs through capillary action. While there are many commercial uses for SIP systems, home gardeners can also enjoy the benefits of lower maintenance gardening! Since water is being stored underneath the plant, not only are you watering less (by simply filling the water reservoir) but less water is getting wasted trying to ensure your plant’s soil is evenly moist1. Some cal it self watering because the rain water is collected into the reservoir to reduce needing to hand fill it.
There are 3 main ways a SIP system can work to deliver the necessary water to your plants. Some systems use battery operated drip systems that pull from a water reservoir, wicking where water is pulled through some type of “wick”, commonly a cotton rope, to deliver the necessary water, or through air & water2. This bed uses air and water to make sure the plants get the water they need. The overflow tubes are installed to leave about 1″ of air in the drain pipes, allowing a barrier between the water and the soil. Just surrounding the drain pipes there is a special soil mixture that allows extra water absorption that allows the water to easily be absorbed up to the plants. This will provide a consistent level of moisture to the plants, which honestly is impossible to achieve when watering by hand. Pretty cool, right?
So Why Make This Bed?
So what makes me love this specific elevated planter so much compared to other beds? Here’s just a couple reasons:
- It’s made of cedar boards and sealed with spar-urethane, making it have the potential to last for 20 or more years. So while you will be spending a little more upfront for materials compared to pine or white-wood, the finished product will last you years and years, making the annual cost minimal.
- It is build with a sub-irrigated system that you refill with a hands free PVC fill tube. What does this mean? Instead of watering your garden constantly, this bed holds about 3.5″ of water at the bottom that gets pulled up into the soil as the plants need it. So if it rains in your area, the water reservoir will collect that water since the top isn’t sealed and if not then all you need to do is put the hose in the fill tube and let it run while you admire your garden or spend some time pruning and weeding. This bed also has 2 drain tubes so if you do get heavy rain or distracted while filling up the reservoir, you don’t need to worry about your plants getting root rot because the excess water will drain out!
- This bed is the perfect height not not have to bend down to plant or weed (though weeds will be minimal since it is raised) or strain to prune taller plants. It’s also raised off the ground enough that you don’t need to worry about animals interfering with your crops (here I have terrible problems with rabbits in my garden but they are too cute to get upset with).
- I’ve designed the perfect fold down side shelf for this bed to use while harvesting or planting, or just to put your coffee down while you work on your garden. The perfect way to save space but still have a resting place for all your tools when you need them.
- This plan is completely customizable for you! I built a 2’x6′ bed for my tomatoes, but you can easily modify this to your liking.
- You don’t need a ton of tools to complete this bed or a professional workspace. In this plan I will walk you through the tools I used to build mine but also give you alternatives where applicable so you aren’t breaking the bank on this build. So in the tools section if you see the word optional next to it, make sure to check the instructions before running out to buy anything.
The DIY Sub-Irrigated (Self Watering) Raised Cedar Garden Planter Woodworking Plan:
At first glance this woodworking plan may seem a little overwhelming but I promise it will come together quickly and you will love the end result. This bed is broken into 3 main components: building the bed, installing the sub-irrigation system, and adding the soil/planting. The first component by far takes the longest, but once it’s done you’ll be so happy you invested the time up front for years of low maintenance gardening!
Download Your Free Woodworking Plan:
Self Watering Bed Soil Mixture:
This bed uses 2 different soil mixtures to make it work: 1 for around the drain pipes for wicking power and 1 for above the drain pipes. While I give exact amounts in the woodworking plan, I think it’s important to know the ratios and rational to each soil component so you can build a bed with different dimensions3.
Drain Pipe Soil Mixture:
- 3 Parts Peat Moss: Highly absorbent material that can hold it’s weight in moisture several times over. Be careful not to overdue it with this since it does have an acidic pH.
- 1 Part Vermiculite: The perfect soil amendment to help with aeration. It is light weight, non-toxic, and will not rot or deteriorate. Vermiculite helps increase water and nutrient retention.
- 1 Part Perlite: Allows water retention like vermiculite, but also allows water to drain more easily. It helps with improving soil aeration and prevents soil compaction4.
Above Drain Pipe:
- 2 cu ft Moisture Control Potting Soil
- 2 cu ft Potting Soil
- 1 1/2 cu ft Pine Bark Mulch (plus extra for top of garden bed if wanted)
- 2 gallons Perlite
- Fertilizer if desired
(Please note: The ratios for the above drain pipe soil mixture is 1 part moisture control potting soil, 1 part potting soil, .75 parts pine bark mulch, and .13 parts perlite.)
Huge shout out to Albopepper for their insane knowledge of SIP raised beds. I went through hours and hours of videos and articles when designing this bed and I found their information not only informative, but also easy to understand. Al was great at helping me get the perfect combination of soils for around the drain pipes to make this bed a huge success! Check them out if you want some more in depth knowledge of SIP beds prior to building this one: http://albopepper.com
References:
- Sub-irrigated planter. (2019, July 20). Retrieved from https://en.wikipedia.org/wiki/Sub-irrigated_planter
- Clayton, T. (2019, July 9). S.I.P. Gardening: Self Irrigating Planters. Retrieved from https://gardenculturemagazine.com/s-p-gardening-self-irrigating-planters/
- Self-watering SIP Sub-irrigated Raised Bed Construction. Retrieved from http://albopepper.com/SIP-raised-bed.php
- Information About Soil, Fixes & Fertilizers. (n.d.). Retrieved from https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers
I would love to read a post specifically on creating your SIP with directions, pics & tips you learned.
I love the looks of this plan and the box itself. Tried downloading the pdf but it would quit near the end and never actually open. Sure would like a copy
Hello Gwen,
I'm so sorry for the late response – somehow your message went into my spam message folder so I'm just now seeing this. I've added the plan to here as well if you wanted to download it – https://onedrive.live.com/?authkey=%21ACCxoK06FFGiV3s&id=237E0CF1F7C2970C%2191570&cid=237E0CF1F7C2970C
Please let me know if you have any questions. Thank you so much!
Hey, how would this hold up in a climate where it drops below freezing over the winter? Would the planter need to be drained before winter?
Hi Kevin,
I don't live in a climate that freezes very often but I would think as long as you stopped watering prior to the weather freezing so it had some time to evaporate a bit (or rather the soil isn't water logged) it should be fine. The drain hole allows a limited amount of water to be stored and the water has room to move up if it freezes so I wouldn't think you have to worry about it. Hope this helps!
Angie
Hi.
Can you please put the soil mix recipe (above drain pipes) in ”part-ratio” so its easier for us in metric countries to convert 🙏🏼🙏🏼🙏🏼.
Thank you.
Hi! Thanks so much for the comment. I've updated the post with the ratios but for your reference they are : above drain pipe soil mixture is 1 part moisture control potting soil, 1 part potting soil, .75 parts pine bark mulch, and .13 parts perlite. The ratios are not as user friendly as I would like but I hope this helps. Please let me know if you have any other questions, thanks!
Angie
Hi! I was looking for the tools and materials section or specific instructions on how to build but couldn’t locate it. Is there a file missing?
Good Morning Ryan, the building plan is located right under the last set of pictures. It's labeled "Download Your Free Woodworking Plan: DIY SIP Planter Woodworking Plan". If you click on it then you will see the entire plan, including a tools and materials list. Please let me know if you need anything else, thank you!
Do you have suggestions for alternatives for Peat Moss as the use of this is discouraged in Europe now, due to the destructive nature of foresting this natural carbon retainer.
Hi Colin,
You could use coconut coir (coco peat) since it also retains water extremely well and it's pH level of 6.0 is compatible with most garden plants. This is a much more eco friendly alternative since it is made with the leftover shorter fibers of a coconut. Hope this helps!
Angie
I’am confused on what 3 parts and 1 part mean for around pipe soil? Gallons? How high do I fill the bed with the pipe soil?
Hi Jesse,
For the soil mixture around the irrigation pipes you want to fill until you are just barely covering the pipes. In terms of the mixture ratio, 3 parts and 1 part is the ratio you use to mix the soil, no matter what measurement type you are using. For example, if you are using gallons it would be 3 gallons peat moss, 1 gallon vermiculite, and 1 gallon perlite. Just mix those together well and fill around the irrigation pipes until just covered. Then fill the remaining space in your garden bed with the above drain pipe mixture. Hope this helps!
Angie
I love your design; it is beautiful. Thank you for posting. The water weight is pretty substantial in these. If this works without the bottom bulging down, and deforming the L2 cross supports, it should last for 20 years.
Hey Angie do you think this could be built out to a 4×8 sized bed? I'm trying to calculate the weight of water and soil at that size and determine if that's doable on legs as we're trying to avoid lower back strain due to health constraints. In a pinch I could just make more that are 2 x 8 but it would increase the cost of materials.
Hi Miro,
I haven't tried making it 4' wide but I don't think it would be a problem with how sturdy it came out. The only thing I would suggest is add an additional leg support width wise instead of just the 2 outer legs. I would also recommend if you are building these due to lower back problems to assemble the bed where it is going to stay. I build mine in my workspace and it was incredibly heavy and difficult to move into the garden even without any soil or water in it. Hope this helps and please feel free to let me know if you have any other questions. Thanks!
Angie
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