Friday, May 17

Garden Fever Prt. 3: Building Raised Sub-Irrigation Beds

Why Raised? Why Sub-Irrigated?
Do you really have to ask? My raised beds sit on my deck and are as work-free as a garden can get! They are self watering, requiring a refill once every two months, and they help extend my summer planting season. Oh, and as for weeding, well...what weeding? *swoon* I love my little deck garden! I promise to give you another peak later in the summer when all my little seedlings are fully grown.

Soooo, have you created your self-watering container garden yet? Wait what? You didn't see that post? Well ok, then you must start with Part 1: Starting Seedlings of my Garden Fever series, then go to Part 2: Container Gardening, and this is the last post in this 3 part series. If you have, then please, by all means...onward!

Necessary Materials
Bed Building Materials
These are the materials I used to build one raised bed, however you can simply adjust the dimensions to suit materials on sale or your desired height, length, and width. There is one reason alone why I chose the type of wood I was cheap. It was $1.89 per 8 ft. board cheap!!! So believe me, if I could have found taller cedar boards at that smashtastic price, I would have used them. *wink* Basically I spent $12 to build two raised beds after purchasing 4 - 8 ft. boards, one piece of framing wood, and some soil . I used leftover deck stain & seal left in my garage by the previous owners, and  I salvaged castors from a piece of roadside furniture. 

To Build One Raised Bed
  • 2 - 1 in. x 7.25 in. x 8 ft. Cedar Board
  • 1 - 1 in. x 1.5 in. x 8 ft. Framing Lumber
  • One Salvaged Pallet 
  • 1 1/2 in. Deck Screws
  • Deck Stain & Seal
  • Castors (optional)

Sub-Irrigation System Materials
  • 3/4" PVC Pipe & Cap
  • 4" Drain Pipe
  • Thick Plastic Sheeting (vapor barrier)
  • 1/2" Vinyl Tubing
  • Top Soil
  • Garden Soil

How-To Build Your Own Raised Sub-Irrigation Bed
Again, some things are just better shown in I will show you via video how to build your bed, and install the sub-irrigation system. If you watched the video I did on how to create self-watering planters here then you should know the idea is the same, however the materials are a little different. 

Drainage Tip
If your garden is on a second story deck, or you just don't want it draining all over your deck floor, be sure to place a plastic drip pan under your vinyl drain tube. Or you can just do what I do, allow it to overflow into one of my planters. 

Create a Shade/Greenhouse Covering
I saw this idea on Pinterest and it really appealed to me.
Use the leftover PVC pipe to create holders for a "shade" useful for those especially hot days. 
This will be very helpful for your transplanted seedlings as they acclimate. They usually can't withstand an entire day of sun, but now that they are being kept moist from the roots up, and have a shade until they are ready, nothing can get them down! 

  •  Use Two Hole Straps to attach the PVC to your beds. You can attach them to the outside of your bed. Or attach them hidden on the inside of your bed before filling with garden soil. 
  • Purchase a thinner bendable PVC that can loop over top of your raised bed. 
  • Create a shade by cutting garden cloth to size over the loops.
  • **TIP: if you created long narrow beds like I did, push them side by side and loop your shade over both as in the picture below. 

Even better, late fall replace the garden cloth with the leftover plastic sheeting to transform your bed into a greenhouse and extend your growing season. Use your plastic sheeting in the early spring and even into the summer for heat-loving plants... it also can help to warm the soil up in spring before seeding into it. 

Enjoy your raised beds! I know I will...


  1. Such a great idea! I love your blog, you have many wonderful ideas. I am going to try this!!

  2. Hallo, ich muss sagen, dass Sie ein paar gute Punkte in der Post. Ich führte Recherchen zum Thema und fand die meisten Leute mit Ihrem Blog zustimmen. Vielen Dank für diese Informationen.


  3. i really like the content of this blog. feeling great to see such kind of blogs.
    Internet based Beds Company

  4. this was great! thank you so much!

  5. Hi there, thank you for that great tutorial! - Two questions: What are those thick black hoses called? Do they already have holes in them, or did you have to make them that way?

    1. They are called "HDPE pipes", or in my hardware store "perforated drain pipe". They are drainage system tubes for sewer and storm. You can purchase them already perforated or solid in a variety of sizes, and you can find them in the plumbing section of your hardware store.
      Hope that helps!

  6. Hi, I love this idea and am thinking about trying it this summer. I have two questions though. Is the small overflow pipe large enough during lengthy rain storms? Would you recommend either increasing the diameter of the overflow pipe or adding an another pipe somewhere? Additionally if I wanted to make my box twice as large e.g. 3ftx2ft would I put double the perforated drain pipes and add an additional overflow pipe? The reason I ask is because I am on a top floor apartment and would love to have a balcony garden but want to make sure my downstairs neighbors don't get my extra water. Thanks again for posting this!

    1. Thank you!
      The small overflow tube is large enough. It pours out like a torrent! Just be sure there are no kinks or the possibility of kinks forming (keep it short enough), and it should go near the top and inside of your irrigation pipes...then when you overfill it will pour out. If you have neighbors below be sure to have a substantial bucket to catch the run off. The amount and size of pipe is only determined by how much water (and for how long) you want to could absolutely do double the perforated pipe if desired.

  7. This is such a neat project. I kept it simple this year and opted for container gardening and tomato towers, but I'd love to try these self-watering planters someday!


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