Filling Up Those Big Planter Boxes – Why Not Use Compost?

At one point or another, you’ve probably had a very large planter that required a ton of soil to fill. The old standby most folks use are either empty milk jugs or soda bottles… those light and big containers that will take up space at the base of the soil bed. Those worked then, and they still do now. But if you happen to have a compost pile (or bin), then I ask: have you ever considered stealing some partially decomposed material from there?

While most of us use compost piles or bins, there is another way to compost directly in your garden beds. It’s simple: you just dig a trench, bury the food scraps and other compost items, and then top with soil. Most people do this outside of the standard growing season (fall and winter), but you can do it year-round. By relocating some of your compost pile into that big planter, you’re basically using this method. Why it took about 3 years for this to dawn on me I will never know. But as I stood over the giant planter I just built for my new herb garden, I couldn’t figure out how to get my hands on that many milk jugs or soda bottles. My family really doesn’t drink any soda, and we don’t go through milk jugs that fast.

This planter is BIG, and filling it would have taken many, many milk jugs. It’s 6′ wide x 19″ high x 18″ deep. (By the way, I found the directions HERE. You can adjust measurements to whatever size you need for your particular project.) So I just stood there staring at this beast of a planter, and scratching my head.

The New Planter & Maya

Maybe I could use inverted Rubbermaid bins that I have on hand? Nope, too wide. Maybe I could build inverted boxes out of scrap wood…but that’s really not a good use of my wonderful firewood stash. And there was absolutely no way I was going to buy enough soil to fill it from bottom to top. That would cost WAY too much. (And I know you’re all thinking… why did I build it that tall to begin with? Well, it just kinda happened. No good reason. Probably a lack of thinking ahead thoroughly about the soil requirements). Well, I credit my Gold-Laced Wyandotte hen (named Lacey) with pointing me toward the solution.

For whatever reason, she decided to start singing away at about 7pm. Who knows why. She did so while standing right in front of my compost pile, and the idea was hatched (pun intended). I have a ton of filler sitting right there! So over I went with shovel and wheelbarrow… and Lacey sang for me the entire time. What a crack up. It was a great solution. As that compost breaks down, it’ll provide nutrients for the herbs in the container, which works out perfectly. My layering choice ended up like this:

Compost LayerBottom Layer: 1 big bag of raised bed mulch/soil (3-cubit feet). I used THIS.

Layer 2: A very thick layer of partially decomposed compost from my pile out back.

Layer 3: A thin layer of fresh compost ingredients from the bucket on my porch (you can read about my composting system HERE.)

Layer 4: Another 3-cubic foot bag of raised bed mulch/soil mixed with 2 small bags of chicken manure.

Layer 5: Another thin layer of partially decomposed compost.

Top Layer: The last 3-cubit foot bag of raised bed mulch/soil.

Those herbs couldn’t ask for a better and more nutrient-filled home. I’m excited to see them grow nice and big so that I’ll have more material for the herb garlands I make for the brooder, chicken coop, and my kitchen (that post is coming soon). There’s nothing wrong with using the common standbys to fill your planters (empty milk jugs, soda bottles, or packing peanuts) they work very well. I just suggest using compost as a filler whenever possible, even if it is fresh. You’re basically creating a slow-release nutrient system for your plants. As the compost breaks down, your plants will use the completed product without you having to add it after-the-fact… it’s already built in!



  1. Cool. Great idea! I do bury my compost in my garden in the winter and it’s gone in about two weeks. I did notice I have very healthy earth worms! But, what a great idea for a planter. Give Lacey a couple extra blood worms…she’s a genius!

  2. Love your new planter, Kerry! And, you built it yourself…so proud of you! Hope Maya doesn’t like the taste of herbs, she’s just tall enough to help herself when they start to grow. 😀
    Love, Aunt Mindy

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