A square foot garden in a round bed.

Hello. Welcome to my garden in subtropical Brisbane  

I decided on my bed layout before deciding on square foot gardening. It was sort of accidental. I went looking for mixes to fill my raised beds and ended up with a copy of Mel’s book and a protractor… This is my first year doing square foot(ish) gardening. 

Here is a little history of my garden. This will be my third season growing in this spot. It’s the sunniest corner of my yard and also in the front yard. The first two years were about clearing the grass. We did the no dig thing, layering cardboard and mushroom compost over the whole area and planting into that with no real structure. Gardening without defined beds was wild and fun but difficult and we were compacting our hard work tending to our plants. We always intended to add raised beds, which is where we are now.  

How it started: 


How it looked last season: 


Where we are now:

Here is one of my beds planted. Each bed is 1m in diameter and divided into 9 planting sections. 8 around the edges and one central.

I used a modified Mel’s mix. Blended composts, vermiculite and coconut coir. I’m not sure on the ratio 🫣 but there is a much higher percentage of composts than everything else. The bottom 1/3 or so of the bed has garden waste and semi-finished homemade compost too.

This one is planted up with tomatoes, lettuce, coriander, and some flowers. Four tomatoes to the one bed is a bit of an experiment but I plan to prune them. Hopefully it works ok.

It’s been three weeks since we set it up and here are my initial thoughts:
1. I really like the soil mix. It holds moisture much better than the ground. I watered the tomatoes only once since transplanting even though we had no rain until today. I have a hot climate and used to water tomatoes daily. I hope I don’t need to do that with this mix.

2. I need to work out better plant spacing in the odd shape

Hi Alice, Your bed area looks so much easier to tend to than last year.

2. Regarding the sectioning of your 1 M round beds, it is better for plant spacing to make a square foot grid. That would mean 9 full square feet plus little spaces at the edges for smaller plants like green onions, radishes, small flower, a couple of garlic, etc. The center sq ft would be dead center in the bed, with the other 8 surrounding it. Yes, you will have to custom cut the slats with angled edges but it will make planting a breeze. The grid would sit on the Mel's Mix and could be removed for cleaning and amending with more compost each season.

You can mulch with straw, dead leaves or pine needles to slow surface evaporation and keep the soil and roots cool in the heat of your summers.

You wrote, "The bottom 1/3 or so of the bed has garden waste and semi-finished homemade compost too." The problem with filling the bottom with plant material and compost, is that the whole bed will drop as the materials decompose. That will eventually leave you with 2 decisions. To make more expensive Mel's Mix until finally the whole bed is MM. Or, carefully remove the MM, set aside, and put inert sand or top soil as the bottom fill and replace the MM on top. You don't have to do this now, but the time will eventually come.

Thank you for a detailed reply. I’ll definitely consider a square grid for the next planting. I love the idea of onions on the edges as it will help keep the possums away. 

Mulching is a must. I use sugarcane which is so inexpensive here it’s almost free. I haven’t done it yet as it’s winter now. Even without mulch Mel’s mix has needed less water than in ground with mulch which is very positive. The  forecasts are for a dry year ahead so I’m feeling very positive. 

I expect the beds to sink. I don’t mind if the soil sits a little lower to contain the mulch but also am happy to top it up with Mel’s mix. I found a cheap vermiculite supplier and we make our own compost. I had to buy a lot of compost for set up because filling 5 beds that hight was a lot but for topping them off over time we should be able to supply our own. 

sanderson wrote:Hi Alice, Your bed area looks so much easier to tend to than last year.

2.  Regarding the sectioning of your 1 M round beds, it is better for plant spacing to make a square foot grid.  That would mean 9 full square feet plus little spaces at the edges for smaller plants like green onions, radishes, small flower, a couple of garlic, etc. The center sq ft would be dead center in the bed, with the other 8 surrounding it.  Yes, you will have to custom cut the slats with angled edges but it will make planting a breeze.  The grid would sit on the Mel's Mix and could be removed for cleaning and amending with more compost each season.

You can mulch with straw, dead leaves or pine needles to slow surface evaporation and keep the soil and roots cool in the heat of your summers.

You wrote, "The bottom 1/3 or so of the bed has garden waste and semi-finished homemade compost too."  The problem with filling the bottom with plant material and compost, is that the whole bed will drop as the materials decompose.  That will eventually leave you with 2 decisions.  To make more expensive Mel's Mix until finally the whole bed is MM.  Or, carefully remove the MM, set aside, and put inert sand or top soil as the bottom fill and replace the MM on top.  You don't have to do this now, but the time will eventually come.  

I couldn't find a real picture of a grid on a circle.  The diagram on the bottom right is close to what I'm trying to describe.  The circle is sitting on a 4' diameter instead of a meter (40").  The white sections will be smaller for you, so I would only make a grid with 4 pieces so you can squeeze that garlic in.     Two (2) across each way, attached at 1' on-center.

Welcome!  I have 2 rounds; one 36 inch (1 meter) has my rhubarb in it. The other, 4 foot (1.3 m) has a variety!  This year, it has my soon to be harvested garlic, cucumbers, training onto trellis, and just pulled radishes.  

I hav 2 other 4x4s, and a cold frame which is currently planted with squash!  Love your setup!

Interestingly, it is easy to calculate either the square footage or the cubic footage of a round raised.

The area is just Pi*radius squared; 36" circle > 3.14*(1.5*1.5) = 7 sq ft.

If that round bed is 18" high, the volume would be 7*1.5 = 10.5 cu ft.

What OhioGardener wrote:Interestingly, it is easy to calculate either the square footage or the cubic footage of a round raised.

The area is just Pi*radius squared; 36" circle > 3.14*(1.5*1.5) = 7 sq ft.

If that round bed is 18" high, the volume would be 7*1.5 = 10.5 cu ft.

Yes calculations for the mix to fill wasn’t too difficult (maths teacher here ). Unfortunately the discrepancy between bag volume which is sold in L here (another easy conversion) and what is printed on the label left us a bit short in the end. The bags had probably compressed and broken down further on the shelf, I’ll give the suppliers the benefit of the doubt. Never mind as we always have plenty of compost on the go. 

I’m going to keeping playing with the radial layout for now. I think it has some potential aesthetics wise and due to where the screws are located on the beds it’s pretty easy to divide up with string. I know Mel doesn’t endorse string but I don’t wants to mess around adding more substantial divisions to the bed. Different strokes… It might take a bit to work out ideal plant spacing for the varieties I use in the different shape but I don’t mind. Experimenting with something different is the fun part of gardening for me.

Hi, Alicej, just to say I'm enjoying your thread on your beds, as you've created and evolved your plan. I was just about to calculate the square footage, y'all got that covered. (Personally, I bet most plants have round roots and it occurs to me we could all start with tangential one foot circles... and plant little onions and such in the negative space, lol. I'm anything but a good gardener but my common sense steps in... What matters to me is that the plant has good space both below ground and above, is easy to tend, and is protected from harm or crowding... concerns like that. I always look at requirements before design. Not to start a controversy. My beds happen to be rectangular with rounded corners. Just having fun this morning. )

Good for you on your ample compost production!! We bought compost last year, our first, and despite trying so very hard to create a proper MM, something was wrong in the mix. We're still not getting the results of friends and neighbors who just amended our native soil.

Buying soil/compost/potting mix is difficult. The mushroom compost we used to sheet mulch over the lawn was all from the one supplier. It worked great for some things but not everything. Tomatoes grew well but peppers would always be stunted. Peas loved it, beans hated it. It could also be user error . 

I was initially going to buy in premium veggie soil from a landscaping supplier for the beds but it wasn’t much less expensive than buying bags and mixing my own. The reviews of all the landscaping options were very mixed (especially post Covid gardening boom) so making our own seemed the safer choice. I think it worked out about $50 more expensive than the premium soil we were considering and we could have easily spent that and more amending the soil. So far the version of Mel’s Mix we used seems good but it’s early. 

The ingredients were: 
- Mushroom compost 
- “Garden compost” (no real indication of what was in it but didn’t appear to be blended with peat)
- Seasol compost (a different brand of compost also from undisclosed sources this one has added seaweed/kelp stuff, gypsum and a wetting agent that isn’t specified) 
- Premium cow manure (composted and claims to be pure)
- Premium sheep manure (same as the cow stuff but sheep)
- Blended cow manure (composted manure and green waste blend) 
- Poutry manure (composted)
- Pelletized chicken manure (a couple of handfuls per bed)
- course vermiculite 
- coconut coir

There is also garden waste (discussed above) and 90% finished homemade compost on top of that below the Mel’s Mix. 

Design wise we were looking for something that would be visually interesting as it’s in the front garden, very close to the house and busy street with lots of pedestrians. We also really wanted something that we could net due to pests. Previously we could only grow mustard greens and rocket for example as possums ate everything else.  I also wanted to be able to remove the nets on large plants like tomatoes when they grow too tall while still being able to protect other beds growing greens, etc so a network of smaller beds works for that. Hopefully it looks as good as I pictured in full growth

Soose wrote:Good for you on your ample compost production!!   We bought compost last year, our first, and despite trying so very  hard to create a proper MM,  something was wrong in the mix. We're still not getting the results of friends and neighbors who just amended our native soil.

Very excited to see the tomatoes setting fruit. It’s pretty early for me to see. It’s our strange winter at the moment, which is the best time to grow tomatoes for me but it can be too cold overnight for proper pollination to occur. One day I’ll experience a frost but hopefully not this year.

It’s been a month since the raised beds went in.

Keeping in mind it’s winter so things grow a little more slowly. We have had warm days but the nights have been cool (5°C-15°C minimums) and the daylight hours are shorter.

The tomatoes went in first and I’ve been direct seeding in the other spaces over the last month, giving the tomatoes a bit of time to establish. I’ll probably mulch in a couple weeks and the nets will have to come off because the tomatoes will be too big. Once the nets are off starts the arduous process of individually bagging each truss of tomatoes…

I struggle with the upload feature on this forum. Sorry for not updating sooner.

So far, just ok in my square foot garden.

My tomatoes, which are my main focus this time of year, are suffering badly from what appears to be herbicide damage. I suspect it came in on the wind or when I mulched as the first few weeks in the beds I had none. Or at least I hope that’s the case because it being in the mix in the beds isn’t a great prospect.

My Zinnias showed signed of it too but they seem to have grown out of it while my tomatoes are still putting out deformed leaves…. They are attracting bag bugs now too. I’ve topped a couple of them in hope that they will ripen what they have on them. Normally I’d keep getting tomatoes into December if not longer. It’s a pretty big disappointment as they are my primary motivation for gardening.

Other things are growing well. Coriander, chard, parsley, carrots, radish, lettuce. We added another smaller bed for strawberries too. I’ve tried and failed at strawberries a few times

Next time I’ll keep the tomatoes to 2-3 beds so I can keep at least one other under exclusion netting for leaf and root crops. Or maybe I’ll experiment with dwarf varieties. The possums have been having a feast.

Not sure what I can do about the herbicide damage. Hopefully it’s not going to linger in the beds. I don’t think I can make compost from what grows this season.