Citrus Potting Mix Test Pt. 2 - 8 months later with results and our thoughts on them!

Its been 8 months since we started our potting mix test.  We had originally planned for it to be a 6 month test but since we did it over the winter there just wasn't a whole lot of growth so we wanted to watch what happened after the spring flush.

Here is the results video:

For those of you would like to read and want to read more about the test, why we did it, the results and our overall thoughts on them then please keep reading.

This is the conclusion to the Citrus Potting Mix test we did at Madison Citrus Nursery in Georgia. We originally planned for this to be a 6 month test but due to it being over the winter we elongated the test to 8 months so we could give the trees a little more time to grow out.

The Experiment:
Mix 1 - Straight 511 Mix (Pine Bark Base, Peat Moss, Chunky Perlite, & Lime)
Mix 2 - 511 Mix with added 13-6-6 Fertilizer
Mix 3 - 511 Mix with added 13-6-6 Fertilizer and 911 Minor Elements
Mix 4 - Miracle Grow Cactus & Citrus Mix
Mix 5 - Miracle Grow Moisture Control
Mix 6 - StaGreen Potting Mix (cheapest option at Lowes)
Mix 7 - Madison Custom Citrus Potting Mix (our in house mix as a baseline)

We have potted up 5 Harvey Lemon trees in each mix, we will water similarly and apply liquid 20-10-20 fertilizer to each as we do with all of the citrus we grow in the greenhouse.

Why we did this test:
Its no secret that we sell the mix we use in our greenhouses but realize its very expensive to ship it because its so bulky. So our intentions with this test were to get more data and get closer to a mix option we can recommend to the rest of our customers who either cant afford to have bulky mix shipped to them or just don't want to. So we tested some locally accessible store bought mixes as well as 5-1-1 which is a popular well draining DIY potting mix.

What were the results:
The 5-1-1 mix did well, the 5-1-1 mix with the added nutrients did well, the Madison Citrus Mix did well and the StaGreen Potting Mix from Lowes did well. The Miracle Grow Moisture Control mix and the Miracle Grow Citrus, Cactus, and Palm Mix both did ok but the trees were showing more obvious signs of nutrient deficiencies. Take a look at the video and see the results for yourself.

What are our thoughts:
I think we were honestly surprised at the results of the test, we were hoping that in general we would be able to see a bigger difference between each of the mixes but if you step back and think about it, almost all were pine bark based mixes, all fairly heavily fertilized and consistently watered so they all did similarly well.

This is a good thing and a bad thing as it leaves a lot of questions still unanswered however it also shows how important consistent watering and fertilizer can be to tree growth.

With that said we are genuinely happy to say that it looks like the Lowes StaGreen potting mix (we tested the non-moisture control version) seems to have done really well and would be something we can actually recommend as an option for customers who are looking for a local option that is more cost effective than shipping our mix and easier than sourcing materials to making their own.


Some things this test does not do or demonstrate well: 
This test does not show the benefits of how well draining 5-1-1 can be for those that live in really wet areas or areas where containers just don't dry out quick enough. 

This test does not show the moisture holding benefits of the long strand peat used in the Madison Mix (the chunks) for those areas where some additional pockets of moisture retention is insurance against a mix drying out too quickly if you live in a hot or dry place.


Whats next:
Maybe we will do an additional test in the future where each mix gets watered on an individual schedule (when it needs it) and maybe we just use slow release fertilizer every month instead of watering with fertilizer injection.  These things may make it more of a real world test but for now we had results and wanted to bring them to you.


Please note, your results may vary based on citrus variety, size of pot, where you live, your local climate, how often you water and how often you fertilize. The pros of these tests is that we get data, the cons of these tests is that there is always more data to collect and more variables to test.