Which Commercial Fertilizer is Best? 44


Which Bunnings Fertilizer is Best?

We purchased a range of “off-the-shelf” fertilizers from Bunnings and tested their performance.

Hungry Bin Worm Farm Worm Lovers

We think our Hungry Bin Worm Farm is great. It’s easy to use, the worms love it, and it produces plenty of worm wee.

This summer we conducted an experiment to test the performance of a range of potting mixes. While setting that experiment up, we expanded it to investigate a range of “off-the-shelf” fertilizers (mostly certified organic ones). For those of us limited to major hardware chains and local nurseries, these are often the only viable ways to replenish the nutrients in our container gardens.

We compared nine different fertilizing regimes. All of them were purchased from “The Big Green Box” and covered a range of powders, pellets and liquid feeds. We also used the home-grown worm wee that we obtained from our Hungry Bin Worm Farm.

ProductCostPackage VolumeCost Per TreatmentOrganically Certified?NPK RatioApplication MethodBatch Number
Fine Farms Blended Cow Manure$3.9525 Litres$1.58NoNot reportedMixed 50/50 (v/v) with potting mix prior to potting upN/A
Osmocote Plus Trace Elements: Vegetable, Tomato, Herb & Garden Beds$6.88500g$0.14No9:1:42 teaspoons mixed through 6 litres of potting mix prior to potting upN/A
Richgro Mega Booster Fruit and Citrus Organic Fertilizer$13.375kg$0.05Yes6:1:24 teaspoons mixed through 6 litres of potting mix prior to potting upN/A
Rooster Booster$16.4620kg$0.17Yes3:2:21 handful mixed through 6 litres of potting mix prior to potting upN/A
Charlie Carp Organic$10.681 Litre$0.96Yes3:1:290 mL per watering can (9L). applied to foliage and soil every 2 weeksBatch No 51 (10/06/15)
Dynamic Lifter Liquid$12.981 Litre$0.52Yes7:1:41 Cap full (40mL) per watering can (9L) applied to foliage and soil every 2 weeksYS1620029 (08/09/16)
Home Grown Worm WeeN/AN/AN/ANoN/A1 Litre per watering can (9L) applied to foliage and soil every 2 weeksN/A
Seasol$34.634 Litres$0.26Yes0:0:430 mL per watering can (9L). applied to foliage and soil every 2 weeks372SR15084 (06/07/15)
Seasol and Charlie Carp Organic MixN/AN/A$1.22YesN/A30 mL Seasol + 90 mL Charlie Carp Organic per watering can (9L) applied to foliage and soil every 2 weeksN/A

Each treatment was used to try and improve the plants growing in two different types of potting mix. Earthwise Multipurpose Potting Mix was the cheapest potting mix we could find. The Bulk Potting Mix from, Fulton’s Garden Supplies, what we would consider an “average” quality potting mix and was the second potting mix we aimed to improve with the fertilizers.

Setting up the fertilizer experiment

Which is the best organic fertilizer from bunnings

We mixed the powdered and pelletised fertilizers through the potting mix prior to potting up.

For both the potting mix and fertilizer experiments, we used capsicum seedlings. These were all relatively the same size, in the same condition and appeared to have been sown at the same time. We potted up five seedlings in each of the different potting mix/fertilizer treatment combinations. We tried to make sure that each soil had a seedling from five different punnets to reduce the chance of experimental error. Any powdered and pelletised fertilisers were mixed through the potting mix prior to use. Liquid fertilizers such as Seasol and Worm Wee were applied immediately after potting up and then every fortnight thereafter.

The potted-up seedlings were then placed in our greenhouse. The pots were alternated to ensure that the five pots for each of the soils were spread across the shelf. Each pot appeared to have equal access to light and water. The automated irrigation system watered every morning with a fine mist for 5 minutes. After six weeks, we assessed the plants and took photos of the results.

Results of the Fertilizer Experiment

We assessed each of the plants and recorded the colour of the leaves as well as the number of plants in each group that had set fruit. We also recorded the total number of flowers and fruit set on the 5 replicate plants combined. See the results tabulated below.

Results of different fertilizers used to treat seedlings growing in the Fulton’s Bulk Potting Mix

FertilizerColour of LeavesNumber of Plants With FruitTotal Number of Fruit across the five plantsOther Comments
Negative Control (No Fertilizer, potting mix only)Light Green0/50 One flower present, but no fruit. One plant showing evidence of disease.
Fine Farms Blended Cow ManureLight Green2/54
Osmocote Plus Trace Elements: Vegetable, Tomato, Herb & Garden BedsDark Green3/551 plant died, probably due to transport shock or not receiving enough water. These plants were the largest and healthiest looking plants with plenty of flowers.
Richgro Mega Booster Fruit and Citrus Organic FertilizerLight Green2/53These plants were also some of the largest. Leaves were starting to turn yellow.
Rooster BoosterLight Green0/501 plant died, probably due to transport shock or not receiving enough water. Plants only slightly bigger than negative control.
Charlie Carp OrganicLight Green3/54Plants look similar to negative control.
Dynamic Lifter LiquidLight Green2/53Plants look similar to negative control.
Home Grown Worm WeeLight Green0/50Plants look similar to negative control.
SeasolLight Green0/50Plants look similar to negative control.
Seasol and Charlie Carp Organic MixLight Green0/50Plants look similar to negative control.

Results of different fertilizers used to treat seedlings growing in the Earthwise Multipurpose Potting Mix

FertilizerColour of LeavesNumber of Plants With FruitTotal Number of Fruit across the five plantsOther Comments
Negative Control (No Fertilizer, potting mix only)Yellow0/50
Fine Farms Blended Cow ManureLight Green1/51
Osmocote Plus Trace Elements: Vegetable, Tomato, Herb & Garden Beds1 x Dark Green
3 x Light Green
1/52These plants look the biggest and healthiest
Richgro Mega Booster Fruit and Citrus Organic FertilizerLight Green0/53
Rooster BoosterLight Green0/50
Charlie Carp OrganicYellow0/54Plants look similar to negative control.
Dynamic Lifter LiquidYellow0/53Plants look similar to negative control.
Home Grown Worm WeeYellow0/50Plants look similar to negative control.
SeasolYellow0/50Plants look similar to negative control.
Seasol and Charlie Carp Organic MixYellow0/50Plants look similar to negative control.

We also took photos of the plants. Below are images of the best plant out of the five replicates for each fertilizer type. As you can see there is a huge variation in the performance of each of the potting mixes.

Results of different fertilizers used to treat seedlings growing in the Fulton’s Bulk Potting Mix

Best Fertilizers from Bunnings

The best plant from each of the 5 replicates. These plants have been planted in Fulton’s Bulk Potting Mix and treated with our selection of “off-the-shelf” fertilizers.

Results of different fertilizers used to treat seedlings growing in the Earthwise Multipurpose Potting Mix

Best Fertilizers from Bunnings

The best plant from each of the 5 replicates. These plants have been planted in Earthwise Multipurpose Potting mix and treated with our selection of “off-the-shelf” fertilizers.

So what do the results from our Fertilizer Experiment all mean?

Well, first there was a huge difference in the responses to fertilizing regimes shown by plants growing in the Earthwise Multipurpose Potting Mix vs the Fulton’s Bulk Potting Mix. It seems that even with the best quality fertilizers, terrible soil is difficult to improve.

The other notable result was the difference in performance between the liquid fertilizers and the powdered/pelletised fertilizers. In our experiment, the liquid fertilizers performed far worse than the powdered/pelletised fertilizers. I suspect that in this experiment, it had a lot to do with the automatic irrigation system. This delivered water to the plant in excess of their requirements. This likely flushed nutrients out of the potting mixes. Liquid fertilizers are promoted as having soluble nutrients that can readily be taken up by plants. Because they are soluble, they are probably also readily flushed from the potting mix faster than the powdered/pelletised fertilizers.

For those of you with container gardens, you are unlikely to be watering your plants as frequently, or with as much water as in this experiment. The use of saucers under your pots will also help to retain nutrients and allow them to be taken back up into the potting mix. It would be interesting to see how the liquid fertilizers perform under these “more normal” sorts of conditions.

The best performing fertilizer was clearly the Osmocote Plus Trace Elements: Vegetable, Tomato, Herb & Garden Beds. However, this fertilizer is not certified organic. If you re after a certified organic fertilizer, then the Richgro Mega Booster Fruit and Citrus Organic Fertilizer is the best performer in our opinion. We would always encourage growers to improve their soil using home made composts. But for those of you with limited space, these products may be suitable for you to try.

On 01/05/17 we contacted the following manufacturers or suppliers of each of the products investigated:

We invite them to leave feedback on our experiment in the comments section below. We’ll look to repeat this experiment again in the future and would appreciate feedback from the public on how it may be improved to obtain even more meaningful results for our readers and gardening community.

Disclaimer: All of the products tested and materials used in this experiment were purchased by Leaf, Root & Fruit at full retail price. No incentives or sponsorship are received from any of the companies mentioned in this blog post.

If you would like further information on using fertilizers in the garden, then please sign up to our Science of Edible Gardening Workshop Series. The March workshop (repeated annually) in the series focuses heavily on optimising nutrients and fertilizers to grow nutrient dense food.


Leave a comment

Your email address will not be published. Required fields are marked *

44 thoughts on “Which Commercial Fertilizer is Best?

  • David

    Love this article and the one on potting mix. Very informative. I’ve used a number of fertilisers in the past and have found that Brunnings and Osmocote were the more consistent performers. Brunnings is much cheaper but unfortunately do have higher than recommended levels of heavy metals.
    I use Seasol more as a plant tonic rather than fertiliser. There’s not much nutrient once diluted at the recommended level.
    But awesome articles.

    • Leaf, Root & Fruit Post author

      Thanks David. Glad you’ve found it useful. Seasol is indeed more of a tonic than a fertilizer and I included it more so to highlight this fact.
      Happy Gardening!
      Duncan

    • Leaf, Root & Fruit Post author

      Hi Steve,
      Thanks for your feedback. Glad you enjoy our work. What do you mean by doing “combined experiments”? We combined two products (Seasol and Charlie Carp) as I knew that Seasol was not considered a “fertilizer” as such, more of a tonic and was interested to see the results of combining it with a more nitrogen rich source. Is that the sort of thing that you would like to see more of? We’d love to do further trials and test as many combinations as possible, but in the end it comes down to time and budget. As it was, the potting mix and fertilizer experiments this summer cost us several hundred dollars in materials alone. Once you start expanding to combinations, then the number of replicates goes up exponentially and so do the costs!

      Happy Gardening!
      Duncan

  • Graham Smith

    Hi Duncan
    You have gone to some serious effort with your experiment, for which I congratulate you, however there are a couple of things I wish to point out. Seasol, as you state in your article, is not a fertiliser, but more a plant tonic, and it has amazing effects on the root growth of plants, whilst at the same time assisting in their ability to cope with a number of stresses.
    In your field showing NPK, you actually list Seasol as having 10:1:18, which is completely incorrect. Seasol has virtually no N, or P but has around 4 in K, plus an array of trace elements and plant stimulants.
    When observing your growth trials, you also correctly point out that the irrigation was probably more than normal, which will indeed leach out the nutrients of liquid fertilisers, again which is why the dry products performed better.
    One of the most important facets of growing is of course the medium in which plants are planted, which is why potting mixes have red ticks for premiums and black ticks for standard. There are minimum requirements for both and they relate to what is in the potting mix and how long a plant survives and thrives.
    One of the most important parts of growing, particularly vegetables, is the preparation of the soil, which is why it is important to incorporate organic material along with other materials to ensure good drainage and healthy root growth.
    On our website you will find footage of our root assays which shows root growth in a standard Seasol solution versus water.
    Seasol actually fires the plant up to go searching for nutrient, and if there is none there, the plant performs as shown in your trials.
    The sister product to Seasol is PowerFeed which is a fertiliser with added compost and fish (NPK 12:1.4: 7)
    PowerFeed is also now available in a granular which has freeze dried microbes to really get the soil humming.
    It would be great for you to trial a combo of all three, as I think you and your audience would be extremely impressed with the results.
    Once again, congrats on putting so much work into your trials. If you need any more information don’t hesitate to contact me.
    Kind Regards
    Graham Smith
    Seasol International Pty Ltd

    • Leaf, Root & Fruit Post author

      Hi Graham, thanks for your prompt feedback. I have updated the NPK ratio for Seasol accordingly. As you say, when growing vegetables it is important to prepare the soil correctly. By adding lots of organic matter and quality compost, then I believe we don’t need any of these commercial fertilizers. Given the huge positive response we’ve already had to this trial and also our previous potting mix trials we will no doubt look to conduct more trials in the future. I’ll certainly consider some of your other products that you’ve mentioned for these.

      Happy Gardening!

      Duncan

      • Scott

        A very interesting experiment. Although research in this area is in it’s early stages, the hypothesis of your experiment may be flawed. One of the current theories regarding organic fertiliser is that bacteria and fungi in the soil break down the organic materials (rot) and via this process carbon and nutrients are released for the plant and soil over an extended period of time. If you put sterilised organic eg Rooster Booster matter into “sterile” potting mix i would expect very little to happen as these microbes are not present in high enough numbers and the fertiliser will remain in an unusable form. If you put in (artificial) (N.P.K) water soluble fertiliser the plant will take up some nutrients straight away while a lot of chemical will leach from the pot. If you use a slow release (artificial) water soluble fertiliser such as osmocote, you will get a long term release of nutrients (N.P.K.) which the plant can use immediately. In your experiment of course this will give the best result.

        • Leaf, Root & Fruit Post author

          Hi Scott,

          Yes indeed you are correct that the conversion of nitrites to nitrates (which plants can use) is conducted by bacteria and fungi. This normally occurs via nitrogen fixing bacteria in the soil. Some of the nitrogen present in these products may already be in the form of nitrates and bacteria will quickly colonise to begin the process also.

          Thanks for your feedback and thoughts

          Duncan

      • Reluctant contrarian

        What does “tonic” even mean???

        I think it’s just a catchy non-thing like “energy” (psychosocial pseudo-jargon).

        If it IS actually a thing, could someone please explain precisely what the physiological mechanisms are by which it operates.

        WOULD DEARLY LOVE TO SEE SEASOL TRIALLED AGAINST CONTROL! PLEASE TRIAL THIS.

        This info is great. Many thanks.

        • Leaf, Root & Fruit Post author

          Hi RC… Indeed, we would like to know the same thing! If Seasol or anyone out there can shed some light we would be most grateful.

  • Pauline Webb

    May I comment from a home gardener’s view. I do a permaculture organic style garden in Doncaster East. It was a difficult summer, short and sharp, preceded by a late chilly spring. Tomatoes may have been easier to test as capsaicum are frequently a challenge. I obtain the best results, fruit wise, from plants which survive the overwinter temperatures, are pruned in spring then flowerquicker as the plant is already grown. Frequently capsaicum and cucumber don’t achieve much fruit until late summer into autumn. They often have weekly feeding of worm wee or seasol on top of compost and peastraw mulch.

    I did grow 2 capsaicum plants in Debco’s best mix with liquid supplement on my patio and they must have had about 6- 8 fruit each.

    Better luck next time

    Pauline

    • Leaf, Root & Fruit Post author

      Thanks for your feedback Pauline. We chose Capsicums as they are relatively small plants, so they don’t take up much room in the green house (compared to say Tomatoes). They require little care such as staking and don’t have much in the way of pollination issues (there’s not usually many bees in our greenhouse!). They also transplant well and can be fairly quick to flower and fruit – some of the better plants in this experiment flowered within four weeks of transplant. We prefer a fruiting plant over leaf or root crops as fruiting plants have more complex nutrient requirements. The capsicums really test out the overall quality of the fertilizer much better than say, lettuces which would really focus on the nitrogen content.

      Thanks again for sharing your experience with us.

      Good Luck and Happy Gardening!

      Duncan

  • Chris

    Charlie Carp
    Thank you for considering Charlie Carp in your trial process, it is a very good product that is both helping the environment and producing better gardens and lawns. I would like to make a few comments on your trial process:
    Firstly, as you note, you have compared certified organic fertilisers with fertilisers that are not certified organic. There is no organic fertiliser I am aware of that would have a level of nitrogen which could compete with non organic fertilisers (which provides that initial growth spurt and extra greening). Organic certified products will have longer term benefits for the plant and soil which non organic products do not have.
    Secondly the application of slow release fertilisers (dry) versus liquid fertilisers require slightly different methods of application. No initial watering is required for Charlie Carp. If water is applied this will dilute the effect of our product (which you have noted). We recommend that you do not use our product if it is about to rain and also do not water immediately afterwards. Dry/slow release products will require water to release the nutrients.
    As you would be aware we also have Charlie Carp Original which has a higher level of nutrients and is 100% natural. This would have provided a greater initial boost to growth if you had used that in your trial. Perhaps you could test that next time
    I look forward to you next body of work.
    Kind regards
    Chris
    Charlie Carp

    • Leaf, Root & Fruit Post author

      Thanks for taking the time to respond Chris. We’ll take your feedback on board and consider it for any future work that we do.

      Duncan

  • scotty 2 hotty

    so to confirm with you Duncan, the conclusion of this experiment is that if you are going to use any type of hardware store potting mix, that it should be treated as a passive hydroponic medium that requires alot of fertiliser and is easily overwatered. ive had so much success before in just coco alone and dirt in pots outside that i cant believe myself when it comes to these scotts products everything ive ever known just goes out the window, they really need to start caring about there customers more i know i wouldnt be able to sleep at night knowing i was having such a negative impact on so many people who are just trying to grow some decent food which is something money generally cant buy

    • scotty 2 hotty

      you know what i might do actually, get all the local trimming services to drop off there chips on my property for free, let them sit till they are fully composted, and then sell them as is in a white bag with big black writing on the front that says “the only potting mix” and just do that for a living, scotts be lackin time for the younger generation to takeover

    • Leaf, Root & Fruit Post author

      Hi Scotty,
      Thanks for you comments. I guess the take home message is that not all fertilizers are going to give you the outcomes you may hope for. Please keep in mind that this is only one trial, with one type of plant over a short period of time. Other trials, with different products, applications and time frames may yield different results. I would always encourage people to grow edible plants in the ground, with good quality, enriched compost. If this is not possible then a good quality potting mix and supplementary fertilizing may be required. Note that good quality and price are not always correlated!

      Good Luck and Happy Gardening!

      Duncan

  • Goshen Watts

    Another great piece of research, and great to read the comments and feedback from suppliers, which help inform us as to how to use these products. I had a feeling that worm juice (although I’ve got lots of it) isn’t quite as magic as it’s made out to me (not a fertilizer by itself). No mention of ‘Blood and Bone’? I know there’s mixed opinions on it…

    • Leaf, Root & Fruit Post author

      Thanks for the feedback Goshen. We’ll consider ‘Blood and Bone’ if we run any trials in future.

      Good Luck and Happy Gardening!

      Duncan

  • john

    Congrats Duncan on all your work on the potting mix and fertiliser trials. Definitely food for thought. Always worth testing and endeavouring to find more definitive answers rather than just accepting the spin like so many ‘garden advice’ sites do. Look forward to further trials. Great stuff.

  • David de Vries

    Thanks for this useful experimenting. Some results show total fruits but no number of plants with fruits – I would have thought there must have been some plants with fruits.

    • Leaf, Root & Fruit Post author

      Hi David,

      Thanks for the feedback. We’ll look to include this result for you in future trials.

      Good Luck & Happy Gardening!

      Duncan

  • Jonno

    These are very interesting experiments, thanks for doing them. It’s great that you have managed to receive replies from some companies.
    One query I have is that the pots you have used do seem a touch small for growing a plant such as a capsicum in a manner that will provide you with any quantity of fruit regardless of growing medium. (for both this and the potting mix experiment)

    • Leaf, Root & Fruit Post author

      Hi Jonno,

      thanks for taking the time to provide some feedback. Yes, the pots are small. Smaller than we would recommend for growing veggies. However, many of the plants do set capsicums in these small pots and go on to develop ripe fruit. We’ve found the plant growth is sufficient enough for us to obtain relevant results. Our greenhouse space available for these trials is minimal. Using small pots means we can fit more plants into our trials. This means more products tested, or more replicates per test product.

      Good Luck & Happy Gardening!

      Duncan

  • Eliott

    Thanks for the trial. This was really what I have been looking for. Some unbiased evidence on different fertilisers. Your trial supports another trial I have seen that achieved best results with cow manure. The trial looked at using different ‘organic’ fertilisers to supplement conventional fertiliser used in broad acre farming. They found that they could achieve the same results as conventional farming using 40 % less fertiliser if supplemented with cow manure.

    I am based in Perth and our climate is a little bit tougher than the east in regards to growing produce. We have long hot summers and cold wet winters. I mostly try to grow my veggies in pots, but really this is only possible in the winter months as it so hot and dry in summer that plants really struggle. I would really love to see some practical examples of people achieving good levels of produce from their home grown gardens (and then learn their secrets!). The best examples I have come across here in Perth is some old Italian gardeners who grow really inspiring veggies in their garden. Unfortunately I dont have the time to learn their secrets as I dont know any personally.

    Its a dying art to grow veggies at home. We are all succumbing to the convenience of the supermarket. But as you say, Duncan, the downside of this is we are loosing our relationship with nature, and hence so many diseases are increasing in society such as obesity, diabetes etc.

    Once again thanks for the time and effort for the trial. It really attracted me to your business. Hopefully you get a return on your investment. If anyone has some great examples of their home gardens that produce great supplies of veggies for home use then I would love to see them, and course know how you achieved it.

    Best regards,
    Eliott

  • Jeremy

    Urine! Organic and free!… maybe a little embarrassing for a publicised trial, but I’d be interested in the results.

    Great trials, very informative, keep up the good work.

    • Leaf, Root & Fruit Post author

      Hi Jeremy,

      Great suggestion, ‘wee-ll’ keep it in mind for a future trial 😉

      Good Luck & Happy Gardening

      Duncan

      • Edwin Schoell

        Hi, Duncan,

        Have established a small north-facing garden (6 by 10m) in Knoxfield (Melbourne suburb) and use raised beds with “Shrubbler” irrigation by computer (8 small streams of water in a circle, but NO misting onto leaves, and individual outlets can be trimmed for volume just by turning the rotating, threaded top. I have 18 sectors of watering. Also minimal blockage from dirt with easy cleaning just by unscrewing the top ring. Really great Australian product made in SA. Buy in 25 packs on eBay. Soil in raised beds is mix of garden loam and treated organic compost from local garden supplier …I get i m of each on a 2 m truckload.

        Re fertilizer, I have used Dynamic Lifter when planting for quite a few years with great success. I trowel a row of it along the seed path, dig in in and plant into the combined soil and DL.

        It is an organic pelleted slow release mix of chook poo, blood and bone and seaweed.

        Works well … wonder if you have done any tests with it.
        Cheers
        Ed

        • Leaf, Root & Fruit Post author

          Hi Edwin,

          Thanks for sharing your experience. I can attest to the great performance of shrubblers. We use them in the nursery for all of our potted plants.

          As for the Dynamic Lifter, no we haven’t trialed it. Glad you are finding it works well for you though.

          Good Luck & Happy Gardening!

          Duncan

      • JL

        Yes back to someone’s comment about organic matter High in nitrogen. I have two little boys who contribute a lot to my vegetable beds….. n that’s what traditionally a lot of Europeans and Asian uses…

  • Eric Dettman

    Keep up the good work . It’s great to be able to read a non biased informative examination and comparison of any products . Any plans to do anything with orchids or bromilliards

    • Leaf, Root & Fruit Post author

      Hi Eric,

      Thanks for the great feedback. Our focus is edible plants and as such we wont be doing any work with orchids or bromeliads.

      Good Luck & Happy Gardening!

      Duncan

  • Richard Scriven

    I found the results of your trial very interesting. My garden includes a number of plants in pots and hanging baskets with a high concentration of succulents and succulent types – cacti, Kalanchoe and Adeniums. Most are growing in a 50/50 mix of a good quality potting mix and Perlite. I am aiming for, and achieving, good drainage in accordance with most recommendations in the research I have conducted. To this point I have applied Seasol solution regularly (twice per month – or thereabouts) and occasionally (twice a year) paletised fertiliser. I live in Brisbane and we have experienced much hot, dry, weather of late. Consequently I have been watering more regularly. But my plants have not responded as well as I would like. I have come to the conclusion my regular watering might be rinsing most of the liquid fertiliser out of the potting mix. It seems your results add credence to my assumption. Whatever, I am going to change my approach and concentrate a little more on adding handful of palitised fertiliser to my potting mix and increase the application of this form of fertiliser to three, possibly four, times a year. Thank you for posting the results of your research. I found it easy to follow and highly credible.

    • Leaf, Root & Fruit Post author

      Hi Richard,

      Thanks for that great feedback. I’m glad you have found a way to relate it to your potted succulents.

      Good Luck & Happy Gardening!

      Duncan

  • Scott Campbell

    Thanks for putting this together. I have wanted to do something similar but lacked the effort!
    I am skeptical about the foilage spray from Seasol, which I currently use. I use the Osmocote pellets you have test above, plus seasol foilage spray to grow citrus in pots. Of course, the foilage spray is not tested in your experiment. Maybe this can be included if you decide to do a second round. You could also do some combinations of the products above, which would be interesting.
    I might take some inspiration from you and test 6 plants with Seasol foilage spray vs. 6 pkants with no foilage spray whilst keeping all other variables consistent.
    Best,
    Scott

    • Leaf, Root & Fruit Post author

      Hi Scott,

      Thanks for the great feedback. There’s certainly no shortage of potential products (and combinations) that we could test. There is however a limit of time, money, and space. We hope to conduct similar trials in the future but for now greenhouse space limits our ability to do so.

      Good luck with your own experiment. Please get in touch to let us know the outcome.

      Duncan

  • jasmine lindsay

    Thanks very much for conducting the experiments which is a benefit to all us gardeners.
    I have good success with my veg garden but this winter I am going to try and grow Basil inside in a pot that’s why I was wanting to buy the best potting mix.
    Most sites you search are all basically advertisers so I feel I am not getting a good comparison or full information
    Thanks again great work

    • Leaf, Root & Fruit Post author

      Hi Jasmine,

      Glad you found it useful. Good luck with the basil this winter. I hope it is successful for you.

      Duncan