Welcome to the first GROW Experiment!

Experiments(Last edited )
Naomi van der Velden
Naomi van der VeldenUnited Kingdom

The GROW Experiments aim to help you better understand your own growing practices and how to improve them and to answer key questions about sustainable growing practices on a broader scale.

This first experiment is designed to take place between August and October 2017, Citizen scientists like you will investigate if and how mulching (adding a layer of compost on top of the soil) affects key soil properties by comparing a plot of land with mulch added to one without to answer the following questions:

? Does mulching improve soils? ? How does location influence any effect of mulching? i.e. does it work better in some places than other places?

You can find out more about the experiment here and sign up here to take part.

This forum is the place to ask any questions about the experiment, to share your triumphs and frustrations and to celebrate becoming a citizen scientist.

We look forward to hearing from you.


Mary SUnited Kingdom

Hi, I can't find enough trays the same to do the soil moisture part. Does it matter if I use different size trays?

Thanks, Mary

Naomi van der VeldenUnited Kingdom

Thanks, Mary, that is a great question!

Because you weigh each empty tray separately it doesn't matter if they are a bit different to each other. Just make sure they are labelled first so that you know which is which when you weigh them again with soil in.

It is a good idea to use light trays where you can - trays from takeaways, or the plastic ones which you might buy veg in are great.

I hope that helps!

Thanks for taking part in the experiment and let us know if you've any other questions.

Best wishes, Naomi

Mary SUnited Kingdom

Hi Naomi, thank you for that. That is really helpful. My soil is now drying on the windowsil. Can't wait to see what the results are! #ExcitingSoil! I'm going to try this test in other parts of my garden too as I'm sure it is always damper at the bottom! Thanks, Mary

Heiko VermeulenNewtownards, United Kingdom

I was really looking forward to joining the mulching experiments, but I don't think my plot is suitable. I don't have any bare soil anywhere and nowhere far enough from shrubs and trees not to be impacted. I don't dig and barely weed, so it would be very difficult for me to even have a 50cm2 piece free of vegetation for very long, unless I mulch heavily. Also I don't think there is anywhere I haven't mulched at some stage during the last 3 years.

Valeri YordanovPlovdiv, Bulgaria

Hi GROW team, two questions:

  1. in the mail I got there is no link to "* Your personal recording and results spreadsheet:"?

  2. I don't have where to buy English mustard, here in Bulgaria.. Сan I use a substitute to drive the worms out.. for example in the drugstores here we have fine ground mustard flour made from Brassica nigra?

Naomi van der VeldenUnited Kingdom

Hi Heiko, The need to be away from shrubs and trees is desirable, but if you can't meet it, that is fine - there is space to let us know this.

The experiment is about soil, so there is a need to dig out soil from your plot to weigh it. It starts with taking some soil crumbs (aggregates) from just below the surface, and then some soil from below that for the soil moisture. So you would need to clear a patch to be able to do this. You don't need to dig it over first though, just remove some vegetation from the top. I hope that helps?

Kind regards, Naomi

Naomi van der VeldenUnited Kingdom

Hi Valeri,

Thanks for letting us know you didn't receive the link. I'm sorry about that. Something went wrong with the link in the first message I sent. You should have received another on Thursday with a proper link. I've sent it to you again though, just in case.

I'm going to check in on the mustard question. We had thought that it would be possible to buy it online. We'll get back to you when we know about alternatives.

Many thanks, Naomi

Alice AmblerDundee, United Kingdom

Hi Valeri,

It is not known whether brassica nigra would work, as all mustard powders are different. I would say that if you cannot get English mustard you could try using Brassica nigra instead. Another option is to use a mixture of washing up liquid and water. Use approximately 40ml of dish soap to the amount of water specified in the protocol. When you are adding your results to the online form, please just pop a note in the comments to say what you have used. If you could get back to us with how well either of these approaches have worked that would be fantastic!

Best wishes, Alice

Jaap BosmanNetherlands

Hi I did receive an email about the experiment last half of september, not august. Is it too late to start the experiment?