Improving clay soils in Melbourne Australia by adding Gypsum

Gypsum is a useful addition to many clay soils, particularly for gardens in the north and west of Melbourne, Australia.
Karen uses gypsum for several situations in her gardening and demonstrates some easy shortcuts to get the right quantity to use per square metre, and how to add it to an established garden bed.
Gypsum (Calcium sulfate) is a naturally occuring material and will not affect the pH of the soil.

[@WhatWeDoChannel]

Thanks for that! I’m going to start adding gypsum to my clay soil here in Ontario Canada. Party because I want calcium for my tomatoes and also because we don’t get free sulphur from acid rain any more. Apparently plant available sulphur really makes your veggies taste better! I think a good sprinkle works out to about 1KG per square meter, judging by how much you put down.

[@karensutherland-edibleeden1916]

Hi, be cautious when adding sulphur, as it usually works to make your soil less alkaline. You need to test your soil pH before adding sulphur. Gypsum is a great soil improver partly because it doesn't change soil pH. Happy gardening!

[@hiroyopoetker]

I don't know what American sources you thought are agains gypsum but we use it to help make the water and soil coincide better!

[@commissary4196]

Hey thanks for this. I’m in Fawkner and the clay is borderline impenetrable.

[@karensutherland-edibleeden1916]

I'm very familiar with that! Keep using gypsum and compost, it can take some years to succeed. I've worked in that soil for many, many years.

[@karensutherland-edibleeden1916]

I hear you! Thta's what my soil was like when I moved to Pascoe Vale South many years ago. It was harsh. But yearly gypsum, lots of compost and then the action of plant roots in the soil has all worked to improve the soil, so I can now grow things like avocados! All the best 😊

[@commissary4196]

@@karensutherland-edibleeden1916 yeh that’s awesome … I’m starting to get a bit more shade as well from established trees and I feel it’s made a massive difference. Also planting perennials that I don’t care much about to get the place growing

[@hiroyopoetker]

Thank you great video and wonder information! Its hard for me to find here in Jpn!

[@sun-man]

It's better to use a fork to penetrate deep holes into the soil then water the gypsum into the holes to get it to the root zones

[@karensutherland-edibleeden1916]

Hi Sun-man yes that is a good method, but it depends on the situation and how large the garden area is.

[@krisb9838]

Thank you for the direct and simple video

[@karensutherland-edibleeden1916]

Glad it was helpful! Cheers

[@phonicfrog]

This was really helpful, thank you ☺️

[@karensutherland-edibleeden1916]

Glad it was helpful!

[@ThatBritishHomestead]

I do use gypsum! :)

[@karensutherland-edibleeden1916]

Good on you, it's a great cheap garden product :)

[@michellemcdonnell5197]

Thankyou

[@karensutherland-edibleeden1916]

You’re welcome 😊

[@mewmew9097]

So helpful . I wanna prepare my backyard for new lawn. Now , the land is dry, hard, some big crack on it ,so looks clay soil. What is you recommendation? Remove the existing soil , or add gypsum on it , mix it and then seeding? Do I need compost on top of clay soil mixed with gypsum?

[@karensutherland-edibleeden1916]

Hi Mew mew, I prefer to improve the existing soil where possible to reduce the environmental harm of soil being mined and sold. My preferred method is to add gypsum to your exisiting soil, digging in lightly if possible then water in well and wait 2 weeks. Then add 25 mm of good quality lawn soil mix over the top, mixing it with the original soil a little. Rake this level. Finally, cover with 50mm lawn soil mix before seeding the lawn. Good-luck Karen

[@SimonFox999]

Thanks for this. I'm in Lilydale (Melbourne) and have quite difficult clay soil which is very waterlogged due to the wet summer we've had. I plan on planting some water loving natives such as Melaleucas, but before doing so, want to prepare the soil. Is it OK / is there a need to dig the compost / gypsum into the top layer of already wet clay? I seen advice that digging up wet clay can compact it further and cause more issues. Hoping that by adding the gypsum and compost, that would counteract that anyway?

[@karensutherland-edibleeden1916]

Sorry for slow reply. Refer to my other videos - ESSENTIAL INFO!! *How to plant grape vine or other ...etc and also *How to plant well with root pruning techniques *Staking young plants... It's true that working/digging in very wet soil can damage the structure, so we have always avoided working in soil at these times. It might be best to wait till drier weather in early spring as the weather warms, to avoid soil damage and plant waterlogging. When you can plant, the short answer is that you can just improve the soil in planting hole areas as outlined below, and spread gypsum and good organic mulch such as tree surgeon mulch over (no need to dig in, but do remove weeds first of course) the rest of the soil and let these additives gradually improve your soil. Also here's some info I just sent to another KZbin fan. "Never dig holes in clay soil that are deeper than your plant's root ball, as you will achieve what we call the 'kitchen sink effect' where the hole has water in the bottom of it and this can cause your plant to have 'wet feet', but always dig the holes twice as wide as the plant's root ball, to allow the roots to spread and establish quickly. Also, deciduous trees such as figs are fine to plant in winter in Victoria, but NOT lemons or other warm climate plants such as passionfruit. They should only be planted in mid spring as the weather warms. Add gypsum to your planting holes and mix some more gypsum and also good quality compost into the soil as you plant (note re compost, if homemade, MUST be fully broken down to avoid root burn). Refer to my planting videos - How to plant grape vine or other ...etc and also How to plant well with root pruning techniques ESSENTIAL INFO!!" Hope this is helpful. All the best

[@ben_jamin91]

Can I plant new plants straight after treating with Gypsum? And for lawns, just spread it over the grass and water in?

[@karensutherland-edibleeden1916]

Hi Ben, As long as the gypsum is mixed in well with the soil it is fine to plant straight away, although bear in mind it takes around 2 weeks for the drainage to improve from the gypsum. Lawns MUST have a lower rate of gypsum, 50 grams per m2, to avoid smothering the grass. No one told me this years ago and I learnt from experience, :(

[@gman8393]

Hi thanks for the great content I am in Geelong. I will be planting a fig and lemon tree, I have dug a large hole 20 inch deep and hit clay as usual. what is my best option now for tree health and longevity?

[@karensutherland-edibleeden1916]

Thanks and, sorry for slow reply. Refer to my other videos - ESSENTIAL INFO!! *How to plant grape vine or other ...etc and also *How to plant well with root pruning techniques *Staking young trees Never dig holes in clay soil that are deeper than your plant's root ball, as you will achieve what we call the 'kitchen sink effect' where the hole has water in the bottom of it and this can cause your plant to have 'wet feet', but always dig the holes twice as wide as the plant's root ball, to allow the roots to spread and establish quickly. Also, deciduous trees such as figs are fine to plant in winter in Victoria, but NOT lemons or other warm climate plants such as passionfruit. They should only be planted in mid spring as the weather warms. Add gypsum to your planting holes and mix some more gypsum and also good quality compost into the soil as you plant (note re compost, if homemade, MUST be fully broken down to avoid root burn). All the best

[@gman8393]

@@karensutherland-edibleeden1916 Thank you

[@maxpain7197]

Gypsum is calcium sulfate. Sulfate is sulfer. Sulfer lowers your PH. Might want to look it up before you give false information.

[@karensutherland-edibleeden1916]

OK, let's sort this out as gypsum is a really useful product. Let's look at chemistry. When elements are combined with each other, they change and have different properties to the original elements, such as calcium or sulfur. But don't take my word for it, here's Iowa State University crops.extension.iastate.edu/encyclopedia/gypsum-old-product-new-use#:~:text=Gypsum%20is%20the%20neutral%20salt,not%20increase%20or%20decrease%20acidity. In the first paragraph, these lines explain it "Gypsum is the neutral salt of a strong acid and strong base and does not increase or decrease acidity. Dissolving gypsum in water or soil results in the following reaction: CaSO4·2H2O = Ca2+ + SO42- + 2H2O. It adds calcium ions (Ca2+) and sulfate ions (SO42-), but does not add or take away hydrogen ions (H+). Therefore, it does not act as a liming or acidifying material." Hope that helps!

[@maxpain7197]

@karensutherland-edibleeden1916 Ok your right. Sheesh... I do use it every year in my garden and has really helped the soil. I did notice that it did not decrease the PH. And have been adding elemental sulfer to correct the problem. It has definitely helped with my clay like soil since it sits more on the alkaline side. Along with ammonium sulfate.

[@karensutherland-edibleeden1916]

@@maxpain7197 Yes, our clay soil in northern suburbs of Melbourne tend to be alkaline too, but I've found from adding lots of homemade compost over many years the pH has corrected to neutral (compost often being acidic). Glad to hear the gypsum has helped you - its so cheap so its a no brainer if it works for you! Good to unpack the details with you 😀

[@WW11110]

Savage. Love it. ​@@karensutherland-edibleeden1916