Lavender Experiment

[cdh]

I've been watching videos by Gary Matsuoka and a few others about mineral-based soils (Grows Gone Wild and The Graft Man are two others). Gary's theory is that organic matter in containers decomposes, depletes oxygen, and leads to anaerobic decomposition. The roots are then starved of oxygen and get root rot from the anaerobic conditions. This doesn't affect things like tomatoes or figs as much as other plants, like English lavender, that need a lot of oxygen around their roots. English lavender apparently needs the most root-level oxygen and is the most susceptible to root rot of any plant Gary has studied. And it's well known as a plant that can die from "overwatering"/letting the root zone stay wet.

So I have devised a study--not really a bona fide scientific experiment--to see if my results match what Gary and the others would predict.

I got a small English lavender plant from a nursery. I rinsed off all the wood and compost it was planted in from around the root ball. I then replanted it in a mix of sand, leca balls (clay), and a little bit of peat. Peat, while organic, breaks down much more slowly than wood does, and so this soil mix would be considered mineral-based.

I'm going to try to keep the lavender pot almost completely waterlogged with tap water. Since tap water is aerated, this should allow enough oxygen to get to the roots.

If Gary's theory is correct (and if I don't kill the plant some other way), the lavender should thrive despite being almost continuously "over watered." And the directions on the lavender plant tag to let the plant fully dry between waterings should be rendered moot (at least with my chosen soil composition). I'll try to post results every now and then for anyone who cares to follow along.

Here is the English lavender plant on Day 2, about 20 hours after transplant (with a 4x9 tree pot for comparison):



Note that the clear plastic tray is filled to the brim with water.

I'll put it in full sun in a day or two.

A potential confounder: I put some Osmocote in the pot. It could theoretically break down more quickly immersed in water than is intended, which could burn the roots or make the water too saline.

 

[Jigfig]

I've been watching videos by Gary Matsuoka and a few others about mineral-based soils (Grows Gone Wild and The Graft Man are two others). Gary's theory is that organic matter in containers decomposes, depletes oxygen, and leads to anaerobic decomposition. The roots are then starved of oxygen and get root rot from the anaerobic conditions. This doesn't affect things like tomatoes or figs as much as other plants, like English lavender, that need a lot of oxygen around their roots. English lavender apparently needs the most root-level oxygen and is the most susceptible to root rot of any plant Gary has studied. And it's well known as a plant that can die from "overwatering"/letting the root zone stay wet.

So I have devised a study--not really a bona fide scientific experiment--to see if my results match what Gary and the others would predict.

I got a small English lavender plant from a nursery. I rinsed off all the wood and compost it was planted in from around the root ball. I then replanted it in a mix of sand, leca balls (clay), and a little bit of peat. Peat, while organic, breaks down much more slowly than wood does, and so this soil mix would be considered mineral-based.

I'm going to try to keep the lavender pot almost completely waterlogged with tap water. Since tap water is aerated, this should allow enough oxygen to get to the roots.

If Gary's theory is correct (and if I don't kill the plant some other way), the lavender should thrive despite being almost continuously "over watered." And the directions on the lavender plant tag to let the plant fully dry between waterings should be rendered moot (at least with my chosen soil composition). I'll try to post results every now and then for anyone who cares to follow along.

Here is the English lavender plant on Day 2, about 20 hours after transplant (with a 4x9 tree pot for comparison):

View attachment 20056
View attachment 20055
Note that the clear plastic tray is filled to the brim with water.

I'll put it in full sun in a day or two.

A potential confounder: I put some Osmocote in the pot. It could theoretically break down more quickly immersed in water than is intended, which could burn the roots or make the water too saline.

I have zero interest in growing lavender myself, but the rest of the experiment interest me. I know lavender is just being used due to its susceptibility. I want to say someone on the site we don’t name grows lavender if you are a member over there they may have some insights to add as well. Could be completely wrong too lol.

 

[cdh]

I have zero interest in growing lavender myself, but the rest of the experiment interest me. I know lavender is just being used due to its susceptibility. I want to say someone on the site we don’t name grows lavender if you are a member over there they may have some insights to add as well. Could be completely wrong too lol.

I don't go to the other site if I don't have to ... Lol. I'll take a look.

 

[IAK]

I've been watching videos by Gary Matsuoka and a few others about mineral-based soils (Grows Gone Wild and The Graft Man are two others). Gary's theory is that organic matter in containers decomposes, depletes oxygen, and leads to anaerobic decomposition. The roots are then starved of oxygen and get root rot from the anaerobic conditions. This doesn't affect things like tomatoes or figs as much as other plants, like English lavender, that need a lot of oxygen around their roots. English lavender apparently needs the most root-level oxygen and is the most susceptible to root rot of any plant Gary has studied. And it's well known as a plant that can die from "overwatering"/letting the root zone stay wet.

So I have devised a study--not really a bona fide scientific experiment--to see if my results match what Gary and the others would predict.

I got a small English lavender plant from a nursery. I rinsed off all the wood and compost it was planted in from around the root ball. I then replanted it in a mix of sand, leca balls (clay), and a little bit of peat. Peat, while organic, breaks down much more slowly than wood does, and so this soil mix would be considered mineral-based.

I'm going to try to keep the lavender pot almost completely waterlogged with tap water. Since tap water is aerated, this should allow enough oxygen to get to the roots.

If Gary's theory is correct (and if I don't kill the plant some other way), the lavender should thrive despite being almost continuously "over watered." And the directions on the lavender plant tag to let the plant fully dry between waterings should be rendered moot (at least with my chosen soil composition). I'll try to post results every now and then for anyone who cares to follow along.

Here is the English lavender plant on Day 2, about 20 hours after transplant (with a 4x9 tree pot for comparison):

View attachment 20056
View attachment 20055
Note that the clear plastic tray is filled to the brim with water.

I'll put it in full sun in a day or two.

A potential confounder: I put some Osmocote in the pot. It could theoretically break down more quickly immersed in water than is intended, which could burn the roots or make the water too saline.

Man, Gary won’t like this then. I started using straight G&B Soil Conditioner for potted trees starting last spring. 3 apricots, 1 peach, 1 mulberry, 2 cherry, and 2 plums. I got them all as whips in the mail, and planted them in 7 gal plastic pots. Straight soil conditioner, no peat, no perlite, no compost. Fertilized with fish emulsion and Jack’s 20-20-20. I experienced great growth.


I just grabbed one for a picture. You can see the summer heading cuts I made to make scaffolds. From the bottom of the pot to the top of the branch is over 6 ft. I need to prune it a bit more. They probably would have grown even better if we didn’t move in the middle of summer (they were ignored for awhile). I started some Desert King cuttings in August in the soil conditioner too. Filled some tree pots and shoved them in. They did good as well.


I’m not discounting Gary’s theory. I have grown in Gritty Mix (1-1-1 bark, perlite, Turface), straight compost, and any number of homemade potting mixes with different ratios of peat, coir, vermiculite, perlite, pumice, bark, expanded shale, manure and compost. I’ve made roots rot in 100% Optisorb because you were not supposed to be able to overwater it. They all had their pros and cons. It just came down to technique and watering practices that changed.

 

[IAK]

BTW, I’m growing lavender too. Hoping it will last as a perennial up here, otherwise I’ll stop.

Hidcote Lavender from seed.

 

[cdh]

Man, Gary won’t like this then. I started using straight G&B Soil Conditioner for potted trees starting last spring. 3 apricots, 1 peach, 1 mulberry, 2 cherry, and 2 plums. I got them all as whips in the mail, and planted them in 7 gal plastic pots. Straight soil conditioner, no peat, no perlite, no compost. Fertilized with fish emulsion and Jack’s 20-20-20. I experienced great growth.
View attachment 20084
View attachment 20087
I just grabbed one for a picture. You can see the summer heading cuts I made to make scaffolds. From the bottom of the pot to the top of the branch is over 6 ft. I need to prune it a bit more. They probably would have grown even better if we didn’t move in the middle of summer (they were ignored for awhile). I started some Desert King cuttings in August in the soil conditioner too. Filled some tree pots and shoved them in. They did good as well.
View attachment 20086

I’m not discounting Gary’s theory. I have grown in Gritty Mix (1-1-1 bark, perlite, Turface), straight compost, and any number of homemade potting mixes with different ratios of peat, coir, vermiculite, perlite, pumice, bark, expanded shale, manure and compost. I’ve made roots rot in 100% Optisorb because you were not supposed to be able to overwater it. They all had their pros and cons. It just came down to technique and watering practices that changed.

Nice work. I think it definitely makes sense that whatever medium you use, you should water the right amount for that medium. That's probably the key.

 

[cdh]

Man, Gary won’t like this then. I started using straight G&B Soil Conditioner for potted trees starting last spring. 3 apricots, 1 peach, 1 mulberry, 2 cherry, and 2 plums. I got them all as whips in the mail, and planted them in 7 gal plastic pots. Straight soil conditioner, no peat, no perlite, no compost. Fertilized with fish emulsion and Jack’s 20-20-20. I experienced great growth.
View attachment 20084
View attachment 20087
I just grabbed one for a picture. You can see the summer heading cuts I made to make scaffolds. From the bottom of the pot to the top of the branch is over 6 ft. I need to prune it a bit more. They probably would have grown even better if we didn’t move in the middle of summer (they were ignored for awhile). I started some Desert King cuttings in August in the soil conditioner too. Filled some tree pots and shoved them in. They did good as well.
View attachment 20086

I’m not discounting Gary’s theory. I have grown in Gritty Mix (1-1-1 bark, perlite, Turface), straight compost, and any number of homemade potting mixes with different ratios of peat, coir, vermiculite, perlite, pumice, bark, expanded shale, manure and compost. I’ve made roots rot in 100% Optisorb because you were not supposed to be able to overwater it. They all had their pros and cons. It just came down to technique and watering practices that changed.

I should say, Gary would agree that starting plants in compost, bark, etc., is as fast as anything at promoting early growth. If it didn't work, wholesale nurseries wouldn't use it. As far as I can tell, the damage doesn't theoretically occur until later on in a plant's life. For short-season annuals--again, with the *theoretically* caveat--organic matter in the potting medium shouldn't make much of a difference. For oxygen-loving trees like avocados, being planted in this stuff can kill them after 3 or 5 years, so the theory goes.

Also, I think figs can tolerate being planted in almost anything.

I should also point out that I had lavender plants that thrived in regular potting mix in a raised bed in Southern California, but I think it was because the medium was often dry between waterings given the desert heat and aridity.