This is second part in the series I'd started here

https://www.gardenweb.com/discussions/6410966/gardening-concepts-explored-and-discussed-overstory-protection

I'm staring down the barrel of what could be a very serious drought. Something going on in the tropics with the ITCZ is apparently hampering the development of hurricanes, which are often the mechanism by which the east coast gets out of dry patterns and droughts. The CPC is not looking promising https://www.cpc.ncep.noaa.gov/

Nor is the tropics: https://www.nhc.noaa.gov/

Several 'areas' all rated 0-10% chance of development. What was predicted to be a strong hurricane season - something I took solace in back in May when the dry spell started - has almost completely fizzled out. Thank goodness for Debby, that at least made a dent back in early August.

The last time I had a late summer dry spell was all the way back in 2007! Although 2010, 2011 and 2012 had very hot, dry starts to summer, the all went into a wet pattern. Especially 2011 - late August to early October was the wettest period I'd ever had with over 30 inches of rain in 40 days! It killed a Rhododendron rex I bought in Washington State, that otherwise had survived the heat earlier in summer.

So getting the most out of my watering is important. If you water something and the water just runs off to spread on the surface of nearby soil or mulch, you're wasting your time. It's just going to evaporate before it reaches the plant's roots. For at least 10 years, I have been judiciously using the very mild surfactants called 'decyl glucosides' or 'coco glucosides' for this purpose. Both on plants in the ground and in pots. This was after a brief study to determine what would likely have the smallest ecological impact on the garden as a whole. They're very safe, having the EWG's best rating for use in cosmetics. Although they are not used in food, they are chemically very similar to the sucrose esters of fatty acids that are.

https://en.wikipedia.org/wiki/Sucrose_esters

https://en.wikipedia.org/wiki/Decyl_glucoside

There are commercially available products for this purpose, but I can guarantee you that they are more expensive than just buying the surfactants sold for use in personal care products. And, for example, one of them uses this chemical: https://en.wikipedia.org/wiki/Cocamide_DEA which is now a suspected carcinogen. (although, for various reasons I wouldn't take the IARC too seriously) In my general study of surfactants, I'd rather avoid the ones that contain nitrogen molecules like Cocamide DEA, and ones that contain aryl/phenyl moieties (related to the the aromatic hydrocarbons like benzene). These chemical structures are more often associated with toxic or endocrine disrupting side effects. Decyl glucoside, and laureth-3 that I've also experimented with but is somewhat unsettling to use because it is just soooo slick and slimy in its un-diluted form, do not. There's a theory I find compelling that, to the degree glyphosate has a toxic effect at all, it's actually the cheap amidated (i.e., nitrogen containing) surfactant that they added to the original "RoundUp" formulation. I have literally never used that. For years I've used the "Rodeo" brand of glyphosate, intended for wetlands, since my property does have wetlands, that has *no* added surfactant. I add my own that I know are safe and mild like methylated seed oil, sometimes adding a bit of decyl glucoside - not too much because it will foam. My yard still has scads of toads and frogs! (although, sadly, the dryness this year has caused them to retreat somewhat from the main areas of the garden, allowing slugs to proliferate) Clearly amphibian life hasn't been impacted by either the glyphosate or the mild oil and coconut based surfactants, but that's an unnecessary digression.

Some of you will say, "well, you could just use dish soap" or washing-up liquid as the Brits call it. And, sure you could. But then you're going to have all sorts of other things you might not want to be adding, that are diluting the product for your intended use, like preservatives, harsher sodium containing anionic detergents, skin moisturizers, denatured alcohol, etc. I suspect the economies of scale are such that if you quantify the per unit non-ionic surfactant 'wetting power', there's going to be no actual difference in cost. I have bought one gallon of this stuff about every 3-4 years, AND used it for other purposes around the house, too, like laundry. I once used a huge amount to clear my drain pipes when they became clogged with sand and soil. I think the average gardener could buy 16oz from cocojojo on amazon or wherever and get YEARS of use out of it. For a 2.5 gallon watering can filled about 70% full, I use one squirt from an old reused detergent bottle, which is about 5ml. JUST spraying a pint or two of this with the watering can, onto the root zone of the plants, means whatever the subsequent methods I use to drip irrigate (nowadays, often a 5 gallon pail with a tiny hole) goes right into the rootzone, without running off. BTW yes, mulch helps, but you have to be careful. I have done the drip on mulch, assumed it was going in, dug down and saw that the water was hitting the dry soil, and still running off under the mulch! Spreading, rather than soaking in!

Here's an interesting overview article of the topic.

https://jerry-coleby-williams.net/2007/02/27/wetting-agents-are-you-buying-trouble/

Although I'm not sure his recommendation of agar agar is very practical. Chemically, I would assume it's similar to the surfactant from yucca. If you really want something arguably more 'natural', I think that would be a better choice. Something like this.

https://www.amazon.com/Extract-Organic-wetting-surfactant-Concentrate/dp/B07TVKCLSG

Decyl glucoside is in the category he mentions of 'non-ionic surfactants'. They work fine but if you have experience with another category of surfactant like yucca, do share it!

It goes without saying, that even at higher use rates in some cases, I have never experienced even a scintilla of evidence that this chemical negatively impacted plant growth. In fact some plants seemed to 'take off' as I suspect hydrophobic soil was making it hard for even rain to penetrate the soil in some areas.

#originaldavidrt28posts