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Horticulture/Wetting agents


QUESTION: Our village has increased water restrictions again, so we can only irrigate twice a week (except for watering by hand). Problem is, much of our garden is a steep slope and the water tends to run off the sandy soil.

I Googled "horticultural wetting agents," but most are for foliage application of insecticides, oils, etc., and not good for the roots. I did find one specifically for increasing water penetration into soil, but it is for golf courses and is sold in 55-gallon barrels.

Do you know of any wetting agents for use in home gardens?


ANSWER: Hi Janet,


There is a polymer which looks like salt crystals when applied, but absorbs 200 times its weight in water, then looks like gelatin. It comes under several brand names, ie Soil Moist, Miracle Grow, etc.  You can order it from Amazon, or call around to find a local carrier in your area.  

It's not expensive, either, and a little bit goes a looong way.  I put a couple of tablespoons into a large planter, and ended up with a 5 gallon bucket of jello which overflowed the pot after a rain.

The thing that concerns me is that they take about 3-9 years to breakdown.  So, what happens if you get a lot of rain, and want the soil to dry out??  I have to admit, I can't find anything on the net about them killing plants by keeping the soil too wet.  

My advice is to do a little research before using, and maybe test it on a small area before incorporating it everywhere.  

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QUESTION: Soil Moist isn't the kind of product I had in mind. The problem isn't so much retaining water as getting the water to the root zone in the first place. The soil gets so dry, it repels water. I'm looking for something that will allow the water to soak into the soil, rather than bead up and roll off.

Some people put a little dishwashing liquid in water to reduce surface tension. The treated water is readily taken up by the soil, but I suspect detergent isn't good for the plants in the long term. I've seen other recipes for homemade soil penetrants, but again, what are the long-term effects?

Golf courses and professional groundskeepers use commercial soil penetrants, but these are not generally available to home gardeners, despite the interest (and need) for water-wise gardening. Any idea why? Is it too easy to kill off plants through over-use?

Hi Janet,

As I live in Louisiana, I don't encounter this problem much, so I doubt I know more than you do about it.  I found the same info on the net as you seem to have already.  Liquid dish soap probably would not be good to use on a regular basis, as all soap is antibacterial.  I found something called "Moisture Manager".  It is a blend of sugar alcohols, polysaccharides, and food acids affixed to a granular substance like corncob.  I'm including a link below with all the info, MSDS, etc.  It takes 3 weeks to begin working, lasts about 3 months.  You can buy it on Amazon.



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Susan Tabor


Entomology,plant pathology, agronomy, native plants, useful and edible plants,medicinal plants,landscape design and installation, plant taxonomy and identification, cultivars and varieties, Botany, nutrient deficiencies, plant recommendations and troubleshooting.


35 years as a professional horticulturist and landscape contractor. I have a network of contacts at leading universities and with acknowledged experts in the field. I've restored the landscapes of several plantations, 2 Governors mansions and owned/managed 3 nursery/garden centers. I discovered a new subspecies of Emelia in 1997. I've locally introduced several native or volunteer species into mainstream landscape design.

Morning Advocate The Register Better Homes and Gardens All Experts - Approx 1996-97

Louisiana State University - horticulture David L. Hoffman - California - phytotheraphy

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