My favorite chemistry gardening hacks

Veggie growing inspiring calendar, hand-drawn and designed by Long Island organic farmer Courtney Pure ( Print-out cheerfully colored, to work in my mostly white kitchen, by me.

It’s not too late to start working in the garden if you live in a temperate climate region.  In addition to growing herbs and fast-growing vegetables, you can start planning for an Autumn/early Winter harvest.  Here are some chemistry-based tricks to boost your confidence and your yield.

Soak seeds in tea or vinegar to promote quick sprouting.  Water awakens the dormant plant inside the seed, but it needs to permeate the protective seed coat, which is mainly composed of cellulose, to get there.  You can weaken the seed coat by puncturing it, but since you could damage the insides, I prefer soaking seeds in leftover tea or in vinegar overnight.  The acid gently breaks up the tight-knit, rigid seed coat structure via acid hydrolysis. For peas, beans and similar ‘seeds’, the protective pod has already been removed and the pea has been preserved by dehydration, so to become active again, the pea only needs to be rehydrated by soaking in water.  If conditions are good, you can get fresh peas pods from planting peas in 2 months.

Dip cuttings in cinnamon to promote rooting.  Salicylates promote rooting, and natural sources of salicylates can be used as natural rooting hormones [Int. J. Advanced Biological and Biomedical Research, Volume 2, Issue 6, 2014: 1883-1886].  If you have a salicylate intolerance/low tolerance, you already know these sources.  This post on rooting hormones for cuttings from PreparednessMama lists 6 of them: yourself, apple cider vinegar, cinnamon, honey, aspirin and willow extract.  I’ve had success dipping cuttings (like rose stems) or garlic cloves in cinnamon and sticking them in wet sand.

Ferment weeds to make a cheap, organic fertilizer.  While you could make a fertilizer from compost tea (taking a clump of composted material from your compost heap and adding water), if you don’t have good composted material at the moment, or if you want a strong, easily absorbed fertilizer, you can take the bounty from intense weeding and ferment it with water in a polypropylene or glass container for a few days or until bubbles stop forming.  Strain the liquid into a watering can and apply near roots.  Fermentation (digestion by microbes) frees nutrients, like potassium and magnesium ions, from the plant material.  This also occurs in soil at a slower rate.  Fermented stinging nettles make a rich fertilizer.

Create copper barriers to keep out snails and slugs.  There is some controversy over whether this works.  However, following the reasoning in this wiki and empirical evidence from this science fair project, I would say that copper barriers do work, but, contrary to the advice given by many popular gardening bloggers, the copper needs to be partially oxidized.  A thick copper band or woven fence allows for regions of elemental copper (copper(0) electrode; anode) and regions of cuprous oxide (copper(I) oxide electrode; cathode).   The electrolyte-rich fluid from the snail/slug completes the circuit (yikes!), but the current is low, so the snail is not killed.  I have copper tape around raised beds, but I have note seen snails/slugs interacting with it.  While the copper barrier is not a foolproof system, I still think that it is better than introducing snail poisons, like copper sulfate, into the garden.  Once, I found a perfectly intact dead mouse in the garden (part of country life), and I believe that he was poisoned after eating a poisoned snail.  On this topic, to naturally reduce the snail population, attract birds and rodents to your garden, but don’t put down poison.

Plant specifically colored flowers to attract bees.  I’ve seen bees on all colors of flowers, but their favorites seem to be blue and yellow, and they aren’t attracted to frilly red flowers.  Unlike us, bees interpret some ultraviolet wavelengths as color.  This is how bees see certain yellow flowers:  hidden patterns.

Practice good companion planting to reduce the number of pests.  Companion planting is simply planting plants closely together that help each other out, often by repelling pests (for example, releasing chemicals into the air) or by creating a better soil environment (for example, attracting beneficial nitrogen-fixing microbes).  A very nice thing is companion planting guides, like this one in Mother Earth News, created from many observations by many people over many years, so you don’t need to know the biochemical basis (only now being studied in many cases) to use this valuable resource.  I especially like how the strong scent of my catmint (Nepeta × faasenii) can repel most pests, including aphids, mosquitoes, ticks and mites.  It is also very drought tolerant and low maintenance, and the bees love the numerous tiny purple flowers.


How to wash dishes with plants and water

High-saponin Plant Tea Foam Soap

Step 1:  Obtain foam soap dispenser.  To be thrifty, I bought some foaming soaps in cute PP or HDPE plastic dispensers made for kids from the local supermarket.  They came with soap solutions that did not contain sodium laureth-sulfate (or lauryl-sulfate or coco-sulfate) but instead micelle-forming betaines and glycosides (saponins), which is the direction that I wanted to go in.  However, they also contained undesirable ingredients, like strong fragrances and preservatives, so I was eager to use them up and have empty dispensers to refill.  The dispenser is important, because the dispenser encourages a super foaming effect (many small bubbles) that isn’t normally found with the water-saponin solution (which forms large bubbles that disappear quickly).  As far as I know, any diluted soap/detergent/surfactant works with a foaming soap dispenser.  Diluting your dish soap of choice and using a foam dispenser saves both soap and water (no guesswork of the soap to water ratio after filling the dispenser).

Step 2:  Make high-saponin plant tea.  By ‘tea’, I just mean dried plant parts steeped in water.  Use cold or warm water and let steep overnight.  Right now, I am using soap nuts and orange ginger green tea steeped together.  The soap nuts have a high saponin content.  I am growing soapwort to potentially replace the soap nuts and be more self-sufficient.  Green tea also contains saponins,  like many plants, but in a much lower concentration.  The orange peel and ginger provide an antibacterial boost and also provide a pleasant scent (I think that soap nuts have an unpleasant fruity scent).  Orange essential oil, from the peel, is also a good degreaser.  While appropriate essential oils could be added later to the final product, I recommend using only scented teas and dried herbs and fruit to avoid adding too much of the essential oil (important to protect skin).

Step 3:  Strain plant tea into empty soap dispenser.  Filter everything through a cloth or filter paper, so small particles do not clog the pump.  Fill the dispenser a quarter of the way and test the foaming ability.  If the solution is too dilute/has too much water, squeeze some concentrated soap from the soap nuts or dump the liquid out and brew a stronger saponin tea.  Afterwards, fill the dispenser, leaving a quarter of the volume for air.

Step 4:  Use foaming soap to wash dishes.  This soap looks like a regular dish detergent when foamed up, but the bubbles disintegrate more easily.  I use a nylon brush, because it works well and does not need to be replaced often, and I am generally pleased with the results.  The soap works well for glass and plastic and rinses off easily (saving water).  The only problem I’ve noticed is that it, ironically, leaves stains on stainless steel.  However, the steel still looks nice.  It is shiny with a rainbow sheen, and this is probably an improvement (filling in pits in steel), but if necessary, can be removed with a baking soda paste.  The pH is close to neutral, based on a red cabbage indicator, but can vary depending on the plants used.

Disclaimer:  This post and blog fall under the heading ‘Personal Experiences’ and is meant to interest, educate and inspire.  All information and instruction is given without the intent to harm or control the reader in any way.


Eco-friendliness:  Soap nuts can be reused until they don’t produce bubbles anymore.  Compost the soap nuts and any tea used (with tea bag if biodegradable), but avoid putting saponins, soaps and oils near lakes and streams (harmful or deadly to fish).  Triterpenoid saponins, since they contain sugar-aglycone linkages, are easily degraded into the sugar and aglycone by acids, enzymes (via microbes) or high temperatures.

Personal Safety:  The soap is much gentler on my skin than most synthetic soaps, including the classic oil and lye synthesized bar soaps and excluding the potassium hydroxide synthesized liquid castile soaps (Dr. Bronner’s).  I used to have painfully dry, cracked skin on my palms, and after switching all the hand soaps to foaming soap nut and lavender oil soaps, my skin is much better and even heals cuts more quickly.  However, everyone’s skin is different, so make sure your skin agrees with all the plants used.  When I rubbed my eyes, they watered up, but returned to normal after some tearing and a few seconds.  Irritation seems to be the extent of the safety hazards.  Here is a helpful article on the uses of saponins, including its use as a pesticide and dermatitis remedy.

Food Safety:  Please use at your own discretion.  While I haven’t gotten sick from using this soap, I don’t drink it or leave it on dishes for a long time.  Many natural food plants contain saponins, including quinoa, yams, clovers, beans, legumes and grapes.  This does not mean that they are harmless but only that they are already in your diet.  This soap is extremely bitter, so it cannot (imaginably) be accidentally mistaken for a beverage.

Pots and Pans:  The burnt parts of pots and pans don’t come off easily with soap and water in general.  I don’t even ‘wash’ my pots & pans anymore.  They are heated while cooking enough to kill microbes.  In addition, microbial colonies form on wet surfaces, not dry oil surfaces (many fatty acids are actually antimicrobial).  I clean the pots and pans with a moistened homemade pot scrubber of a nylon stocking stuffed with jasmine green tea and double wrapped and tied.  Excess liquid is wiped with a paper towel or cloth until the pot shines again.