Plants used to wilt noticeably in the hot afternoons even during non-record breaking summers. It was always such a sad sight that I used to avoid the garden during that part of the day. But now, well into what will likely turn out to be the hottest year yet on record here on Planet Earth, my humble veggies are basking and flourishing.
The Five-Step Drought Busting System works.
Although the portentously titled "System" is just a collection of simple practices that many gardeners follow, I believe it is the combination of five techniques that is making a noticeable difference in keeping the plants happy. Here's how it all fits together.
Step One: Add lots of organic matter to the soil, and
Step Two: Don't dig!
Add organic matter and don't dig????? But . . . but . . . how??? Simple. Just layer it on. This approach works just fine for Mother Nature. Go to a forest and take a look at what's going on beneath your feet: you will see layers and layers of leaf litter covering dark, rich, moist loam.
A statistic I've seen quoted frequently states that for every one percent increase in organic matter in an acre of ground, an additional 16,500 gallons of water can be held in the top one foot of soil. That's a lot of liquidity! And all that water stays in the soil.
I once saw a demonstration (most likely in Debra Koonz Garcia's wonderful film Symphony of the Soil) by a scientist who had set up four clear plastic cylinders of different types of dirt. He ran water through the cylinders to show which soil types held water and which did not. Soil with plenty of compost held nearly all the water poured on it and the little bit that trickled through was clear, showing that nutrient-laden silt was not washing away.
Even more convincing is the experience of Paul and Elizabeth Kaiser of Singing Frogs Farm in Sebastopol, California. They use massive amounts of compost on their three acres of vegetables to produce numerous harvests per year. After five years of building soil they have reduced their water use by more than 50% and their ponds and run-off are "almost crystal clear." Tests by experts have shown that their storm water run-off shows no leaching of excess nutrients to pollute waterways, confounding conventional wisdom about heavy use of compost.
The secret to the remarkable results at Singing Frogs Farm may well be the Kaiser's no-till philosophy. The active approach of adding massive quantities of organic matter is balanced by a passive avoidance of tilling or digging. The hands-off dig-free style allows the billions of life forms in rich soil to flourish. An intricately patterned living web holds on to the water and prevents leaching.
Bringing this data down to earth in our backyard means that the summer plantings -- about 100 square feet of ground -- should be holding plenty of moisture and retaining plenty of nutrients after a couple of years of intensively layering on various types of organics:
- chopped up cover crops such as fava beans and mustard
- fallen leaves
- yard debris
- small amounts of manure
- small amounts of organic fertilizers
- rock powder (for minerals)
- lots and lots of compost.
The only digging implement used is a trowel to loosen up the top few inches of soil right before planting.
Step Three: Install Drip Irrigation
Drip irrigation delivers a slow steady trickle of water right to the root zone of a plant and is nearly 100% efficient: pretty much all of the water reaches its objective and is not lost through evaporation or run-off. By contrast, overhead watering is thought to be about 50 to 70% efficient. Drip irrigation works even better with rich soil that holds the moisture in place so thirsty roots can make the most of it. Despite all that, until very recently I never used a drip system, preferring to water by hand with a spray nozzle on a long hose. I couldn't face the myriad tiny plastic parts and teeny hoses that have to be meticulously assembled and maintained.
Then I found the marvelous "Snip and Drip" irrigation system from Gardener's Supply. Nice fat soaker hoses with Tinker-Toy sized plastic connectors are so easy to assemble a kindergartner could do it and even a senior citizen has a good chance of success. Included in the package is a length of regular hose. Both the soaker hose and regular hose can be cut with scissors (that's the "Snip" component) so the pieces can easily be customized for a raised bed garden. Sections of regular hose run across the paths and link together the raised beds outfitted with lengths of soaker hose (the "Drip" component). Very sweet! Plus, it can all be disassembled and reconfigured as needed from one season to the next.
Step Four: Make Some Ollas
Oh-yahs, oh yes! Ollas are unglazed clay pots sunk into the ground and filled with water that will be sought out by the roots of nearby plants. It's an ancient system thought to have originated in Africa, with the first written record coming from the Fan Sheng-chih Shu, a guide for farmers compiled more than two millenia ago in China.
In case you are wondering why an African or Chinese system has a Spanish-sounding name, our modern terminology is derived from the Latin word for "pot," olla, which passed unchanged into Spanish, The word, plus the technique was brought to the Southwest USA by the early explorers and taken up by Native Americans.
It is now re-emerging in our water starved regions of the West. The research is advancing as well, proving the extreme efficiency of a system where every drop of water goes straight to roots that need it and not a single drop is wasted. A good overview of the method (lots of research citations and further reading) is to be found at the Permaculture Research Institute website.
When I first started using clay pots several years ago I felt like an early explorer myself, trying out something known only to readers of obscure gardening blogs and permaculture websites. Now ollas are to be found at local nurseries and hardware stores or online from a variety of sources. As they are not only amazingly efficient but amazingly pricey, I still make my own from cheap clay planting pots stoppered with rubber corks and lidded with the pot's own overflow dish.
In our summer garden each plant of tomato, zuccini, and cucumber has at least one sunken pot to ensure a reliable supply of water through the heat of the day.
Step 5: Mulch, Mulch, Mulch
The last step in the Five-Step Drought-Busting System is to add a thick layer of mulch such as dry straw which covers the other elements: the rich undug soil holding moisture like a sponge, the soaker hoses tricking water sparingly into the sponge, and the sunken pots of hidden water nourishing thirsty roots directly. A thick mulch helps to keep the whole garden bed moist and prevent the small percentage of evaporation that occurs from the drip irrigation lines and the unglazed clay pot lids that remain above the surface of the soil.
Mulch is almost a religion with some gardeners for very good reasons. In general, it's a good idea to avoid bare soil. Nature abhors a vacuum and Mother Nature abhors uncovered ground.
The final step is to go out on a searingly hot day and enjoy looking at your happy plants!!