by Anna Lear

Now that the rains have begun, gardens everywhere seem brighter. Even plants on my drip system bolt after a deep rain, glowing a rich green unmatched during the dry season. Why is this? It’s the water – not just the amount but the quality.

Many plants including most vegetables and nursery flowers prefer slightly acidic water with a pH of 6 or so (7 is neutral). Well water throughout the southwest (whether individual or municipal) is alkaline, with a pH of 8 or above, because as normally acidic or neutral rainwater passes through earth it picks up calcium and magnesium salts that “harden” the water and create scale, a whitish residue that builds up on fixtures and clogs small openings such as screens and drip emitters.

Hard water also stunts plant growth because alkalinity lowers and even blocks plants’ absorption of key nutrients such as iron and zinc. Our water is so alkaline that non-adapted plants can’t get the nutrition they need, even when you water well and amend the soil with manure, compost, pine needles, and other good stuff. Have you noticed that some plants turn yellow after you put them in your garden, most noticeably on new leaves? This is chlorosis, caused by an iron deficiency that abates when we add a handful of Ironite to the soil, yet the problem returns not because the soil is iron-deficient but because the salts in alkaline water block much of that iron from getting to the plant tissues.

So when it’s not raining (and we don’t have a rainwater catchment system in place), how can we give our plants better water? The first step in addressing water issues is to test its pH. I use widely available pool/spa testing strips because they’re inexpensive and easy to use. In June I tested my Magdalena tap water at 8.4, well above the ideal for most plants’ growth. The next step is adding an acidic substance to counteract the tap water’s high alkalinity. I decided on white (pickling) vinegar, cheaply available at any supermarket and much safer for home use than other acids such as muriatic, sulfuric, or nitric (used in commercial greenhouses). It can be added to any liquid fertilizer, homemade or commercial, and applied to the garden by hand, hose-end sprayer, or fertilizer injector.

To calculate how much vinegar to add to my pH 8.4 water, I measured one gallon of water, added one tablespoon of vinegar, and tested it at pH 6.4, right in the target range. One tablespoon per gallon scales up easily, and I decided to test this formula with a batch of manure tea which, yes, is as gross as it sounds but is manna for young plants. I tossed a 5-gallon bucket of aged horse manure into an old pillowcase, tied it off, and suspended it in a 32-gallon trashcan full of water; after two days I pulled out the “tea bag” (keep it; it’s good for several batches), tested the solution (even with manure it tested at pH 8.4), and added two cups (32 tablespoons) of vinegar. The pH tested at 6.2, perfect for vegetables. Manure is nitrogen-rich, which promotes fast growth but not flowering or fruiting, so use this solution on young plants and make the solution with finished compost later in the season (like now) for fruit-promoting fertilizer.

I used a 5-gallon bucket to apply this lovely concoction to my struggling winter squash plants, which were barely a hand’s width after May’s strong winds and chilly nights. Now dozens of vigorous vines clamber over a 20-foot-long wooden fence and will give my family (and likely several others) a winter’s worth of organic squash and pumpkins. I also add vinegar to an even more fragrant concoction of liquid compost and fish fertilizer that goes through my drip system via fertilizer injector, a $60 apparatus I bought from Dripworks. If you water by hose, you can add vinegar and anything else using a hose-end sprayer such as the Ortho Dial-a-Spray, available locally at Ace Hardware, Raks, and Walmart (seasonally). Good luck, and enjoy your summer gardening!

Picture: A baby pumpkin will thrive with good water and strong support.

Anna Lear lives and gardens in Magdalena and is currently a family therapy intern at Southwest Family Guidance Center in Albuquerque. She blogs about gardening, photography, jewelry, and life in Magdalena at thelaughingraven.blogspot.com/.