Now is the time to start thinking about rainwater storage for starting your productive spring garden. Rainwater is the perfect medium to enhance growth in veggie seedlings as you prepare them for planting in the ground.
Rainwater is much purer than tap or even filtered water. does not contain chemicals like chlorine, fluoride, calcium and magnesium so common in the hard water in this area. It also contains more oxygen than tap water.
“But what's the point- there’s no rain!” - people cry. Well, all the more reason to get water harvesting set in place. Rainwater Harvesting is especially beneficial in low rain years. I have previously explored the wonders of rain gardens in our projects and other articles on this website. For right now, I want to focus on rainwater storage for a specific purpose -irrigating seedlings and your veggie beds.
In recent years, we have had even less rain than usual. However, it’s still true that for every 1000 sq feet of roof, you can capture and store 600 gal in every 1-inch rain. Santa Barbara received approximately 7 inches of rain during the current rain year, which means that on a 1000 sq ft roof, we could have captured and stored 4200 gallons. On a 350 sq ft section of roof, that number would be about 1400 gallons.
For many years, I urged storage of rainwater only in the soil and not in tanks, because it would be expensive and cumbersome to try to capture enough rainwater to satisfy irrigation needs throughout our typical dry season. However, I have moved beyond that black-and-white thinking. Instead of thinking of the amount of storage for that huge undertaking, I have started to think about using rain tanks for specific purposes for which a much smaller amount is needed. Using rainwater for irrigation seedlings is one of those purposes.
Rain barrels capture so little water at a time that most of it is lost, unless the overflow is directed into the soil. Even so, the amount of water stored in a barrel is not really enough to do any significant gardening.
However, because we typically have dry spells in between rainy periods, we could get a 530 or 600-gal tank, either which is fairly reasonable, use some of it between rains, and still have a full tank at the end of the rainy season- enough to use liberally to start a vegetable garden and give those productive plants the best water source possible. We won’t be able to rely just on rainwater for the whole growing season, but we can give those productive plants a good start, and irrigate them with rainwater for at least part of the year. This size tank could also provide some water on hand in case of emergencies.