Providiing rainwater for seedlings and veggie beds

Providing Rainwater for seedlings and veggie beds by Barbara Wishingrad

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.


Mulch is a great ground covering that reduces weed growth and retains water in soil. Mulch can be used around trees and on paths, and helps stop erosion on slopes too. I cannot emphasize how often mulch is the solution to so many problems in a garden. 

There are numerous benefits to using mulch for your landscaping and gardening needs, especially in a year with such little rainfall like the current one:

  • Increases the soil’s organic content
  • Reduces water usage by minimizing evaporation
  • Controls soil erosion
  • Suppresses weed growth
  • Provides nutrients
  • Builds sound root structures

In Santa Barbara County, we have a wonderful resource through the County mulch program. Our community green waste is collected, composted in windrows to kill pathogens and unwanted seeds, and given away for free.

There is a free mulch pile located on the County road up to the Transfer Station, on the right side heading up, near the Hearts Riding Academy. Simply drive up with a pair of gloves and a garden fork and help yourself to as much mulch as you like.

Delivery of County mulch is also offered for a minimal charge, and City of Santa Barbara or Goleta Water District customers can get rebates for two deliveries of mulch every year.  Mulch can usually be delivered within one to two weeks of a request. Replenishing a garden with mulch twice a year is ideal.

There are two versions of the County mulch- unscreened and screened. The screened mulch breaks down quicker and needs to be replaced more frequently. Some small bits of plastic are sometimes found in either mulch, although in the past few years, the County has greatly improved their methods for detecting and eliminating this nuisance plastic in the mulch.

Learn more about this great community resource at

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