Rainwater Quality: Why Plants Love Rainwater Best

by Jesse (Froehlich) Savou, ARCSA A.P.

Rainwater quality is better for plants than water from any other source. Learn the four reasons why!

Imagine walking through your garden after a fresh rain. Thirsty plants doused in droplets fallen from the sky, their leaves expertly channeling moisture down stalks and into the soil—right to the root zone where it is needed most.

Greens are vibrant, and so are the color-pops of flower petals. The soil is moist and alive. This is a happy garden!

While it might not come as a surprise that there's no water plants love better than rainwater, do you know the four (4) reasons why?

Read on to learn about the water quality benefits of rainwater for garden. Listen to our podcast feature expanding on this topic and more!

Four Rainwater Quality Benefits

YoungPlantsLoveRainwater

Why is rainwater such a preferred water source? There is more than just one reason—in fact there are four!:

1. Rainwater is 100% soft water

Free of the salts, minerals, treatment chemicals, and pharmaceuticals that are found in municipal water, groundwater, and surface water, rainwater is pure hydration. Salts and chemicals build up in your soil over time and these residues are tough on plants. This effect is exaggerated in potted plants where the accumulation is more pronounced.

2. Rainwater is slightly acidic—naturally!

Green gardeners know that most organically grown plants prefer soil pH levels between 5.5 and 6.5. This is on the acidic side of the neutral pH 7, and by nature's design, it is the exact pH range for rainwater. City water, on the other hand, is treated to be alkaline to protect metal pipes from corroding, and can have a pH level upwards of 8.5. Greywater (once-used household water from a laundry machine, shower, or bathroom sink) will start with the same pH as your tap water, but can have a pH as high as 10.5 once it gets to the garden depending on the types of soaps and detergents that are in it. Irrigate with rainwater to flush out your soil and help keep your soil pH in perfect balance ongoingly!

 

3. Stored rainwater contains some organic matter

If collected from your rooftop, rainwater contains traces of organic material. While the water is very clean and should run clear, it has been exposed to anything on your roof. We're not talking about chunks (these get pre-filtered out on their way into properly-designed rain barrels)we're just talking about contact exposure to leaf litter, pollen, bird droppings and the like (which perhaps not surprisingly are great for your plants). A rain barrel hosts a beneficial biology to keep the water alive—literally. It's like a light application of fertilizer every time you water!

 

4. Rain contains nitrates—an important macro-nutrient

Rainwater contains nitrates, the most bio-available form of nitrogen. Nitrogen is one of the three key macro-nutrients that plants need to thrive, necessary for the development of lush foliage. That said, many forms of nitrogen are not actually absorbable by plants. Nitrates, which are made up of nitrogen and oxygen, are formulated by nature for maximum uptake by your plants. Plants typically absorb most of their nitrates from the soil. And where do those nitrates come from? Rain!

Plants have very unique ways of gathering moisture from the air and delivering it to their root zones. Nature's design!
Plants have very unique ways of gathering moisture from the air and delivering it to their root zones. Nature's design!

On a personal note, before I discovered rainwater, I doubted I would ever be able to keep a house plant alive. I had somewhat better luck outdoors in the garden, but little did I know that the potted plants were really suffering from the salt, chemical, and mineral buildup of tap water. Then I learned about watering with rainwater.  Rainwater straight from my rain barrels into a watering can is what I use for my potted plants and nursery starts. A gravity fed drip line allows me to apply rainwater directly to my in-ground garden with no effort at all. And what a difference it makes. Suddenly I have a green thumb... but (shhh, don't tell.... rather, tell EVERYBODY!) : the secret is the water.

Plant health is just one of the many benefits of harvesting rainwater. Click here for a handful of great reasons to collect the rain that falls on your roof!

Summer Inspiration: Why Summer is the Best Time to Install a Rainwater Collection System

Summer is upon us and depending on where you live, rain may be the last thing on your mind. In the arid western United States, skies can be dry from May to October with only the occasional off-season storm.

In the rest of the country, however, rain falls much more regularly throughout the year, with summer storms recharging rain barrels at intervals – perfect for irrigating during the short “droughts” between rains.

USA Climate Precipitation Graph

The red line on the right shows precipitation in the arid west (San Francisco, to be exact!), with the green band showing the more even distribution of precipitation throughout the USA on average. The graph on the left shows those soaring summer temps!

 

Ice Cold LemonadeBut regardless of where you live, this article makes the case that summer is your absolute best bet for seeing your rainwater harvesting project through to completion.

Just imagine pitching your shovel at the end of a warm summer evening, drawing up a glass of cold lemonade (or brewed beverage of choice!), and admiring a rainwater catchment system that’s ready for the rainy season…. and every cell in your body exclaiming: Ahhhhhhh that feels good!

Knowing you’re protecting the environment, getting prepared for emergencies, increasing self-sufficiency and resilience in your garden, providing the highest quality water possible for your plants, and saving money on your water/sewer bill are all part of the equation; but finishing a well-thought-out summer project just plain feels great. With long days to think, plan, and play in the garden, now is your chance.

 

Why is summer the best time to build a rainwater catchment system?

 

1. You’ve got time to plan

It doesn’t need to be complicated, but some folks like to do a careful job sizing and siting a rain collection system. Find the perfect spot, figure out how much water is available from your rooftop, think through your layout, and order your materials! We surveyed our customers this year, and found that most spend 30 – 90 minutes on our website customizing their BlueBarrel System, so it’s best to get a head start. Summer days are long, and many of us have lighter work and school schedules during the summer holidays.

2. You’ve got dry ground to build on

Even though this project is all about rain, the truth is, nobody wants to be rained on while

Summer Garden Work

Summer’s the time for garden projects!

they’re working. Installing a BlueBarrel System is an intermediate-level DIY project. If you have any leveling to do, you’ll want dry ground to work with.

3. You’re all set and ready for fall’s first catch (in the west)… or the next summer storm (for the rest)!

At the solstice, summer can feel like a long lazy road stretched out in front of us. But as June turns over to July, suddenly August is near and it’s almost time to resume the busy autumn bustle. Once those fall rains return, you’ve lost your chance to harvest autumn’s first rainfall. Remember that cold lemonade (or brewed beverage of choice)? It’ll taste better in the summer after you’ve triumphed over this incredibly worthy project.

3. You won’t have to wait in line

Many folks contact us right around the time of the first autumn rain hoping to make the best of the year’s capture. The truth is by that time, once you figure your sizing, siting, budget, and path forward, you’ve missed the first set of storms. Then you have to find some dry days to install the system when everybody in the rainwater world is scrambling. If you’re opting for a professional installation, you might find yourself in line as many hopeful rainwater harvesters compete for winter’s dry days. Summer’s slower pace offers a much more spacious experience for rainwater-harvesters-to-be.

So why wait? Here are a few simple steps to get you going. Click the image to get started…. and remember that cold glass of lemonade awaits you!

Plan your rain barrel system