How to Build a Rain Capture System for Your Greenhouse

After building her dream greenhouse and falling in love with raising tropical plants, Jennifer Ainsworth (@jjays_greenhouse) found an easy way to water her growing family without any expensive plumbing. A rainwater capture system uses gravity, gutters, a big container and a hose to create a free-flowing spigot, making it easy to irrigate your potted plants all year long.

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The COVID-19 pandemic changed many things in people’s lives. Some of the changes were not welcome (although many surprisingly were), but human resilience and resourcefulness often turned them into something good. For Jennifer Ainsworth, the pandemic brought her a lush greenhouse, a new place for family to gather, and an ingenious eco-friendly way to water her plants.

Dreams of a Greenhouse

Jennifer Titus, a busy database manager in Wilmington, NC and mom to a seven-year old, wanted to try her hand at vegetable gardening “when she had some time.” That time didn’t come until 2020, when the pandemic forced non-essential workers to stay home. Jennifer had a shed but wanted to add a light-filled greenhouse onto it. She found a large one on Facebook Marketplace and her husband Jayson dutifully set out to pick it up.

Things didn’t turn out as planned.

“It was a disaster,” Jennifer admits. “My husband and his friend drove out of town to disassemble a giant greenhouse and then brought it home in a million pieces, with no instructions on how to reassemble it.”

Frustrated by a greenhouse “kit” that had thousands of pieces and no instructions, the Tituses started collecting windows and built a custom greenhouse of their own design.

Her husband scrapped the kit and ended up surprising her with a greenhouse of his own making, which he attached to their existing shed. The result feels like a natural part of its surroundings and Jennifer couldn’t wait to start filling it with plants.

A Better Way to Water

After a year of experimenting and teaching herself about plant care, Jennifer’s success as a tropical plant grower increased significantly. She quickly filled her new greenhouse with potted tropicals, while at the same time planting exterior gardens including vegetable beds and a wildflower patch.

Soon the hand watering became an onerous task. “I was filling up watering cans to water everything, which wasn’t too bad when we first started, but it got old quickly,” Jennifer says. Her husband did a little research and decided to create a simple rain capture system.

The result was a game-changer. “We save time and energy,” Jennifer says. “The plants really thrive on the rainwater.”

The gutter is 20 feet long and the rain barrel holds 55 gallons. According to Jennifer’s calculations, the system can collect as much as 2,000 gallons during the five-month rainy season.

Here’s how they did it.

Rainwater Capture System

What You’ll Need

Rain barrel stand (bricks, cinderblocks, pressure-treated wood)
Rain barrel
Gutters
Downspout
Flexible gutter extension
Garden hose
Female hose adapter
Spigot

Instructions

Choose a location for your rain barrel and stand. It should be close to the downspout from your gutters and on level ground.

Install the rain barrel stand. Make sure everything is level and stable. Then, place the rain barrel on top of the stand.

Install the gutters on your greenhouse roof if they’re not already in place. Ensure that they slope slightly towards the downspout.

Attach the flexible gutter extension to the downspout. You’ll want the end of the gutter extension directly over the opening on the top of the rain barrel. We screwed the gutter extension to the top of the rain barrel, so it stays in place.

Cut the hose to the desired length. This hose will run from the rain barrel to the inside of your greenhouse.

Drill a hole, the size of your hose, through your greenhouse, to run the hose through.

Attach your hose to the threaded spigot at the bottom of the rain barrel. Run your hose through the hole you drilled out.

Attach the female hose adapter to the end of the hose that you just ran into the greenhouse.

Next you attach your spigot to the female hose adapter inside that’s inside your greenhouse. Make sure it’s tightened securely!

Finally, make sure your spigot is in the closed position before the rain barrel fills up. Once the barrel is full, open the spigot and use the rainwater water as needed!