Now that we're finally getting some rain, don't let it fall off your house, down your gutters and into the storm drain. Catch some of it and use it in your garden.

I do two things to catch rainwater. I have eight swales, which are open ditches that are closed at each end. Rainwater gathers in these swales and remains there up to three days before it is absorbed into the soil. 

The swales work well, and I love telling people when there's water in them. Later, when the weather is dry, my soil still has moisture for the plants growing in it. It's fun to landscape around these swales.

Some swale builders fill the swale with twigs and then cover with soil. I prefer an open swale so it can be cleaned out annually. Also, I can see that it's working.   

My other rainwater catchment method is a little more involved, but it saves water for my potted plants. I have two 1000-liter plastic containers. Both are elevated so that gravity helps me use the water. At the bottom of each container is a drain. One container has a garden hose connector.  

I use this water when I'm repotting or need to do a quick individual watering. These two tanks saved my potted plants a few years ago when I had no electricity for five days due to the wildfires. My water comes from a well, so no electricity means no water.

These tanks also fill when I turn the sprinkler on the potted plants. A gutter collects the water and funnels it into the tanks.

My other system is connected to a drain pipe on the house. This water drains into five 55-gallon tanks. The tanks are under a tall deck, and they are elevated and connected. I use that water to refill my small fish pond after it is cleaned.

Every few years I have to clean the tanks as dirt settles on the bottom. I drain them and clean out the sediment. A window screen on the open top of the tank keeps mosquitoes out.  

There are many ways to collect rainwater; search online for “rainwater tank” to find other systems. Luckily my tanks were free. Some tanks just catch the water, while others have built-in ways to drain them. Some people also install a small pump to deliver the water faster.   

Often before a storm, I will set out buckets on my sidewalk or driveway.  I use the water on my plants in the days afterward. 

California has some regulations regarding downstream water use. In 2012, the state passed a law allowing homeowners to maintain a rainwater collection system. However, the water can't be used for drinking as it may contain harmful bacteria. The state does not limit how much water you can collect as long as public health is not affected. Your catchment system needs to have a relief system so that, in a major storm, rainwater does not back up in the gutters.   

If you have a 1000-square-foot roof, you can collect about 550 gallons of water from an inch of rain.  This is much better than letting it run down the gutter and out to the sea. My swales also collect an amazing amount of water from road runoff. 

If you live in a community with an HOA, check its regulations before you install a catchment system. If your plan is not within the rules, then join the board and change the rules!

Library Talk: Join UC Master Gardeners and Napa County Library for a free talk on “Trees: Moving to Greener Pastures” on Thursday, January 5, from 7 pm to 8 pm, via Zoom. Learn about the intricate subterranean fungal network that supports trees. Imagine with us what needs to take place for a community of trees to meet the challenges of our changing climate. Register to receive the Zoom link at https://ucanr.edu/2023JanTrees&FungiLibraryTalk

Workshop: Join UC Master Gardeners of Napa County for a workshop on “Winter Rose Care & Pruning” on Saturday, January 14, from 10 a.m. to noon via Zoom. Learn how to prepare your roses for the upcoming growing season and how to choose the right rose for the right place in your garden. Attendees will be invited to join a hands-on pruning workshop at Napa's Fuller Park rose garden on Thursday, January 19, from 10 a.m. to noon to practice pruning one-on-one with a Master Gardener. Register at https://ucanr.edu/2023WinterRoseCare

Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 a.m. until 1 p.m. Send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description of the problem.  For best results, attach a photo of the plant. You may also leave a voicemail message with the same information at 707-253-4143.