We usually talk about sustainability in terms of what we pass on to future generations. We have to preserve this planet for our children and their children after them, and what we do now matters. Yet what our children do with the planet once they inherit it also matters. So how do we instill in them that same drive to protect the earth?

Like good hygiene and a strong work ethic, sustainability is something parents can teach their children by example. For instance, if you go out of your way to never litter, then your kids are more likely to grow up with the same principle. Likewise, if you constantly throw trash on the ground and never recycle anything, they may never learn that littering is bad — or why.

Therefore, being conscious of your actions is the best way to teach children that every decision affects the planet. Even something as simple as the sandwich you eat can have larger consequences. A prepackaged sandwich, for example, has a much bigger environmental impact than one you make at home. In the U.K., the British public’s yen for prepackaged sandwiches yields a carbon footprint about as large as the emissions from 8 million cars.

Like buying a prefab sandwich instead of making one, the little things we do every day have a big impact on our planet. Consequently, true sustainability requires teaching kids mindfulness lessons they’ll carry with them for the rest of their lives and, eventually, pass on to their children, too.

Make Every Moment a Teachable One

As a concept, sustainability is fairly simple to define. As a life lesson, however, the education is ongoing. For example, the ready-made sandwich mentioned above offers at least three important lessons you could teach your child about sustainability:

1. Be mindful at the grocery store.

As we’ve seen, prepackaged sandwiches aren’t exactly manufactured with the environment in mind, but they aren’t the grocery store’s only offenders. In fact, grocery shopping provides ample opportunities to teach your children that being conscious of what they buy can influence how companies make and package these products. As Peter Seligmann, founding CEO and chairman of Conservation International, points out, “We are the purchasers, and our likes and expectations shape the supply chain.”

Before going to the store, research specific products that have been applauded for their sustainability, like Humm Kombucha. When you’re at the store, show your child how to pick environmentally friendly foods and items that don’t deplete the earth. Buy products made with recycled materials, choose organic foods, and buy in bulk to reduce packaging waste. Pick up biodegradable cleaning products, and explain how even the chemicals you use to clean your home can impact the environment.

2. Grow your own food.

The grocery store is a great place to teach children that things like sandwiches and other necessities don’t just fall out of trees. It can spark an ongoing conversation about how things are made. Growing food in a garden at home can further their knowledge and curiosity about how their food is produced.

Tending a garden teaches a number of life lessons, especially about monitoring resources. Many schools have already added gardening to their curriculum. Megan Bang, an associate professor of education at the University of Washington, says school gardens encourage kids to think critically about the interconnectedness of the world’s resources. “What I’m after,” she says, “is having a citizenry that’s capable of engaging in those real 21st-century problems.”

3. Respect the planet.

Respect for the planet comes in many forms and is taught through many lessons. Choosing or growing environmentally friendly foods is one. Limiting waste and recycling more are others. Respecting nature itself is a slightly different lesson, though it’s equally important to creating a mindset of sustainability in children.

Every time a child catches an insect or inspects a plant, it’s an opportunity to teach the importance of sustaining nature. As they become adults, that respect builds and influences how they care for the world on a larger scale. Britt Crow-Miller, sustainability scientist at Arizona State University and executive director of environmental education not-for-profit CityWildPDX, sees this as one of the most important lessons to teach. “From curiosity comes learning,” she says, “from learning comes respect, and from respect comes stewardship and advocacy.”

For us adults, the most important lesson is that securing the planet’s future means more than changing how we care for it now. Long-term sustainability only works if we teach our children to be proper stewards of the planet in their own time, and it’s never too early to start their education.