High Altitude Gardening in an 18 foot Greenhouse at 8000 ft

April 2020 Dome of the Month – Rob and Barb

Rodney Hoffman and Barb Smith do everything they can to live more sustainably. Their 18′ Growing Dome, located 8,000ft above sea level in Conifer, Colorado, is a 100% solar-powered greenhouse. They even gather rainwater to keep the tank full. The Dome was initially supposed to be featured on our Evergreen/Conifer tour. But since we were forced to postpone, we thought you might like to hear a little more about them and watch some of the video tours they filmed from 2018. Hint: they are filled with many helpful tips for high altitude gardening!

High Altitude Gardening

Barb was a “frustrated Iowa farm girl living in the mountains.” She grew up gardening and enjoying the outdoors, but moving to the Colorado foothills made growing HARD. So they did what any other high altitude gardener would do. They bought a Growing Dome Greenhouse and built it themselves. See the slideshow at the bottom of the post for pictures of their greenhouse build.

Barb’s Dome Yield Spreadsheet

Since 2008, the year they purchased their greenhouse, Barb has been adding to a spreadsheet. She uses this unique spreadsheet to plan precisely what they will be planting in their Dome. Then throughout the year, she records how the crop performed, how long it took to fully grow and records the production yield. Did we mention she grew up on a farm? Barb was very kind to share her numbers with us. After over 20 years of high altitude gardening in the Growing Dome, Rod and Barb have certainly returned their investment many times over.

Inside Their Growing Dome

Rod and Barb are what we would call “expert high altitude gardeners.” With only two perimeter beds, they have managed to keep their Dome producing almost non stop even when they travel for a month at a time. They have a drip irrigation system that is directly connected to their pond.

They start most of their plants from seed, and because they opted for more hangout space, they must choose their plants wisely. Normally sticking to crops that don’t take up too much space. Things like tomatoes, leeks, oregano, cilantro, radishes, and scallions. Barb said she “tends to steer clear of peppers.” She can’t keep the bugs away from them.

Pest Management and Spring Cleaning

Many Growing Dome owners choose to heat their greenhouses all winter to sustain certain crops. Rod and Barb are not those people. Similar to Growing Dome expert Claudia Stover, they only heat their Dome on a rare winter night when the temperature drops too low. They also choose to “shock” their Dome. This is the process of removing all of the plants and letting the Dome get nice and cold. The shock gets rid of any pests like whiteflies or aphids that may have developed through the year and start fresh in the springtime.

*Pro Tip* This is a great time to clean your Growing Dome panels & refresh your soil.

The videos also show a cable system they use for the many varieties of tomatoes they have growing in their dome in the spring. As they climb up the levels, they have the added advantage of providing additional shade in the summertime. They also found a variety that grows well in the shady corner of the dome!

Advice to Future Dome Owners

“Get the biggest one you can fit on your property and add extra insulation to the foundation wall.” During the winter months, when Colorado’s foothills are covered in white fluffy stuff, Rod and Barb use their greenhouse as “a second living room.” They step inside, away from the chill, and hang out in their warm getaway spot amongst the green plants and healthy soil.

Rod and Barb’s 18′ Growing Dome Build

Rod and Barb’s 18′ Growing Dome Build