You’ve heard it before and you’ll hear it again...”The right plant in the right place” is always something to keep in mind, and now there is more help available to be sure we are all doing just that.

There are plants being grown in our gardens that are welcome additions to our gardens but there are also many commonly used landscape plants that your garden would really be better off without.

The ongoing All-Stars program, through the UC Davis Arboretum is making plant selection much easier. Easier on us, as gardeners, because these plants are not troublesome to grow, don’t drain our wells dry (or increase our water bill) and don’t expose us to dangerous chemicals...and easier on the environment for the same reasons. Yet these plants give us what we expect to see in our gardens and this knowledge is where the program began.

All-Star Eligibility

Plants, mostly California or other Mediterranean area natives, are first tested by UC staff for a period of time before even being considered possible All- Stars.

To be an All-Star, plants must thrive under a low water regimen (after being established), they must look attractive during most of the year, must resist pests (including diseases) and it’s a big plus if they also attract bees and other beneficial insects.

Then, because California is a complex state with at least 7 USDA zones and 24 Sunset climate zones, there are now test gardens all the way from Shasta County to San Diego County. The plants are monitored by Master Gardeners to determine how well plants do in various climates. The Master Gardener Demonstration Garden in Nevada County is one of the test gardens.

In each of these gardens, on a monthly basis, Master Gardeners observe the groups of plants, recording foliage appearance, floral display, insect and disease damage and overall vigor, as well as weather (heat and frost stress) and make note of any maintenance required.

Four times a year, Master Gardeners also measure height and width of each plant, as well as the monthly observations. All of this data is submitted electronically by me or a member of our team to the UC Davis horticultural staff.

At the end of the study for each plant group (usually after two years), extensive information is submitted before determining that it is a plant that does well in our area and one we can now recommend to our neighbors as an All-Star.

Since 2006, one of these test gardens is right here in Nevada County where the public can see these plants in place and talk with the Master Gardeners who tend them. The Nevada County Master Gardener Demonstration Garden is on the NID property at 1036 W. Main Street in Grass Valley. Just follow the signs to the garden and enjoy. The public is welcome any time the gates are open (locked at 5:00PM during the week and 3PM on weekends). Just look for an Arboretum All-Stars sign near plants currently being studied and plants from past studies.

Visit Arboretum All-Stars.

A few of the plants that have done very well in Nevada County include:

• Rosy Coral Bells (Heuchera rosada)
• Serpentine Columbine (Aquilegia eximia)
• California Lilac ‘Valley Violet’ (Ceanothus maritimus)
• Penstemon ‘Margarita BOP’ (Penstemon heterophyllus)
• Muhly Grass (Muhlenbergia dubia)
• Pacific Coast Iris ‘Canyon Snow’

Some of these plants are now being propagated at the Nevada County garden and are available at our twice-yearly plant sales.

UC is working with the horticulture industry to include plants that carry the All-Star label, but knowing that this industry thrives on introducing those plants that the public has never seen before and must have NOW is a problem.

If you don’t see plants identified as All-Stars at your favorite nursery, let them know you would be interested in purchasing such plants and hopefully, you can encourage their participation in this great project. And then you too, can plant the right plant in the right place and enjoy the easy growing of these plants!

References

California Agriculture Magazine, July-September 2008 edition 

All-Star link updated 12/2025