Hi Andrew,

Thank you for your photos- the juniper berries/needles on the ground looks familiar! While I could not find any information on what the pH of the juniper duff/litter is, I did read that levels of calcium, potassium, and pH are generally higher under mature western junipers than in interspaces: https://www.fs.usda.gov/database/feis/plants/tree/junocc/all.html

One of the biggest issues with growing plants under/near juniper trees is that they are known to out-compete surrounding vegetation for water resources. Also, the interception of rainfall via the canopy and duff/litter limits moisture from reaching the soil. The thick duff layer as well as dense shade under juniper trees makes it difficult for seeds to germinate and presents a challenge for sun loving plants.

Drought tolerant native plants such as rabbitbrush, sagebrush, native grasses, and wax currents are seen growing within canopy of junipers although become more sparse under large trees. In the past year, I have transplanted rabbitbrush, sagebrush, yarrow and native bunch grasses under a juniper tree making sure their roots are planted in the soil and not in the duff/litter layer; I have also provided supplemental water. So far they are doing fine although the yarrow did not have many flowers due to shade. Of note, the juniper duff/litter can be added to compost pile.

Please feel free to contact me directly if you have further questions!

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

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