or …Why I remember a Sunset Magazine article from 1999.
A few months before we bought our place here in the shadow of Peckinpah Mountain, I read an article called ‘What to plant under native oaks and pines?’ Do you still have the September issue of Sunset magazine? No? Well, if you live in the mountain community around Oakhurst, CA or in any area of the foothills of the Sierras, then you deal with gardening amongst the native live oaks, blue oaks and black oaks with stickery leaves that never decompose. Or you have Ponderosa pines or grey or Bull pines, which drop pine needles.
This article first made me aware of the watering, or I should say no watering zones around oaks. Here in the wet winter, dry summer Mediterranean climate of California, the oaks are not used to any summer water, however, the folks at Sunset Magazine have been planting under their native oaks for 40 years, they say. They say, “Under oaks, plant companions that like it dry.”
Most shade loving bedding plants like water in the summer and oaks just can’t tolerate that water because it encourages oak root fungus(armillaria mellea) that will enter the roots and slowly kill the tree. Even if you should remove a dying tree, the fungus remains to affect other trees and shrubs that are susceptible like elms, grapes, pines and rhododendrons.
To reduce the spread of oak root fungus, I underplant my trees with the drought tolerant varieties of plants in this article’s list and I’ve kept it so I can refer to it over the years. They suggest providing a bit of summer water in the first year and the plants should manage well later with what nature provides. Experts recommend that you plant nothing in the zone 4-6 feet from the oak’s trunk.
Pines can be very frustrating for gardeners. Their roots can suck the soil dry, making life impossible for many plants. Some give up and let the needles accumulate and decompose. I do this in the outer natural areas beyond our fire safety zone of 100 feet around the house.
Sunset recommends planting a ‘skirt’ of open branched shrubs just outside the drip line that will ‘swallow’ the needles. Shrubs like rhododendrons and viburnums will do especially well under pines.
Autumn sage (Salvia greggii)
California iris (I. douglasiana)
Catmint (Nepeta faassinii)
Coral bells (Heuchera)
Red Valerian (Centranthus rubra)
Rosemary (Romarinus officinalis)
Santa Barbara daisy (Erigeron karvinskianus)
Blue fescue (Festuca ovina)
Dusty Miller (Senecio cineraria)
Fountain grass (Pennisetum alopecuroides)
St John’s Wort (Hypericum calcyinum)
For under pines only