• What to plant under oaks and pines in the garden?

    by  • April 8, 2011 • Design, Garden

    Caring for native trees in the garden

    …and a list of what to plant

    Toxicodendron diversilobum Poison Oak

    Toxicodendron diversilobum Poison oak under the trees is a hazard in the garden

    When faced with a new, mountain or rural garden, you need to make peace with your oaks and pines. These beautiful trees can be unkempt, stickery and surrounded by brush and poison oak at the start. I wondered what could be planted under them with their dry shade and falling leaves.

    Here are a few things we did to fit our garden around these stately trees:

    Protect them

    First, we protected them from damage, from construction equipment by marking off our trees as “out of bounds” to construction equipment before building. One sad homeowner in our mountain community has lost close to one hundred trees around his luxury home, by neglecting to do this. Compaction from heavy equipment, irrigation drip lines and grade changes are bad for oaks and pines.

     

    Trimming the oaks to reveal the huge rock

    2001-Trimming the oaks to reveal the huge rock

    Groom them

    Grooming the branches and brush, 10 feet up and ten feet around our trees allow us to walk safely under them and see down through them on a slope. We cut poison oak off at the base and then spot spray the new sprouts with aa systemic herbicide for several years. Raking and a light covering of gravel, river rocks, pine chips or needles make a neat appearance.

    2006- Planting Western sword fern and heuchera

    2006- Planting Western sword fern and heuchera

    Plant under them

    Oaks must have dry roots in summer.  Oak fungus can grow in moist soil and slowly kill the tree. Clusters of plants arranged around accent rocks outside a 4-5 foot diameter circle all around the tree work, and planting in the fall or after the first rains means you won’t need to provide extra water while the plants adjust to their new homes. Between two oaks here  is a natural winding drainage area about four feet away from each oak. The water flows down through and I put rocks along the natural curves to slow it and planted Douglas iris.

    Planting under pines

    Planting under pines, thyme, ajuga, Lamb’s ears, California yarrow, behind

    Under pines, plants with open habits like rhododendrons or Western azaleas work well because the needles just fall through their leaves. I plant rhododendron, iris, lilac, lilies and viburnum in small groups just inside the drip lines of our pines close to the house.

    2009-Planting under oaks5

    2009-Planting under oaks, Helichrysum ‘Moe’s silver’, Blue fescue, Lamb’s ears

    Under one oak, I planted Helichrysum petiolare ‘Moe’s silver’ and Blue fescue, Festuca ovina ‘Glauca’ and I’m pleased with the silvery-grey carpet near it’s base. Helichrysum is ‘evergrey’ and needs so little water that’s I consider it a very valuable Mediterranean in the garden.

    2008-Planting under oaks3

    2008-Planting under oaks Leave a space around the trunk, Artemesia, wild rose, sage

    Under oaks and pines these plants need little water and work well if kept about four feet away from tree trunks:

    Columbine, Aquilegia formosa
    Low-growing Manzanitas, Arctostaphylos
    Artemisia, any
    Oregon Grape Berberis or Mahonia aquifolium
    California native bulbs, Brodiaea and Triteleia
    Catmint, Nepeta faassenii
    Helichrysum, any
    California wild lilac Ceanothus, any
    Soap Plant, Chlorogalum pomeridianum
    Ferns: Wood Fern, Sword Fern, Maidenhair Fern
    Alumroot or coral bells, Heuchera
    Douglas Iris hybrids, Iris

    Planting under oaks6

    Planting under oaks, Helichrysum ‘Icicles’, Golden oregano, Lamb’s ears, Rosemary

    Rosemary
    Western Wallflower, Erysimium capitatum
    Pacific Woodrush, Luzula comosa
    Sulfur Flower Eriogonum umbellatum  ‘Shasta Daisy’
    Autumn sage, Salvia greggii
    Bush Monkeyflower, Mimulus aurantiacus
    Purple Needlegrass, Nassella pulchra; also other native grasses
    Evergreen Currant, Ribes viburnifolium
    Lamb’s Ears, Stachys byzantina
    Snowberry, Symphoricarpos albus laevigatus
    Blue fescue, Festuca glauca
    Dusty Miller, Senecio cinararia

    2008-Planting under oaks

    2008-Planting under oaks, lavender, heuchera, fern, sage, iris

    All these plants I hand water during the hottest part of the summer and some have light sprayers for when we travel.  I’m happy that I’m being able to replace spray emitters with more and more ‘goof plugs’ because the plants are established enough to do without.  With proper care our oaks and pines to have long, long lives and be a pleasure all through the seasons.

    2008-Planting under oaks

    2008-Planting under oaks, Cleveland Sage, White sage, Lamb’s ears

    About

    Sue Langley, a passionate gardener and photographer lives and gardens with her husband and Corgi, Maggie on 7 acres just south of Yosemite, Zone 7 at 3000 feet. She also manages the Flea Market Gardening Facebook page and website.