What to Plant in Clay Soil in the Santa Cruz Mountains

              "The soil is made of butterfly wings, dinosaur teeth, pumpkin seeds, lizard skins, and fallen leaves.
                  Put your hands in the soil and touch yesterday, and all that will be left of tomorrow shall return
                                         so that new life can celebrate this day."  -Betty Peck

Soil is a wonderful thing. It grows our food, anchors our trees and provides a foundation under our feet. But it sure can be hard to work with if it’s not the soft, crumbly loam that many plants prefer. It’s amazing that anything grows in some of the soils here in the Santa Cruz mountains. Some folks garden in an ancient sea bed of sand and there are others who have such heavy clay in their gardens that you wonder how anything survives.  Recently I helped plant in the dense clay of Garrahan Park in Boulder Creek and I dedicate this column to those of you with similar inhospitable soils.

The soil in Boulder Creek required a pick ax to break up enough to plant. Sound familiar?  Although rich in nutrients it needed compost in many areas to provide the environment  necessary so beneficial microbes, worms and other critters could do their work and aerate the soil. A thick layer of mulch will be spread over the soil by The Boy Scouts to preserve the structure and prevent it from packing down again.

There are many plants that are tolerant of clay soils and plant selection is half the equation. The park chose mostly California natives that won’t need fertilization or pruning, can be eventually weaned from irrigation and will provide food for the birds and visiting children. Juncus, a type of grass, red-flowering currant, redtwig dogwood, California rose and western redbud will be the stars of the park in the wet, clay soil. The drier side of the park was planted with deer grass, toyon, California rose, huckleberry, coffeeberry , ceanothus, native honeysuckle, vine maple, native iris and California fescue grass.

I’m sure the park will be the crown jewel of the area and hopefully you will come to visit and see the progress of the plants. Kinda like a local demonstration garden in the San Lorenzo Valley.

There are plants from similar environments in other parts of the world that would also do well if you garden in heavy soil. One of my favorite trees for these conditions is the strawberry tree. Also hackberry, ash, gingko and paperbark trees work well also. Shrubs to try include flowering quince, bottlebrush, Australian fuchsia, smoke tree, escallonia, pineapple guava, mahonia, osmanthus, Italian buckthorn, elderberry and vitex. Easy perennials for clay soils are yarrow, bergenia, carex grasses, fortnight lily, coreopsis, echinacea, nepeta, salvia, teucrium and verbena to name just a few.

If you’re not familiar with some of these plants it’s easy to see what they look like by Googling images. It’s what I do to see a plant full grown and not just a line drawing or a close-up of the flower.

So you see, there are plants that will be successful even in heavy, clay soil, you just have to pick the right ones.

Attracting Birds to your Garden

Fall brings with it not only foliage color but also colorful fruits and berries that invite birds into your garden. If you’re a backyard birder you probably already have lots of plants to lure our feathered friends,

If you have room for a new tree, consider Paul’s scarlet hawthorn.  With clusters of double rose flowers and small vivid red fruits resembling tiny apples in late summer and fall that hang from the branches well into winter, this tree offers interest in more than one season.  Robins are attracted to hawthorn berries.
 
Flowering crabapples sport showy edible fruit relished by many birds in the winter, including black-headed grosbeaks.  Fruit color ranges from reddish purple, brilliant red to golden orange.  Crabapples are good lawn trees and their spring blossoms are stunning.  To avoid disfiguring diseases, choose varieties that are resistant to cedar-apple rust, scab and powdery mildew.   Among these is ‘Prairiefire‘, with pink flowers and dark red fruit.  This tree grows 20 feet tall.
 
A native that puts on a fall show is  A background plant most of the year, the white berries on this 4-foot shrub stand out when the leaves drop.  Snowberry is a good choice for erosion control on banks.

Looking like clusters of pale purple pearls, the gorgeous fruits of beautyberry ( Callicarpa ) are born well into winter.  This deciduous shrub reaches to 6 feet and takes sun or light shade.
 
For both bird-attracting berries and brilliant winter stems, plant redtwig dogwood.  Native along creeks and other moist spots from northern California through the Northwest, it performs well with little additional summer water once established in gardens
 
Other shrubs with beautiful colored berries include barberry, cotoneaster, currant, elderberry, mahonia, nandina and pyracantha.  As an added bonus many of these berries make good holiday decorations, too. 

 

La Nina 2010 in the Santa Cruz Mountains

Mother Nature sure knows how to throw a curve ball. She can dish out balmy 75 degree weather one day, then switch it up to 107 in a heart beat.  Cold and windy comes to the mound next followed by "what’s next?"  from the pinch hitter.  I hear rumblings about a strong La Nina coming to town this winter.  What will this mean to us here in the Santa Cruz mountains? Will it be a dry winter?

To understand major climate trends, scientists collect temperature readings every week from dozens of buoys in the Pacific Ocean. They combine them with satellite images and temperature readings from ships, then plug the data into computer models from scientific agencies around the world.

According to Klaus Wolter of NOAA’s Earth System’s Research Laboratory, water along the equator in the Pacific is currently between  2 – 3.8 degrees Fahrenheit cooler than normal. In extreme La Nina events, it can get up to 7 degrees F cooler.

While a La Nina often allows the Pacific jet stream to trend further northward, bringing increases precipitation to the Pacific Northwest and below normal for So California, across the northern 2/3 of California, there really isn’t a strong precipitation signal in either direction for this event.  Northern California is the dividing line between the two extremes and it’s hard to say where exactly that line will fall in any given year. Klaus Wolter contends that we may be subject to notably strong and cold storm systems later this fall but La Nina’s effect on our rainfall is not clear enough for him to draw any definite conclusions.

Jan Null, a former lead forecaster with the National Weather Service who now runs Golden Gate Weather Services in Saratoga, thinks . That’s because in some La Nina years, rainfall has been more plentiful than normal. In one such year, 1999, San Francisco rainfall hit 115 percent of normal.

How’s that for hedging your bets? Just thought you’d want to know the latest predictions for this winter so you can so a little planning!

 

The Mountain Gardener's Weblog