Monthly Archives: March 2011

California Native Plants

Quail Hollow & the Gene Pool

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Few things can compare to walking on a scenic woodland trail lined with wildflowers.  Now that it’s officially spring I recently took a hike in Quail Hollow Ranch County Park to see what I could find. One of the unique aspects of this park is the number of rare plant and animals that make this valley their home. It didn’t take long to find the threatened Silver-leafed manzanita although it wasn’t blooming yet. The sandhill ecosystem where it grows among ponderosa pine is found in Santa Cruz county and no where else in the world.

Once upon a time, this land was under water, part of an ancient ocean, which uplifted to form the Santa Cruz Mountains about three million years ago. According to the Santa Cruz Department of Parks, the silt, sand and mud that had been deposited in that shallow sea later turned into the shale, sandstone and mudstone that make up Quail Hollow today. The diversity of this special place is mirrored in the patchwork of 15 habitats that are located in this small, secluded valley. Mixed evergreen forest, redwoods, grasslands, and a pond with surrounding riparian ecosystem mix with hot, dry chaparral and sandhill environments. The sandy soils here have eroded from the Santa Margarita sandstone and serve as an aquifer for the San Lorenzo Valley.

Hiking the trails among the blooming mimulus ,large-leafed lupine, Western Hound’s Tongue, manzanita and ceanothus made me think about the impact of our own gardens on the populations of native plants like those here.
Are we contaminating the native gene pool if we plant a mimulus, for instance, from southern California or a hybrid in our own garden?

The genes of all native plants have been sorted out over a very, very long time scale and they’re finely tuned to their environment. When you introduce an exotic gene – exotic meaning not of this place- it could be from a neighboring county, we don’t know the long term effect they’re going to have. If you live next to a wild population of a certain plant, like ceanothus, you should try to plant locally collected and propagated plants and seed. They are harder to find but local growers do collect seed and identify the source. On the other hand, ceanothus is a fire-dependent species and does not regenerate from seed except in the presence of fire or some other disturbance. If in doubt you could substitute a drought tolerant Mediterranean shrub that wouldn’t interbreed with local native plants.

It is probably not a problem for the home owner who lives in a neighborhood and wants to plant a couple of those cool, new sticky monkey flower hybrids in his own garden. If they do interbreed with the native population, in time whatever genetic pollution there is will probably die out. The home gardener is not planting fields of one type of plant that will interfere with the wild population.

There are many philosophies about planting California natives. There is no one-size-fits-all when it comes to this subject.  One thing for sure, we all want to preserve our wild areas like Quail Hollow.
 

Design trends, fertilizing, mulching, organic fertilizers, pruning tips

Garden Tips for March

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Spring is in the air. It’s always exciting to see the plants in the garden come to life. I’ve been invited to tour a  garden in Scotts Valley in April when many of the early flowering plants will be in bloom.  I’ve been to this garden before and there’s always an interesting tree, shrub or flower to enjoy.

One of my long term goals is to view the great gardens in the Santa Cruz Mountains. If you have a garden that you think others would like to hear about and you are willing to share it with me, please contact me. I’d love to spend time with you in your garden.

There’s so much to do now in the garden. If you are feeling overwhelmed here are some suggestions for the more important to-do’s.

* Check drip systems for leaks or clogged emitters. Flush sediment from filters and check screens for algae. You may need to add emitters if plants have grown significantly.

* Finish pruning and clean-up of trees, shrubs, vines and perennials. This includes fireblight die-back on pears, apples, hawthorn, pyracantha, photinia, crabapple quince and toyon., Prune out and discard diseased branches making the cut at least 6-8" below blighted tissue. Clean the pruning blades with alcohol or a 1:5 solution of household bleach to prevent spread of the disease. Also finish pruning and cutting back perennials and ornamental grasses. Go ahead and give grasses a 3-5" crewcut so fresh growth can emerge. Cut back old foliage of maiden hair ferns to allow new growth to take center stage. If you have Western sword ferns or another type that has winter or thrip damage, remove shabby looking fronds. Even if you have to cut back the entire fern it’s OK. It will regrow in just of couple of months.  Prune any other frost damaged plants when you see new growth begin.

* Spread fresh compost around all your plants. Good soil is the secret to successful gardening. The first principle of organic gardening is to feed the soil and it will feed the plant. Remember that all gardening used to be organic. Layer compost and or mulch on top of the soil and let it slowly decompose and filter down into the earth.

* As you plant new additions to the garden add organic matter to the soil. If your garden’s soil is sandy, organic matter enriches it and allows it to hold water more efficiently. If your soil tends toward clay, organic matter will loosen it up and improve drainage. In well-amended soil, plants grow deep roots, are hardier and more resistant to disease. Organic matter, such as compost, planting mix and well-rotted manure, boosts nutrition and improves soil structure.

* Fertilize if you haven’t already done so. Citrus, shrubs and fruit trees just emerging from dormancy are begging for their first meal of the season. Lawns begin their spring growth now also and benefit from a boost of nitrogen. You can also spread a thin layer of composted manure over you lawn. Leaving you grass clippings on the lawn will benefit it by shading the roots as it get warmer and as they break down they help feed it, too. Perennials benefit from both a fresh layer of compost or manure and a light application of balanced fertilizer. They respond to phosphorus especially in the spring for root growth, stem sturdiness and flower development. Wait until azaleas, camellias and rhododendron have finished blooming before feeding them.

* The most important to-do for March is to take time out and enjoy your garden and our beautiful surroundings. Those last few weeds will be there tomorrow but you’ll never get another today.

allergy-free gardening, California Native Plants

Allergy-Free Gardening

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Mea culpa. It was brought to my attention by a reader who suffers from pollen allergies that blooming . Acacias are largely pollinated by insects and have heavy pollen that doesn’t tend to become airborne.  It’s the non-showy, quiet ones you have to watch out for. Warm temperatures earlier in the year are already creating havoc for those who have to deal with seasonal allergies.

About 25-30 popular landscape plants are responsible for the majority of plant-related allergies in California.   During the height of the pollen season- from late February to June- there are often thousands of pollen grains in every cubic meter of air.  One can breathe hundreds of them with every breath.  Though pollens can travel many miles, the majority tend to stay in the general area of their origin.

Redwoods, oaks, alders, ashes and other wind pollinated trees like olives, birch, box elder, cypress, elm, juniper, maple, fruitless mulberry, pine, walnut, willow and privet are the major source of spring pollen. Most  native plants are good in the sneezeless landscape but if you have bad allergies or asthma it best to avoid wind-pollinated ceanothus, elderberry and coffeeberry. 

You may not be able to avoid these culprits growing on other’s property but you can get the most out of your own backyard by creating a sneezeless landscape.  Replacing existing plants may be impractical but planning future plantings with these things in mind will save you a lot of headaches down the road and let you enjoy the sunshine outside in your garden.

Flower type is a good way to judge plants.  The best looking flowers usually cause allergy sufferers the fewest problems.  Plants with bright, showy flowers are usually pollinated by insects, rather than by the wind.    These flowers produce less pollen and  their pollen is larger and  heavier and sticks to the insect rather than becoming airborne and lead to sneezing, a runny nose and watery eyes. 

Some trees that are good for anti-allergy gardens are apple, cherry, dogwood, magnolia, pear and plum. Shrubs like azaleas, boxwood, lilac, Rose-of-Sharon, hydrangea and viburnum are also not likely to cause problems. Good flower choices include  alyssum, begonia, clematis, columbine, bulbs like crocus, daffodil, hyacinth.  Also dahlia, daisy, geranium, hosta, impatiens, iris, lily, pansy, petunias, phlox, roses, salvia, snapdragon, sunflower , verbena and zinnia.  Lawns of perennial rye grass, blue grass and tall fescue blends are usually OK as they will not flower unless allowed to grow to 12" or higher.  Bermuda grass, on the other hand, can pollinate when the lawn is very short, sometimes as quickly as a few days after mowing.

Hopefully, this cooling trend will not cause problems for allergy sufferers. Symptoms may become worse if the body reacts to the disappearance of the pollen following its initial appearance only to have to have more of it later in the spring. According to Dr. Stanley Fineman, an allergist with the Atlanta Allergy and Asthma Clinic, "You become sensitized to it, so when you’re…re-exposed, you can get an even more violent allergic reaction."

Here’s to a sneezeless spring for you allergy sufferers.