What to Do about Invasive Plants

bull_thistleWe can't control those pesky weed seeds that blow into our gardens and take hold. There are ways to keep them from taking over, however. But what about those invasive plants that are already in our gardens like ivy and vinca major? What's the best way to deal with them? Then there are plants we buy ourselves that can invade natural areas. Are there better plants to use that are just as attractive and useful? Here are some solutions to make your garden happy.

One invasive thug that can take over is bull thistle, a relative of the edible artichoke. The seeds of this vigorous exotic take hold in disturbed areas including your beautiful garden soil and if not controlled can become a solid mass of impenetrable thistles in just a few seasons. Bull thistle only reproduces by seed so removal of the flowering stalks at this time of year will prevent them from spreading. The flowering heads must be discarded in a plastic bag and destroyed to keep them from forming viable seed. Because this weed is biennial you also need to dig out the first year plants that have not formed stalks. You can also mow thistles close to the ground a couple of times before they form stalks to reduce the population over time.

As a landscape designer and consultant I'm often called upon for advice for an area covered with vinca major or ivy. Both of these invasive species are too successful for their own good, smothering native plants and harboring pests such as rats and snails. Vinca major also serves as a host to the bacteria that causes Pierce's disease in grapevines. For your information, vinca minor has not been found to be invasive in California so far

You can choose organic methods to control vinca and ivy rather than chemical herbicides. Hand vinca_majorremoval is labor intensive but the results are good if all the root nodes and stolons are removed. Work inward from the perimeter of the patch and pull the plants back. You will need to do this every 3 months during the first year to remove resprouts but native plants may recolonize the area and reduce the chance that other weeds will move into the area following the disturbance caused by the removal activities.

Replanting with another more desirable groundcover is another solution. For shady areas, try planting wild ginger  (Asarum caudatum), Catalina perfume ( Ribes viburnifolium), creeping snowberry ( Symphoricarpos mollis), yerba buena ( Satureja douglasii ), bear's foot hellebore (Helleborus foetidus), winter saxifrage (Bergenia cordifolia), pachysandra, Serbian bellflower (Campanula poscharskyana) or Asian jasmine.

Good substitutes for vinca or ivy in sunnier spots include groundcover types of manzanita and ceanothus. Also attractive are Taiwan raspberry (Rubus pentalobus), California fuchsia (Zauschneria), or beach strawberry (Fragraria chiloensis ).

Some plants even though purchased from a nursery can cause problems. You wouldn't buy a Scotch or French broom knowing how invasive they can be. Forsythia, Japanese kerria, golden currant and Jerusalem sage all provide that beautiful spring butter yellow color in the garden.

The licorice plant (Helichrysum petiolare) gained popularity for its deer resistance and foliage color many years ago. Unfortunately, it self sows wildly and the spreading branches will root at any point of contact with the ground. Try instead better behaved plants like California natives salvia leucophylla or eriogonum giganteum. Teucrium germander or Powis Castle artemisia also work well in the same area.

Another good plant gone wrong is cotonester  lacteus (parneyi).  The red fall berries are spread by cotoneaster_lacteus_Parneyibirds and with their rapid growth and competitive roots they can overtake the garden and wild areas. Fortunately there are many other plants to use instead that provide food for birds and are beautiful, too. Try planting toyon (Heteromeles arbutifolia) a California native with delicate white flowers and large clusters of brilliant red berries. Pineapple guava is another good substitute as is strawberry tree (Arbutus unedo).

These are just some of the suggested alternatives for invasive garden plants for this area. Don't give an invasive an inch, it can take over your garden, the neighbors and our wildlands.
 

Roses of Yesterday

rose_Kathleen_closeup 3Under blue skies on a perfect spring day I sat recently with Colly, my friend, fellow columnist and gardening enthusiast, surrounded by roses, roses and more roses. Next to an old apple tree and a gnarled cherimoya we enjoyed a delicious picnic lunch Colly brought while she shared stories about this rose nursery called Roses of Yesterday.

Back in the 1960's one of Colly's many jobs was to proof read the catalog for Roses of Yesterday and Today as it was then called so she is quite familiar with the history of this rose business located on Brown's Valley Rd. in Corralitos. It's not quite a grand as it was in the old days but the massive old roses growing in the ground were magnificent in size and we admired and rated each one on the fragrance scale.

Roses of Yesterday, one of the oldest antique rose nurseries in the U.S., was established in the 1930's. It has passed through several generations and owners since then. They still use the honor system to sell their old, selected modern, unusual and rare rose varieties. A young father, kids playing in the car, loaded up a collection of potted roses and deposited a check in the cash box before leaving.

Another sign advised that the nursery doesn't spray their roses with fungicides, insecticides, rose_Kathleen_bench 3herbicides or other chemicals and the rose petals can be used for salad, jams, spritzers and teas. I did notice some rose slug damage on some of the roses but it was minimal. We noted the Sally Holmes roses and the rugosa roses had the least pest problems.

The garden contains many huge old roses. The first mammoth plant we encountered, Newport Fairy, was over 15 feet tall and nearly as wide. Covered with hundreds of small pink flowers it provided cover for many small songbirds who hopped inside searching for insects. This hybrid multiflora rose was first bred in1908. Lots of Red Admiral butterflies and Swallowtails found the surroundings to their liking, too.

We walked under a Cecile Brunner– engulfed pergola and then we saw it. Against a fence in filtered light, a spectacular single white rose with stiff, butter yellow stamens shaded an old wooden bench. We searched for the name tag and found, buried among a groundcover of sweet violets, the name Kathleen. This unusual and unforgettable hybrid musk rose from 1922 blooms repeatedly with blossoms richly perfumed. The catalog states the flowers drop cleanly and orange rose hips form along with the new blooms.

Several English lavender plants grew between the rugosa roses. We especially liked a small double magenta one called Rugosa Magnifica as well as a lovely white variety named Rugosa Blanca. Rugosa roses are very old dating back to before 1799 and bloom repeatedly with a marvelous fragrance. Large orange rose hips will form when the disease and pest resistant foliage drops. These edible hips are very high in vitamin C and are also relished by wildlife.  I've been told the crinkly foliage of rugosa roses is deer resistant.
rose_Stretch_Johnson 3
Growing nearby, a burnt orange rose got our attention. This amazing rose with two tone reddish orange petals and a lighter orange to yellow reverse is similar to Hot Coca. Called Stretch Johnson the flowers have the classic fragrance of rose petals and the disease resistant dark green glossy foliage of this floribunda was lovely.

The garden contains roses of all types especially old fashioned single roses as well as ruffly cabbage varieties. One bright pink single rose was especially beautiful. We thought the name tag read Rosa Wichuraiana but it must have been referring to the white groundcover rose nearby. We also loved a bright pink rose called Marguerite Hillig with its sweet fragrance and graceful arching canes.

The 4 inch dusky pink blossoms of Dainty Bess, a hybrid tea climbing rose, decorated one of the fences. rose_Sally_Homes2 3I learned this is a classic variety among hybrid teas since 1925 from the online catalog. The non-stop blooms are exceptionally long lasting on the plant and in bouquets.

From Ballerina to Climbing New Dawn to a huge Heinrich Munch with double pink blossoms covering a rose bush 20 feet across with a foot wide trunk, I enjoyed every inch of this old rose garden and nursery and it was fun to hear personal anecdotes from Colly about Dorothy Stemler,  the rose aficionado who's touch can be still be seen in the gardens of Yesterday and Today.
 

A 100 Year Old Garden near Quail Hollow

lawn_perennial-bordersVisiting gardens is one of my passions. Wherever I travel I take time to enjoy an arboretum or a historical garden wherever I find them. Local gardens can be just as exciting and recently I was invited to stroll and marvel under majestic oaks in a beautiful garden near Quail Hollow.

This 25 acre property was first developed by an Englishman in the very early 1900's. After building an Italian Mediterranean style house featuring plenty of earthy materials such as terra-cotta paver floors and patios, red clay tile roof, stucco walls, rustic wood beams and enclosed outdoor spaces, he set out to landscape the property.

A spring fed creek provides water to a woodland garden with 40 foot rhododendrons still thriving and in full  bloom during my visit. Western azaleas scented the air and the horsetail, columbine and white calla lily rhodie_bicolor2grew lush in the moist soil. The original owner built Japanese inspired stone bridges over the creek, the remnants still poking through the ferns.

Huge stands of black bamboo and golden bamboo border the creek in another area making me wonder if perhaps he became interested in these exotic plants after the 1915 San Francisco Panama-Pacific Exposition that showcased plants from all over the world. The current owners have installed a 3 foot barrier to keep the bamboo in check. Now towering 25 feet tall, the black bamboo shades the house on the south side with stems 2" thick.

The property passed from the original owner to a concert pianist who lived there until she died. The current owner bought the property in an estate sale in the early 1970's. When he married Nancy 23 years ago the garden again came to life. The front yard which had been a flood-irrigated horse pasture was transformed into the magical place it is now.

Nancy is the perfect steward of the land. Interested in all growing things she has surrounded the lawns with shrubs, perennials, grasses and flowers of every type. Sunny borders bloom with trellised Cecile Brunner roses, pink clematis montana and purple Jackmanii clematis along with lots of bright red climbing roses. By providing support, Nancy has even coaxed Apple Blossom and other carpet roses to bloom off the garden floor.

In addition to her gardening successes, Nancy shared her ongoing nemesis. Every year she said she hand picks at least a hundred white gaura that have self-sown. Seems Siskiyou pink is not as prolific. The crocosmia Lucifer have overtaken one bed and she begged me to take some. I politely declined. Her white Japanese anemocourtyard2ne threaten to march into the lawn but the pink variety is better behaved. Nancy takes it all in stride. You can feel her love of gardening and plants at every turn.

Nancy loves perennials. The chocolate cosmos were just emerging but the double coreopsis, Spanish and English lavender, Moonshine yarrow, Japanese iris, douglas iris and columbine were in full bloom. In a shady spot by the old icehouse daphne, azalea and pieris had just finished their show. The hydrangeas were all budded and ready to take over the spotlight.

We walked through a lovely enclosed courtyard complete with formal fountain and Nancy pointed out containers of gardenias, Evergold carex grass, a deep red Bob Hope camellia and huge woodwardia ferns. She planted the rhododendrons bordering the courtyard over 20 years ago. A gopher did get 3 of the camellias last year but she's now replanted in gopher baskets. Her Japanese maples, started from seedlings, are now 6 ft tall with trunks over an inch thick.

I'll never forget the afternoon Nancy shared her garden with me and Sherman, the springer spaniel I was dog-sitting.  It's an enchanting place and I'm looking forward to visiting again.

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