All posts by Jan Nelson

I am a landscape designer and consultant in the Santa Cruz mountains in California. I write a weekly gardening column for the Press Banner newspaper. I am also a Calif. Advanced Certified Nursery Professional and managed The Plantworks Nursery in Ben Lomond, Ca. for 20 years.

Groundcovers

Ground covers are like a fancy carpet in the garden.  They add richness and beauty under trees and become the stars of the show in sunny apots.  Ground covers reduce maintenance by preventing weeds and reduce watering by acting as a living mulch.  

 

When choosing ground covers, assess the conditions of the area you want to plant.

  •  Is it in the sun or shade?
  •  Is it a naturally moist area or dry?
  •  Do you intend to water it or go with our natural cycle of wet in the winter and dry in the summer?
  •  Matching the plant to the site conditions will ensure success.

When designing a plant layout I consider whether I want a sweep of the same plant or a tapestry effect with a variety of plants.  Using more than one type of plant allows me to work with foliage contrast adding pattern to my composition. 

Splash color and texture on the ground under trees and shrubs with shade-loving ground covers like   Serbian bellflower.  It needs little water, blooms with star-shaped 1/2" blue flowers in spring and summer and spreads vigorously without becoming invasive.  Heart shaped foliage covers this mounding plant.

Lamiastrum is another perennial ground cover for partial or full shade.  Silvery variegated foliage can lighten up dark corners and small yellow flowers are a bonus in late spring.

To preserve good visibility along a walkway or lawn, use low-growing, long blooming perennials like diascia, Santa Barbara daisy and achillea.   All prefer full sun and moderate to little water.

 

Diascia is a So. African native with 1/2" wide flowers that appear on the ends of spreading stems.  Pink used to be the only flower color but now hybridizers have developed apricot, coral and lavender, too.  Diascia’s are hardy to 0 degrees and bloom nearly continuously if old flowers are cut off after flowering.

 

Santa Barbara daisy has become a popular ground cover as it reseeds readily and can cover a large area fairly quickly.  This 10-20" tall trailing plan spreads rapidly to about 2 ft, making it a great filler between larger shrubs and perennials.  Dainty 1/3" pinkish white flowers cool down hot sunny spots.  Trim this plant several times a year to keep tidy and encourage blooming.  

 

Achillea or yarrow are among the most carefree perennials for summer and early fall bloom.   They spread by underground runners and make great ground covers. Keep this in mind if you have a limited space.   The most common variety is Summer Pastels but if you want to add a punch of color to your garden, plant Cerise Queen with it’s cherry red flowers.   

 

Rockrose provide large-scale cover for expansive sunny areas.  Their dense strong root systems help prevent soil erosion.   Choose from white, pink or magenta flowers on plants varying from 1-5 ft. high depending on which variety you choose.  This Mediterranean native is fast growing and drought tolerant. 

 

To create stunning combinations of ground cover plants. choose 5 or 6 styles and repeat them in small drifts to carry the eye through the composition.

 

Add grasses for linear texture.  Good candidates are Blue Oat grass, a non-spreading clumping grass with silver leaves.  Carex Ice Dance is a spectacular evergreen ornamental grass with dark green narrow foliage edged with a pure white border.  Ice Dance spreads by underground runners in partial sun or shade.

 

Take the opportunity to survey your garden for bare spaces that can come alive with added texture and color.  


Homegrown carrots

 If you love carrots like I do,  now is the time to plant  the seeds  directly in the ground.

Carrots as we know them originated from forms grown around the Mediterranean.  By the 13th century carrots were well established as a food in Europe and came with the first settlers to America, where Indians soon took up their culture.

Flavor differs greatly among varieties and planting time affects flavor, too.  September is one of the best months to plant.  Carrots achieve their sweetest taste when the last few weeks of growth occur in cool weather.  Also, unless a carrot is bred to be harvested young, it won’t develop full flavor until mature.

Two ingredients determine a carrot’s flavor- sugar and terpenoids ( volatile compounds that impact the carrot flavor ).   Because terpenoids develop earlier than sugars, a carrot that is harvested too young might taste bitter. For peak flavor and texture, dig carrots anytime after they’ve developed a deep orange color.

Commercial carrot varieties have been developed for uniformity of shape, as well as for color, disease resistance and ease of harvest.  But home gardeners can select a carrot more for flavor than appearance.  So how do you choose the sweetest ones to grow?  

Carrots are normally grouped into several types-  Nantes,  Chantenay, Danvers, imperator and Paris market.   For flavor it’s difficult to beat a Nantes.    Nantes Coreless or Little Finger are two popular varieties.  They’re not a carrot you’ll find in the grocery store because they’re difficult to harvest commercially and don’t store well.  Both are juicy and sweet.  Nantes coreless grows to 6-7 " long, is blunt-tipped and fine grained.  Little Finger is unmatched for snacks, pickling or steaming.  It grows to just 3-4" long and is ideal for container gardening. too.  

Red Cored Chantenay has broad shoulders and strong tapered tips.  This wedge-shaped carrot is rarely grown by commercial growers.  For the home garden it produces 6" long carrots that keep well when left in the soil, store well after digging and are sweet and crunchy.  They perform well in heavy soil, too.

Danvers Half Long are another variety that are tasty raw, cooked, or juiced.   Carrots found at the super market are usually Imperators just so you know.

Whichever variety you choose to grow, prepare the soil by deeply working in organic matter.  Avoid fresh manure or your carrots will develop fine, hairy roots.  Remove exposed clods and stones from the soil and soak the bed before planting.  Scatter seeds thinly on top and cover with 1/4" compost to keep soil from crusting so the seed can punch through.  Firm soil gently and keep moist.

Germination take 10-17 days.  To help keep the tiny seeds moist, you can cover the seedbed with wet burlap just until they germinate.   When seedling have 2 or 3 leaves, thin them to 2" apart.  Keep soil deeply and evenly watered.   Control weeds with shallow hoeing.  Fertilize once a month and in a 60-75 days your carrots will be a deep orange color and at their peak flavor.  You just can’t beat pulling a sweet carrot straight from the earth for sweetness.  

 

Primroses

Primrose

Looking for something new for the shade? Primroses are back in more brilliant shades than ever.  I  chuckle when I see the catalogs originating from the east coast offering these beauties for sale at prices befitting tulipmania.  Here English primroses are a cool season staple.  By planting these little jewels early you can enjoy months and months of blooms.

Primula Fantastique is a new cultivar with exquisite richly colored flowers feathered at each tip with a contrasting shade.  Super Nova and Rosanna are also new introductions that have to be seen to fully appreciate the brilliant additions they will make to your shady borders.  Add some new color to your garden.  You’ll be glad you did. 

 

Echinacea

Echinacea Need more late summer perennials to extend your season?  Purple coneflowers will continue to bloom until frost then go dormant for the winter.  Showy 4" rosy purple daisies are lightly fragrant and make good cut flowers for bouquets.  The clumps spread slowly and can be carefully divided after 3 or 4 years.  There is also a beautiful white variety called White Swan.  If faded flowers are left in place, the bristly seed heads provide food for finches in winter.  

The herb echinacea is derived from varieties of this flower.  E. angustifolia is used nowadays as a fortifier of the immune system, mainly to prevent flu and minor respiratory diseases by increasing the body’s production of interferon.  The roots are the part of this plant used for medicinal purposes.   Echinacea was used by Native Americans more than any other plant in the plains states.  It’s antiseptic properties were used to treat snake and insect bites, to bathe burns and to help cure the “sweats.”  They chewed the plants roots to ease the pain of toothache.  It was also used by the Native Americans for purification.  The leaves and the flowers can be used in teas as well.

Gloriosa Daisy ‘Prairie Sun’

Gloriosa Daisy 'Prairie Sun'

Late summer color can be an opportunity to add new plant that will bring beauty to your garden right through fall.  Many summer annuals are leggy and in need of cutting back about now.  If you like spending time outdoors at this time of year take advantage of this glorious weather and make sure your garden has lots of colorful flowers. 

Golden yellow perennials like gloriosa daisies, coreopsis and golden mums stand up to strong sun now, and later in the season burn like embers under gray skies.  You’re probably familiar with the traditional Black-eyed Susan with a prominent purplish black cone in the center.  There are many varieties of this type with russet, bronze or mahogany bands.  But a gloriosa daisy I especially like has huge 5" golden yellow blooms with pale yellow tips and sports a light green central cone instead of the familiar brown one.  Prairie Sun looks stunning with any shade of blue or lavender like asters, Russian sage or salvias.  Try it in front of the sky blue flowers of cape plumbago for a breathtaking combination.

Gloriosa daisies make good cut flowers and are tough and easy to grow.  They are descended from wild plants native to the eastern US and require only moderate water once established. 

Things to do in the garden in August

Here are some reminders of things to do in your garden in August.

  • Cut back  berry vines that have produced fruit.  Canes of the current season should be trained in place.
  • Spider mites are especially prolific during hot, dry weather.  Sometimes you don’t even know how bad  the infestation      is until all your leaves are pale with stippling.  Periodically rinse dust and dirt off leaves with water.  Spray the undersides of infected leaves with insecticidal soap, switching to neem oil if they build up a resistance to one of the pesticides. 
  • Start cool season veggies seeds now so they are ready to put in the ground in 6-8 weeks when the  weather is cooler.  You can start broccoli, brussels sprouts, cauliflower, cabbage, chard, lettuce and spinach seeds in containers.  Carrots, onions, peas, beets and radishes can be sown directly in the ground. 
  • One last to do:  Make a journal entry celebrating the best things about your garden this year