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.

Indian Summer in the Santa Cruz Mountains

We tend to think of September and October as ‘Indian Summer‘  because the weather is balmy,  even on the foggy coast.  The actual definition from the American Meteorological Society describes  ‘a time interval, in mid or late autumn of unseasonably warm weather, generally with clear skies, sunny but hazy days and cool nights.’
Several references make note of the fact that a true Indian Summer can not occur until there has been a killing frost or freeze.  And while we may expect wintery weather to arrive in November or December, here in this part of the world we consider this time of year our Indian summer.

The term ‘Indian Summer’ dates back to the 18th century.  A Frenchman named John de Crevecoeur wrote in 1778 about  ‘an interval of calm and warmth which is called the Indian Summer, it’s characteristics… a tranquil atmosphere.’   No one know if is has anything to do with Indians, either.  It has been speculated that cargo ships in the 1700”s did much of their sailing over the Indian Ocean during the fair weather season in ‘Indian Summer’.  No one theory has been proven and since it’s been centuries since the term first appeared, it will probably rest with it’s originators. 

One thing we do know, fall is the best planting season of the year.  The soil is still warm encouraging root growth, the nights are cooler and days shorter which helps to conserve water, too.  This is a good time if you’re looking to add a new tree to shade the south side of your home, or perhaps start a hedge to screen the road.  If you want to add perennials to a border or start cool season annuals this is the time.

There are lots of deciduous trees to choose from that provide shade in the summer while letting the sun warm the house in the winter.  At this time of year trees with fall color come to mind. 

Maples like October Glory, Autumn Fantasy, Red Sunset and Autumn Blaze have gorgeous crimson red, magenta pink, or scarlet fall foliage,  Growing fairly fast to a mature height of 40-50 ft, they are large enough to provide that much needed summer shade.    Provide them with occasional deep watering and periodic feed to help keep roots deep. 

What about a hedge that screens the neighbor while also producing fruit?  Strawberry guavas can be grown as a 20 ft. single trunk tree, or a 10-15 ft multi-trunked tree , but are more often seen as a shrub 8-10 ft high.  Their 1 1/2" fruit is dark red or nearly black when ripe, with whiteRose of Sharon Red Heart flesh that is sweet but tart.  It can be harvested green and ripened at room temperature and is good eaten fresh or used in jellies, purees and juice drinks.  Even the bark of this evergreen shrub is a beautiful reddish to golden brown.  If you’re looking to add more edibles to your garden this is a good candidate.

Another shrub that would make a good addition to your garden is Rose of Sharon.  This hardy member of the hibiscus family blooms from mid summer until frost.  When dry summers have taken a toll on the rest of your border let this tough plant provide you with spectacular flowers.

There are dozes of varieties from double flowering forms to those with a contrasting eye.  Some reach 10 ft tall but can be pruned to shape.  One smaller one that I particularly like is called‘Red Heart‘.  It blooms with large white flowers with a burgundy eye, grows only 3 ft tall and looks beautiful when combined with the wine red flowers of chocolate cosmos.  Another favorite is ‘Blue Bird’ , a rich lavender blue variety with a deep red eye.  This one grows 3-5 ft tall and fits into the smaller garden, too.  Hibiscus syriacus are easy to grow.  They prefer full sun and tolerate some drought.  They are hardy to -10 degrees so our winters are a picnic for them.

Take advantage of Indian Summer to plant something new.

Late September “to do’s”

Cool Season Vegetables

Plant cool season veggie starts like broccoli, cabbage, cauliflower, chard, lettuce, spinach, brussels sprouts, onions and leeks in soil enriched with 4-6" of compost as summer vegetable crops will have used up much of your soil’s nutrients.

You can sow seeds of beets, carrots, radishes, spinach, arugula, mustard and peas directly in the ground.
If you aren’t going to grow vegetables in the garden this fall consider planting a cover crop like crimson clover after you’ve harvested your summer vegetables.  Next month I’ll talk about how to go about doing this and how this benefits your soil.

rocking garden saying

This is also the time to start perennial flowers seeds so that they’ll  be mature enough to bloom next year. 

 Now through October, divide summer blooming perennials like agapanthus, coreopsis, daylilies and penstemons that are overgrown and not flowering well.  You can also divide spring blooming perennials like candytuft, columbine, astilbe, bergenia and bleeding heart but sometimes they don’t bloom the first spring afterwards due to the energy they use re-establishing themselves.  If you’re on  a roll out in the garden, though, go for it now.  You never know what other projects you may be working on next spring. 

Enjoy our early fall weather out in your garden.
   

Chrysanthemums

 I can think of only a handful of perennials that bloom so easily, so prolifically and come in so many colors as the chrysanthemum.   Although they will be available throughout fall, the best supplies are often found now.  If you need to perk up your tired containers of flower beds, think of the reliable mum.

Actually, their botanical name has been changed to dendranthemum grandiflorum but I never hear anyone use this name.  It doesn’t exactly roll off the tongue.
Purple Mums

Mums represent the changing season with their bonze, yellow, orange and red tones.  Other flower colors include pink, lavender, purple and white to match any color scheme you might have.

Grown for years to flower only in late summer and fall, they are short day plants, setting buds when they receive light for 10 hours and darkness for the other 14 hours of the day.  This is why mums bloom in the spring on leggy stems if they are not cut back.  And this is how growers manipulate their blooming, adjusting the dark and light periods with shades in the greenhouse so buds will form in any month.   They’re nearly constantly available in grocery stores and florists in every season.

    At this time of year, garden mums abound.  Pick a plant with lots of buds, they bloom only once and won’t set more flowers until next year.  Those buds, though, last a long time if you don’t let them dry out. The specific type of plant doesn’t matter since they all have long term growth potential.  There is a European mum that produces hundreds of buds and stays relatively small and compact when set out in the garden.  If you particularly like one color or form of chrysanthemum, plant it now to enjoy again next year.  You never know what the growers might decide to grow next season.

Choose a well-drained, sunny spot to plant them.  Like many members of the daisy family, mums don’t tolerate soggy ground.  After blooming, trim off the old flowers and cut back plants to within 6-8" of the ground.  If you started with 4" pots trim back by half.

Next spring pinch them back whenever growth gets to 8" tall.  Keep pinching until July, then allow plants to start forming buds for the traditional fall show.  Mums need regular water so plant them in spots where you have other plants with the same water needs.

This fall, add to your mum collection or start a new one.  The pungent scent of their leaf reminds us that cooler weather is on the way.  And don’t forget to cut some for a bouquet to bring inside the house.