Plants have temp preference

The Coastal Gardener

June 25, 2010|Ron Vanderhoff
  • The aeoniums, senecios and juniper in this garden are all cool-season plants. Keeping cool season and warm season plants grouped seperately is one of the important principles of garden success in southern California.
The aeoniums, senecios and juniper in this garden are… (Daily Pilot )

All day at local nurseries, the questions come every few minutes: "Why are my aeoniums shriveling? What can I do to keep my sweet peas blooming? Where did all the native plant inventory go? Why are my freesias and daffodils drying up?"

This time of year in Southern California, gardeners are seeing a lot of changes in their plants, and local homeowners continue to be baffled by what they see.

Probably the most important, yet poorly understood aspect of garden plants, is the distinction between cool-season and warm-season plants. If I ever write a book about local gardening, this topic will likely be dealt with in the first paragraph, especially since it is so poorly presented by most authors. It amazes me how many gardeners still don't understand that plants, almost all plants, can be divided into two groups, cool-season plants and warm-season plants.

When gardeners fully comprehend this cool season-warm season concept, their world will change. A knowledge of the seasonal scheme of the individual plants in their gardens will alter their entire approach to gardening. It will open your eyes, like the day they tasted their first ice cream or learned to swim in the deep end of the pool. This discovery will be an "aha" moment for many gardeners, a moment of tremendous relief, satisfaction and understanding.


Plants have seasons. All plants do — even plants in Southern California.

Plants grow, flower and thrive during their pre-determined preferred season. Generally, this is either in the cool half of the year or in the warm half of the year. During a plant's non-preferred time of the year it retracts in one way or another, sometimes in obvious ways but often in subtle ways, not noticed by casual gardeners. This off-season usually results in the plant stopping or slowing down its growth, dropping its leaves, contracting its roots or generally just sulking. Of course, a gardener's wishes and desires won't change a plant's preference for either a cool or warm season in the slightest.

Unfortunately, plants can't talk, and they don't come with labels that say "cool-season" or "warm-season." I wish they did, but a warm-season plant in Seattle might be a cool-season plant in Orange County. They may even be different in Riverside than in Newport Beach. Plant tags couldn't possibly keep up with all the nuances of regionality, nor can books, websites or other references that deal with more than very local areas.

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