Why are some plants drought tolerant?

'Garden of Dreams' (CSUDH) features local native drought tolerant plants

 

After four years of serious drought and water restrictions, most California gardeners are concentrating on drought tolerant solutions.  But what makes one plant drought tolerant and another water-loving?   The answer is more complex than you might imagine.  

To learn more see: http://mother-natures-backyard.blogspot.com/2015/10/how-things-work-plant-drought-tolerance.html

 

 

 

  

    

 

Shade Trees for a Changing Future Climate

Blue Elderberry tree once provided needed shade in Garden of Dreams,
 CSU Dominguez Hills

The past few years have been sobering for anyone concerned with our planet’s future.   In Southern California, the effects of four years drought can be seen in nearly every garden and wild place.  Record-breaking heat and winds have also plagued us, compounding the effects of the drought.   Climate change is happening right now – and we’d best be planning for more to come.

In 2014, we gave a talk on Climate Change and the Southern California Garden.    We discussed the climate models, their predictions for Southern California and the implications for local gardens.  Two conclusions are clear: 1) overall temperatures – and the number of high heat days (> 95° F; 35° C) – will increase in S. California over the next century; 2) the frequency of extreme precipitation years (both drought and greater than normal precipitation) are also likely to increase. For more predictions see our 2014 talk: http://www.slideshare.net/cvadheim/climate-change-2014.

Our gardens must provide more shade in the future.  Hardscape features like patios, arbors and awnings are one way to create shade.  But ‘living shade’ – that provided by trees, shrubs and strategically placed vines – has additional benefits.  Plants cool the surrounding areas by evaporative cooling; that’s why the shade under trees feels cooler than the shade under a patio roof.  Plants also release oxygen, clean the air of contaminants and provide habitat for numerous creatures.  If chosen carefully, shade trees and shrubs provide colorful flowers, edible fruits and a green oasis in summer.

 

Toyon (Heteromeles arbulifolia) - pruned as tree

 

Ideally, shade-producing plants are long-lived – 50 or more years is ideal.  That means that shade trees planted now must be tough enough to thrive in the climate of 50 years and more in the future.  We’re betting strongly on California natives, including some trees and shrubs that already grow in the Los Angeles Basin.   Locally native survivors are appropriate for our soils and provide key habitat for local creatures.  So we should use the local natives when appropriate.

But the choice of trees that can survive and thrive into the future is anything but straight forward.  To learn more - and for a list of suggested trees and shrubs - see: http://mother-natures-backyard.blogspot.com/2015/09/sustainable-gardening-trees-for.html

Surviving the Drought

Plenty of summer flowers, seeds and fruits for bird & pollinator habitat:
 Garden of Dreams, CSUDH, in July, 2015 (after 4 years of drought)

The past four years of drought have been tough on gardens and gardeners.  Even water-wise native plants are showing signs of stress.  For some practical ideas on surviving the drought see: http://mother-natures-backyard.blogspot.com/2015/07/surviving-drought.html




Water-wise native plants from the Channel Islands stand up well to the drought. St. Catherine's Lace (Eriogonum giganteum) and Catalina silverlace (Constancea nevinii) with background of Mulefat (Baccharis salicifolia) and Southern Island mallow (Lavatera assurgentiflora)



Harvesting Rain: Consider Planting a Rain Garden

The past few years have got us thinking about using rain water effectively.  There are many reasons to consider infiltrating more water  into your garden.  These include: 

1. Saving money – rain water is free water
2. Conserving a valuable and increasingly scarce resource – water
3. Helping replenish the ground water
4. Providing habitat for insects and birds
5. Providing a place to plant interesting stream and pond-side plants
6. Teaching children the values of conservation and water-wise gardening
7. Deep watering your garden’s trees and shrubs (in winter/spring in our area)

One simple but effective infiltration tool is the rain garden or vegetated swale.  Rain gardens/swales capture water that would otherwise run into the storm drains - and allow it to percolate into the ground.   They make sense for many home gardens and are becoming increasingly popular throughout the world.   To learn more see: 

http://mother-natures-backyard.blogspot.com/2013/03/harvesting-rain-rain-gardens-and.html   and http://www.slideshare.net/cvadheim/infiltration-gardens-2015

 

There's still time to install a rain garden this year.  To help you out, the CSUDH Native Plant Nursery will be offering native plants suitable for rain gardens in February.  For a reasonable donation you can get the plants you need to install your new rain garden.   Look for the plant list next week!

 

 

What does a water-wise garden look like in summer?

 

Hooker's evening primrose (Oenothera elata ssp. hookeri) in 'Garden of Dreams' on the CSU Dominguez Hills campus.  Garden is watered once a month in summer.

 

Water-wise gardens have definite seasons.  Right now we're well into the dry season.  The annual spring wildflowers are just a memory; grasses have magically transformed to gold and silver.   Yes, we're in the dry season, which will last until the fall rains.

 

The dry season is the time of rest for some plants.  In the Garden of Dreams and Heritage Creek, the California encelia (Bush sunflower) and Salvias (native sages) are mostly dormant now.  The Salvias have produced a small second set of leaves to get them through the dry period.

 

Other plants are evergreen - but still mostly resting.  These include Mulefat (our large hedgerow plant in Garden of Dreams), Coyote bush (Baccharis pilularis) and Lemonadeberry.  Some shrubs have green berries that will ripen in fall: Toyon and the native cherries (Prunus ilicifolia) are among the most prominent.

 

But even in summer and fall, a surprising number of native plants are blooming.  They range from the larger Laurel sumac (Malosma laurina) and Southern island mallow,  to Annual sunflowers and Hooker's evening primrose (Oenothera elata ssp. hookeri) that brighten our summer with their yellow flowers.  The summer-blooming buckwheats add a touch of pink and white to the summer palette.  In fact, there are many native plants blooming on campus right now (see the 'Blooming Now on Campus' page).

 

 

Annual sunflowers (Helianthus annuus) brightens the foreground. Native buckwheats (Eriogonum species) bloom pink and white (left) against a background of green and gold.

 

So take the time to visit Heritage Creek Preserve or one of the native plant gardens on campus.  If you come from 11:00-3:00, notice the bees, butterflies and other pollinators busily at work.  If you visit earlier or later you'll be surprise by the number of birds you'll see.   Sit a while, relax, unwind.   And then you'll know what a water-wise, life-friendly garden looks and feels like in summer.

 

 

Mulches : Beautiful, Water-wise and More

CSUDH students and faculty apply mulch to 'Garden of Dreams' native plant garden

 

The CSUDH Ecology Club and students in BIO 310/311 (Plant Physiology & Lab) classes recently applied a new layer of mulch to the ‘Garden of Dreams’ native plant garden on campus (above).  You can see how much better the garden looks in the pictures below.

 

'Garden of Dreams' - before new mulch

 

'Garden of Dreams' - after new mulch

 

 In addition to their aesthetic appeal, mulches help keep the soils cool in summer, help conserve water,  keep garden vegetables clean and pest-free and much more.  In short, mulches are a good idea.  But you need to know how to apply them, when to apply them and which mulch to choose.  You can read all about mulches at: http://mother-natures-backyard.blogspot.com/2012/07/understanding-mulches_23.html

 

 

 

Planning a New Garden? Re-thinking Your Old Garden?

Planning a new garden can be a daunting task.  There are so many things to think about – and so many good ideas.   It’s hard to know where to begin.   Fortunately, our sister blog, Mother Nature’s Backyard, has something that can help.   Their series ‘Planning Your New California Garden’, which began in July 2013, takes you step by step through the garden design process.   See the first posting at: http://mother-natures-backyard.blogspot.com/2013/07/designing-your-new-california-garden-1.html