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Want to make your vegetable garden more waterwise?  Here are two suggestions:

• Switch to drip irrigation

Most vegetables dislike having wet leaves. In fact, wet leaves often become mildewed leaves.  Drip irrigation is far more efficient than overhead spray and it keeps leaves dry and mildew free.

• Mulch with a three-inch thick layer of home-made compost.  If  you don’t have enough compost, use seedless straw.


Straw is the perfect vegetable mulch. It is lightweight, keeps weeds down and soil moist

Wood based mulches, stone and gravel mulches are fine for ornamental plants, but in the vegetable garden, home made compost and seedless straw are better choices.  Both insulate the soil from water loss and both are light enough for seeds to push through.

Zinnia seedlings poke up through the straw

If you opt for straw, be sure you don‘t get hay or alfalfa or anything  that has lots of seeds.  Why?  Years ago, I mulched with straw and grew a lovely bed of wheat…. instead of tomatoes!

If you can get old straw, that’s even better.  As straw ages, the  fibers start breaking down and residual seeds begin to rot.   That’s a good thing.

And, old straw can’t be sold for animal bedding, so feed stores (the best places to get straw) often regard them as waste.  In fact, they may even give you the straw for free!

If you don’t have room to store an entire bale of straw, ask for a “flake.”  A flakes is simply a section of a bale.

This bale of straw will last me two or three seasons

Is it okay for my blog to quote another blog?  Oh, what the heck!

The wonderful Sharon Cohoon, Southern California editor for Sunset Magazine (and the woman I’d like to be when I grow up) wrote about my new garden wall in her blog, Fresh Dirt.   I love what she wrote!

When you walk out onto Nan Sterman’s back patio, you see this intriguing fountain wall ahead of you that invites you to come out and explore the garden.  It looks so right where it is I figured it must have popped into Nan’s mind as a fully-fledged idea.  Not exactly.  The truth is the San Diego garden writer/designer/lecturer got all the favorite men in her life involved in coming up with this perfect-for-her-garden design. (read more)

Had a great time doing my quarterly gardening radio gig on KPBS FM 89.5, Public Radio in San Diego. Host Maureen Cavanaugh is a blast to talk with, and the callers had great questions about tomatoes, how to water, the cool weather, and lots more.

Click here to listen!

When Maury and Heather Callaghan moved to their newly built Olivenhain home in 2001, they carpeted the two-thirds-acre lot in sod. The New Zealand natives had lived all over the world, most recently in Kentucky where they had a large, woodland garden. Both had gardened with their parents as children. As adults, however, Maury’s business had taken them around the world, mostly where there wasn’t much opportunity for gardening, until they landed in Kentucky, where Heather became a Master Gardener. (read more…)

People constantly ask me how much and how often to water their plants.  There is no definitive answer.  It depends on your microclimate, the type of soil in your garden, the type of irrigation you use (drip, overhead, etc.) and more.

That said, figuring out how to water your plants isn’t all that difficult if you use my “Canary Test.”

In the old days, miners took canaries with them into coalmines. Since canaries are very sensitive to lethal but odorless carbon monoxide gas, the miners knew to leave the mines when the canaries started to get sick.

My “Canary Test” is way to test how often and for how long each of your garden’s watering zones actually needs run. In your garden, the “canary” is the first plant to show signs of water stress.

The Canary Test

Test one watering zone at a time (a watering zone is a set of sprinklers or drip emitters that are connected to the same valve and run at the same time).

Figure Out How Often to Water

1. Pick a zone. Make sure you know which plants that zone waters
2. Turn the zone off.  Mark the date on your calendar
3. Wait and watch for the canary -  the first plant to show signs of water stress.  When you notice a plant whose leaves look a bit wilted, you’ve found your canary. It might take several days or it might take several weeks. Eventually, you’ll see the canary.
   
4. Check your calendar to see how many days passed since you turned that zone off.   Make a note of it.
5. Figure out how often to water.  If, for example, it took 14 days until you noticed a canary in a particular zone, then water that zone every 12th or 13th day (that’s two weeks, minus one or two days). If it took seven days, then water every sixth day, and so on.

Your goal isn’t to get your plants to wilt, but rather to to avoid watering before plants need the water.

Figure Out how Long to Water

1. Once you identify your canary, run the irrigation in that zone.  Check the soil every five or ten minutes for overhead sprinklers, every 10 to 20 minutes for rotating nozzle sprinklers, and every 30 minutes for drip irrigation.
2. Note how long it takes for water to soak deep enough that when you stick your finger all the way into the soil, it is saturated not just at the surface but as deep as you can feel.

If the soil is really hard, you may need to dig down with a hand trowel or soil probe rather than using your finger.

1. Repeat the process for each watering zone.

The point is to get water to plant roots deep in the soil. However long that takes is the amount of time to irrigate that zone.

You’ll soon realize that each zone needs to run on its own schedule. Your lawn, for example, may need to run ten minutes, three times a week in summer, but your flower border can go for a week between waterings.  Your shrub border can go two weeks or a month, especially if you deep-water each time.

Areas irrigated with overhead spray  need to run for only minutes at a time, but drip irrigated areas run for an hour or longer since they release water very slowly.

Repeat the Canary Test for each zone, once a month to create a year-round watering schedule. Winter’s rainfall may provide enough water for weeks or months. On the other hand, in the dry heat of summer, plants need watering far more frequently.

Every time you water, water deeply and thoroughly. Don’t be afraid to use your finger as a  probe to test how wet the soil is.

Whether you control your sprinklers manually or use an irrigation clock, adjusting your watering schedule to match your plants’ needs saves tremendous amounts of water and grows healthier plants.

Ever drive along the roadways of California and notice a huge, fountainy grass with big, feathery, buff-colored plumes?  To the untrained eye, pampas grass (Cortaderia selloana)  looks like a statuesque, beautiful grass, but oh!  Beware!

Pampas spreads out of control

In her wonderful horticultural history, Southern California Gardens, Victoria Padilla tells how in the mid 1800s, Joseph Sexton “the father of horticulture in Santa Barbara” popularized pampas.
Vast acreage was devoted to pampas as demand grew, not just for  garden plants but also for plumes to decorate hats and other items.  “Pampas grass became so popular.” Padilla writes, “that it was almost a national emblem, and was used not only for indoor decorations, but for parades and even on holiday greeting cards”

Notice how the pampas towers over John Sexton!

If only Sexton had known what would happen not a full century later.  Pampas was so well adapted to growing in California’s Mediterranean climate, this South American native has become one of our worst invasive plants.   It invades natural habitats, crowding out the plants that native animals depend on for food, shelter, and cover.  It clogs waterways causing the buildup of sediments and again destroying native habitats.  Its dry leaves and plumes allows fire to jump from plant to plant, even across wetlands.

Pampas’ destructive nature has not gone unnoticed.  There are efforts at every level in the state to stop the sale of pampas in nurseries.  At the same time, millions of dollars are spent annually in eradication programs both for habitats and for garden situations.

In fact, home gardener Sandy Shapiro initiated a backyard pampas eradication program in his hometown of Encinitas, California.  Project RIP, or “Remove Invasive Pampas Grass” was intended as a model program to show residents how to get pampas off their properties.

Still, wholesale and retail growers continue to offer dwarf and variegated hybrid pampas such as such as ‘Gold Band,’ ‘Silver Comet,’ and others.    Because identical looking seedlings don’t pop up in the nurseries, they assume these plants are sterile and “safe” for garden use.   But are they right?

Pampas is beautiful, but beware!

Not according to Marie Jasieniuk, Assistant Professor in the Department of Plant Sciences at UC Davis. Jasieniuk identified genes found in both wild (invasive) pampas populations and cultivated landscape pampas varieties sold by nurseries and garden centers in California, in other states across America, in Europe and New Zealand.  She compared the genetics of cultivated varieties to 29 wild populations of pampas from Crescent City in the north to La Jolla in Southern California.

Jasieniuk’s research determined that wild populations of pampas have genes in common with the so-called sterile, cultivated varieties.

In other words, while they don’t breed true-type offspring, cultivated pampas definitely breed with the wild growing pampas and contribute to the overall problem of invasive pampas.

According to Jasieniuk, ” landscape plantings are probable sources of invasive populations…  Our results strongly suggest that …. landscape planting has contributed to the range expansion of invasive C. selloana in California.”

Further, results suggest that even as we spend millions of dollars eradicating wild growing populations of pampas, landscape plantings continue to “replenish” the wild populations. Therefore, Jasieniuk writes, ”management efforts that target secondary releases by eradicating landscape plantings may be highly effective in controlling existing invasive populations as well as preventing further invasive spread.”

In other words, to eliminate invasive pampas from both native habitats and cultivated areas, we need to stop planting all varieties of the pampas, Cortaderia selloana in our gardens.

Beautiful but dangerous.  Sounds like the beginning of a good novel.  If only it were fantasy rather than reality….

Thanksgiving leftovers are almost eaten, my guests have all gone home, and it rained last night.  It was the first rain of the year.  Granted it was only a tenth of an inch, but to my rain-deprived brain, it sounded like a deluge.

The skies have been gray all day, which, combined with sweatshirt temperatures, propelled me into the garden to prune.

I have a love-hate relationship with pruning.  I know, that if I want abundant crops of apples, nectarines, pluots, apricots, peaches, grapes, and figs, I have to prune.

Beautifully pruned grapes at Copia

While there is a certain satisfaction that comes from snipping and cutting and shaping trees, I have so many to do (about 20 at last count) that the prospect of  annual pruning is totally overwhelming.

And it isn’t just the pruning that’s the issue.  There’s the disinfecting too.

Peaches and their relatives in particular are very susceptible to pests and diseases.  If I’m not careful, my pruning tools can transmit them from one tree to another.  To avoid that kind of contamination, I disinfect my tools as I finish pruning each tree.  Tools get dipped in a 10% bleach solution or spritzed with spray or foaming bathroom disinfectant, then wiped with a dry towel.

The foaming disinfectant is definitely more fun.

Because pruning is such a huge task, I tend to take it in stages.  Figs are far and above the easiest trees to prune thanks to their soft wood.  I hardly ever need to use a saw, just pruning shears, a lopper, and my favorite pruning tool, a Fiskars pruning stick (no, they don’t pay me to say that).

Fiskars Pruning Stik - I love it!

There is another reason I like to start with figs; I want to prune them before they develop next year’s fruits.

Shortly after I pick the last, succulent fig of the year, tiny green orbs begin to form at the  tips of each fig branch.  Those orbs are next year’s fruits.  If I wait too long, I’ll prune off those developing fruits and voila!  No figs next year!

I learned this the hard way.

Today, I started my pruning with the ‘Brown Turkey’ fig that stands aside the stairs to my vegetable garden.

'Brown Turkey' Fig

I first pruned off all the branches that were growing too tall. I cut off some dead wood and then I worked on the arch I’ve been directing over the stairs.

I started the arch several years ago.   It is slowly taking on the shape I want - one that will eventually allow me to reach up and pick figs as I walk down the stairs!

My post-pruned fig  doesn’t look beautiful now, but when the new leaves come out in the spring, my tree will be gorgeous!

'Brown Turkey' Fig Post-Pruning

In a future blog I’ll explain how to prune to control the direction of branches.  But before it gets dark, I have to head out to the garden and finish one more task.

Rather than composting the branches I pruned off my figs, I’ll cut them into 8″ long lengths and pot them up.  With a protective cover (i.e. a loosely tented clear plastic bag), they’ll root over the winter.

By next spring, I’ll have baby trees to share with my fig loving friends!

One of my greatest honors is to have my work inspire others.  When students email me with stories and photos of their water-wise gardens inspired by one of my classes, for example, I am thrilled.

Imagine my delight, then, to discover that my book, California Gardener’s Guide vII inspired a gorgeous mosaic mural!

A few months back, public artist Christie Beniston invited me to the dedication of her tile mural as it was unveiled in its permanent home at the main entrance to  Flower Hill Mall in Del Mar, California.

The images in Christie Beniston's mosaic mural are based on photos from California Gardener's Guide vII

Christie’s 5′ x 9′ mural features oversized flowers and critters in fantastic colors.  She designed it and assembled it with the assistance, she tells me, of many hands “The mural was created by members of the community” she says, “under (my) design for ‘Arts in Bloom 2009‘ sponsored by the Solana Beach Art Association and Flower Hill Mall.”

Book Works, one of our finest local independent bookstores, invited me to speak at the event, but for some reason, I didn’t get a chance to see the mural that day.

Later, Christie told me that she’d used my book as a reference guide for the flowers.  “The flowers pictured are meant to represent verbena, cape mallow,  California fuschia, matilija poppy, penstemon, and marigold” she explained, “I took some artistic liberties along the way but your book was the guide, it is a beautiful resource.”

How thrilling!

The mural is both colorful and whimsical

I asked Christie how the piece came together.  She said, “Teen Korps volunteers helped supervise and break tiles.  I painted a cartoon outline on the cement substrate to help guide the placement of the broken tiles. We used commercial tile and some handmade tiles from my studio.  The tiles went on with thinset.  I then grouted (with some help from friends!) and the sign company that works with Flower Hill (Mall) donated the frame and helped with the permanent installation.”

Several months back, I had seen the mural in-progress when I visited   the Center for a Healthy Lifestyle at Solana Beach Boys and Girls Club.  Our mutual friend, garden designer Katie Pelisek, who runs the center,  had generously allowed Christie to use her facility to assemble the mural.

At the time, I had no idea that there was any connection to my book.  I just admired its whimsical, colorful, oversized flowers.

The mural’s beauty is the result of Christie’s magical touch, just as she has a magical touch with all the art pieces she creates.  And she creates alot of art!   Murals, sculptures, garden art, and more.

Take a look at her on-line galleries!  Recently, the San Diego International Airport held a dedication for Christie’s installation “Time Interwoven.”  (It also won a coveted “Orchid” award from the San Diego Architectural Foundation’s Orchids and Onions Awards).

I’ve always been fascinated by mosaics, though I’ve yet to try my hand at making any (anyone want to invite me to a mural making session?  I’d like to learn!).

I’d love to have one of Christie’s pieces in my own garden, but for the moment, I’ll have to live with having my garden in her art instead!

Visit Christie’s Beniston’s mural at the main entrance to the lower level of Flower Hill Mall , 2720 Via De La Valle, Del Mar, CA 92014-1923

Hidden Pleasures

Plants are so amazing….

Last night, my husband and I took an evening stroll and as we stepped out the front door, I was struck by a sweet fragrance.   I couldn’t quite pinpoint its source, and since my husband was already half way up the street, I scrambled after him rather than taking the time to find it.

Upon our return, however, I stopped him before he made it to the front door.  “Honey,” I said, “do you smell that?  Lets figure out where it is coming from.”  I happen to have a better smeller than he does, but I like to involve him in my plant escapades from time to time.

I know from experience that the biggest smells often comes from the most demure or subtle blooms.  In fact, it is a common strategy for plants whose flowers aren’t very showy to make a big smell.  We humans may think that the fragrance is for our enjoyment, but in truth, that’s how the plants attract pollinators.  And the fragrance isn’t always sweet.

In the case of Stapelia, for example, the genus is known for its off-color, star-shaped  flowers that nestle deep among succulent branches.  It would be pretty challenging for an insect or bird to find their blooms by sight.  But the flowers emit a terrible odor, like rotten meat.  And guess what their pollinator is…   flies!  What better way to attract a fly than to smell like rotten meat?

Pale colored flowers are often fragrant too.  Angel trumpet (Brugmansia) for example, has lovely, huge, dangling trumpet-shaped flowers, typically in ghostly white, pale, yellow or pale pink/coral.

Beautiful white flowering angel trumpet is fragrant from afternoon to evening to attract its pollinator, a night flying moth

These big-blooming South American natives are pollinated by moths at night.  So, how do the moths find their targets in the dark?

If you grow angel trumpet, you’ve probably noticed that they emit a wonderful floral fragrance starting in the late afternoon and lasting through much, if not all of  night time hours (I’m never awake long enough to figure out when the fragrance abates).  The moths simply follow the scent.

By the way, hybrid angel trumpets are selected for more intense-colored flowers.  And the  cold-tolerant, Andean red angel’s trumpet, Brugmansia sanguinea blooms deep orange-red with a yellow throat.

One of my favorite species gladiolas, Gladiolus tristis (South African marsh Afrikaner) uses the same strategy as the angel trumpet. These January/February bloomers have tall, narrow leaves and the palest of yellow flowers.  Starting late afternoon, their perfume fills the air, just in time to attract their own moth pollinator.

But this time of year, the angel trumpet has yet to flower and the gladiola is long past.  So what was so fragrant?

Amazingly enough, it was a Sansevieria, a plant whose unfortunate common name is mother-in-law’s tongue.

Sansevieria are evergreen plants of tropical and subtropical Africa and Asia.  They were tremendously popular in the era of  mid-century modern and modernistic architecture (roughly 1940s - 70s) because of their own architecture. Tall, smooth, single pointed blades each rise straight from the ground, some solid green, some pale green, some green with yellow margins, and others spotted.  Some blades are straight while others twist slightly.  Still others fold into themselves to form a solid cylindrical spear.

Sansevieria with spotted blades

Sansevieria with patterned blades

Sansevieria with cylindrical blades

Sansevieria continue their popularity in part because these oddities are able to live in the shade outdoors (in frost free areas) or indoors with almost no water at all, as long as they are planted in very well draining soil.

I have a Sansevieria given to me years ago that was my very last houseplant after the rest died or migrated outdoors.  It sat in my office and was watered about once every six months - when I remembered.  I finally took pity on it and moved it outdoors where it really isn’t as happy as it seemed indoors.

This demure little Sansevieria bloom has the fragrance of fresh Freesias

But last night as I searched my front entry patio, I noticed a very small, very unobtrusive, and unfortunately no longer labeled Sansevieria.  It sat in a small pot where it had produced a tall flower stalk, the source of the evening’s perfume extravaganza.

The funny thing is, I have at least a dozen kinds of Sansevieria, most given to me more than 25 years ago by the late plant explorer Manny Singer of Singer’s Growing Things.  All these years, they haven’t even hinted at blooming, and this year, at least four different types are in bloom.  And all fragrant.

Ah, the wonder of plants!

What’s the surest way to get the most flavor from vegetables and fruits?  Grow em yourself…..from seed!

Starting vegetables from seed was the topic of the talk I gave at the Los Angeles County Arboretum and Botanical Garden’s Festival of Flavors this past Friday. The topic seemed fitting since the huge variety of vegetables seeds on the market offers gardeners their widest range of possiblities!

It always seems so magical to me to start with little pieces of what look like wood; Add with some water, light, and a bit of seed starting mix to make those seeds  sprout and grow into bountiful plants that produce delicious vegetables.

Homegrown veggies always put supermarket veggies to shame.

By 3 pm Friday, the seats in the speakers’ area were full and everyone had a package of gourmet red chard ‘Scarlett Charlotte’ seeds I brought with from my good friend Renee Shepherd of Renee’s Garden Seed.

My dear friend and mentor Jan Smithen, author of Sun Drenched Gardens, introduced me to the audience and away we went.

I love the fact that people are interested again in growing their own vegetables, herbs, and fruits. It only follows that they are interested in starting them from seed. It is a skill that was once commonplace, then nearly lost, but is now coming back around again. Much to my delight!

We started with a lesson on reading seed packets.

Its ironic how important label information is and how little effort most companies put into their labels. Some companies do a great job and Renee writes some of the best. She deftly combines romance and detailed how-to with delicious suggestions for cooking and eating each variety.

Being a frugal gardener (is there any other kind?), I presented several examples of containers for starting seeds – old cottage cheese or yogurt containers, take-out food containers, or plain ‘ole four packs recycled from the nursery.

I prefer four packs to six packs, since the cells in a four pack are large enough to support seedlings all the way to transplant. With six-packs, seedlings can get only so large before they need to be “moved up” to larger containers. Saving that step saves my time, and it also means seedlings develop faster since they don’t have to go through transplant shock twice (once being moved up and the second time when I put them in the ground).

And by the way, someone asked me about using egg cartons. The simple response is: “don’t bother.”

Anything being reused has to be disinfected first, of course, to keep the tiny seedlings free of deadly bacteria and fungi. I give containers a good soak in a 10% bleach solution (one part bleach to 9 parts water). While I’m at it, I throw in plastic plant labels so I can reuse them, and I give my pruners a dip too (I dry and oil them afterwards).

Fresh seed starting mix is important as well. As compared to potting soil, Seed staring mix is more finely milled so the tiny seedlings have an easy time pushing up through the surface. It is also pasteurized to kill the pathogens. Black Gold seedling mix is one of my favorites. I had the purple-and-black label bags with me on Friday.

We spent half an hour going through the how-to process of how to start seeds, both small and large, in containers and as what I like to call “seed sandwiches” (more on that in a future blog).

When we ran out of time to talk about how to do cuttings, the audience insisted on continuing. So, I spent another 15 minutes demonstrating cutting basics a beautiful pink-flowering perennial Salvia chiapensis from Monrovia growers.

The audience was wonderful. They were tremendously enthusiastic asked great questions – always the most fun part of any talk.

During the hour-long presentation, I divulged some of my favorite hints for success …Think I’m gonna give them all away here? No way! But I’m happy to share those secrets when you invite me to speak to your group or event!