Annual Wildflower Tests Challenge Conventional Wisdom

Lee Gordon, CNPS San Diego Gardening Committee

Wildflower seeds sown in June 2016 and left uncovered produced a nice bloom of wildflowers in April 2017: Eschscholzia californica (poppies), blue Gilia capatita, yellow Camissoniopsis bistorta (sun cups), and white Cryptantha intermedia (popcorn flower).

Conventional wisdom says that the best time to sow annual wildflower seeds is in the fall, just before the rains, and that seeds should be covered with a thin layer of soil to protect them from predation. This conventional wisdom may be wrong. Tests in Scripps Ranch and Poway (San Diego County) suggest that it is better to sow wildflower seeds months in advance of the fall rain, and that covering seeds may actually prevent them from germinating.

The first test was in my friend Bob’s back yard in Poway. I mixed packets of seeds, and he sowed them in three adjacent areas in July, September and early November. He covered half of each area with a thin layer of soil and left the other half uncovered. The worst results were in the November area covered with soil. The best were from the half of the September sowing that was left uncovered.

I tried a similar test in a small Scripps Ranch open space, dubbed the “Canyonito” by CNPS member Sarah. I sowed seeds in three adjacent areas in June, September and November, leaving them uncovered. Workmen later covered the last two areas with a thick mulch to suppress weeds. No wildflowers grew in these areas at all. However, the area sown in June was left alone, and this area had a beautiful spring bloom. This test shows that you can get good results from sowing seeds early.

In a third less formal test, I sowed wildflowers on a hillside brush management zone in Scripps Ranch in October. This is an area of trimmed chaparral with considerable bare dirt. Two of the species behaved differently here compared with how they grow in the wild. While some plants grew to a normal size, many more grew late and stunted. Plants that grow stunted like these are uncommon in the wild.

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Watering Strategies from South Bay Botanic Garden

by Susan Krzywicki

Eddie Munguia, Horticultural Lab Technician South Bay Botanic Garden

Eddie Munguia, Horticultural Lab Technician South Bay Botanic Garden – Photo by Susan Krzywicki

After so much debate about how to water native plant gardens, you’d think it had all been said. Let me add some tips and techniques from Eddie Munguia, who is the Horticultural Lab Technician at the South Bay Botanic Garden, located on the campus of Southwestern College in Chula Vista. Eddie installed a native garden over four years ago and one of the key objectives of the botanic garden is to do just this sort of closely observed research and analysis.

Split Cycle Watering – preventing root zone waterlogging
Last July, after attending a professional workshop, Eddie decided to experiment with split cycling – taking the duration of watering proposed, and dividing it into two segments with a two hour gap in between. For example, instead of running a sprinkler zone for 10 minutes, he runs the zone for 5 minutes, in the early morning hours. This allows for absorption by the soil, while avoiding swamping the plant, which can lead to disease and plant death. Eddie has decided that his clear mandate is to “imitate rainfall” by providing supplemental irrigation that looks more like our natural pattern: gentle, sparse summer rains, not heavy storms. During Santa Anas, he recommends 2 minute spritz to cool the plants off. If the plant is suffering from summer stress, he doesn’t dump a lot of water on it, he just refreshes it.

The garden, which is well over 5,000 square feet, is mostly Diablo clay with native hybrid species originating in San Diego county and the Channel Islands.

A view of South Bay Botanic Garden

A view of South Bay Botanic Garden – Photo by Susan Krzywicki

Results: longer bloom times, good growth
Within two weeks of implementing this strategy in July, everything was flourishing. Coast sunflower (Encelia californica) now blooms two months longer. Bladderpod (Isomeris arborea) now produces flower for him all year round. Showy penstemon (Penstemon spectabilis) is blooming later in the year. Bush poppy (Dendromecon rigida) species doubled in size. The garden stay a little greener into summer. And Eddie even observed a third flowering cycle for San Miguel Island buckwheat (Eriogonum grande rubescens).

Advice: Experiment and adjust
Eddie says, “Don’t be afraid to experiment with your watering cycles. As long as you are not bogging them down, or the root zone is getting drenched, they will do OK.” He says he got lucky on the first try with his split-cycle low-impact changes. So, if you follow his method, note garden changes over at least a month, then adjust again.

Would you consider this for your native garden? Please let us know your thoughts, and, if you try this method, please do keep us up-to-date with your progress and observations.

This article was first published in the San Diego Horticultural Society October 2016 newsletter.

Susan Krzywicki is a native plant landscape designer in San Diego. She has been the first Horticulture Program Director for the California Native Plant Society, as well as chair of the San Diego Surfrider Foundation Ocean Friendly Gardens Committee, and is on the Port of San Diego BCDC for the Chula Vista Bayfront.

Ribes in Spring

RibesArticle and photos by Jennifer Jewell

The spring woodland garden has many bright stars in the form of shrubs: ceanothus and mahonia come immediately to mind. But look a little closer and you will see how lovely the ribes are as well this time of year. The native ribes are far more soft-spoken but have equally nice things to say as their brighter companions. Continue reading

Landscaping for Southern California Gardens

Summer-dry, drought tolerant, naturalistic, Mediterranean garden with California native Acer circinatum (Vine Maple). Photo by Saxon Holt.

Summer-dry, drought tolerant, naturalistic, Mediterranean garden with California native Acer circinatum (Vine Maple). Photo by Saxon Holt.

By CNPS and Modernize

The unique environment of Southern California, while often a source of great appeal for its residents, poses distinctive challenges for anyone wishing to develop and maintain the aesthetics of their yard. The dry climate, paired with an increasingly limited water supply, means a lush green space is no longer ecologically viable. However, there are many other possibilities for creating a beautiful outdoor space.   The folks at Modernize, a website devoted to home remodeling inspirations, like to view this landscape challenge as an opportunity to create a uniquely Californian place for outdoor living.  Here, they share two approaches to this challenge- xeriscaping and hardscaping- including along the way some of their favorite California native plants for the garden. Continue reading

It’s CNPS Fall Plant Sale Season!

liliesFall is the right time to prepare your garden for spring!

When is your local chapter hosting a plant sale, presentation, or native gardening workshop? The CNPS Horticulture Events Calendar is searchable by CNPS chapter and type of event, including “Plant Sale” to help you plan for regional CNPS Chapter plant sales. The calendar is frequently updated, so be sure to check back for events in your area, or follow the CNPS Facebook page where we are posting many of these events as well. There’s never been a better time than now to transform your yard into a water-thrifty, habitat-extending, native garden!

Buckwheats by the Bay

Buckwheats

It’s fairly warm in most parts of California and the northern end of Baja. And dry. People are talking dry dry dry…so here is a bit of refreshment.

I took this photo at the Waterfront Grill in National City. The cool water and colorful surfboards reinforce the beautiful rusts and creams of this field of buckwheats. Eriogonum species always turn up on drought-tolerant plant lists everywhere. For ornamental gardening, they are usually conceived of as plants for the typical dry-looking garden.

But here, they were positioned at water’s edge and they really made a hit, visually.

The Eriogonum family is a pretty diverse group, with a wide cultural range. Great pollinator attractors, too. Find out what grows nearest to your location, find it at a local nursery and try one soon. Then plant more!