The Bold Dry Garden

Book Cover

It’s not often that we see a new book about a garden that’s both famous and near enough for a one-day visit. We now have The Bold Dry Garden: Lessons from the Ruth Bancroft Garden (Timber Press, 2016), written by Johanna Silver, with historic photographs and excellent new photographs,

This is a three-acre garden in a residential neighborhood, packed with over 2,000 cacti, succulents, trees and shrubs. Visiting is not a sprawling and overwhelming experience, with too much to take in without camping out, or an extended visit. Instead, it offers a relatively compact display of a wide variety of succulent plants.

The book begins with the garden’s history. Ruth Bancroft developed this garden at her home in Walnut Creek, beginning in the 1950s. Like all personal gardens, it began tentatively, with the purchase of few small plants, and grew slowly as the owner’s interest deepened and her vision broadened.

By the early 1970’s, Ruth was ready to map out her future garden. She brought in garden designer Lester Hawkins, to draw the setting for a dry garden, and to recommend plants to add to her growing collection. The initial planting was accomplished formally in 1972, although Ruth had already collected a significant number of plants.

The plants grew in number and size, and the collection grew in sophistication and beauty. It deeply impressed, Frank Cabot, a nationally prominent gardener from the Quebec area, who became concerned about preserving the garden into the future. In 1989, he founded the Garden Conservancy with the goal to preserve exceptional private gardens, with preservation of the Ruth Bancroft Garden as its first objective. By 1994, the Garden’s site was officially transferred to a non-profit corporation, Ruth Bancroft Garden, Inc., dedicated to maintaining and improving the garden, and to make it available to the public.

Today, Ruth Bancroft is recognized as a dry gardening pioneer and innovator. She has reached the age of 107 and she maintains her love of her collection.

The longest chapter of The Bold Dry Garden, “Signature Plants of the Dry Garden,” describes and pictures garden’s diversity, organized in sections: The Smallest Players, Aeonium, Crassula, Echeveria, Haworthia, Sedum, Sempervivum, the Importance of Rock, Architectural Elements, Agave, Cactus, Yucca and Other Swords, Flowers and Foliage, Aloe, Euphorbia, Gasteria, Protea, Terrestrial Bromeliads, The Softer Side, California Natives, and Trees. Whew!

Reading this fine book can be a pleasant introduction to the world of succulent plants. Visiting this extraordinary garden is an opportunity to see many different forms of these plants, and to become inspired to develop your own collection…and to come again to the garden.

For more about this garden, and everything you need to prepare for a tour, visit the garden’s website.

The Garden Conservancy is both a preserver of private gardens and guide to seeing them through its Open Days program. Browse to the Conservancy’s website for more information.

The long-time curator of the Ruth Bancroft Garden, Brian Kimble, is scheduled to speak at the Monterey Bay Area Cactus & Succulent Society on Sunday, March 19th. See the Society’s website for details.

The Bold Dry Garden is a good read for any gardener, excellent preparation for a visit to the Ruth Bancroft Garden, and a fine addition to any library of garden books.

Controlling Annual Weeds

 

The gardener’s war on weeds cannot be ignored at this time of the year, as cool-season annual weeds respond to the current temperatures and recent rains. By popping up in our gardens.

The weeds in front of us always command immediate attention, but they also encourage a broader view of weeds. Let’s review the sources of the problem and the strategies for weed control.

The first step in control involves knowing the three broad categories of weeds: annuals, which are usually the most troublesome, and biennials and perennials, which we will consider on another day.

Annual weeds are those that grow and die in one season. This cycle begins with seed germination and ends with the dispersal of a new generation of seeds.

Annual weeds include two sub-categories: summer and winter annuals, which are also referred to as warm season and cool-season annuals. The names of weeds in each of these groups could be identified, but their botanical or common names are less important than their life cycle.

After Annual Weeds Sprout

Cool-season annual weeds germinate from seed in the late summer or early fall. They grow during the winter, flower, set seed and die from heat in the late spring or early summer. This approximate calendar guides actions to reduce weed growth in the garden. Right now, these pesky plants have already germinated, so the appropriate action is to minimize the production and dispersal of seeds. Do this by removing the flowers as soon as they appear. Depending on the circumstances and other factors, this can be done by plucking the flowers, mowing the weed batch, or pulling the entire plant.

Warm-season annual weeds germinate and grow in the spring, and thrive throughout the summer and into the early fall. They will die by frost, however, in the Monterey Bay area, where frost comes later if at all, these plants can persist for quite a while. Controlling warm-season weeds after germination uses the same techniques outlined above: minimize the spread of new seeds by removing the flowers or the entire plant before, or as soon as, the flowers appear.

Up to half the weeds that are pulled from the garden are still capable of dispersing seeds, so the safest plan is to dispose of them in the green waste. They could be added to a compost bin, but only if your compost maintains a temperature of 160 degrees Fahrenheit or more for three hours or more, the seeds won’t survive.

Before Annual Weeds Sprout

Methods to minimize the production and dispersal of seeds are highly recommended, but inevitably some seeds will make their way into in your garden. Seeds will arrive from weeds that already grow there, or are brought in by the wind, by the dropping of birds, or by hitching a ride on people’s shoes or clothing, animal’s fur, or imported plants, even plants from a garden center. The result of these several sources is the weed seed bank tat exists in all gardens.

All seeds require light and moisture to germinate, so the basic method for discouraging the germination of seeds already in the garden begins with mulch. Two or three inches of organic mulch will deny the seeds light, and most will not be able to sprout.

Viable seeds can remain in the soil for years, waiting for light and moisture. They might be surprisingly deep in the soil. The best plan is to let sleeping seeds lie. The worst plan is to dig up the soil to give the seeds access to light and moisture. If you need to dig up your garden, even to install a new plant, cover the exposed soil immediately after with mulch. Mechanical tilling of the soil will reliably produce a new crop of weeds.

In addition to mulching, close placement of desirable plants also will deny light and moisture to the dormant seeds. In many cases, a closely planted bed is also attractive.

Also, controlling access to moisture with drip irrigation, while controlling access to light with mulch and landscape plants should minimize weed growth significantly.

Finally, let a few weeds grow. You are unlikely with a goal of complete eradication of unwanted plants, and there is some value in the contribution of weeds to the flora and fauna of the garden. In any event, a casual (but systematic) approach to weed control allows you to relax in the garden.

Cold, Rain, and Buttercups

We have had welcome rains, and apparently we should expect more around the time that this column appears. That’s good, but that weather prompts some salient observations.

First, although the drought has been broken for the present, we should regard the present period as a hiatus, rather than an end to dry times. Long-term projections still indicate below average rainfall in future years,

Most importantly, our aquifers were depleted significantly during the drought years, and replenishing them will require many years of at least normal rainfall. We will have to wait for encouraging reports on that front.

Meanwhile, examine your garden for possible negative impacts from the recent cold and rainy days. The plants in my garden are nearly all native to California or other summer-dry (Mediterranean) climates, so they managed well during the dry days.

One exception was a mature Chilean Myrtle (Luma apiculata) that succumbed to the drought, and had to be removed.

That experience recalls a thoughtful comment by Alexander Graham Bell: “When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us.” In this case, the tree had grown larger than expected and closer to the house than wanted, so while I regretted its loss, its absence opened space for new plants.

Almost all my succulent plants shrugged off the cold spell, with the exception of a Foxtail Agave (Agave attenuata), which I had been growing in a large container. I planned to plant it in the ground eventually, to provide the space it will need to reach its full size of four feet high and eight feet wide. The plant’s rosette is quite attractive and dramatic, but its distinctiveness is based on its flower stalk, which grows five-to-ten feet, reflexes to the ground and then arches upward again. I learned too late that this plant is unusual among Mexican native succulents for its susceptibility to cold weather. I should have covered it, or brought it inside. It lost some leaves, but now appears to be coming back.

I have been taking advantage of the fine weather between rainstorms by catching up (with help!) on the seasonal weeding tasks. This work includes the annual battle with Bermuda buttercup (Oxalis pes-caprae), a South African native that thrives in California’s coastal gardens, and opens its bright yellow blossoms in late winter or early spring.

Bermuda Buttercups

Bermuda Buttercups

I have been puzzled by the relentless and random spread of this annoying plant. The explanation on UC’s Integrated Pest Management website (ipm.ucanr.edu/) has been incomplete:

“Viable seed never has been documented in California, and rarely has it been seen anywhere else in world. Foliage dies and the bulbs become dormant when temperatures rise in late spring and summer. Bermuda buttercup reproduces vegetatively by bulbs and spreads when plants are divided or soil containing the bulbs is moved to un-infested areas.”

I have learned that this plant is tristylous, an uncommon morphology meaning that it has three flower shapes (morphs). All the flowers on a given plant will have the same shape, but the pollen from a flower on one morph cannot fertilize another flower of the same morph.

Tristyly does not necessarily affect the propagation of the Bermuda buttercup, but it might explain its spread in gardens, and provide a clue to its management. The search goes on!

Meanwhile, we continue with weeding and mulching, and preparing to enjoy the garden in the spring.