Filoli’s planned water conservation measures and recommendations.
Find out what's blooming at Filoli from January to December.
Learn about Filoli plants and gardening practices—ask the experts.
Autumn at Filoli Festival
Saturday, Sept. 27 is the day for family fun.
Plant Highlights This Week
Flowers are one of the most pronounced markers of the progression of time in a garden. Each month we scout the Garden for amazing blooms and feature our favorites here. Check back often to see what we have in store for your next visit to Filoli.
Week of September 22 - 28, 2014
This is the last week when most of the beds will still be in place. Next week, after this Saturday’s Autumn Event, signals our start of the fall planting season. Several of the beds will be pulled next week, and we will embark on our annual hedging of the parterres. With our big bulb delivery happening any day now, we will start planting once the beds are pulled, hedged and forked.
Plant of the Week:
One of my favorite fall waifs in the garden is the ivy-leaved cyclamen (Cyclamen hederifolium). Also known as baby cyclamen or dwarf cyclamen, these tuber-forming perennials were planted in the garden decades ago, although the exact period is unknown. Many know cyclamen for the fall-blooming plants used for decorating our homes around the holidays, the florist’s cyclamen (C. persicum). The ivy-leaved is one of about fifteen cyclamen species native to southern Europe and Asia Minor (Turkey, and the surrounding countries). This region is rich in many of our common bulb-forming plants, including tulips, hyacinths and daffodils. C. hederifolium is the most wide-spread in its native region and is the most hardy, growing as far north as USDA Zone 4, which includes the northern planes and upstate New York.
The ivy-leaf cyclamen was originally planted in the Woodland Garden, as well as other shady spots around the formal garden. (The other common cyclamen in the garden in C. cuom, which is our spring-blooming species.) One of the reasons that the ivy-leaf is more commonly found in the garden is both because it is well adapted to our site and it also self-seeds and has naturalized in other places. It can sometimes be found growing on in areas outside the garden that receive no irrigation.
Cyclamen were formally in the primrose family, but have recently been reclassified to the Myrsinaceae, which includes Myrsine africana, African boxwood. Cyclamen are known for their charming inside-out flowers. Ivy-leaved cyclamen comes in pink hues and white. Its tuber, a flattened, hard, potato-like tuber has roots on the bottom side and produces flowering shoots on the top. Tubers increase in size each year and can become over a foot in diameter. Most of ours range in the 3-4” size. Plants bloom in fall and go dormant by spring. They prefer well-drained soil and need little summer water.
We have occasionally offered cyclamen corms at Holiday Traditions, but its availability can be very difficult. Some bulb companies carry it, but be sure to ask about its origin as sometimes bulbs are collected from the wild, which should not be promoted.
The tomography scan of the large coast live oak in the Walled Garden is happening as I write this week’s installment of the Garden Happenings. I will report on the results next week. Stay tuned.
As gardens age, we are forced to respond to woody plants that are facing the end of their road. The latest tree of concern in the garden is the stately oak between the Dutch Garden and the Walled Garden lattice area, home of the purple, blue and white hydrangeas. The vigor of this old, coast live oak (Quercus agrifolia) has been decreasing for at least a decade and over the past few years has been displaying some significant disease issues and has reached the point where we are very concerned.
Most recently, a large fungal growth arose from the base of the tree on the east (Dutch) side. This organism is called weeping conk (Inonotus dryadeus), and like the more common shelf conk (Ganoderma applanatum), is an indication of root and buttress rot. Prior to this, large clumps of oak root fungus (Armillaria mellea) have grown from the west (hydrangea) side of the trunk. And on top of this, where the two major scaffold branches arise from the trunk, there is an accumulation of soil and other debris at this crotch, which often is indicative of a lack of solid structure.
We plan to undertake further investigative work to thoroughly validate the problems. With this triumvirate of serious issues, the outlook is not good. At the very least, we will plan to heavily reduce the weight of the north scaffold branch, which is the more weakly attached, to reduce its weight.
There is a strong possibility that the tree may need to be removed. Removal will be a significant job and come at a significant cost, since all the wood will have to be cut up small enough to haul out of the garden through the garden gates. It will also mean that this part of the garden won’t be in 100% shade anymore. Fortunately, there are other large trees (southern magnolia, New Zealand black beech) around the tree that will continue to shade many of the plants.
Update: We had a second arborist look at the oak tree last Friday. Jim McClenahan, our primary large tree work provider, recommended Deborah Ellis, who came out for a consultation. One of Deborah’s services is providing tomographic scanning. Tomography is a process using sound wave scans to assess the state of the interior of the base and trunk of the tree. We hope to have the scan done this week, which will help us to better understand the state of our oak tree. The tomography scan will be happening on September 22.
Many of the summer beds are still looking very nice, particularly the begonia and SunPatiens displays. The Dutch planting of Begonia ‘BIG Red with Green Leaf’ is over three feet tall at this point. The annual phlox in the Sundial Bed is still colorful and fragrant on warm afternoons. The dahlias are still blooming away.
The Kitchen Garden is looking very bountiful presently. Gourds, peppers, Brussels sprouts, cabbages, tomatoes and eggplants are all laden with gifts for the harvest. The big pumpkins will be pulled for the Autumn Event.
Fruit picking wraps up this week as the Autumn Event approaches on Saturday. Next week, the Second Harvest volunteers will come in to glean most of the remaining fruit in the Gentleman’s orchard.
As of now, we have sent two deliveries of fruit to Hurley Farms in Napa for our jam project. The first jars came back recently. Look for an opportunity to taste and buy apple butter, pear butter, and grape jelly at the Autumn Event.
The topiary olive trees in the Sunken Area are being somewhat renovated to make them more manageable. Our plan right now is to shape them somewhat more loosely, rather than the tight sides and top. This should result in a more sustainable ability to maintain these trees.
Notes and Common Questions
Another tree that has been in decline is the olive across from the Lock and Key sculpture near the front drive. The top of the canopy was mostly dead, probably from Verticillium wilt, while the lower trunk and roots were still quite vigorous. Olive trees are good candidates for renovation when they are too vigorous or lack vigor and this technique of cutting the tree back to six feet is often employed in orchard management. Our plan is to retrain the sprouts that emerge into a new, healthy canopy. The fencing added around the tree is to keep the deer from eating the sprouts as they emerge.
A plant the horticulturists, and volunteers as well, are being asked about recently, concerns the stunning southern magnolia (Magnolia grandifloria) guests encounter as they approach the house and garden from the Visitor’s Center. This magnolia, one in the collection of magnolias added to the front of the house by Mrs. Roth, often introduces visitors to the high horticultural standards for which our gardens are known. (I can still remember seeing the tree when I visited Filoli for the first time on a rainy, spring day in 1994.) The question is in regard to the thinning canopy on the southeast side of the tree. The branches are not as full and the color is a bit off from the rest of the tree.
The short answer is that we are still unsure what is causing the lack of vigor. We had wood samples tested from the top of the canopy, and nothing came back conclusive. Visually, the condition looks more like a Verticillium wilt, but none of the samples showed it was this fungal pathogen. We also had the roots tested, which showed Phyophthora, a root rot fungus, but this is common in our soils, and would show symptoms throughout the canopy.
Recommendations we’re received, and the actions we are taking include giving the tree supplemental water through the summer and composting under the canopy. We’ve increased the water the past few weeks and plan to mulch with 4” of compost in the coming months. We’re hopeful that with some TLC the tree will grow out of the condition and begin to fill back in over time.
The Filoli drought page is on our website (http://www.filoli.org/drought/). As many have noted upon visiting this summer, many of our lower-profile lawns are somewhat to completely brown. We’ve also reduced our water use in our orchards and any other woody plantings by approximately 40%. We felt that these two major reductions in irrigation use would be the best ways we could do our part in conserving water along with everyone else in California. At this mid-year point, Dave Herrington, head of our maintenance team, reports that we have reduced our total water use by over 55% over last year! Considering that last year was the driest calendar year on record, and that we had no conservation plan in place, with our use up approximately 25%, the outstanding savings this year might be somewhat inflated. That said, looking back to 2012, we’re still probably saving 45-50% over a typical rain year.
“New” Garden Room
When Mrs. Berenice Spalding, one of the Roth twins, passed away last year, a bequest was made to Filoli on her behalf. Mrs. Spalding wanted her donation to be used on lasting improvements to the house and/or garden. Cynthia approached Board member Denise Bates (daughter of Lurline Coonan) with the concept of a garden space honoring the Roth Children. Filoli staff and the governing board agreed that a new seating patio under the persimmon tree in the Rose Garden was the best fit. Denise, who is a landscape architect, designed the new patio. The rectangular patio surrounding the persimmon tree has been laid with two patterns of brick separated by a frame of bluestone. In the center of the patio, a medallion with FI-LO-LI, like the one above the Filoli Gate, is at the center, surrounded by the names of the three Roth children: William, Lurline and Berenice. The patio is now complete and the accompanying flower containers are in place. The benches arrived last week.
The Colors of Hydrangeas
In the wild, Hydrangea macrophylla, which is native to Japan, has pink flowers. Over the last century, different cultivars (cultivated varieties) have been bred to have darker pink, blue, or white flowers. To understand color change in hydrangea flowers, we have to delve into some basic chemistry. Hydrangeas prefer a slightly acid soil (pH 6.0-6.2). At this pH, hydrangeas will maintain their original color. As the soil approaches neutrality, and then becomes alkaline (above pH 7.0), and aluminum becomes less available to the plant, and thus, the pinks will become darker pink and the lighter blue shade will turn pink. In acid soils (lower pH), the pink flowers will become blue and the pale blue will become dark blue or purple. The exact shade of blue depends on the original color, how acidic the soil is and how much aluminum is available to the plant. White flowers will not change color with changes in soil chemistry.
At Filoli, to acidify our soil and enhance the color of our blue hydrangeas, we add one-quarter to one-half pound of granular aluminum sulfate around the base of each large plant in November. If your soil is in the neutral range, it is fairly easy with the addition of aluminum sulfate to enhance the blue color in hydrangeas. It is much more difficult to achieve an alkaline soil, but this can be done by adding dolomitic lime several times a year around your plants. If your soil naturally runs acid or alkaline, it can be extremely difficult to sway your soil to the opposite end of the spectrum.
For more information on Filoli’s hydrangea care, please see the Garden Resource Center page of the Filoli website (http://www.filoli.org/garden-reference/). Here you will find a reference sheet on hydrangea care, many other Filoli plants, as well as other garden maintenance situations.
Bloomin' Bucks Program
Whenever visitors, volunteers or anyone else asks about where Filoli purchases our bulbs, after telling them that the bulk of our bulbs are purchased wholesale from the Netherlands, I tell them the best retail vendor in the US that I know is Brent and Becky’s Bulbs. Brent Heath’s family has long been in the bulb business and because of their lasting relationships with the Dutch growers, Brent and Becky are able to sell top quality bulbs. If Filoli could afford to buy all of their bulbs from this company, we would.
As part of the company’s commitment to public gardens, schools and other non-profits, Brent and Becky established the Bloomin’ Bucks program. With each purchase from Brent and Becky’s through the program, the designated non-profit receives 25% of the funds. Filoli is a participant in this program. So, if you’re planning to order bulbs this year, and like Brent and Becky’s products, please go to the Bloomin’ Bucks page (www.bloominbucks.com) to start your purchase by choosing Filoli as your non-profit of choice. From there, you will be sent to the regular Brent and Becky’s Bulbs website to start your shopping.
Written by Jim Salyards, Filoli's Manager of Horticultural Collections and Education, and Internship Program Coordinator