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Elisabeth C. Miller Library

Archives: Plant Answer Line Q & A

Plant Answer Line questions and answers.

Dividing and transplanting lilies

I have a question about what is the best time of year to transplant and
divide Asiatic lily bulbs? Is it fairly easy to identify where the bulb
should be divided? Also, someone told me to use a rooting solution on the
divided bulbs. Is this necessary? Is late October too late in the fall to divide
them?

 

Most sources say to divide lilies in the fall. You do not need to use a
rooting solution on the divided bulbs. Sunset’s Western Garden Book
(2001) says the following: “If clumps become too large and crowded, dig,
divide and transplant them in spring or fall. If you’re careful, you can
lift lily clumps at any time, even when they are in bloom.”

One rationale for lifting them when in bloom is provided in an article
from the Wisconsin Regional Lily Society, no longer available online, but excerpted here:

“After three successive years of making this futile pact, I finally
concluded that books were wrong! Fall isn’t the time to transplant
lilies. It’s a job best done in mid-summer when they’re in full bloom.
This eliminates most of the guess work, since at this point, the plants
are at their maximum height, making it nearly impossible to make the
mistake of planting the tall ones to the front of the border, the short
ones at the back. It also affords a crystal-clear picture of concurrent
bloomers. In fall, no matter how carefully one does the job, when digging
dormant bulbs at least one bold orange always manages to get itself
placed directly beside the brightest pink. The clashing colors burn
themselves into your retinas nearly as well as flashbulbs-blink quickly
and the image reappears!

“The maximum size of the plants in mid-summer is another advantage. When
autumnal plants have shrunk to a mere fraction of their former selves,
it’s too easy to misjudge your space placement. Who hasn’t heard the
disheartening ‘crunch’ of a spade slicing through the most expensive bulb
in the bed? How it knows the price, I’ll never know.

“Spring is the only time I’d actually refrain from moving lilies. The
delicate new shoot is easily broken, and once gone, the poor bulb has
only two options: It will either die or spend an entire year below
ground, depleting its energy reserves as it forms a new shoot for the
following spring. All the while it’s caught in a perilous game of Russian
roulette. Without aboveground parts to warn of its existence, it can
never quite be sure when a spade might suddenly come slicing down.
Crunch! -The second most expensive bulb gone?

“Certainly no plant will be thrilled at being dug up and moved in full
flower, but if it’s kept well watered and blooms are removed, almost any
perennial will have recovered fully by the following season. One of the
best gardeners I know says that the best time to move any perennial is
when you have the time!”

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Caring for Sago palms

My Sago palm hasn’t shown any
new growth or hint of life for several years, other than the same few fronds. The remaining fronds are still a uniform
green and appear healthy. I water periodically,
when the soil feels dry to the touch.

About 2 years ago, I emailed a Sago palm specialist website and
inquired; they advised transplanting it into a new pot with new soil and
to stop feeding it African Violet food (which I had been), saying that it
was raising the electricity in the soil (which Sagos evidently don’t
like). I did as they said, using a soil mix that was a Sago preference,
and only gave it plain water, but still nothing.

I’ve read that it enjoys direct sunlight; so I put it in the sun (during
the warm seasons) and the leaves began to show signs of burning and
prematurely drying out. I’ve also read that it enjoys shade or indirect
light, and that’s where it is now inside by a window; its leaves are
not yellowing (at least not as fast as when in the sun; they are
beginning to age as they ought), but, as said, it is fast, fast asleep.
Our condo is not heated so the temp inside is relatively cool most of the
time. I’m beginning to wonder if it is worth keeping; I really would
like to see it flourish, of course, but how long do I wait?

To wit, is there a way to wake up this sleeping beauty?

 

The book Cycads of the World by David Jones (Reed Press, 1993) says that
as a potted plant, Cycas revoluta will do well indoors with poor light
and neglect, but does prefer sun. (The information from a nursery owner
below says that the plant orientation is more important than the amount
of sun). Good drainage is key, and watering when dry, and regular
applications of light fertilizer should be helpful.

Through University of British Columbia Botanical Gardens online forum, I
came across information from the owner of a British Columbia Cycad specialist nursery,
Lori Pickering:

“Cycads are very hardy plants and are rarely bothered by pests or
diseases. They do, however, require very loose soil with perfect
drainage. Allow the soil to dry out somewhat between watering. If
possible, use rain water or filtered water, which is pure and free from
contaminants.

“Cycads do exceptionally well in pots. They actually like being
root-bound, so do not be too anxious to re-pot. Always keep pots
oriented in the same direction (e.g. facing north) to prevent the leaves
from spiralling and twisting out of plane. Just write “N” on the pot
with a felt marker.

“Cycad potting mix: 3 shovels friable loam, 2 shovels coarse sand, 4
shovels milled pine or fir bark, 1 shovel peat moss, one cup complete
organic fertilizer (OR 45 grams slow-release balanced pellet fertilizer
such as 18:6:18 with micro-elements, 40 grams dolomite lime, 3 grams iron
sulphate, 3 grams magnesium sulphate). Mulch with compost.
Cycads grown in pots do not have access to all the nutrients available
when growing in the ground. During the growing season, when your cycads
are summering out of doors, water every so often with a weak dilution of
sea kelp or de-odorized liquid fish fertilizer, according to package
directions. This will provide the trace elements they require for
optimum growth.

“Complete Organic Fertilizer recipe: 4 parts seed meal (i.e. flax or
canola), 1 part rock phosphate OR 1/2 part bone meal, 1 part lime, 1/2
part kelp meal.

“When planting cycads in the garden be sure they have excellent drainage.
The best way to ensure this is to plant them on a mound and incorporate
lots of sand into the soil. Some species are more tolerant of rainfall
and frost than others, so be sure to choose the right plant for your
situation.

“Asian Cycad Scale (Aulacaspis yasumatsui), a native of Thailand, is a
pest that has been spread to cycad populations of the southern U.S., the
Western Caribbean, and Hawaii. It has proved devastating to growers in
those areas. So far it has not been found in Canada. That is another
reason we grow all our cycads from seed and do not import any plants from
abroad. (This scale looks like a white powder on the leaves).”

Cycad care instructions from the Jurassic Plants website (no longer available online):

“Cycads are generally very easy to grow. Their main requirement is perfect
drainage, as they will develop root rot if water remains stagnant in the
soil. A loose, fast-draining potting mix such a cactus mix is preferred,
with a neutral to slightly alkaline soil, pH6 to 7. Terra cotta pots will
help to keep the soil on the dry side and provide aeration. Fertilize
with a low phosphorus (3-1-3 ratio) timed-release fertilizer including
trace nutrients. All cycads benefit from a mulch, which will encourage
the growth of their coralloid roots. Rain forest cycads especially are
sensitive to salts in the water, so use rainwater or filtered water, if
possible. Those from drier habitats are more tolerant of mineralization
in the water. Some cycads prefer full sun, others shade, but always keep
them oriented in the same direction (e.g., north) to keep the leaves from
spiralling out of plane.”

Cedar flagging

I have noticed that my old cedar has a very large number of cones
on it this year. Several areas of foliage have
turned reddish brown. This has all appeared in the past month or
less. Some of the other cedars
in this area appear to have these characteristics. Is something different going on this year? I am concerned that there may be a disease that is affecting them?

 

Is your tree a true cedar (Cedrus) or a species of Thuja? The Thuja plicata (Western red cedar) in my garden also had a huge number of cones this year, and just like yours,
it has some foliage turning reddish brown. This is probably cedar
flagging, as described in this Washington State University Extension
page. Flagging–the browning of older leaves and twigs–is a common occurrence
on western red-cedar and related trees, such as arborvitae. It usually
develops in late summer to early fall. Often, very hot, dry weather,
followed by rain, will stimulate the sudden dropping of this older
foliage.

If the browning were to be widespread, that might be more of a cause for
concern. Additional links:

Cedar Flagging from University of British Columbia Botanical Garden’s online forum.

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Night light and plant growth

My neighbor has floodlights shining into my garden all night. It’s annoying for many reasons, but I am also wondering if artificial light affects plant growth?

 

Washington State University professor and Extension horticulturist Linda Chalker-Scott addresses this issue in her factsheet, “The Myth of Night Light.” Here is an excerpt:
“When urban trees, especially street trees, are exposed to extended light periods, those leaves and buds nearest the source perceive an endless summer and keep on growing. While this phenomenon is difficult to see initially, in the autumn it is quite distinctive: affected leaves retain their green color while
those leaves under natural conditions have already started to senesce and change colors (see photo). When the first autumn frosts arrive, these green leaves die and the tree loses the resources that normally are scavenged during senescence. Recent research has demonstrated that high-intensity light sources,
such as high-pressure sodium lamps, have the greatest impact on delaying leaf senescence and subsequent dormancy of landscape trees.”

Similar information is available from Purdue University Extension, in the article “Does Night Lighting Harm Trees.” It includes a list of woody plants and their degree of sensitivity to artificial light pollution. It also mentions which types of lighting have the greatest and least potential effect (incandescent and high pressure sodium lights have a greater effect than fluorescent, mercury vapor, or metal halide). It is interesting to note that continuous lighting, as opposed to lighting that goes off at some point during the late night, is especially damaging:
“The foliage of trees grown in continuous lighting may be
larger in size and more susceptible to air pollution and
water stress during the growing season because the stomatal pores in leaves remain open for longer periods.”

There is additional information about the effects of light pollution on animals, humans, plants, and the environment as a whole, on the website of the Florida Atlantic University Observatory, and from the International Dark Sky Association.

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Plants for privacy screens

Could you recommend some plants for a privacy screen that are also narrow? These would be planted in front of a fence in our backyard.

 

Here is some general information on plants for creating a screen.

Trees for Problem Landscape Sites — Screening from Virginia Cooperative Extension

Bet on Hedges by local garden writer Valerie Easton.

Landscaping for Privacy: Innovative Ways to Turn Your Outdoor Space into a Peaceful Retreat by PNW author Marty Wingate.

Here is a list of narrow plants for a screen from local garden designer Chris
Pfeiffer: “Fastigiate shrubs for naturally narrow hedges.” Compiled by Chris
Pfeiffer. 2005.

Zones 5-6:

American arborvitae ‘Rheingold’ (Thuja occidentalis ‘Rheingold’) 5’h x
3’w

Barberry ‘Helmond Pillar’ (Berberis thunbergii f. atropurpurea
‘Helmond Pillar’) 6’h x 2’w

Boxwood ‘Graham Blandy’ (Buxus sempervirens ‘Graham Blandy’) 8’h x 1-1/2′
w

English yew ‘Standishii’ (Taxus baccata ‘Standishii’) 4’h x 1-1/2′ w

Irish yew (Taxus baccata ‘Fastigiata’) 20′ h x 4′ w

Japanese holly Jersey pinnacle (Ilex crenata ‘Jersey Pinnacle’) 6′ h x
4′ w

Japanese holly Mariesii (Ilex crenata ‘Mariesii’) 3′ h x 1-1/2′ w

Zones 7-9, in addition to the above:

Dwarf yeddo rhaphiolepis (Rhaphiolepis umbellata Gulf GreenTM) 3-4′ h x
2′ w

Heavenly bamboo ‘Gulf Stream’ (Nandina domestica ‘Gulf Stream’) 4′ h x 2′ w

Japanese euonymus ‘Green Spire’ (Euonymus japonicus ‘Green Spire’) 15′ h x
6′ w

 

You might also consider installing a trellis to increase the height of
the fence, and then growing an evergreen vine such as Clematis armandii,
evergreen hydrangea (Hydrangea seemanii), or star jasmine
(Trachelospermum jasminoides).

This link is also helpful (scroll down to
“Evergreen Vines” and look for appropriate height and light requirements).

You could grow bamboo, but I would recommend growing it in a container,
or a series of containers, as you do not want the roots to spread. I have
seen an effective bamboo screen between two houses growing in a long
rectangular lined wooden trough (lined with bamboo barrier). Some species
of bamboo are more tolerant of partial shade than others. Look for a
clumping, rather than a running, bamboo (like Fargesia) to be on the safe
side.

Growing Bamboo
in Georgia

Running and Clumping Bamboos

Bamboos for hedges or
tall privacy screens

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Are fig trees aromatic?

Are fig trees known for being particularly aromatic?

 

I looked in a large number of our books on aromatic and fragrant plants,
and none listed fig (or Ficus carica) in the index. Although the leaves
may be mildly aromatic, it is not the usual reason people cultivate the
plant, so apparently not much is written on the subject. I found a highly
technical scientific article on a study comparing male and female fig
trees and fragrance emission. To the best of my understanding, the
composition of the volatile emissions and the quantity differed from male
to female, and were subject to seasonal and diurnal changes (most
emissions during the day, and in synchronization with the need to attract
pollinators). What this suggests to me is that the scent of an
individual tree may vary considerably.

The following is from general information on figs, from Purdue
University’s horticulture department. Excerpt:

Leaves: Fig leaves are used for fodder in India. They are plucked after
the fruit harvest. Analyses show: moisture, 67.6%; protein, 4.3%; fat,
1.7%; crude fiber, 4.7%; ash, 5.3%; N-free extract, 16.4%; pentosans,
3.6%; carotene on a dry weight basis, 0.002%. Also present are
bergaptene, stigmasterol, sitosterol, and tyrosine.
In southern France, there is some use of fig leaves as a source of
perfume material called “fig-leaf absolute”, a dark-green to
brownish-green, semi-solid mass or thick liquid of herbaceous-woody-mossy
odor, employed in creating woodland scents.

The following information from a 2004 article by Tony Burfield entitled “a Brief Safety Guidance on Essential Oils” indicates that “fig-leaf absolute,” as an
essential oil, is phototoxic, in other words, will cause skin irritation
when exposed to light. For this reason, it is banned from inclusion in
perfumes by the International Fragrance Association.

Another site, BoJensen.net, includes “A small guide to Nature’s fragrances,” describing various essential oils.Excerpt:

“Fig leaves have a characteristic sweet-green fragrance, perceptible when
one stands close to the sun-warm trees or by handling the leaves. They
have been extracted on a limited scale for perfumery use in Grasse in
southern France. According to Arctander, fig leaf absolute is a dark
green to brownish green, semi-solid mass or viscous liquid of a
delicately sweet-green, herbaceous and somewhat woody odour with a mossy
undertone.

“Roman Kaiser, among 200 identified constituents of fig leaf absolute,
found a number of olfactorily relevant N-containing trace constituents,
one of them 2-isobutyl-4-methylpyridine, characterized by an attractive
tobacco-like, green, herbaceous odor. Major odorants were linalool,
benzyl acetate, methyl salicylate, beta-ionone and (Z)-3-hexenyl benzoate
[137].

“Buttery et al. identified germacrene D as a major volatile component in
fig leaves. Other major volatiles were beta-cyclocitral, (Z)-3-hexenol
and (Z)-3-hexenyl acetate [129].”

Ultimately, it seems to me that if you want to plant a fig tree with
fragrant leaves, you will have to do a sniff-test of your own. In my
experience, all fruit–fresh and dried–from the tree is aromatic,
regardless of variety, but you may detect more subtle differences. Buy
different types of fresh and dried figs at the market, and visit gardens
where figs are growing. I’m afraid that’s the best I can come up with.

Fig tree pruning and care

We recently moved into an old house with a huge fig tree in
the back. We just missed this whole season’s crop because I was waiting
for them to turn brown but the birds got them all first. Then I saw some
green figs for sale in the grocery store and it appears that some
varieties don’t turn brown. Is this true or did mine not ripen? Also, the tree is probably close to 30′ and we’d like to add a screened-in porch under part of it. I’d really like to keep the tree and a good
bit of fruit but I want it to grow more in the other direction. I’ve read
that “hard pruning” is encouraged, but does that really mean cutting down
a thirty foot tree? Do I need to do it in stages? What’s the best size
and shape and how do I get it there?

 

There are different types of figs, and some are green, some are brown,
some are purple, as the images on the commercial site of Adriano’s Fig Trees illustrate.

Figs should be picked when ripe, as they will not ripen off the tree. The California Rare Fruit Growers site has good general
information on growing figs.

As for pruning, the best time to prune is late winter/early spring. To
control height, open the center of the tree and remove any dead wood or
drooping branches. I don’t think radical pruning is the standard practice
in maintaining a fig tree. University of Arizona article on growing figs describes pruning practices for several different varieties of fig.

Most pruning is best done when the tree is dormant, during the winter
when it is leafless. Even during the spring and summer, however, you can
start by removing all branches and stems that are obviously dead.

The rest depends on how your tree is growing (single trunk or
multi-stemmed), what kind of results you would like (how large, small or
what shape) and how long the tree has been unpruned. Our rule of thumb is
to go by thirds. Remove about a third of the wood that you would
eventually like to have gone. On multi-stemmed figs that are becoming
large, we recommend selecting a few oversized stems and thinning those
out to the ground, rather than “heading” all the branches to stubs. Let
the tree rest for the summer and see what new growth appears. We
recommend keeping fig trees small enough that all the fruit can be easily
reached from the ground but in some areas of the south and southwest,
folks treasure the deep shade of the larger figs. The final shape and
size are up to you.

A 2006 article by Bunny Guinness in the British newspaper the Telegraph also describes how to prune an older fig tree. Excerpt:

“Figs really are a lazy man’s fruit and, once they have had their
formative training, mature trees or wall-trained shrubs do not need much
attention apart from some replacement pruning. This involves removing one
of the seven or so main limbs every three to four years in March or
April, to stop the whole bush becoming too old and unproductive. Apart
from this, providing you have the wall space, you can leave well alone. I
have seen many such ‘neglected’ plants, and they still fruit well,
although perhaps not as well as they might.

“On the other hand, if you want to maximize your crop (assuming it is
against a wall), buy a copy of Clive Simms’s Nutshell Guide to Growing
Figs (Orchard House) to see how to fan train it
against a wall–it is not hard. Once you have established an approximate
fan of branches, you can start the ongoing pruning regime.

“Firstly, remove any weak branches in winter. Then, in April, remove the
very tips of the main branches, above the developing figs. This will
encourage side shoots, which are summer-pruned by cutting back in June to
about four leaves. This technique can almost double the crop and bring it
forward by a couple of weeks. Do not be tempted to cut back hard in
winter, unless you don’t mind forgoing a lot of your crop–this will
cause lots of new growth but little fruit.”

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Acacia trees in the Pacific Northwest

Can you tell me if Acacia trees grow in Seattle? Could I obtain a small cut branch from one? I am a funeral director, and the last wishes of the deceased we will be burying were to have a sprig of acacia placed inside the casket. This man was very active in the Freemasons, and evidently the acacia is an important symbol for them.

 

Most Acacia species are marginally hardy in our area. According to local tree expert Arthur Lee Jacobson, most gardeners who plant Acacia end up with a large pile of exotic firewood once the trees have died off during a serious winter. Therefore, your most likely source for a cut sprig would be to ask local florists, who obtain this plant regularly for use in flower arrangements. You can also contact the source the florists use, Seattle Wholesale Growers Market (where they will order it from California).

In Freemasonry, acacia symbolizes the soul’s immortality, perhaps because of the evergreen foliage. The book of Exodus in the Hebrew bible seems to have been the inspiration for choosing this tree, called shitta [singular] or shittim [plural]. According to the text, the wood was the raw material for the Tabernacle and its contents, the Ark of the Covenant, the Altar and the Table and the Pillars of the Curtain. Biblical botany scholar Lytton Musselman speculates in his book Figs, Dates, Laurel, and Myrrh (Timber Press, 2007) that the species might have been Acacia albida, now renamed Faidherbia albida. However, the masonic texts have another view. According to Mackey’s Encyclopedia of Freemasonry, “It is the acacia vera of Tournefort [refers to 17th century French botanist Joseph Pitton de Tournefort], and the mimosa nilotica of Linnæus. It grew abundantly in the vicinity of Jerusalem, where it is still to be found, and is familiar to us all, in its modern uses at least, as the tree from which the gum arabic of commerce is obtained.”

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Douglas fir tea

There seems to be a new fad of local foragers making tea from the needles of Douglas fir and Grand fir. I am guessing there are Native American origins to this practice. How safe is it, especially in an urban environment? Are there supposed to be benefits to drinking this kind of infusion?

 

There is a deep tradition of ethnobotanical uses of various parts of both Douglas fir (Pseudotsuga menziesii) and Grand fir (Abies grandis). Nancy Turner’s book, Thompson Ethnobotany: Knowledge and Usage of Plants by the Thompson Indians of British Columbia (Royal British Columbia Museum, 1990) says that “a beverage tea was made by boiling Douglas-fir twigs with their needles. This tea was said to have tonic and diuretic properties.”

Turner says there is a great deal of confusion surrounding both the English common names and Thompson Indian names for various fir species. This makes it difficult to know which species were intended for which uses. An infusion made from the boughs of a species that might be Grand fir (Abies grandis) “could be drunk for any illness.” In Ethnobotany of Western Washington (University of Washington Press, 1973), author Erna Gunther notes both distinctions and confusions between Abies grandis and Pseudotsuga menziesii: according to the Green River informant she consulted, tribe members boiled Grand fir needles as a tea to treat colds, but a Swinomish informant believed Grand fir and Douglas fir to be the same species.

Douglas fir and Grand fir are not mentioned in Toxic Plants of North America (George Burrows and Ronald Tyrl, Wiley-Blackwell, 2013), but a plant’s absence from a list of toxic plants does not mean that it is risk-free. Common sense says it would be best not to gather needles from urban trees that are not your own, since there is no way of knowing whether those trees might have been sprayed with pesticides, or exposed to air pollutants.

According to Stephen Facciola’s Cornucopia II: A Source Book of Edible Plants (Kampong Publications, 1998), tea made from young foliage and twigs of Pseudotsuga menziesii is both refreshing and high in vitamin C. He says that the young branch tips of various species of Abies, including A. grandis, are used as a tea substitute.

I could not find reliable information about the recommended quantities of needles to water, ideal length of boiling time, or chemical properties of needles used for tea. Elise Krohn, author of Wild Rose and Western Red Cedar: The Gifts of the Northwest Plants (self-published in 2007) has information on her Wild Foods and Medicines blog about “making evergreen tree tip tea.” My advice would be to proceed with caution and consult a medical professional in case a coniferous tisane might have potential interactions with other substances. (Even a popular beverage like Earl Grey tea can be problematic due to the Citrus-derived bergamottin which interacts with some medications).

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Green figs in November

It’s November, and my fig tree still has hundreds of hard green figs. Will they be the ones to ripen next spring?

 

There ought to be a simple answer to your worthwhile question, but according to Ben Pike’s The Fruit Tree Handbook (Green Books, 2011), “It is very easy to become confused by the fruiting cycle of figs, because they carry different generations of fruit on the tree all at the same time. In the British climate [similar to Pacific Northwest], once the ripe fruits have been picked, there will be two types of fruit left on the tree. The larger ones, from about marble size upwards, are fruits produced this season that will not ripen properly. The fruits that will ripen next year are now the size of a pea or even smaller. They can be seen mostly on the final 20-30 cm. (8-12″) of shoots that have grown this year. The larger fruits are likely to split or fall off during the winter. Removing all the fruits larger than a pea in November allows the tree to put its energy into developing small fruits ready for next season. In other words, the fruits need to develop over two seasons in our climate. It is the fruits that would normally develop and ripen over one season in a warmer climate that are removed in order to help the embryonic fruits develop by the following year.”

There is similar information in Grow Figs Where You Think You Can’t by Steven Biggs (No Guff Press, 2012). Here is a section of the book which is available online.
Excerpt:
“It will break your heart, but there will be figs that don’t ripen. As you tuck in your trees for the winter, remove any remaining figs that are bigger than the size of a pea.”

You will sometimes see references to the breba crop and the main crop. Breba is an alteration of Old Spanish bebra, meaning twice-bearing, from Latin bifera. In terms of your fig, the breba crop is the first crop which ripens on last season’s wood (the ones that are tiny right now). Steven Biggs says that the breba crop ripens as early as July in his climate (Ontario), and the main crop (figs which form on new growth) ripens in September or October, or sometimes not at all, depending on the weather. While some fig aficionados say the breba crop is inferior, he cherishes it because it may be the only one to ripen in a short-summer climate.

Not all varieties of fig produce a prolific breba crop; some produce only the main crop. The web page of California Rare Fruit Growers discusses this in detail.

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