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music and plant growth

How does music affect plant growth?

 

Washington State University professor of horticulture Linda Chalker-Scott
uses the example of a book on the effect of music on plants as an instance
of ‘bad science’ in one of her articles. In other words, the idea is not based on repeated
experiments, and has not been put to the test of attempts to prove or
disprove it. Many student science fair projects pursue this question. There are many other scientists discussing this, and sites on the topic, too.

The TV show Mythbusters Episode 23 has dealt with this question.

There are also two questions exploring this at the MadSci network, a scientist-staffed question site. Here is an excerpt from the MadSci network’s discussion:

Experiments on the effects of sound or music on plants are very difficult
because you need a lot of replication (number of plants for each
treatment) and
identical environments for each treatment other than the music or sound
level.
That is difficult to achieve even for a professional botanist much less
in a
home or classroom. You also need a statistical analysis to determine if
the
growth differences are real or just due to natural variability. No
botanist has
yet found a beneficial effect of music or sound on plant growth that is
reliably repeatable and statistically significant.

The idea that plants grew better with certain kinds of music apparently
arose in the best selling book, ‘The Secret Life of Plants.’ That book
was filled with incorrect information. Botanists have failed to find that
plants grow better or worse with a particular type of music or that music
has any effect on plants.
While the stories in ‘The Secret Life of Plants’ are intriguing, they are
not based on careful scientific experiments. For accurate scientific
details on plants try a college botany textbook (Stern, 1991) or popular
books on plants written by scientists (Attenborough, 1995; Wilkins,
1988).

Reference:

Attenborough, D. 1995. The Private Life of Plants. Princeton, NJ:
Princeton University Press.

Stern, K.L. 1991. Introductory Plant Biology. Dubuque, Iowa: Wm. C.
Brown.

Wilkins, M. 1988. Plantwatching: How Plants Remember, Tell Time, Form
Relationships and More
. New York: Facts on File.

Professor Ross Koning, who teaches Plant Physiology at Eastern
Connecticut State University has addressed this question at length, too. Here is an excerpt from that site (now archived), as well:

“If plants don’t have music appreciation, do they respond to sound?
It is possible for a plant to respond to the vibrations accompanying
sounds. A short bibliography at the bottom of this page gives you some
references…but to almost ‘nothing to report.’ I emphasize again that
while there ARE responses to sound/vibration in plants, there is NO
controlled study published on the MUSICAL TASTES or MUSIC APPRECIATION by
plants in reputable journals.

One plant that responds to sound-induced vibration is Mimosa pudica, also
known as the ‘sensitive plant.’ Vibrations induce electrical signals
across the leaflets of this plant, and cells at the base of the leaflets
respond to these action potentials osmotically. This response results in
a sharp change in the turgor pressure in these pulvinus cells, and that
pressure change, in turn, results in the folding of the blade at the
pulvinus. Another pulvinus at the base of the petiole may also respond if
the vibration is severe enough. This kind of response is known as
seismonasty.

How would this plant respond in terms of growth if its leaves were kept
closed by constant vibration? If you think very long about photosynthesis
in leaves as the driving force for growth, you will realize that
continuous leaflet closure would inhibit rather than stimulate the growth
of the plant. Indeed loud sounds (vibrations really) have been reported
to negatively impact plant growth (reference below).”

cause of red leaves in rhododendrons

I have some native rhododendrons that have tan or reddish leaves every spring. The red leaves are new leaves, and they are red for about two weeks. They are under some 100 year old Douglas fir trees, and get some shade and some southern light. They were moved to my garden from and altitude of 4000 feet to my altitude of about 1850 feet. What causes the red leaves?

 

New red shoots and bronze leaves are not uncommon in Rhododendrons. In fact, some are grown purposely for their colorful new growth. The creator of Paghat’s Garden, a local website writes enthusiastically of a Rhododendron ‘Hill’s Bright Red’:

“When it is first finishing with its bright red blossoms, it begins producing new leaves, that are at first bright red themselves! …The new red leaves mature to green..”

She also has written specifically about the Pacific rhododendron, Rhododendron macrophyllum.

As to why this coloration sometimes happens, it is possible that the reddish-brown pigment seen in young [Rhododendron] leaves
affords tender foliage some protection from sunburn. This is important because too much ultraviolet radiation can destroy chlorophyll in plant
leaves. Plants avoid getting too much UV radiation by producing red pigments called anthocyanins, which can absorb UV radiation and thus prevent it from damaging other parts of the leaf. Because
the pigment “accumulates in the cell sap, and is usually located in the
epidermal and subepiderma cells,” its presence vividly changes the color of the
leaves (Levitt, p. 294). This, and more information about anthocyanins is available in a book available at the Miller Library called Responses of Plants to Environmental Stresses, volume 2, by J. Levitt (New York:
Academic Press, 1980). In effect, your plants are producing their own sunscreen for the tender new
growth!

You can also find more information about anthocyanin in the article “Nature’s Swiss Army Knife: The diverse protective roles of anthocyanins in leaves,” by Kevin S.
Gould, hosted by PubMed Central.

Ilex crenata and cross-pollination

I want to be sure to get berries on my (female) Ilex crenata convexa
so went looking for male Ilex crenata cultivars. It is not that easy.
So my question is: will Ilex species pollenize each other? For example, I have
a big male holly tree (Ilex aquifolium) close by, will that pollinate the
female Ilex crenata convexa?

 

The best berry production will come from planting a male and female of the
same species, but you can sometimes get away with using a different
species as long as both the male and the female plants are the same type
of Ilex (that is, both deciduous or both evergreen) with the same
(potential) color berries (red or black-berried species). Also, you want
two plants which flower at the same time.

Ilex crenata potentially produces black fruit. Ilex aquifolium produces
red fruit, so this would not be a good match. I. aquifolium is also
considered an invasive species in our area.

This link to a page from Clemson University Extension, describes various species and cultivars of Ilex. Ilex glabra is another species which produces black fruit.

There are some male cultivars of Ilex crenata, such as ‘Green Dragon,’
‘Hoogedorn,’ ‘Nigra,’ ‘Rotundifolia,’ and ‘Beehive.’

According to the website of a local gardener, there are other hollies
which will cross-pollinate with Ilex crenata, but she does not specify
which ones.

You are in good company in your quest for male Ilex crenata
cultivars–a local (Seattle) garden writer had a very similar question
recently. I hope you are able to get berries on your plant–you could try
waiting to see if perhaps you do get fruit (if there are other hollies in
the neighborhood), and then mail-order a male specimen or ask your
favorite local nursery if they sell any of the varieties mentioned above.

pruning and caring for rhododendrons

I need to know what to do with a rhododendron that has grown too big. I want to keep it, since it is a bookend to another plant. Can I cut it back, and if so, how far and when? Will it be okay and continue to bloom if I cut it back?
Could you suggest something and also suggest a really good book on care, etc., for rhodies?

 

The American Rhododendron Society’s page on pruning should be helpful. It describes clean-up pruning, shape pruning, and rejuvenation pruning.

Seattle author Cass Turnbull’s Guide to Pruning (Sasquatch Books, 2012). Plant Amnesty, founded by Turnbull, also has information on pruning an overgrown rhododendron.

The Rhododendron Species Foundation in Federal Way is a place you can visit to get an idea of the wide range of species available. They also have general information on rhododendron care on their website.

The Miller Library has a substantial collection of books on rhododendrons, including quite a few by Pacific Northwest authors, and you can browse them or check them out to see which species and varieties might be more suitable for your garden.

cherry tree leaves and cyanide

Last fall, I raked up my fallen cherry tree leaves, and put them in my vegetable garden bed to use as leaf mulch. I don’t know what our cherry tree species is, except that it appears to be ornamental. Then I covered the leaves with burlap coffee bags to winterize the garden bed.

I’ve recently heard that cherry tree foliage and twigs release cyanide when they wilt and decompose. Does this mean that there is cyanide in my garden soil? And if so, will the cyanide be transferred to any vegetables that grow in it? Safe, or unsafe?

 

A general rule of thumb with fruit trees (in case your cherry is an edible cherry variety) is to gather up fallen leaves under fruiting trees and remove them for good garden hygiene (preventing the spread of disease and any unwanted insects). Provided your cherry is healthy, I don’t think the leaves would pose a serious problem if used as leaf mulch on top of the vegetable garden beds.

The leathery evergreen leaves of English laurel (Prunus laurocerasus, same family as deciduous cherries and plums) are not a good choice for the compost pile because they take a very long time to decompose (which is not the case with deciduous cherry), and they contain cyanide compounds. However, so do apples, plums, almonds, peaches, apricots–all have some cyanide in them.

This link briefly mentions the question of cherry leaves and cyanide in terms of toxicity to animals. Fresh new leaves have a higher concentration of hydrogen cyanide; toxic potential is gone when the leaves turn brown. True enough, this is about eating the leaves, not letting them sit on the soil, but I imagine the concentration would be very low, and there are all sorts of things in our soil that in small doses are not likely to cause harm, and may or may not even be taken up into the roots of anything you plant there.

I asked Washington State University Extension Horticulture professor Linda Chalker-Scott what she thought about the safety of using those leaves and twigs on your vegetable bed, and she said, “Cyanide does not persist in soils. It is HCN [Hydrogen cyanide], which is quickly broken down by microbes in search of nitrogen. It is really nothing to worry about.”

Christmas trees and organic farming

Is there such a thing as a certified organic Christmas tree? If so, where might I find one?

 

The Washington Department of Agriculture has a list of certified organic producers (current as of 3/7/2019) and on this list I found farms which have carried organic Christmas trees in the past if not currently:
Lazy J Tree Farm in Port Angeles, WA
Buttonwood Farms in Redmond, WA

Fall City Farms states on their website that, while not certified, they grow their trees using organic practices.
Washington State University’s Farm Finder
describes Fall City Farms as follows:
“They practice ecologically-sound farming and sustainable agriculture and serve as an agricultural education and culinary resource.”

The Farm Finder lists a number of other farms which carry “claimed ecologically sound” Christmas trees. The only other farm in King County is Carpinito Brothers in Kent. (There are other farms in other counties.)

In Oregon, there are two types of organic certification, described in this Oregon Public Broadcasting feature:
SERF (Socially and Environmentally Responsible Farm)
and Coalition of Environmentally Conscious Growers certification.

This New York Times article, “How Green Can a Christmas Tree Be,” by Annie Raver (12/3/2008) mentions there is a certification called “Certified Naturally Grown” for Christmas trees in 47 states.

Another option, if you have the space in your garden, is to buy a living tree from an organic nursery and then plant it.

attracting pollinating insects

What flowering plants should I place near my two blueberry plants in containers on my driveway that might attract the kinds of insects to maximize pollination of the blueberry plants?

 

Almost any plant that flowers at the same time your blueberry plants flower will help attract pollinating insects. This could be anything from apples to clematis to more blueberries. The Xerces Society (a Portland-based conservation organization) has published this useful fact sheet about choosing plants to help our native bees.

difference between Zauschneria and Epilobium

Is there a difference between Zauschneria and Epilobium, also called California fuchsia in some sources? I’m trying to figure out if I can grow it here in the Northwest, with our wet winters. Also, any additional information about this plant (these plants?) would be appreciated.

 

The United States Department of Agriculture’s Germplasm Resources Information Network (GRIN) prefers the name Epilobium canum, though you will find this plant under Zauschneria as well. I have certainly seen this plant being grown in our area, but the wet winters could be a concern. According to the book, Plants and Landscapes for Summer-Dry Climates of the San Francisco Bay Region (2004), Zauschneria californica (synonymous with Epilobium canum)needs good drainage and occasional to no water.

Anecdotal evidence from Houzz’s online forum suggests that if you have a well-drained spot, you may be able to grow this plant there successfully. Oregon State University Extension has this to say:
“California fuchsia (Epilobium canum, also sold as Zauschneria californica) is another California native that grows well in Oregon both east and west of the Cascades.”

There are several journal articles which have information about this plant. The Oct-Dec 2007 issue of Pacific Horticulture includes Bart O’Brien’s “Getting Enough Zs in Your Garden: Enjoying Zauschnerias.” Here is an abstract:

The author discusses growing Zauschnerias in the Mediterranean climate of the Pacific Coast area. The plants are native to California and commonly known as California fuchsia. They bloom in an orange-red color during the autumn and the flowers attract hummingbirds. Varieties and cultivars vary in size to suit a variety of garden applications.

Avant Gardener, April 2007, has an article entitled “Hardy Fuchsia Bushes.” Here is the abstract:

The article discusses the varieties of California fuchsias, or Zauschneria, which has been renamed Epilobium. The shrubby 3′ perennials are cold hardy to -25 degrees F and are native from Idaho to New Mexico. They have tubular flowers that bloom in late summer and early fall. Sources for plants are presented.

Robert Nold has written about Zauschneria in American Gardener, Jul/Aug 2005:

Presents information on California fuchsia or zauschneria shrub. Temperature resistance of the plant; species of the shrub; tips on growing zauschneria.

on protecting plants from frost

I have some newly planted small shrubs and trees which are now in 3 inches of hard frozen snow. Everything was mulched well before it snowed. Yesterday I covered the plants with large inverted plastic pots, sheets, rice bags, and whatever I had at hand. The plants that are completely under pots will get no light. Can they stay in the dark through this entire cold snap (a week to ten days)? I’m not worried they will overheat under the pots,
with the sun so low in the sky, and the temperatures so cold, but should I be concerned with lack of light?

 

I have some personal experience with using just such pots to protect perennials, leaving the pots in place (and the plants in the dark) for a week or more. I would expect your plants to be fine. They will not overheat, though drainage holes help with air
circulation. Sheets and rice or burlap bags are fine as well, though the weight of
snow (in addition to the cold) can damage or break plants. You might want
to check the status of the covers if more snow falls. In addition, your mulching will help protect the roots. If the shrubs and trees are deciduous, they do not photosynthesize in the winter (low light and low moisture levels serve as the limiting factors, in general), so your plants will not suffer from the dark environment in
the short term. If the trees and shrubs are evergreen, they do photosynthesize in the winter, but the process is subject to the same limitations mentioned above. Again, no worries in the short term–frost can cause more damage to most plants than a few days in the dark.

Once temperatures are above freezing (32 degrees F or 0 degrees C)–and don’t forget to
consider nighttime temperatures–you can uncover the plants. Usually our
cold weather doesn’t last too long, so I think you can adopt the philosophy “better safe than sorry” and leave the pots in place until you are sure the cold weather has passed.

Below are some helpful links for additional information about predicting
frost and protecting your plants:

managing and controlling aphids

I have a small snowball bush that I planted three years ago. Each spring this plant is inundated with more and more ants and aphids. I try to garden organically and could use Safer Soap on it, but it is large and the leaves are all curled under and withering from the insects. Is there anything other than Safer Soap that I could use to help the plant, either systemic or otherwise?

 

Following are the best sources I have found about environmentally friendly control of aphids.

Aphids (order Homoptera)

Host/Site:

Almost all plants have an aphid species that may occasionally feed on them. Many aphid species attack several plants rather than having only one host. Trees (esp. birch, beech, maple, apple, peach, apple, plum, cherry, spruce, dogwood, willow); annuals (esp. nasturtium, snapdragon); perennials (esp. lupine, roses, lilies, begonias, columbine); vegetables (esp. peas, beans, brassicas, lettuce, spinach); fruit (esp. apple, peach, cherry).

Identification/appearance:

Small (2 mm long), pear-shaped, softbodied insects in a range of colors (green, brown, red, yellow, black). Most are wingless, but winged aphids appear at certain times, especially when populations are high or during spring or fall. A few species appear waxy or woolly. A magnifying glass will reveal the long, slender mouth parts used to suck plant fluids. Aphids are usually found in clusters, especially on new growth. Signs of aphid infestations include sticky honeydew on leaves or under plants, distortion of leaves, stunting of shoots, or large numbers of ants on the plant.

Life Cycle:

Overwintered eggs of some common garden species hatch in spring. These wingless females reproduce asexually, bearing live young (up to 80 per week) that already have the next generation developing inside. Young aphids, called nymphs, molt four times before becoming adults. There is no pupal stage. This simple, rapid reproduction allows for very large population increases in a short time. Late in fall, males and females are produced, mate, and the females subsequently lay eggs. Winged aphids may appear at certain times, allowing the colony to move to other locations. Not all aphid types have this reproductive pattern, but many do.

Natural Enemies:

Aphids have many natural enemies, including birds, spiders, ladybird beetles, lacewings, syrphid fly larvae, and braconid wasps. A naturally occurring fungal disease can also kill aphids when conditions are right. Ants have a symbiotic relationship with aphids: ants milk the aphids for honeydew while protecting the aphids from natural enemies.

Monitoring:

Check plants often, since aphid populations can rise rapidly. Inspect growing tips
and undersides of leaves. On trees, clip off leaves from several parts of the tree to look for aphids. If you see large numbers of ants on tree trunks, check for aphids on limbs and leaves. Look also for associated signs, such as yellowed leaves, stunted or distorted growth, or dripping honeydew. Sticky traps can be used to monitor for winged aphids. Check for signs of predators (named under Natural Enemies above), aphids that have been parasitized (look for a small exit hole on a dead, brown aphid body), or that have been killed by disease. Substantial numbers of any of these natural control factors can mean that population numbers will fall rapidly without the need for treatment. Because of the rapid changes that can occur in aphid populations, it is important to record monitoring data to detect changes due to predators or treatments.

Action Threshold:

Due to the incredibly high numbers that may be present, counting individual aphids is usually not practical. Action thresholds can be based on general descriptions of aphid density, plant damage such as stunted or distorted growth, or unacceptable amounts of honeydew beneath trees. Treatment should be triggered by rapidly rising numbers, unacceptable plant damage, or by honeydew falling on structures and people. Aphids seldom kill a plant, but they can cause defoliation. They also carry diseases from one plant to another. It is usually not necessary or even desirable to treat at the first sign of aphids, since low populations are needed to sustain predators.

Cultural/Physical Controls:

Plant selection: If possible, avoid or consider replacing varieties such as birch that have ongoing, serious aphid problems. Check transplants for aphids and remove them before planting.

Water spray: A strong blast of water knocks aphids from the plant, and most will not return. Water also helps rinse off the honeydew. Do this early in the day to allow leaves to dry and minimize fungal diseases.

Pruning: Where high aphid populations are localized on a few curled leaves or new shoots, prune these areas out and drop in soapy water to kill the aphids.

Fertilization control: High nitrogen levels favor aphid reproduction. Avoid over-fertilization and use slow-release rather than highly soluble fertilizers.

Sticky or teflon barriers: If you see ants crawling up the trunk of trees or other woody plants, place a band of sticky material (such as Tanglefoot or Stik-Em) around the trunk. Place a protective band of fabric tree wrap or duct tape underneath the barrier first. Teflon tape barriers may also be effective. Prune out branches touching the
ground, buildings, or other plants.

Biological Controls:

Since aphids have many natural enemies, biological control usually means protecting these enemies from ants and avoiding broadspectrum pesticides that kill beneficial insects. Recognize that predator populations usually lag behind aphid populations in time. A number of aphid enemies can be purchased for introduction into landscapes. Ladybird beetles, lacewings, and parasitic wasps and flies are all available. Although such introduced predators may not remain where released, some benefit is likely, especially if releases are staggered in time. Many of the natural predators of the aphid are especially attracted to a garden with plants in the Umbelliferae family, such as angelica, sweet cicely, dill, and Queen Anne’s lace. The flowers of these plants provide a good food source for insects, especially parasitic wasps, who may stay to prey on some aphids as well.

Chemical Controls:

Insecticidal soap is widely recognized as the least-toxic chemical aphid control. Although its effect is temporary, it can help to bring aphid numbers down so that natural enemies can take care of them. Repeat applications within a few days may be necessary. Soap works only by direct contact with the insects. Be sure to cover both sides of the leaves. Although readily biodegradable, soaps are highly toxic to
fish, so avoid runoff or direct application to water. Avoid using when
temperature exceeds 90 degrees F.

Oil sprays:

Supreme or superior-type oils will help to kill overwintering aphid eggs on fruit trees if applied as a delayed dormant application in early spring. Although perhaps not justified for aphid control alone, oils can also control other overwintering fruit pests. Oils may, however, kill some beneficial species. Summer weight oils are also available, but they can burn tender leaves when applied in hot sun.

Conventional chemical control:

Foliar applied insecticides (malathion, diazinon, carbaryl, pyrethrin) are broad spectrum and will kill beneficial insects. They should be avoided, especially in
home gardens and landscapes. Remember that allowing some aphid population in the garden helps to keep predators available.

ProIPM Integrated Pest Management Solutions for the Landscaping Professional

The Green Gardening Program is a collaborative effort of Seattle Tilth, Washington Toxics Coalition, and WSU Cooperative Extension, King County.

Sponsored by the Seattle Public Utilities in an effort to promote alternatives to lawn and garden chemicals.

Funded by the Local Hazardous Waste Management Program in King County.

Written by Philip Dickey, Graphic Design by Cath Carine, CC Design

Pest description and crop damage:

Aphids are soft-bodied insects that typically feed on leaves and succulent stems. They may vary in color from pale green or reddish to dark or black. Aphids are usually less than 1/8 inch in length.

Feeding damage to the plant is usually minor, although some leaf and shoot distortion can occur if populations are high. Aphids also produce honeydew, a sweet, sticky secretion that collects on plant tissues and encourages growth of a black sooty mold. This can interfere with photosynthesis of the plant. Honeydew is also a nuisance when it falls on decks, cars, or other landscape surfaces. They are a problem in early summer.

Biology and life history:

Most species of aphids have similar life cycles. Aphid females give birth to live offspring all year without mating. When other hosts are not available, aphids live on a wide variety of weeds. Aphids usually are found in colonies on new growth, the underside of leaves, and near flower and fruit clusters. In summer and fall, aphids may produce winged females and, later, winged males. They mate and produce eggs for overwintering, especially in colder climates. Otherwise, adult aphids overwinter on crops, weeds, or trees. There may be as few as 2 or as many as 16 generations each year, depending on the species and climate.

Management & biological control:

Aphids have many natural enemies, including lady beetles, syrphid fly larvae, and green lacewings. Avoid broad-spectrum insecticide applications that would disrupt these controls.

Management & cultural control:

Wash aphids from plants with a strong stream of water or by hand-wiping. Aphid populations tend to be higher in plants that are fertilized liberally with nitrogen and heavily watered, as this produces flushes of succulent growth. Avoid excessive watering, and use slow-release or organic sources of nitrogen. Control ants, which farm aphids and protect them from predators in order to harvest their honeydew.

Management & chemical control (home):

It is important to cover foliage thoroughly, including lower leaf surfaces.

1. Beauveria bassiana

2. horticultural oil

3. insecticidal soap

Source:

http://pnwpest.org/pnw/insects