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Elisabeth C. Miller Library

Archives: Plant Answer Line Q & A

Plant Answer Line questions and answers.

Attracting bats and bat-like plants

I have a couple of questions. Are there plants I can grow that will attract bats, and are there plants that are bat-like in appearance?

 

The organization Bats Northwest recommends providing habitat (such as hollow trees and snags). The Washington Department of Fish and Wildlife has information on bat houses you can build or purchase. More information can be found at Bat Conservation International.

I did not find specific lists of bat-attracting plants, but providing a diverse tree canopy which includes trees that attract moths (for bats to eat) may make your landscape more bat-friendly. The British Bat Conservation Trust suggests that you leave some wild areas in the garden, add a pond if you can (as a place for bats to drink and forage on insects and their larvae), and plant night-scented flowers. Plant diversity seems to be the key: you can try growing flowers of different shapes, sizes, and fragrances, pale single flowers, and flowers which are good “landing platforms” for insects (such as daisy and carrot family plants).

There are several plants that resemble bats. Here are a few suggestions:

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Noug or Niger seeds

I bought some shiny dark seeds at an Ethiopian grocery store. The proprietor said they were good for sore throat. The name of the seed sounded something like ‘nuk.’ Can you tell me what plant they are from? And is it safe to use them?

 

By guessing at different possible spellings, I came across a plant whose Amharic name sounds like ‘nuk’ or ‘noug.’ I also showed your sample seeds to an Eritrean colleague, and confirmed that they were familiar to him for their high oil content, but also for steeping in hot water to make a kind of tonic. I can’t recommend consuming them medicinally; you would need to speak to a medical professional. But I can tell you that the plant source is Guizotia abyssinica. It is in the daisy family (Asteraceae), and has a yellow flower that might remind you a little of a yellow daisy. There is research being done at University of British Columbia’s Botany department on this plant and its potential as a crop to increase food security and alleviate poverty in Sub-Saharan Africa.

Purdue University researchers are looking into cultivating this plant (also called Nigerseed) in the Midwestern United States.

Wikipedia has additional information about this plant.

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Health benefits of Chia seeds

Chia seeds: what are they, and what are they good for, besides sprouting on clay animals (Chia Pets!)? Lately, I’m seeing them promoted everywhere for their health benefits. Is there any validity to this?

 

The common name Chia refers to several species of Salvia, and to Hyptis suaveolens. The species that is imported into the United States is usually Salvia hispanica. Purdue University’s New Crops database has information about the uses of chia seeds:
“The seeds of chias have been eaten for centuries by native North Americans, either raw or parched. They are used in sauces and as thickening agents. When soaked in water the seed envelops itself in a copious mucilaginous polysaccharide, excellent for digestion, and together with the grain itself forms a nutritious food. Mixed with orange juice the gel-like seeds make a nutritious breakfast and can help to control excess weight. Users report that a glass full of orange juice with a teaspoon of presoaked seeds leaves one feeling full and without hunger until noon. The plant explorer Edward Palmer wrote (1871): ‘In preparing chia for use the seeds are roasted and ground, and the addition of water makes a mucilaginous mass several times the original bulk, sugar to taste is added, and the result is the much prized semi-fluid pinole of Indians and others, and to me one of the best and most nutritive foods while traveling over the deserts.'”

The New York Times published an article (11/24/2012) on the current trend for consuming chia seeds as a nutritional supplement (purportedly high in antioxidants and omega-3 fatty acids). More studies are needed to substantiate the health claims, as this information from Columbia University’s “Go Ask Alice” website points out:
“People eat chia seeds for diabetes, high blood pressure, and to reduce the risk of heart disease and stroke. However, there is currently no good evidence to support chia consumption for these uses. People have also tried using chia seeds as a weight loss aid, as the high fiber content is thought to suppress appetite and ultimately help with weight loss. There’s not much support for this claim. One study found that eating chia seeds had no effects on body weight, body fat, or changes in appetite over a 12-week period. However, studies have shown that a particular variety of chia seeds, marketed under Salba, can reduce certain risk factors for heart disease such as blood pressure, clotting factors, and inflammation.”

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Acorn-producing oaks and SOD

I have a few acres in South Kitsap where I am creating
pasture by cutting down many of our firs and pines. We will have herds of goats and sheep and swine. I like the idea of acorns for swine and the increased btu of oak for firewood. From my research, it seems that Garry oak and White oak grow too slowly, while Red oak and Pin oak are fast and produce a lot of acorns.

So, I’m leaning towards Red and Pin Oaks, particularly Pin Oaks, but is the fact that these aren’t native a problem? Would these trees grow well in the Pacific Northwest, in sandy loam with low nitrogen a pH of 5.3. The soil has pretty good organic matter, Potassium and Magnesium. The trees will
be planted in a full sun to mostly sunny area, but depending on the angle
of the sun, the surrounding firs throw a pretty big shadow.

Are there other oaks with good acorns I should consider?

Also, is Sudden Oak Death a problem in the Puget Sound?

 

I’ll start with your last question first. Washington State University has a Sudden Oak Death information page. A summary of the work researchers are doing may be found in a 2013 edition of WSU’s online newsletter, On Solid Ground.

I have certainly heard that it is present in our region. If you are concerned, you may want to purchase from nurseries with certifications from the USDA Plant Health Inspection Service saying that they are free of the disease. Here is a list of nurseries that have such a certificate. Interestingly, the plants on which Phytophthora ramorum has been detected (in nurseries) in our state are not oaks, but Rhododendron, Viburnum, Camellia, Kalmia, and Pieris. Outside of nurseries, the pathogen has only been found on salal.

The USDA Plant Health Inspection Service has a list of other plants which are hosts of SOD.

Returning to your questions about species of oak, Oregon State University’s Landscape Plants Database has information about Quercus rubra (Red oak)and Quercus palustris which confirm that they prefer sunny sites. Red oak will produce acorns in two years. Pin oak is one of the fastest growing oaks, and its acorns (also produced after 2 years) are small.

Local tree expert Arthur Lee Jacobson has this to say about Quercus rubra in his Trees of Seattle (2006):

“New Jersey’s State Tree proves to be Seattle’s fastest-growing oak, on average. […] the safest bet if you want an oak in a hurry is to plant a Red oak–and then stand back!” Here is what he says about pin oak, Quercus palustris: “Seattle’s most abundant oak. […] Pin oak is slender in all respects: trunk, limb, branch, twig, leaf–only the tiny squat acorns belie the name. Rapidly growing, it can attain up to 135′ x 23 1/4″. Inexperienced tree-watchers must be careful not to confuse it with Scarlet oak, which is less common, less slender, makes bigger acorns […].”

The only aspect of your site description that concerns me, as far as these two oak choices, is the sun exposure–you might want to see how far the shadow of the firs extend, as these oaks will do best in sun. Unless your goal is to plant native species only, I do not see a problem with adding these non-natives to your landscape. You can certainly add lots of native shrubs and perennials if you feel that would be advantageous. There are some excellent resources for selecting native plants:
Washington Native Plant Society’s landscaping guides

King County’s interactive Native Plant Guide

As far as other good acorn-producing oaks which are also large trees, I can see that Arthur Lee Jacobson mentions English oak (Quercus robur) for its large acorns–and this is also potentially a very large tree (150′ x 40+’). Scarlet oak (Quercus coccinea) has notably large acorns too. Burr oak (Quercus macrocarpa) has the largest acorns, but does not do very well in our area. The native Garry oak (too slow a grower for your needs) Quercus garryana does produce acorns.

If you want to diversify the source of nuts (in case of Sudden Oak Death), you might want to consider adding some hazels and filberts (Corylus species) which should do well here. (I don’t know if pigs and goats will eat these, though.)

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On safety of using biosolids

I noticed at the Flower and Garden Show that King County Master Gardeners were giving away samples of biosolids for use in the garden. Is sewage sludge really safe? Is it acceptable if you garden organically?

 

The Environmental Protection Agency defines biosolids as treated sewage sludge. In January 2009, the EPA surveyed samples. Here is a brief summary of some of the findings:

  • The four anions were found in every sample.
  • 27 metals were found in virtually every sample, with one metal (antimony) found in no less than 72 samples.
  • Of the six semivolatile organics and polycyclic aromatic hydrocarbons, four were found in at least 72 samples, one was found in 63 samples, and one was found in 39 samples.
  • Of the 72 pharmaceuticals, three (i.e., cyprofloxacin, diphenhydramine, and triclocarban) were found in all 84 samples and nine were found in at least 80 of the samples. However, 15 pharmaceuticals were not found in any sample and 29 were found in fewer than three samples.
  • Of the 25 steroids and hormones, three steroids (i.e., campesterol, cholestanol, and coprostanol) were found in all 84 samples and six steroids were found in at least 80 of the samples. One hormone (i.e., 17a-ethynyl estradiol) was not found in any sample and five hormones were found in fewer than six samples.
  • All of the flame retardants except one (BDE-138) were essentially found in every sample; BDE-138 was found in 54 out of 84 samples.

Additional information is available from Cornell University’s Waste Management Institute.

Here is King County’s own information on biosolids recycling. Since the EPA is currently evaluating the results of their own survey, there may be revisions to previous notions that the concentration of toxins in biosolids was so low as to be inconsequential. In fact, the Center for Food Safety has petitioned the city of San Francisco to stop distributing biosolids at “compost giveaway events.” Their website has additional information about potential risks associated with using sewage sludge.

In Washington State’s Lincoln County, residents of a community that includes an organic farm fought to block a nearby mega-farm from applying sewage sludge to fields that would drain into Mill Canyon Watershed. While it is legal to use biosolids, there have not been enough studies of the effects on the environment to prove that it is safe.

The short answer is that there is uncertainty about the safety of using biosolids in the garden, and if you are attempting to garden organically, it may be best to avoid using them.

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Passionflower winter care

I have a passion flower that I brought in for the winter. It has lost all leaves and has sticky little brown spots on it . How do I get rid of the brown sticky things? And how do I get the leaves to grow back. Would putting under a grow light for the winter help.

 

I read up on Passionflower cultivation and pests in the book Passiflora: Passionflowers of the World by Torsten Ulmer & John M. MacDougal, Timber Press (2004).

Under the section, Overwintering, it says that in winter, passionflowers suffer from lower temperatures, shorter days, and low light, and therefore this season is the most critical period for these plants. Before night temperatures drop below 10 degrees C, the more sensitive container plants, such as Passiflora quadrangularis and P. vitifolia, should be taken indoors. Depending on their resistance to cold, other species will need to be taken to their winter quarters later on; for now, though, these plants should just be cut back and thoroughly scrutinized for pests. Unlike many other decorative plants, passionflowers keep their foliage in winter, with the exception of certain herbaceous species such as P. incarnata, P. lutea, and P. bryonioides. Do you know if your plant is any of those three (so we will know if its loss of leaves is normal and not a sign for alarm)? [This is from p. 49.]

About the brown sticky spots, it is extremely difficult to make a diagnosis or suggest a treatment, sight unseen. If your plant was not supposed to lose its leaves, and the leaf drop is a sign of severe stress, then those spots could be the result of the plant’s health being poor (as in low resistance to disease). The spots could be bacteria, viral, fungal or even from some insect (although I read through the list of these and could not tell what it might be).

Your plant would be a great candidate for the Master Gardeners to whom the public can take their plants for advice and diagnosis of problems. I found a Master Gardeners of Ontario, which you can search for your particular region.

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Ripening figs in cooler climates

The house that we purchased and moved into last spring came complete with a gorgeous, huge fig tree. It is currently full of gorgeous, huge figs, all rock-hard. It is planted against a south-facing wall, so it gets lots of reflected heat, but of course that is diminishing by the day.

So two questions:

1) Is there anything we can do to encourage at least a few figs to ripen before it is too late and

2) Is there anything worth doing with under-ripe figs?

 

I found information originally published in the summer 2009 issue of Edible Toronto about ways to increase the chances of figs ripening on the tree in cooler climates. In an article (no longer available online) entitled “Fig Fetishists in Ontario” author Steven Biggs says:
“The real secret to coaxing the fruit to ripen in our climate is to gain a few days of ripening time. Ferreira shows me a couple of trees over which he’s draped clear plastic bags. This creates a warm microclimate around the tree, helping it to come out of dormancy more quickly. Once the current year’s growth is underway and figs are forming, another trick is to break off the tip of the branch, leaving four leaves on the current year’s growth.

What’s Ferreira’s big secret? Extra virgin olive oil. In the first week of September, he looks for figs that don’t seem as if they will ripen before winter, and puts a drop of extra virgin olive oil on the eye. After six or seven days, he repeats the step. While this doesn’t work on all of the fruit, he says, it helps some to ripen.”

Most sources warn against using unripe figs. Not only would they not be tasty, but according to the Purdue University’s New Crop Resource, “the latex of the unripe fruits and of any part of the tree may be severely irritating to the skin […]It is an occupational hazard not only to fig harvesters and packers but also to workers in food industries, and to those who employ the latex to treat skin diseases.”

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Propagating weeping willows from cuttings

I know you can plant willows from cuttings, but what about weeping willow trees? Can they be grown from a cutting (by an amateur)? If so, how?

 

Following is a suggestion from American Horticultural Society Plant Propagation, ed. by A. Toogood, 1999, p. 89.

“The most reliable method for propagating weeping willow (Salix babylonica) is by cuttings. Hardwood cuttings of vigorous willows may be as long as 6 feet and planted out immediately to mature faster than standard 8 inch cuttings. Take cuttings in late autumn from new, fully hardened wood that does not need to be very woody. Line them out in open ground, pot them, or place them in bundles in a frost-free sandbed to root. Select those in active growth in spring to pot. Cuttings may also be taken of green or semi-ripe wood. “

Here is additional information (no longer available online) from a British nursery called JPR Environmental:

“The best way to propagate weeping willows is first to find a mature tree that you like the look of and then go and ask the owner if you could take a small branch from it in the winter (most are happy to oblige and will tell you about their tree in great detail!).

“Once a source has been identified then look to prepare the ground. Make sure that the site is not near the house and not near any old water pipes etc. – it would be a shame to have to cut it down just when it is getting a good size. A site near water is good, willows like moist soil but do not do well in soil that is waterlogged for long periods. Dig a square pit say 18 inches wide and deep. Break up the soil and add some compost if the soil structure needs it.

“Now is the time to take a cutting. The best time of year is whenever the leaves are off the tree with the optimum being February to early March – so long as there is not a hard frost on the ground. The branch should be between 1 and 2 inches at the base and not more than 6 feet tall. Plant it in the hole that you have made, firming up the soil so that you cannot pull the branch out. If you are in a windy site it may be worth staking the tree and a rabbit guard will protect it from grazing in the first year or so.”

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Transplanting roses

I have a rose bush in the back yard, under a tree, it seems to be thriving but no one can see it blooming. I want to move it to a more prominent place in our yard. What is the best time of year for transplanting this rose?

 

Moving your rose out from under the tree is probably a good idea. Roses: 1001 Gardening Questions Answered by the editors of Garden Way Publishing (1989), says that the best time to transplant it to its new location is early spring or late fall. Before moving it, prune it, leaving three to four canes. Prepare the new hole in the ground (and) give it some extra attention after it is planted. This resource says that spring transplanting is preferred, because with warm weather on the way, the rose will have a better chance of starting new growth. When digging up your rose, dig a circular trench one foot away from the crown of the plant, removing the soil around the plant with your shovel. Loosen the root ball, and then take hold of the crown and push it back and forth to loosen it. Then lift it out of the hole. Dig a deep hole in the new location. Add two inches of compost, build a mound of soil, and spread the roots over it. Fill in with topsoil, make a ridge of soil around the base of the plant, and water well. Afterwards, water carefully, neither too much nor too little.

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Pruning ornamental cherries

I live in Seattle. My condo board is having a debate about
whether pruning an ornamental cherry after May will kill it or
not. Can you help? Also, when should it be pruned?

 

According to Cass Turnbull of the local organization, Plant Amnesty, the
main reason pruning ornamental cherries is problematic is that the branch
system of these trees is complex, and it is hard to tell (if you are not
an experienced gardener or a professional arborist) what to prune. In her
Guide to Pruning (Sasquatch, 2006), Turnbull says that ornamental
cherries are prone to dieback if their branches are shortened. Besides
the dieback issue, improper pruning can give rise to watersprouts (the
branches grow straight up). I consulted two other pruning guides, both of
which advised against any pruning of ornamental cherries.

Do you know why the board wants to prune these trees? If the trees are
too large for the site, it might make more sense to remove them and plant
something appropriate which will not require risky pruning. You may find
this discussion forum from University of British Columbia Botanical Garden helpful.

Excerpt:

“These generally disease susceptible trees resent severe heading back.
Trying to force it to become a perfectly symmetrical shape will also
destroy its natural character; much of the appeal of aged Japanese
cherries (and related trees) is the contrast between the prettiness of
the flowers and the rugged appearance of the trunk and branches.”

My summary is that, while pruning the trees may not kill them outright,
it could make them aesthetically unappealing and more susceptible to
disease, so it would be best to let them be.

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