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Plant Answer Line questions and answers.

Deciduous or evergreen Dendrobium?

I just got a Dendrobium, it is Dendrobium eima x impact. The
flowers are pink and white. I was wondering how I can tell if it is a
deciduous one or an evergreen one. I still have months before winter,
but want to make sure I give it the rest it needs when the winter does
get here.

 

There are deciduous and evergreen types of Dendrobium. Unfortunately, I could not find information about the variety you are growing. If yours has soft canes, it is deciduous; hard canes are characteristic of the evergreen type. Here is information from Orchids Made Easy:
“Dendrobiums are separated into two main groups: hard-caned and soft-caned.
Hard-caned Dendrobiums have tall pseudobulbs that are very thin and their leaves are generally a little darker in color than the soft-caned. Hard-caned Dens are evergreen and often keep their leaves for many years before they drop them. Hard-caned Dens grow spikes from the top of the cane and produce gorgeous flower sprays.

“Soft-caned Dendrobiums have leafy pseudobulbs that are long and slim. Their leaves are generally a little lighter in color than the hard-caned Dens. They grow leaves along the length of the cane and the blooms sprout from the individual stems that are along the cane itself. Soft-caned dendrobiums are deciduous and drop their leaves
when the weather gets cold.”

The American Orchid Society has a guide to growing evergreen Dendrobium for beginners.

There is also good general information on caring for orchids in the Brooklyn Botanic Garden guides on the subject. Generally, winter is the time to hold back on watering a bit, but also be careful about the plant’s need for humidity–our heated homes in winter can be exceedingly dry. According to Orchids by Joyce Stewart (Timber Press, 2000), most orchids prefer 65-75% humidity during the day. She recommends “damping down last thing at night” during the winter (using a spray bottle or mister), if you have heat on in your house overnight.

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Cryptomeria and dieback

My Black Dragon Japanese Cedar has a lot of dead branches. The tree is healthy otherwise. A foot of new growth this year. The nursery told me this was normal. Can you give me an opinion?

 

Apparently, dieback is often seen on Cryptomeria, as the following
information from North Carolina State University Cooperative Extension, no longer available online, suggests:

Cryptomeria can have leaf blight or spot. Branch dieback is common.
Dieback has not been associated with a disease but has been touted as the
nature of the tree. Pathologists are still researching this. There may be
some tip dieback associated with a disease.

There is another discussion of a Cryptomeria with dead branches on
University of British Columbia Botanical Garden’s forum which mentions
rust and needle blight (both fungal diseases) as possible causes.

You may want to bring samples of the affected branches (along with your
photo) to a Master Gardener Clinic for diagnosis.

You may find this University of British Columbia Botanical Gardens Forum discussion of interest.

The growth rate of a foot a year makes sense, considering that this is
not a large tree. See below what Great Plant Picks, a Seattle-based website, has to say about this tree. An earlier version of the page linked here, from Iseli Nursery, indicates a growth rate of only 3-6 inches a year.

Information from Iseli Nursery: Cryptomeria japonica ‘Black Dragon’ (Japanese cedar )

Cryptomeria japonica is one of the most variable conifers you can imagine, with plants ranging from very dwarf rounded shrubs, trees with golden or contorted leaves, and wild forest trees to 80 feet high and 20 feet wide. ‘Black Dragon’ takes the middle road,
neither too small nor too big. It has the deep green, needle-like leaves characteristic of this species and grows to about 7 feet high and 8 feet wide in twenty years. This very dark-foliaged conifer is easy to grow and combines well with plants having larger or variegated leaves.

Japanese cedars thrive in full or part sun in well-drained, humus-rich, acidic soil and average moisture. May grow quickly when it first comes home from the nursery, due to the added fertilizer it gets there, but within a year it will settle into its dense, compact habit of growth.

Cryptomeria japonica ‘Black Dragon’ is an evergreen, coniferous shrub. It grows wider than high, with an overall pyramidal shape. In 20 years it will reach only 7 feet high and about 8 feet wide.

Hardiness: USDA zones 6 to 9

Sea buckthorns in Washington State

I am wondering about whether or not sea buckthorn grows here
in Washington, if you have examples of it at the arboretum, or if anyone
here sells the tree or the berries/extracts. A Ukrainian
friend told me about the health benefits of the berries, and I was
curious as to whether sea buckthorn can be found in Washington state.

 

Washington State University’s Fruit Research Station in Mount Vernon has
been growing sea buckthorn, or Hippophae rhamnoides, in its fruit trials.
Below are the varieties they grew:

Sea Buckthorn (Seaberry)
‘Frugana’
‘Hergosa’
‘Leikora’
‘Pollmix’ male
‘Russian Orange’

Here are results from the Washington State University fruit trials:

“Sea Buckthorn (Hippophae rhamnoides) is a very thorny shrub or small tree
native to eastern Europe and Asia. It has nitrogen fixing properties and
is very tolerant of drought and poor soils, so has been introduced as a
shelter belt plant in some of the plains States and Canada. In eastern
Europe and the former Soviet Union the berries are commonly harvested for
juice, which has nutritious and other healthful properties. Medicinal
uses of extracted plant oils are also well documented in Europe and Asia.
Plants on trial at Mount Vernon have fruited very successfully for the
past 3 years, and appear quite well adapted horticulturally. The plants
are very productive, setting many small orange fruits with a citrus like
flavor. The juice is high in vitamin C. We have not had any problems with
pests thus far and this shows great potential for organic growing. The
commercial potential of this plant is being pursued by the British
Columbia Sea Buckthorn Growers’ Association, in the Okanagan Valley.
Information on the Association and on sea buckthorn is available from
Okanagan Sea Buckthorn. More information in a paper on the fruit potential of sea buckthorn by Thomas S.C. Li from the Summerland, B.C. fruit research station.”

According to Arthur Lee Jacobson’s Trees of Seattle (2006), there is a
specimen in the Washington Park Arboretum, but it may be easier to
locate the 19-foot example at the Good Shepherd Center on the south wall
of the annex (see directions to Seattle Tilth) There are others at Meadowbrook Park, and
individual residences at 4015 NE 70th St., and 208 NE 42nd St. You might
also ask the manager of the U.W. Medicinal Herb Garden if he has grown
it: Keith Possee, UW Medicinal Herb Garden 206-543-0436, 543-1126;
kpossee@u.washington.edu.

From an older Raintree Nursery catalog:

“Perhaps the most widely grown, northern hardy, fruiting plant in the
world and most Americans have never heard of it. Incredibly productive
and great for your backyard. This attractive small tree or shrub from the
Russian Far East has narrow silver leaves. It grows from 6-10′ tall with
a narrow upright growth habit. Space 7′ apart or 3-5′ for a hedge. It is
extremely hardy, to -50 F. It is disease resistant and easy to grow.
Plentiful round yellow orange fruits cover the female plants making them
beautiful edible ornamentals. Branches are used in florist displays.
Commercial crops are harvested by cutting off entire fruit laden
branches. Very high in Vitamin C, ln Europe the fruit is made into sauces
or jellies and as a base of liqueurs. The juice is sour and has an orange
passionfruit like flavor when sweetened. Blended with other fruits, or by
itself, it makes a delicious juice. It is also used widely in Europe and
Asia as a healing oil and for other medicinal purposes.”

Non-blooming Wisteria

We have a Chinese wisteria which we’ve had for 20 years. We’ve
trained it on a trellis to the side of our covered porch and then
on a rope across the front so there is a nice green, leafy fringe
along the porch front. However, this plant has never bloomed.

We have consulted with our local horticultural experts and they have suggested various treatments. The lawn care
people do not fertilize near the roots of the wisteria so it
doesn’t get too much phosphorus, we have done root pruning, we have
even hit the trunk with a board to shock it, have applied super
phosphate but no blooms. We get some pretty cold
winters, but I’ve never even seen flower buds anywhere on the
plant. I know wisterias are sometimes late in blooming, but this
is a long time to wait! The roots of the plant face east and get
lots of sun. The part across the porch is shaded in the afternoon
because we have two pine trees in the front yard. We prune off the
tendrils that form during the summer to keep the plant in check,
but what else can we do to get blooms? I know it would be a
spectacular display if it ever bloomed and have almost given up
trying. I’m thinking of hanging artificial blooms just to get the
effect!

 

 

I found quite a bit of discussion in online gardening forums about
flowerless wisterias, so you are not alone. You may find this information
from Cass Turnbull of Plant Amnesty helpful:

“THE MOST COMMON COMMENT I get at classes and at the PlantAmnesty
educational booth is, “My wisteria won’t bloom.” It is natural for these
vines to take between three and seven years to start blooming. I have
read that frequent, proper pruning may help them to begin blooming
sooner, or at least more. On the other hand, some people have old vines
that have never bloomed. I am told that these are seed grown plants or
“mules.” I have often heard root pruning recommended to force an older
vine to bloom. Basically, this means that you use your shovel to cut the
roots in a circle (or dotted circle) a foot or two from the vine. I have
also heard people recommend fertilizer formulated to encourage blooms,
(not heavy on nitrogen). However, I have been faced with such a vine and
had no luck with either technique. In that case, as with all
non-performers, removal is the best option, and no one will blame you for
it.”

Here are gardener Ketzel Levine’s comments, from her NPR.org site:

“Depending on how old your wisteria is, do know that young plants can take
up to eight or ten years before they flower, especially if started from
seed. Other reasons wisteria fail to bloom: lack of adequate sunlight
(needs at least six hours of full sunlight); too much nitrogen fertilizer
(causes more vegetative growth); pruned heavily in winter or spring (also
encourages vigorous vegetative growth); severe winter injury/cold-blasted
flower buds (though that is clearly not a problem this year) or a bum
plant. It happens.”

You could either try the method described above, of cutting a circle with
a shovel, or you could replace the vine, or you could follow through on
your artificial flower idea! (I’ve heard that Bellevue Botanical Gardens
hangs Wisteria-shaped lights from their arbor for their holiday light
show.)

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Managing hemlock woolly adelgid

My Western Hemlock is infested with woolly adelgid. Help! How can I save my tree?

 

The USDA Forest Service website
includes information on different ways of managing the Hemlock woolly adelgid.

The most effective approach is prevention, as treatment tends to be expensive
and is not always effective. Information from University of Maryland Extension does describe the use of dormant oil spray in late winter and summer application of horticultural oil and
insecticidal soap, but care must be taken to cover the entire tree. Also, it is
important to avoid the use of nitrogen-heavy fertilizers which create a lot of
succulent new growth attractive to the pest.

I recommend that you consult a certified arborist for advice on how to save your <em?Tsuga heterophylla (Western hemlock). You can obtain
referrals from Plant Amnesty or you can select an arborist from the directory of the Pacific Northwest Chapter of the International
Society of Arboriculture.

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Flower proliferation

Seven of my ‘Smokin’ Hot’ hybrid tea rose blooms have buds coming out of the middle of the flower. All of these flowers are from the same cane which shot up from the very bottom of rose bush. I have never seen any other roses do this before.

I cut off these seven strange roses to the next five leaves. My question is whether I should remove the entire cane?

 

This is a genetic mutation called flower proliferation. The cause is not known; it can be triggered by late frost, insect damage, extreme heat, or sometimes by a virus. If your rose does this each year, it might be due to a virus. Usually, in roses, the next set of flowers that develops will not have this odd formation of buds inside it. If it does, you can prune back that shoot (the way you already did). This information from the Royal Horticultural Society explains the phenomenon. Local gardening expert Ciscoe Morris has this to say about flower proliferation:
“The condition is not caused by a disease, so if the affected flowers look bad, simply prune them off. The next flush of flowers that take their place should be normal. There really is nothing to worry about, however, so if any of the multiple-blooming roses look really cool, don’t be in a hurry to remove them.”

A related flower anomaly that can affect roses is phyllody, in which leaf-like structures appear in place of flower organs. When phyllody occurs repeatedly in roses, it can be a sign of disease.

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Pearl bodies

A plant that was given to me as a cutting has clear beads at irregular intervals along the stem. They are firm rather than sticky, but can be mashed between thumbnails. Is this insect- or disease-related, or something else? (The plant may be Abutilon but it has not flowered yet, so I am not sure.)

 

It is possible that these are ‘pearl bodies‘, also called ‘pearl glands’ or–if seen on grapes–‘grape balls.’ According to this scientific article, they are a type of food body (a nutrient-dense plant structure that offers food rewards to creatures such as ants). Other types of food bodies are extrafloral nectaries that secrete nectar, and domatia (chambers a plant produces to house ants or mites). Pearl bodies are part of a system of mutualism between plant and arthropod: ants gather the pearl bodies and take them to their nests, prompting the plant to form new ones in their place; in return, the ants may defend the plants against insect pests. Pearl bodies may be found on many different plants, particularly on a plant’s most robust branches.

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Common groundsel and the groundsel tree

I came across a reference to a “groundsel-tree” in a novel, and I wonder what its connection is to the weedy groundsel. In the book, it is found growing near the beach at Coney Island in the 19th century.

 

The weedy groundsel is Senecio vulgaris (a Class C noxious weed in Washington State, with a more colorful common name, old-man-of-the-spring, presumably because of its fuzzy white seedheads), but ‘groundsel tree’ refers to a tree-like deciduous shrub, Baccharis halimifolia. It goes by other common names as well: sea-myrtle, saltbush, consumptionweed, silvering, coyotebush, and salt marsh-elder, to name just a few.

One obvious connection between the weed and the shrub is that they both belong to the daisy family (Compositae/Asteraceae). There is similarity in the shape of the flowers; according to Missouri Botanical Garden, the shrub’s common name “refers to the similar appearance of the tufts of pappus on mature seedheads of this species and those of common groundsel (Senecio vulgaris).” (To me, Baccharis seedheads resemble the brushes on old-fashioned typewriter erasers!) Both plants have toxic properties. The weed is harmful if consumed by cattle or horses, and humans—though less likely to ingest it—can also suffer liver damage or death from eating it. The woody plant has toxic leaves and seeds. Both the weed and the shrub have the ability to spread aggressively, and according to this blog post from Buffalo Bayou Partnership, that trait is embedded in the common name groundsel, “from the Anglo-Saxon groundeswelge, meaning “ground swallower.”

It makes sense that the plant would grow in a place like Coney Island (even in a fictional setting), because it is a salt-tolerant shrub. Baccharis halimifolia is native to the Atlantic and Gulf coastal areas of the eastern and southern U.S.

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Standing cypress

Why is the flower ‘standing cypress’ called that? It’s obviously not a cypress (as in the tree). I am just curious about this great plant that brings all the hummingbirds and butterflies into my garden.

 

Ipomopsis rubra goes by several other common names (Texas plume, red gilia, red Texas star, Spanish larkspur, and more). The common name you are wondering about may be derived from an impression of the feathery leaves echoing the foliage of true cypress (Cupressus) trees, though they more closely resemble Taxodium (bald or swamp cypress). ‘Standing’ is also puzzling, since these biennial flowers stand much less tall than a cypress tree. Maybe it is because when grown from seed, Ipomopsis forms a basal rosette the first year, and it doesn’t ‘stand up’ and grow a tall spike until its second year.

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Staghorn sumac flowers and fruit

I planted three staghorn sumacs several years ago. They have done well, and have nice fall color, but I was hoping to see the flowers and fruit. This summer, for the first time, there are flowers on one shrub. What prompted the change? Will the flowering plant have fruit?

 

Anecdotally, there are reports of Rhus typhina (staghorn or velvet sumac) taking a while to flower and fruit. If you don’t have flowers on more than one of your three plants, you are not likely to get fruit (unless your flowering plant is female and someone nearby has a male, in case your other two are also female). Rhus typhina and Rhus glabra (smooth sumac) are dioecious, meaning that they produce male and female flowers (yellow green upright cone-shaped panicles) on separate plants. Plants of both sexes need to be grown together, and pollen from the male flowers needs to reach the female flowers, for the the upright clusters of the fuzzy disc-shaped dark red fruit (berry-like drupes) to develop on the female plants. These fruit clusters are colloquially referred to as ‘bobs.’

You can examine the flowers on your plant closely (with a hand lens) to determine if they are male or female. Male flowers tend to be larger and have five yellow-tipped stamens, while female flowers have a three-lobed style in the center, and a calyx with five pointed lobes nearly the same length as the petals. Both flower stalks and calyx are densely hairy. [Source: Minnesota Wild Flowers field guide online] Here are additional photos to clarify the description.

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