My camellia is potted and lives on an urban deck. In the spring, it was full of beautiful blooms and lush foliage. This summer it has been plagued with aphids and mealy bugs. I have sprayed two different times, 3 times each. My bush appears to continue to fail. It is dropping perfectly healthy-looking leaves and getting new growth, but it has few new buds and looks very “naked.” What is wrong with it? I have noticed small insects in the soil as well. I have added a watering of Safer-soap-with-water mixture but it seems to have had no improvement. Please help!
I wonder what kind of spray you have been using. Was it the Safer soap product?
Aphids seldom cause the demise of a mature plant. Aphids are attracted to lots
of leafy new growth, so it is best to avoid quick-release high-nitrogen
fertilizer. The best way to keep aphids in check is to encourage natural
predators like ladybugs, syrphid flies, lacewings, and parasitic wasps. Broad
spectrum pesticides will harm the helpful insects as well, so I would avoid use
of those. Mealy bugs are also a favorite of natural predators like those
mentioned above. Usually, regularly spraying jets of water to knock the aphids
and mealy bugs off the plant’s leaves should keep the damage in check. If
necessary, you can use insecticidal soap, but always test it on a small area of
the plant to make sure it does not cause any damage to the leaves.
It is possible there is something else going on with your camellia. Here is a
link to University of California, Davis’s Integrated Pest Management website,
with a list of problems affecting camellias. My own camellias do shed a certain number of healthy green leaves every year, but still manage to keep flowering. Excessive leaf drop may indicate overfertilizing, but it could also be a sign of too much or too little water.
Did buds drop from the plant, or did they simply not form? Failure to form buds
might be a result of cold injury (although since you had flowers in spring, this
seems to not be the problem), or it could also be a sign of overfertilizing with
a nitrogen-heavy product which encourages leafy growth at the expense of
flowers.
You may want to bring samples of the insect-affected leaves and the insects in
the soil to a Master Gardener Clinic for identification and diagnosis. You might
also mention the excessive leaf drop, which can be a symptom of Sudden Oak Death
(Phytophthora ramorum).
Our maintenance contractor has told us that our grass is infested with the dreaded sod webworm, and that we should attack it immediately with the insecticide Covert. A little research tells me that this product is very toxic. Question: true or false? What are some commercially available alternatives if this is a toxic product?
It would be best if you could avoid using pesticides to control sod webworm. If you can encourage natural predators in your garden (such as ants, ground and rove beetles, parasitic wasps, and particularly birds), this should cut down on the infestation, whereas pesticides may well have a deleterious effect on beneficial insects and wildlife. University of California, Davis Integrated Pest Management also suggest that reducing thatch, and proper irrigation and fertilization of lawns will cut down on infestations of sod webworm.
Covert is a synthetic pyrethroid (as opposed to a natural pyrethrin). You may have already looked at the
Material Safety Data Sheet for this product, but in case you have not
seen it, here is a link. This document lists the product as highly toxic to bees, extremely toxic to fish and aquatic life, and notes that it contains ethyl benzene, a confirmed animal carcinogen. The Northwest Coalition for Alternatives to Pesticides also has information about the toxicity of permethrin (an ingredient of Covert). Here is more on permethrin and pyrethroid insecticides. Essentially, synthetic pyrethroids last longer in the environment than pyrethrins. They may be less toxic than some pesticides, but they are not without health and environmental concerns. Since there are nonchemical methods of control, it does not make sense to take a chance using something which is potentially harmful.
Bt or Bacillus thuringiensis is registered for use on sod webworm, and you can find it as well as beneficial insects, Steinernema
nematodes from some gardening suppliers and well-stocked nurseries. Peaceful Valley Farm & Garden Supply has a large inventory of organic pest control products:
Organic Pest Control
Safer Caterpillar Attack
Parasitic Nematodes, Steinernema carpocapsae
Moth Egg Parasite – Trichogramma Wasp
I encourage you to pursue these alternatives to using the toxic product
suggested by the maintenance contractor. Toxic chemicals can harm birds
and beneficial insects, and using such products starts a vicious cycle,
since those creatures would actually help keep down the undesirable
webworm population.
I live in Wausau, Wisconsin. Our city planted small
maples two years ago near the street. They are now about 8-10 feet
tall. Both of ours show some encircling roots above the surface of
the ground under the mulch. The roots are about 1/2 inch diameter in one case
and a bit larger in the other. Is it too late to prune these
away? Any other suggestions?
The answer to your question will depend, to some extent, on the
type of maple tree you are growing. Silver maple will tolerate
root-pruning, but sugar maples are intolerant of it, and can be
more likely to break in windstorms if roots are pruned. There is
always some risk of loss involved in root-pruning a tree.
Source: Iowa State Extension.
Since encircling roots are not good for the tree, you probably will
need to prune, but it would be best to consult a certified arborist
in your area to make sure this is done correctly. University of Minnesota
has a guide (now archived) called “Stem Girdling Roots: The Undergound Epidemic Killing Our Trees” by Gary Johnson. Excerpt:
Removal is the most common treatment of encircling roots or SGRs
that have caused minimal stem compression. Roots may be removed
with wood gouges, saws, or pruners during the examination process.
When SGRs have caused extensive stem compression and are fully or
partially embedded in the stem, modify the removal treatment to
avoid damage to the stem. Embedded and severely compressing SGRs
are often left in place when they cannot be safely removed; there
is some belief that SGRs reduce the typically short life span of
urban trees by only a few years, and the potential damage
associated with SGR removal is not justified (Watson et al. 1990;
Tate 1981). A compromise is to prevent the SGR from growing and
further compressing stem tissues by severing it at the edges of the
stem. Remove the remaining root to a distance where it no longer
poses a threat to the stem and allow the severed SGR to decay with
time. Annual examination of the stem to assess for decay is
recommended.
The season during which SGRs are removed might influence the
success of the treatment. Smiley (1999a) found that summer removal
resulted in better diameter growth over two years than did fall
removal or a combination of summer and fall removal for red maple
trees under an irrigation system.
Regardless of treatment, do not backfill the examination area.
Lightly mulch the exposed roots but not the root collar flare or
stem area. Subsequent examinations will not require the
time-consuming removal of soil.
To find a certified arborist in your area, you can search your
local chapter of the International Society of Arboriculture.
I just bought a Ficus lyrata that was heavily treated with pesticide. As the plant makes my eyes burn, how can I minimize the pesticide residues on the large leaves? Is the citrus-based Veggie Wash appropriate and not harmful to the plant, or is there a better solution? If changing the soil and pot is necessary, does Ficus lyrata like any particular soil?
Without knowing what pesticide(s) were used, it is difficult to say how the residues could be removed. Looking at The Complete Houseplant Survival Manual, I can see that you would do no harm to the Ficus lyrata by washing the leaves with a sponge dipped in soapy water and then rinsing them with fresh water (this is a remedy often suggested for spider mites). Ficus also tolerates insecticidal soap well, so I imagine that the citrus-based veggie wash would not harm the ficus either. Of course, if the plant is making your eyes burn, it makes sense to take precautions to protect yourself while you are working with it–wear safety glasses, gloves, and a mask, and don’t continue to work with it if it still bothers you.
Ficus lyrata is not picky about soil, any good potting soil will do, and it is
generally suggested that a smallish pot will help keep the plant from getting
too big.
We’ve lived in the Northwest for years and love madrone trees. Yesterday, we “rescued” two madrone trees from a construction site with the hope of transplanting them to our Seattle garden. After reading more information on madrone transplanting, I don’t think it’s an easy task. Do you have more information on this subject?
I’ve seen several references to madrone trees being difficult to transplant.
This one is from Wikipedia: “The trees are difficult to transplant and a seedling should be set in its permanent spot while still small. Transplant mortality becomes significant once a madrone is more than one foot (30 cm) tall.”
According to Native Plants in the Coastal Garden (April Pettinger, 2002),
“Arbutus seedlings do not like to be transplanted because they have a single,
long taproot.” However, she does suggest they are not difficult to grow from
seed by planting the whole berries in fall where you want the tree to be, and
pulling up any extra seedlings that arise. According to Propagation of Pacific
Northwest Native Plants (Robin Rose et al, 1998), the seedlings will grow only
a centimeter a year at first.
Even if the trees aren’t looking great, it might be worthwhile to plant them and
see if they come back from the roots, as they tend to have an underground burl
that can re-sprout after the original trunk dies.
You might also try contacting the King County Master Gardeners clinic for additional tips.
I was wondering if you could send me information about Floribunda roses. I’m doing a research paper.
We have a large selection of books on roses here in the Elisabeth C.
Miller Library. You are welcome to come in and browse as well as borrow
books.
The Seattle Rose Society says the following about Floribunda roses:
Floribunda roses combine the best aspects of their parent plants: the
Hybrid Tea rose and Polyantha rose. They receive their flower form and
foliage from the Hybrid Tea while taking after the Polyantha in increased
hardiness and exuberance of blooms. This link is to their lists of recommended roses for the Puget Sound region, including the best Floribundas.
Here are additional links which may be useful.
Roses and everything rose & gardening related
American Rose Society
Most of our books have at least a little information on Floribundas, but
none is specifically and exclusively about them. I recommend The
Companion to Roses by John Fisher (Salem House, 1987) for history of rose
classification, and Jeff Cox’s Landscape with Roses (Taunton Press, 2002)
for practical ideas on using roses in the garden, and recommendations of
specific Floribundas which do well. Cox says that Floribundas are the
best of the Modern roses for most landscaping situations because of their
hardiness, free-flowering habit, bushy form, and flowering season. They
work well both as specimen plants and in combination with other flowers
and shrubs in beds and borders. Most grow 2-4 feet tall, and are dense
enough to be used as hedge plants. Varieties range from single,
semi-double, to double flowers. Some are fragrant. Specific varieties
mentioned by Cox are ‘Gruss an Aachen,’ ‘Iceberg,’ ‘Queen Elizabeth,’
‘Marmalade Skies,’ ‘Showbiz,’ ‘Betty Prior,’ ‘Escapade,’ ‘Nearly Wild,’
‘Lilac Charm,’ ‘Europeana,’ ‘Sunsprite,’ and ‘Apricot Nectar.’
Can you give me some suggestions on how to treat a Nandina infected with powdery mildew?
Apparently, powdery mildew on Nandina is becoming a common problem in our
area, as the article linked here indicates.
While this fungal disease is unsightly, it generally does not kill
affected plants. Sometimes improving air circulation around the plant (by
pruning congested growth) can help, and making sure to practice good
sanitation by picking up fallen leaves affected by the mildew is also
important.
There is an interesting idea in this Science News article on
using milk powder in water as a spray to control the disease.
Several organic gardening sources recommend a baking soda spray. The
Organic Gardener’s Handbook of Natural Insect and Disease Control by
Barbara Ellis (Rodale Press, 1996) recommends dissolving 1 teaspoon of
baking soda in 1 quart of warm water. You can add up to a teaspoon of
dish soap to make the solution stick to the leaves more effectively.
Here is another source with slightly different recommendations, from the
National Sustainable Agriculture Information Service.
More from University of California, Davis. Excerpt:
Shade and moderate temperatures favor most powdery mildews. Locate plants
in sunny areas as much as possible, provide good air circulation, and
avoid excess fertilizer. A good alternative is to use slow-release
fertilizer. Overhead sprinkling may actually reduce the spread of powdery
mildew because it washes spores off the plant; also, if spores land in
water, they die. The best time to irrigate is in mid-morning so that the
plants dry rapidly, reducing the likelihood of infections by other fungi,
such as the ones that cause rust or black spot infections on roses. As
new shoots begin to develop on perennial plants, watch closely for the
appearance of powdery mildew.
I saw some moss balls for sale in the gift shop of the new Nordic Museum. What type of moss is used? Is it native to Nordic countries? How do I care for one indoors?
The “moss” is actually a type of freshwater alga, Aegagropila linnaei, found in only a small number of northern hemisphere lakes. Other common names are lake ball or Cladophora ball. In Japan, they are called marimo (meaning a bouncy ball that is in water). The Ainu people of Hokkaido hold an annual Marimo Festival at Lake Akan to celebrate these charming lake goblins.
Iceland’s Lake Mývatn once had the world’s largest colony of lake balls but pollution has been altering the ecosystem there, and the mats of algae balls (colloquially called round sh*t or muck balls by the fishing community) began dying out. Their disappearance was first noted in 2013. There are some recent signs that the nutrient imbalance of the lake (caused by fertilizer runoff, and accumulation of bacteria) is correcting itself and that the ecosystem of the lake is bouncing back to better health.
To grow marimo inside, you will need a container that holds water, and a spot where the algae receive indirect sunlight. They prefer cool locations in nature, so they will do best if they do not get too hot (don’t put them near a heat source, and if it gets hot in your home, you can cool them off in water in the refrigerator). To keep the balls floating, squeeze out some of the water from time to time. To propagate the algae, use scissors to divide the marimo in half after squeezing out some of the water (you can repeat this process and cut into fourths or eighths). Use thread to wrap the cut algae back into a rounded shape, tie the thread close to the ball, and put back into the water. Some people combine them with other plants and tiny shrimp in indoor aquascapes.
If you have just acquired your marimo, inspect it for signs of invasive zebra mussels, which sometimes hitch a ride on the moss balls in the import process. According to a 2024 report from the Washington Department of Fish and Wildlife, they have been found in marimo imported to a Renton aquarium supply wholesale business. If you need to dispose of a moss ball, keep it out of local waterways, and dispose of it safely, as follows: “If there is any sign of invasive mussels, do NOT dispose of them in drains, waterways, or gardens! Contaminated moss balls must destroyed (either by freezing, boiling, or bleaching), disposed of in a sealed plastic bag in the trash, and your aquarium must be drained and decontaminated.” Sightings should be reported here.
I have a very large, mature Portugal laurel hedge. A tree service is coming out next week to see about pruning it. It is February and I heard that Anna’s hummingbirds are beginning to build nests in our area. I have a hummingbird feeder near the hedge. So, my first question, is now an OK time to have the hedge trimmed for the health of the plant? Second, am I risking disturbing nests at this time? In addition, if the neighbors cut back a significant amount of hedge on their side of the fence last year, am I safe to cut some of the height now, or do I need to allow more time for the shrub to recover?
According to the American Horticultural Society’s Pruning & Training (ed. Christopher Brickell, DK Publishing, 2011), the ideal time to prune Prunus lusitanica (Portugal laurel) is late spring or early summer. However, it can produce new growth easily from old wood, so if a plant or a hedge requires renovation, it shouldn’t pose a problem. It’s always best to avoid pruning on very hot days. The Royal Horticultural Society website has general guidelines for hedge pruning:
“Evergreen hedges
Formative pruning: In the spring after planting and for the first two years after planting
Maintenance pruning: Each summer”
If you are concerned about disturbing the Anna’s hummingbirds, it makes sense in any case to wait until late spring or early summer. See this information on Anna’s hummingbirds from Washington NatureMapping Program:
“Nesting: As is the case with other hummingbird species, male and female Anna’s Hummingbirds associate only long enough to mate. The female is responsible for construction of the nest and care of the young. The breeding season begins in December and usually lasts until May or June. Females will lay a clutch of only two white eggs and will produce only one brood per season. The hummingbird eggs are roughly the size and shape of a small jellybean. The hatchlings will remain in the nest for three weeks.”
Portugal laurel is generally considered pretty tough, but if you are concerned about pruning too much at one time, you might want to wait until it is in the height of active growth. To sum up, it seems best for both the hummingbirds and the hedge to wait a while.
I am looking for advice on how to obtain an oak log or two. I got some shiitake mushroom starter plugs at the garden show in Seattle, and it seems that they grow best on oak logs. But I am having the hardest time trying to find one or two oak logs to plant them in. I’ve tried craigslist, and can’t seem to find a thing. My tree identification skills are not exactly up to par, and I don’t know the rules for cutting parts of trees in the forest, so I wonder if you have any advice for a novice mushroom grower. I really only need two logs, about 6 inches in diameter and maybe 3-4 feet long. This is proving to be a much more daunting task than I ever imagined!
Have you tried contacting Plant Amnesty? They maintain a list of certified arborists, some of whom will probably have occasion to prune or cut down an oak tree at some point. That might be one way of obtaining a log.
You might also try posting on the Pacific Northwest Garden Exchange (watch out–annoying ads!).
As far as cutting branches on public forest land, you should contact the Washington Department of Natural Resources before proceeding. They have information on harvesting and collecting forest products, and how to obtain a firewood permit.
Once oak trees have leafed out fully, they should be easier to identify. See the following tree identification guides: