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Gardening Answers Knowledgebase

Plant Answer Line Question

Keywords: Lonicera, Poisonous plants, Berries

Are the berries of wild woodbine poisonous?


Wild woodbine or woodbine is Lonicera periclymenum. But many species of Lonicera are found in the United States.

For photos of L. periclymenum, see the two sites below:
West Highland Flora
Paghat's Garden

North Carolina University's poisonous plant website indicates that the berries of Japanese honeysuckle (Lonicera japonica) are poisonous.

Toxic Plants of North America (G.E. Burrows and R.J. Tyrl, 2001, pp.321, 322) says that while some species of Lonicera (i.e., L. involucrata) are edible, the rest are associated with digestive tract problems in children (nausea, vomiting, diarrhea), especially the European species. In the U.S., on the other hand, records of complaints are not often associated with records of clinical signs.

Date 2018-03-01
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Plant Answer Line Question

Keywords: Weed control, Equisetum, Lonicera, Geranium, Cistus

What does "horse grass" look like? According to Ciscoe, it can't be gotten rid of and I want to see if this is what I have.


I wonder if you are referring to horsetail, or Equisetum, which is a very persistent weed.

Wikipedia has a picture, and here is another from CalPhotos

Here is an article on Field Horsetail and Related Species from Oregon State University Extension.

Here is what Ciscoe Morris said about this plant in the Seattle P-I (April 29, 2006):

"Hands down, horsetail (Equisetum arvense) is the worst weed you can get in your garden. If you've got it, just be glad you weren't gardening in prehistoric times. Back then, horsetail grew to 90 feet tall and you were in danger of being stepped on by a brontosaurus while weeding.

The worst thing about horsetail is the speed with which it returns to make your life miserable after you weed it. No matter how great a weeding job you do, it will be back, practically to full size, within a week!

Do what we did at Seattle University. Plant a mix of shrubs, ground covers and fast-growing perennials that are thick and tall enough to hide the horsetail. Shrubs that hide horsetail include Cistus (rockrose) Lonicera pileata (privet honeysuckle) Lonicera nitida (Box honeysuckle) and rosemary. My favorite perennial to hide horsetail is the prolific hardy Geranium oxonianum 'Claridge Druce.' It will seed all over your garden, but new seedlings are easy to remove in spring. These drought-tolerant plants look great in their own right and because they are so thick and tall, no one will see the hoards of horsetail growing within."

Washington Toxics Coalition recommends controlling it by persistently hand-pulling or hoeing the above-ground growth as soon as it appears. This will weaken the plant over time. It does die back over winter, when you could cover the affected area with black plastic (for a duration of 2 years), but even this may not be entirely successful.

An article by Irene Mills in the Fall 2008 issue of the Northwest Perennial Alliance's Perennial Post says that pulling, digging, and covering with black plastic are a waste of time. The author recommends keeping an eye out in April for emerging spore-bearing stalks, and cutting these off and disposing of them in the garbage. She suggests improving the soil texture (improve drainage, add organic matter, increase soil fertility, and in some cases increase soil pH). She recommends this guide called "Controlling Horsetail" from Swanson's Nursery, originally published in Gardens West by Carol Hall.

Date 2017-12-09
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Plant Answer Line Question

Keywords: Fungal diseases of plants, Insect pests, Lonicera

I noticed my honeysuckle, which is intertwined to look like a topiary bush with the greens and flower all bunched up at the top, to have yellowing of the leaves and drop off. Why are the leaves yellowing? It smells lovely and is green on the outside, but if you look under the canopy you can see many yellow leaves. Is it a disease? Should I use a fungicide?


There are a few possibilities. It might be a kind of leaf blight, as described by Iowa State University Extension.

Leaf blight is a fungal problem, but the control methods described above are not nontoxic, so you may want to look for a safer fungicide (example here), and also try to prevent the ideal conditions for fungus. Avoid wetting the leaves of the plant, and make sure there is good air circulation around the plant (by siting it properly, and by pruning to keep the plant's shape open).

Yellowed leaves could also be caused by scale, which is an insect. Do you see small bumps on the leaves and stems? If so, here are recommendations from The Organic Gardener's Handbook of Natural Insect and Disease Control edited by Barbara Ellis (Rodale, 1996):

"Minor infestations can be controlled by scraping the insects off the plant with your fingernail, and by pruning out the most infested parts of the plant. You can also use a soft brush and soapy water to scrub scales off the stems, or you can apply dormant oil to the trunk and stems of the plant just before growth begins next spring, and use superior oil during the growing season."

Because I'm not certain which type of problem your honeysuckle may have, you should bring a sample to a Master Gardener Clinic.

Date 2017-05-24
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May 23 2018 14:32:42