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Gardening Answers Knowledgebase

Search Results for: Ilex | Search the catalog for: Ilex

Plant Answer Line Question

Keywords: Poisonous plants, Ilex

Is a holly tree toxic to animals (dogs/cats)?


The ASPCA website on plants which are toxic to animals lists holly (Ilex spp.), as does the Humane Society website.

According to Plant Alert, A Garden Guide for Parents (by Catherine Collins; 2001), and Plants That Poison (by Ervin M. Schmutz and Lucretia Breazeale Hamilton; 1979) the red or black berries on holly are poisonous to humans as well, and can be fatal to small children if eaten in quantity.

If you believe your dog or cat has consumed holly berries, call your veterinarian for advice as soon as possible, or call the ASPCA Animal Poison Control number, 888-426-4435 (not a free service).

Date 2017-05-26
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Plant Answer Line Question

Keywords: Euonymus, Osmanthus, Ilex, Hedges

Can you all give me some recommendations for plants that will form a tight hedge? I want a fast growing plant that does not get more than 2-3 feet tall and 2-3 feet wide. I do not want boxwood. Evergreen with glossy leaves is preferable; flowers do not matter to me.


I collected some information from websites and a couple of books for you. I am making one other plant suggestion, and it is the last item.

Euonymus japonicus 'Microphyllus'

Ilex crenata 'Northern Beauty' is described on the website of Great Plant Picks

Ilex glabra 'Shamrock'
See Missouri Botanical Garden for information and an image.

Osmanthus delavayi
This can be grown as a dense hedge. It can reach about 8 feet, but takes pruning well. Evergreen and attractive all year. Small, oval, tooth-edged leaves. Fragrant tiny white flowers in spring. Here in Seattle it can take the full sun but partial shade is okay too.

Great Plant Picks is a local organization with information about plants that do particularly well in the Pacific Northwest.

Date 2017-12-08
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Plant Answer Line Question

Keywords: Berberis, Trachelospermum, Euonymus, Taxus baccata, Screens, Thuja, Nandina domestica, Hydrangea, Ilex, Hedges, Clematis, Buxus, Bamboo

Could you recommend some plants for a privacy screen that are also narrow? These would be planted in front of a fence in our backyard.


Here is some general information on plants for creating a screen.

Trees for Problem Landscape Sites -- Screening from Virginia Cooperative Extension

Good Hedges Make Good Neighbors from the Humane Society

Bet on Hedges by local garden writer Valerie Easton.

Here is a list of narrow plants for a screen from local garden designer Chris Pfeiffer:

Fastigiate shrubs for naturally narrow hedges. Compiled by Chris Pfeiffer. 2005.

Zones 5-6:

American arborvitae 'Rheingold' (Thuja occidentalis 'Rheingold') 5'h x 3'w

Barberry 'Helmond Pillar' (Berberis thunbergii f. atropurpurea 'Helmond Pillar') 6'h x 2'w

Boxwood 'Graham Blandy' (Buxus sempervirens 'Graham Blandy') 8'h x 1-1/2' w

English yew 'Standishii' (Taxus baccata 'Standishii') 4'h x 1-1/2' w

Irish yew (Taxus baccata 'Fastigiata') 20' h x 4' w

Japanese holly Jersey pinnacle (Ilex crenata 'Jersey Pinnacle') 6' h x 4' w

Japanese holly Mariesii (Ilex crenata 'Mariesii') 3' h x 1-1/2' w

Zones 7-9, in addition to the above:

Dwarf yeddo rhaphiolepis (Rhaphiolepis umbellata Gulf GreenTM) 3-4' h x 2' w

Heavenly bamboo 'Gulf Stream' (Nandina domestica 'Gulf Stream') 4' h x 2' w

Japanese euonymus 'Green Spire' (Euonymus japonicus 'Green Spire') 15' h x 6' w

You might also consider installing a trellis to increase the height of the fence, and then growing an evergreen vine such as Clematis armandii, evergreen hydrangea (Hydrangea seemanii), or star jasmine (Trachelospermum jasminoides).

This link is also helpful (scroll down to "Evergreen Vines" and look for appropriate height and light requirements).

You could grow bamboo, but I would recommend growing it in a container, or a series of containers, as you do not want the roots to spread. I have seen an effective bamboo screen between two houses growing in a long rectangular lined wooden trough (lined with bamboo barrier). Some species of bamboo are more tolerant of partial shade than others. Look for a clumping, rather than a running, bamboo (like Fargesia) to be on the safe side.

Growing Bamboo in Georgia

Running and Clumping Bamboos

Bamboos for hedges or tall privacy screens

Date 2018-04-11
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Plant Answer Line Question

Keywords: Veronicastrum, Thalictrum, Actaea, Filipendula, Baptisia, Eupatorium, Berberis, Euonymus, Digitalis, Taxus baccata, Thuja, Verbascum, Helenium, Anemone, Ilex, Buxus

I am redoing the narrow planting areas (2-3' wide) on either side of our 20' long entry. Garages from next door townhouses butt up against the outer edge on each side, causing morning sun and afternoon shade on one side, and vice versa on the other side. I have picked out some euphorbias, heucheras, and carexes which should do well. I'm wondering if I should have some taller, more dramatic plants to offset these and if you have any suggestions of ones which might work. Also, any bulb ideas would be appreciated.


Have you considered putting up trellises on one or both sides? Then you could grow vines which require little width, but still have the advantage of height. You could also grow taller plants (maybe some grasses like Miscanthus or even a well-restricted--using root barrier--Bamboo) in containers, and keep them shaped to suit the narrow space. Some shrubs and trees are naturally narrow or fastigiate in growth habit.

Here is a list of narrow plants compiled by local garden designer Chris Pfeiffer,c2005. Some will be too wide for your planting area, but you might want to research those that fit the site.

American arborvitae 'Rheingold' (Thuja occidentalis 'Rheingold') 5'h x 3' w

Barberry 'Helmond Pillar' (Berberis thunbergii f. atropurpurea 'Helmond Pillar') 6'h x 2'w

Boxwood 'Graham Blandy' (Buxus sempervirens 'Graham Blandy') 8'h x 1-1/2'w

English yew 'Standishii' (Taxus baccata 'Standishii') 4'h x 1-1/2'w

Irish yew (Taxus baccata 'Fastigiata') 20'h x 4'w

Japanese holly Jersey pinnacle (Ilex crenata 'Jersey Pinnacle') 6'h x 4'w

Japanese holly Mariesii (Ilex crenata 'Mariesii) 3'h x 1-1/2'w

Dwarf yeddo rhaphiolepis (Rhaphiolepis umbellata 'Gulf Green') 3-4'h x 2'w

Heavenly bamboo 'Gulf Stream' (Nandina domestica 'Gulf Stream') 4'h x 2'w

Japanese euonymus 'Green Spire' (Euonymus japonicus 'Green Spire') 15'h x 6'w

There are also a good number of tall perennials you might try, such as (for your afternoon sunny side) Helenium, Verbascum, Baptisia, Eupatorium, and bulbous plants like Allium and Eremurus, and for your shadier morning sun side, Macleaya, Digitalis, Filipendula ulmaria, Anemone hybrida, Actaea (formerly called Cimicifuga), Lilium martagon, Thalictrum, and Veronicastrum.

There are many excellent gardening books you could consult for ideas. Since you have a small, narrow space, I highly recommend local garden writer Marty Wingate's book, Big Ideas for Northwest Small Gardens (Sasquatch Books, 2003). You are welcome to visit the Miller Library, where you can do further research and also borrow books.

Date 2018-03-01
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Plant Answer Line Question

Keywords: Ilex

We are planning a 30' x 100' planting bed to screen a metal building and have been thinking about using a variety of holly for the background evergreen tree in this bed. Do you have any recommendations for varieties that do well in the Puget Sound area and are as pest free as possible, and yet have good color, berries and form. Setting has: sun, good soil, irrigation if needed and no height restrictions.


The local resource, Great Plant Picks, recommends the following hollies:

  • Ilex aquifolium 'Ferox Argentea,' or hedgehog holly. Note that this clone does not produce berries, which is considered by some to be a positive attribute, as berries can lead to nuisance plants sprouting in the garden.
  • Ilex crenata 'Convexa' (convex-leaf Japanese holly)
  • Ilex crenata 'Mariesii' (columnar Japanese holly): this is a female clone whose flowers will develop black berries if pollinated. Great Plant Picks offers more information and images.

Ilex aquifolium (the species) is now considered an invasive plant in our area. The Tacoma News Tribune published an article on this topic, with suggested alternatives. Excerpt:
"Just don't plant English holly (Ilex aquifolium), the species with the dark, glossy leaves and bright red berries that most people picture when they hear the word 'holly.' This non-native species has become invasive here and isn't recommended for home gardens (see box for more information), so leave it to the professional growers. But that still gives gardeners about 400 species of holly to choose from, and many can be seen at the Washington Park Arboretum in Seattle, which has the second-largest holly collection in the U.S. 'Our U.S. native Ilex opaca (American holly) and its many cultivars are underutilized and in many cases better ornamentals than (the) Ilex aquifolium counterparts,' said David Zuckerman, horticulture staff supervisor at the arboretum, which is part of the University of Washington Botanic Gardens."

Like American holly, some hollies have the 'traditional' holly look, while other holly species display different charms. One of Zuckerman's favorites is the deciduous Ilex verticillata. Although the plant's oval leaves drop in the fall, 'the berries persist through winter and can really liven up the winterscape,' he said. Japanese holly (Ilex crenata) is a family of 'quite handsome shrubs' with small evergreen leaves and black berries, Zuckerman said. These hollies look more like boxwood than holly, and lend themselves to hedging and topiary. 'I really enjoy some of the whimsical dwarf-forms,' he said, such as Sky Pencil, which grows 6 to 8 feet tall but just 12 to 18 inches wide, adding a vertical accent to the landscape.

When adding holly to the garden, remember that hollies are dioecious and both male and female plants are needed for the female to produce berries, Zuckerman said. Good companion plants for evergreen hollies include deciduous choices like witch hazel, lindera (spicebush) and corylus (filbert), Zuckerman said. And Asian plants such as Japanese maple and bamboo can partner well with the more formal-looking Japanese hollies, he said.

I wonder if you might also consider other plants which have colorful fruit but are less likely to become invasive. This article, from local website Rainy Side Gardeners, lists a few possibilities, like Arbutus, Gaultheria, Mahonia, Skimmia, Nandina, and Sarcococca.

Date 2018-04-11
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Plant Answer Line Question

Keywords: Ilex

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.

Date 2018-03-01
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May 31 2018 13:14:08