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Gardening Answers Knowledgebase

Search Results for ' Thujopsis'

PAL Questions: 2 - Garden Tools:

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Keywords: Zelkova, Xylosma, Thujopsis, Taxodium, Tamarix, Poa, Pennisetum, Casuarina, Baccharis, Festuca, Juglans, Alnus, Palms, Allergies

PAL Question:

What could cause sinus allergy symptoms every December?

View Answer:

According to Thomas Ogren's book, Allergy Free Gardening , the genera Alnus, Baccharis, Casuarina, Festuca, Pennisetum, Juglans, Poa, Tamarix, Taxodium, Thujopsis, Xylosma, Zelkova, and palm trees all produce pollen during December.

(Source: Ogren, T.L., Allergy-Free Gardening: The revolutionary guide to healthy landscaping , 2000, pp.262-265)

Also check out Allergy Free Gardening website. There are a number of articles article on low-allergy gardening listed.

Season Winter
Date 2007-04-02
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Keywords: Ornamental conifers, Thujopsis, Pruning trees

PAL Question:

I'm looking for resources on proper pruning or rejuvenation for Thujopsis. We have a 50-60 year old specimen.

View Answer:

According to Michael Dirr (in Dirr's Hardy Trees and Shrubs: an Illustrated Encyclopedia), Thujopsis dolabrata is "too beautiful to mutilate with pruning shears." This website of a Seattle-area gardener suggests that you may be able to prune it lightly by candling the leader.

According to George Brown's The Pruning of Trees, Shrubs and Conifers (Timber Press, 2004), specimens of this tree vary widely in habit. Some form a definite leader, while others are "untidy, spreading shrubs. Of those which grow out of this shrubby habit, a number produce rival leaders and the result is a small tree made up of slender upright trunks with their supporting branches." If your tree has multiple leaders, it is probably too late to prune them--this kind of pruning would be done on a younger tree.

I spoke with a docent at Seattle's Japanese Garden, which has Thujopsis, and she said that they are not pruned, except to remove dead, damaged, or diseased branches. You may find this general information on pruning conifers from Brooklyn Botanic Garden useful.
"As with any plant, dead or diseased conifer branches should be removed immediately, regardless of the time of year. Any other pruning should be done when the plant is dormant. Unlike many deciduous shrubs, most conifers can't re-sprout from older wood (yew, arborvitae and podocarpus are exceptions), and so a good rule of thumb is never to remove more than one-third of the total growth at a time. If you prune too drastically, the plant may never fully recover. Many of the dwarf varieties never need to be pruned, but do appreciate some thinning to allow air and sunlight to penetrate to the interior of the plant.
The most common method of pruning evergreens is known as 'cutting' or 'heading' back. Only part of the branch is pruned; the terminal or tip growth is trimmed to side or lateral buds or branches. This promotes thicker, more compact foliage and a smaller overall plant."

It sounds as if you should do the bare minimum in terms of pruning. If you really need to reduce the tree's size, it would be wise to consult a certified arborist.

Season All Season
Date 2010-03-11
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December 12 2014 11:33:49