Les fruits du marronnier sont-ils comestibles?
Are the chestnuts from Quebec’s chestnut trees as edible as those offered in Europe?
Answer
There has long been confusion, both in Europe and here, between the horse chestnut (Aesculus hippocastanum) and the Sweet chestnut (Castana sativus). Chestnuts, erroneously called marrons, are edible, but the true chestnuts produced by the horse chestnut tree are not, at least not without special treatment to remove their bitterness. In Quebec, the European chestnut tree does not grow. Instead, we grow horse chestnuts. In other words, our chestnuts are not edible.
Sparse Thuja Hedge
We’ve had a cedar hedge planted for 13 years. We find it lacking in foliage, even though it’s quite tall. We use a liquid cedar fertilizer every year. Is there anything else we can do?
Answer
Pruning the shoot tips every year helps to densify a hedge by stimulating the growth of secondary branches. However, to avoid disturbing bird nesting, we recommend waiting until late August or early September to carry out more extensive pruning. If you insist on pruning earlier, make sure there are no active nests in the hedge.
As far as fertilization is concerned, a slow-release organic fertilizer applied in spring can give a good boost, especially if the hedge appears to be lacking in vigor. That said, many hedges thrive without fertilizer, provided the soil is rich in organic matter. Adding compost and using organic mulch (shredded leaves, RCW, mature compost, etc.) improves soil structure, supports microbial life and slowly releases nutrients. These long-term solutions do not always replace direct nutrient input, but they are often sufficient in healthy soil. Too much fertilizer can encourage rapid, but sparse growth: it’s best to remain moderate.
Unselected Common Cedar
In your case, it’s quite normal for the base of the hedge to begin to recede after 10 to 15 years, especially if the plants have not been pruned regularly over the years. As thuja is a tree that naturally grows tall, without intervention, light eventually stops reaching the bottom of the plants, leading to a gradual loss of the lower foliage. This is a common phenomenon, particularly in unselected common cedars.
Finally, you should know that a hedge planted with unselected common cedars – often simply identified as Thuja occidentalis without a cultivar name – will never achieve the density or regularity of one planted with selected cultivars. If you ever need to replace it, it’s worth thinking about.
Larry Hodgson published thousands of articles and 65 books over the course of his career, in both French and English. His son, Mathieu, has made it his mission to make his father’s writings accessible to the public. This text was originally published in Le Soleil on June 7, 2008.
Arborvitae hedges only became available here in the past several years. They had been rare prior to that. Therefore, not many are old enough to be exhibiting these symptoms of maturity. However, a VERY long time ago, during the Victorian Period and prior to the importation of many of the ornamental species that are available now, hedges were made from redwood! That seems like such a foreign concept now.