Things are going crazy in my garden. Literally. The squirrels planted a lot of nuts, mostly black nuts, and I joined in removing the excess seedlings, leaving only a few in the right places.
For the past few years, I’ve even joined the squirrels and planted nuts myself, including chestnuts, hearts, pine nuts, and hazelnuts.
Hazelnuts (also known as hazelnuts) were particularly satisfying. And quickly so, producing their first nuts within three years of planting. Unlike squirrels, I planted nursery-bought hazelnut shrubs rather than nuts.
The plants, which grow as tall multi-stemmed shrubs or small trees, are attractive, especially in winter when their catkins (male flowers) gracefully hang from bare branches.
My first planting was of American hazelnut shrub seedlings (Corylus americana), a short hedge of them. The plants bore in three years, and each autumn their leaves lit up with fiery colors. Unfortunately, the nuts themselves weren’t worth eating; they were small and had a bad flavor.
So, a few years after that first planting, I planted more hazelnuts, but this time named varieties – that is, clones selected or bred to produce big, flavorful nut meats. Such plants would be pure species or hybrids involving the European hazel tree (C. avellana), a different species from the American hazel tree.
These European hazelnuts are commonly called filberts. These are the nuts that you find in supermarkets, and they are typically grown in either the Mediterranean region of Europe or the Pacific Northwest.
Come in, a disease
A disease called filbert blight is what historically prevented people from growing filberts in the eastern United States. This native disease has little effect on our native hazelnuts but can be devastating for European hazelnuts.
The “plague” in the name says it all: branches collapse and death, shriveled leaves sadly still cling. A more telling symptom is dark, raised bump lines along the branches. The disease can go unnoticed for years because it has a long cycle and a long latency period; 10 years can pass before a tree is killed.
Easy avoidance of the disease
Pruning and spraying are two ways to control the blight. But even better – to deal with most pest problems for all plants – is to plant resistant varieties.
Many years ago, the blight spread to commercial hazelnut orchards in the Pacific Northwest, which has had the positive effect of prompting research and breeding for high quality hazelnut varieties. who would not succumb to the disease.
Hall’s Giant and Willamette were identified early on as being somewhat resistant, and the old variety came into my garden. After a while, Lewis, Clark and Tonda di Giffoni arrived, all three even more resistant to the plague. And all three of them found their way into my yard. More recently, the varieties Gamma, Delta, Epsilon and Zeta have been selected; they will soon be in my yard.
But hazel blight is a finicky organism, and although a plant may resist it in one part of the country, the plant may succumb elsewhere. What most of mine have done. (My garden is in the Hudson Valley in New York.)
Breeding for new varieties continued and I have since planted what I hope will be the best of the best for here, which are varieties born and raised east of the Rocky Mountains. The plants – varieties such as Truxton, Donald, Raritan, Somerset, Geneva and Monmouth – all look fine, so far.
I keep my shrubs healthy by mulching and, if necessary, fertilizing them. To thwart disease, and to encourage a certain amount of new growth on which the nuts are born the following year, I prune regularly to let all the branches bathe in light and air.
The combined effects of pruning and fertilization coax 6-10 inches of new growth each year for consistently good nut production.
This week, I’m collecting the delicious pieces of hazelnut that fall from the trees. I bring them together frequently because the squirrels got involved in this part of the “nut” game as well.
Lee Reich writes regularly on gardening for the Associated Press. He is the author of several books, including “Growing Figs in Cold Climates” and “The Pruning Book”. He blogs at leereich.com/blog. He can be contacted at gardenleereich.com.