Chestnuts from Tree to Grill (Pt 1)

Since prehistoric times, wild chestnuts have likely been harvested across Europe and Asia Minor for winter nourishment. After the domestication of the tree and its introduction to orchards, it gained the mark “bread of the woods” during the Middle Ages when it became part of the essential European diet. In times of scarcity, chestnut flour was used in place of wheat.

While today’s global consumption does not rely this heavily on it anymore, Christmas time is often accompanied by the sweet smell of roasted chestnuts and infused with festive chestnut dishes. This article, written just in time for the roasting season takes you from planting to caring and picking the best chestnuts to enjoy on an open fire.

In Lebanon, chestnut planting began about fifteen years ago. Many people established orchards that included 20–500 trees. The trees were acquired from whatever source was available at the time and planted randomly, which led to some failures in growth. However, some chestnut orchards are thriving nowadays, especially in the mountains of Tarshish and demonstrate the potential for chestnut success in Lebanon as its cultivation begins to perform best at a height of 1,000 meters above sea level.

Several factors need to be considered before planting chestnuts. Like many other fruit trees, chestnuts require “cross-pollination” for the development of nuts. Even if the female flowers don’t receive any pollen, burs will still form, but the nuts within will be flat and unable to grow. Get two or three trees and plant them close together (30m apart at most) for the best nut production, or use the pollen from a neighboring tree. Chestnuts of all kinds can cross-pollinate.

Chestnut trees can withstand low temperatures reaching down to -20ºC, and reach extreme temperatures of up to 27 to 31 °C. They can also endure frost and might live through lower temperatures if transitioned slowly. However, it is important to remember that if trees are not yet familiar with cooler temperatures, sudden late spring or early fall frost might harm them.

Chestnuts thrive on acidic, fine-sandy well-drained soil and do not like alkaline, calcareous soils.

Make sure the chestnut tree is placed at the same level as it was in the pot when you plant your trees. When a tree is planted too deeply, oxygen is unable to reach the roots. The top 20 to 25 centimeters of soil are where “feeder roots” grow. The latter, are responsible for absorbing water, oxygen, and nutrients. Additionally, chestnuts produce “tap roots,” which bury themselves deeply and serve as anchors of the tree.

Chestnut trees require an average of 800mm of rainfall annually.

During the first summer, water the trees once a week unless a considerable amount of rain has fallen during that week. Usually, one gallon of water is sufficient for each tree. They might require a second watering input during the week if the weather is hot.

It is important to keep the space around the trees clear. Grass and weeds should be kept out of a circle about a meter wider than the diameter of the trees. This protects trees against damage from weed and lawn mowers. To aid in water retention, mulch can be used, but it shouldn’t be applied deeper than two inches or right up against the tree trunks (allowing easy access by rodents in the winter).

After the initial year, once the trees are established, fertilization is crucial in the early spring (March-May), when new growth begins, and during the summer rains (June-July). Never fertilize a newly planted tree before its second growing season so that it can focus its resources on developing strong roots in the new location. Chestnuts benefit from an annual fertilizer application that can be made-to-measure to the needs of specific trees and sites through soil testing. For a good growth rate, use solid fertilizer composed of ammonium sulfate such as YARAVERA AMIDAS.

Granular fertilizer formulated for soil with nitrogen, phosphorus, and potassium, in addition, to trace elements for the fertilization of chestnut trees like YARAMILA COMPLEX (12-11-18+2.7MGO+7S+TE).

Humic acid, such as HUMI K, improves the overall fertility of the soil, favoring root development and the growth of chestnut trees. Increases water holding capacity and reduces nutrient leaching losses.

Pruning can be performed in early summer when the weather is hot and dry or during late winter when the trees are dormant (not later than the first week of July). This reduces the likelihood of infection. Lower branches can be cut off to manage shape as the trees mature. Any tree can have around one-third of its foliage removed each year during pruning without doing any damage.

If a chestnut tree was planted at 1 to 2 years old, it will typically begin to produce fruit 3 to 5 years after being planted. This indicates that chestnut trees can begin producing fruit between the ages of 4 and 7.
Chestnut yields will rise as the tree matures in size. Once established, a tree can grow to be over 100 years old and produce fruit every year.

Chinese chestnut trees have an annual growth rate of one-third to two-thirds of a meter, maturing at a height of 12 to 18 meters. American chestnut trees can reach heights of 15 to 30 meters and develop more quickly than Chinese chestnut trees.

When buying chestnuts, it can be difficult to discern the good from the bad. The next time you are shopping for delicious chestnuts to roast, consider these tips for the best pick:

1. Consider the fruit weight. Always opt for chestnuts that feel heavy for their size. You should avoid it if it seems dry or hollow. As the secret is all about the weight-to-size ratio, the chestnut should feel as heavy as its size or volume gives off.
2. Examine the shell. A healthy chestnut should be hard and shiny as opposed to cracking, chipping, or flaking off from the flesh.
3. Give it a shake. If you hear rattling when shaking, take it as a sign that it’s an old chestnut that you don’t want to purchase.
4. Pay attention to the container. If you keep chestnuts in plastic bags or containers, they are prone to molding. Mold may occasionally be visible on the shell, but it may also be hidden until you crack the shell open. It’s a good idea to buy loose chestnuts whenever possible.

By Eng. Maryse Bou Zeid