Walnut family

Plant family

Season Overview

Details

Light requirement

Sunny

Water requirement

Moist

Soil

Medium (loamy)

Nutrient requirement

Medium

Dark germinator

Germination temperature

20 - 25 °C (Degrees Celsius)

Plant distance

1000 cm

Row spacing

1000 cm

Seeding depth

7 cm

Instructions

Description

There are various species of walnut with different origins. However, the trees require very similar site conditions and do not differ significantly in their use. Walnut trees are generally fast-growing 15-30 meter tall trees, which can easily grow 50 cm or more per year as a young tree. They form a moderately dense, spherical but mostly flat-elliptical crown. It is quite popular as a park tree, sometimes also as an avenue planting, and is also becoming increasingly important in forestry, as the deciduous tree can grow to a considerable trunk diameter of 1m within 50-70 years and the wood is now traded not only in interior fittings as veneer and in instrument making, but also outdoors as a good alternative to tropical woods (at several hundred euros per cubic meter of wood). The crowns often divide at a height of just a few meters and are a feast for the eyes, especially with their reddish shoots and 20 to 40 cm long leaflets. However, it is best to have a cozy seating area underneath until late summer, as the leaves of the walnut in particular contain juglone which keeps annoying rivals away from the light-loving tree and has an unfavorable effect on most other plants as a growth inhibitor. For this reason, the walnut is not welcome everywhere and in some allotments it is apparently not even allowed to be planted. It is therefore essential to find out in advance what is allowed and what is not. If you still want to underplant the tree, stork's beak, for example, is said to be well suited for this and ivy (as is usual with it) apparently has no problem with it. From my own experience, goutweed, hawthorn, raspberries and blackberries also grow well in the immediate vicinity if the leaves are regularly removed in the fall. The leaves are said to have antiseptic and other healing properties. When used as bedding in stables, it is said to repel pests. Hedgehogs and other wild animals also appreciate this and some gardeners are keen to use the slowly decomposing leaf humus because of its relative sterility. It is therefore not worth throwing it away in the nearest organic waste garbage can. As a rule, however, walnuts are mainly desired for their nuts. They are extremely nutritious and healthy. For a good harvest, you just need to provide the right conditions and have a little patience, as the tree usually produces male and female flowers and pollinates them via the wind. Pruning is not necessary (it is better to look for a variety with suitable growth behavior) but is possible in August and September if necessary (time of best wound healing). Most of the work is actually done by the fruit itself. When they ripen in September, the thick green shells break off and release the nuts. These then fall to the ground, sometimes with and sometimes without the shell, and just need to be picked up. Depending on the variety, the first nuts can be collected from the ground as early as the 2nd year. Older trees can yield over 100 kg of nuts in good years. We have already collected more than 2 large laundry baskets full of nuts from one half of a tree. But be careful - the shells quickly become mushy and also contain a lot of tannic acid when green. If you don't wear gloves when collecting them, you will quickly end up with unsightly yellow to brown fingers for days. This results in real stains on clothing that cannot be washed out - which is of course also used in dyeing. If you want to eat the fresh nuts (which I can highly recommend to anyone with patience), you should note that there is a thin skin around the nut meat, which is not only bitter, but also contains some unhealthy hydrocyanic acid. It is therefore essential to peel this off fresh nuts, even if it is a fiddly job. To get rid of hydrocyanic acid, avoid mold in the nut and preserve the nuts for a long time, dry the nuts in a dry, well-ventilated place, e.g. well spread out in an uninsulated attic. However, you should also expect a certain amount of wastage from rodents in the house and not be too surprised if there are suddenly nuts lying around in the half-timbered house. Alternatively, you can dry them in a rodent-proof way. For example, on hanging flat baskets that the short-sighted animals cannot reach (house mice do not "jump over" 1 meter visibility) or protected by fine-meshed wire (house mice can squeeze through anything with a mesh size of more than 8 mm). It is no longer widely known that the unripe green fruits are eaten pickled as a delicacy in some places and are also used in plum jam. Young leaves can be made into tea. If you don't have the space to plant the real walnut (Juglans regia), which is considered native, you can look around for the much smaller dwarf walnuts. There are also some cultivars which, like the Juglans regia 'Dwarf Karlik 5', grow rather slender and upright or remain significantly smaller overall at only 4m high and 2m wide. In addition to the true walnut, there are also beautiful Asian varieties or the frequently imported American walnuts. In my experience, the latter have a much sharper taste than the pleasantly mildly nutty domestic variety. Connoisseurs probably also differentiate between the individual varieties according to taste. Finally, it should be noted that walnut trees are quite robust and have hardly any problems with pests. However, it is now advisable to choose a variety with a particularly hard nutshell. Although these can no longer be cracked open between the hands, they are also better protected against the walnut fruit fly. This invaded Europe in the 1980s and, according to my sources, is now slowly spreading northwards from the Alpine region. The infested nuts are then unfortunately no longer edible, often black and wormy and should be disposed of. Powdery mildew and fungi are mainly a problem in permanently damp or insufficiently airy locations. Waterlogging or flooding over a few weeks, on the other hand, is tolerated surprisingly well.

Growing tips

Walnuts are best purchased from a good tree nursery as a young, possibly grafted tree. There you will also get appropriate advice on the variety. Alternatively, you can collect the nuts in the fall, for example, store them in damp sand in winter (stratify them if necessary) and sow the nuts in March to protect them from rodents and birds.