Discover how to germinate a walnut in various possible ways, taking into account the natural behavior of this seed and without needing more than a walnut, a little soil and a pot, or the soil failing that. Before starting to explain the procedure that we must follow how to sprout walnuts, let’s see some basic things that will help us better understand the process and reduce complexity.
It is perfectly normal for someone facing this challenge for the first time to feel confused or to think that it will be very difficult to make a walnut grow from a walnut; It really seems like a miracle, but nothing could be further from the truth. We must understand that germination is the sole purpose of all seeds. The walnut is the solution that walnut has found to reproduce in a simple way and, therefore, the strange thing is that it does not germinate, although it can and does happen.
Like the seeds of many other deciduous trees, walnuts must wait for the winter to pass to germinate in spring, when the most favorable conditions will allow their development. If they germinate as soon as they fall to the ground, the cold of winter would surely kill the young plants. Walnut – like other trees – have found a very practical solution to this problem: induce a state of dormancy in the seeds – they remain asleep – from which they emerge after spending a more or less long cold period. When conditions improve, after the cold period, the seed “awakens” and germinate strongly. Many people when they see that the weeks go by and that the nuts do not germinate, they believe that they will no longer do so and get rid of them. They wonder: would they be sterile? Were they toast? Have they rotted? They may actually just be “sleeping”.
This means that, if we want to do it well, we must plant the walnuts in autumn so that they overwinter and germinate in spring when the walnut tree can really develop safely. This is the easiest way since we take advantage of natural conditions.
But what happens if there is no real winter in our region or if, for whatever reason, we want to germinate the nut at another time of the year. Well, we have two options:
– The first consists of cold stratification, which is nothing more than storing the walnut in the refrigerator for a few weeks —at least 3 or 4—, wrapped in a damp paper or cloth and placed inside a container with a lid.
– The second option, which is not the most suitable, would consist of drilling a hole in the shell of the walnut, or slightly separating the valves, to force moisture to quickly enter the seed and, if we are lucky, it will begin to germinate.
As we have already seen, germination is a natural process that all seeds end up reaching, as long as the conditions are right. And to achieve that they are, we will have to perform a series of steps and use some materials.
The simplest thing is to sow the walnuts in autumn directly in the ground and forget about them, although most likely we will not remember where we planted them and we end up crushing or cutting the shoots when they germinate. If we mark or protect the area, we can try; sure that some will manage to germinate in spring. To do this, it is only necessary to bury the nuts lightly – just enough to cover them – and keep the soil moist, especially when spring approaches.
But the process that we are really interested in explaining here is germination in pots – or other common containers. Let’s go with her.
We will only need a pot -the size does not matter, although it is better if it is large and tall-, a little substrate -anyone can serve us, but better one based on coconut fiber and vermiculite or perlite-, water and, finally, the walnuts — if they are picked under a better walnut tree, the ones sold by shops may have more problems germinating.
As we have explained previously, for the nuts to germinate well, it is advisable to store them for at least 3 weeks in the refrigerator, wrapped in a damp absorbent paper and placed everything in a closed container. For the process that we describe below, it is assumed that this cold stratification has already been done or that we are going to sow in autumn so that the walnuts spend the winter outside.
➊ We fill the pot with the substrate up to about 2 cm from the upper edge.
➋ We place the walnuts on the substrate and press with the hand we introduce them into it.
If you want to speed up germination, you can slightly open the suture of the leaflets, prying the part of the nut opposite the beak with the tip of a knife.
There are those who say that it is better to place them with the vertical suture to the ground, others say that it is better with the horizontal suture – lying nut – but the truth is that in any position they will germinate and, given that in nature they most often remain in a horizontal position —it is the most stable form— we will put them like this, that is, in the same position that they remain when we leave them on a table.
➌ We put a handful of the substrate on top of each nut to cover it but without it being too buried, it is not necessary.
Once covered, if we see that the substrate is very dry we can moisten it by adding water, although if we are going to leave the pot outside (recommended) it is not necessary to water since the rain will take care of wetting it.
➍ We take the pot to a cool and humid place —if it is autumn and we want it to germinate in spring—, for example behind a wall that covers the sun.
If we are sowing in spring, we will put the pot in a warm place but not too exposed to the sun.