how to save onion seeds

How to save onion seeds

How to save onion seeds, the onion is a very simple species to grow, which should not be missing in every home garden. Its unmistakable flavor, combined with the fact that the vegetable comes from our garden, makes cultivation rewarding. It is a biennial herbaceous plant (Allium Cepa) of which we collect the bulb, closely related to garlic, leek, shallot, and chives.

Normally, for convenience and speed, we are used to planting onion bulbs directly, but also the cultivation starting from the seed is easy to manage and allows us to use seeds obtained by ourselves from the plants of the previous year, maintaining from year to year the variety of onion we like best.

Storing vegetable seeds is a good practice, and represents an extra step towards self-sufficiency, avoiding having to buy seeds, seedlings, or cloves every year. So let’s find out how the onions bloom and the subsequent seed harvesting, in order to obtain our seeds for the following year’s garden.

The flowering of onions

Onion seeds are not difficult to obtain. However, it must be remembered that onions are biennial plants, so they will produce seeds once every two years.

The onion as a vegetable is harvested in the same year as sowing, if we want to get the seeds instead we have to give up harvesting the onion and wait for the following year. For this, I recommend growing a few more onions, so that you can leave some plants to bring to bloom.

During the first year of the plant’s life, the clover swells, forming the classic onion. This, left in the ground, will act as an “energy reservoir” for flowering in the spring of the following year. This can be understood because the tip of the onion stem, instead of being filiform and pointed, forms a “ball” and a kind of “tuft”.

Early flowering

Sometimes the onion mounts early, due to less than optimal environmental conditions, such as drought or extreme heat. It is a reaction of the plant which, warning of being in danger, accelerates the reproductive phase. This spoils the harvest, so it should be avoided.

Also from the point of view of the seeds, it is better not to take seeds from early blooms, favoring the correctly formed flowers, to which the plant has been able to allocate the right resources.

When to take the seeds

During the drying phase, the flower changes its appearance: it loses its initial turgidity and vigor, leaving room for warmer flower shades. The individual cells begin to dry out, the stem to empty inside.

The onion seeds are ready for harvesting when the flower is completely dry, brown. The stem will be empty inside and will have a whitish color, tending to cream. This indicates that the flower is almost completely dry and ready.

How to save onion seeds
How to save onion seeds

The individual alveoli open, revealing the onion seed: it is a black speck with a length of 1-2 mm.

On average, an onion flower can contain 50 to 100 seeds or even more. It is therefore clear that the ratio between flower and seed is very high (from a planted onion you can even get 100 onions!).

Extracting the whole onion plant, bulb included, you will notice how it has been completely “dried up”. To the touch, it will be mushy and empty, since it served the plant as “fuel” to bring the onion to flower and therefore to seed. For this we have to choose whether to grow a plant for the bulb or the seeds, we cannot get both.

How to collect the seeds

To remove the onion seeds, the flower must be cut with a pair of pruning scissors, leaving a few centimeters of the stem to facilitate the shaking operation to collect the seed.

You need to get a paper bag, or in any case, a container to drop the seeds, and then shake the flower vigorously: if it is dry enough, the seeds will fall by themselves. For the most stubborn seeds, we can rub the flower in your hands. The residual “powder”, composed of the parts of the crumbled alveoli, can be blown away delicately, it will remain the seed.

How to save onion seeds
How to save onion seeds

Alternatively, we can sift the contents of the bag with a sufficiently large mesh.

Seed conservation

Onion seeds keep very well for one or two seasons, then the germination capacity decreases and too old seeds risk not being born. The normal rules of conservation apply: the seeds must be placed in a glass container or a tin can, to be stored in the dark in a cool and dry place.

Possible pollination crosses

When planting onions to take them to seed, it must be taken into account that plants of different varieties will pollinate each other if they grow too close. This means that the seeds could give plants different from the starting ones.

If you are growing onions for consumption, that’s not a problem. If, on the other hand, you want to recreate the same variety from the seed, adequate measures must be taken to prevent cross-pollination: when the “mother onions” are transplanted (with the waning moon, if you want to follow tradition), you need to be careful to do it in rows spaced at least 50 cm, in well-worked and fertilized soil, in a protected environment or the open field, but always isolated from other onion crops (at least 500 meters) to avoid cross-pollination and therefore pollution of the biotype. Those who preserve the seeds professionally create boxes in which the onion plants of a single variety are isolated and insert pollinating insects.


Recipes with onion

Tuna sauce with onions recipe/ Zucchini omelet with onion recipe/ Onion gratin recipe/ Onion flowers with herb dip recipe/ Salsiccia with roasted nuts and onions recipe/ Onion soup with gruyère bread/ Caramelized Onions recipe/ Onion jam recipe.


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