LAST week I told how I sowed my leek and onion seeds over Christmas. Well, the propagator is doing its job quite nicely and I can confirm I have good germination.

These will remain in the propagator for a little while longer, though I have opened the vents to allow a drier and cooler atmosphere. When they are large enough, I will prick off the seedlings into celled trays where they will be grown on in my cold frame for planting out in the kitchen garden come April.

Leeks and onions belong to the allium genus (allium itself is the Latin word for garlic). So, it will come as no surprise to learn that shallots, chives and scallions also belong to the same genus.

There are quite a few types of eating alliums and you might be aware of spring onions and even Welsh onions – but have you ever heard of the Egyptian Walking Onion or the Green Potato Onion?

Well, I’ve been wanting to grow these two types for quite a while and my opportunity to do so came to a reality when I manage to source some sets of the two onions. As you can see from my photograph, they are already beginning to develop shoots and wanting to grow.

I’ve been unable to prepare the ground for planting them, though, as the weather has been so wet. So for now I have placed the onion sets in celled trays in my cold frame, which will allow them to grow in a controlled environment until the ground dries. By starting them off in celled trays the sets can grow, and as they develop I will be able to transplant them with minimum root disturbance.

Egyptian walking onions and green potato onions are what we call bunching onions, similar to shallots in that, when you plant one onion bulb, as it grows it then produces up to five bulbs which you harvest for eating or storage.

As with shallots, the green potato onion is planted early in the year and lifted at harvest time, normally around August.

Though the Egyptian walking onion is planted once and left in the ground, it almost an evergreen onion! As the onion grows you can use as spring onions or let the bulbs get a little larger and lift them as required, though leaving a few to continue growing and make yet more bulbs. Both these types of bulbs will produce onions, but don’t expect them to reach the size of a typical onion.

Interestingly the Egyptian walking onion is so called because once it planted it will walk around the garden! It does this by producing a central flowering spike which reaches around 60cm tall, and these flowers then produce what is called a top set, essentially a cluster of miniature onions. As these miniature onions get larger, they also become heavy which causes the stem to collapse and fall over, up to 60cm away from its original position. As the top set comes into contact with the ground, the miniature onions then grow to make a new clump, creating the illusion that the plant is walking across the garden.

Regardless of the type of onion you wish to grow or whether it is for eating or ornament, do be aware they don’t like acid soils, particularly with a pH below 6.5. The soil also needs to be fertile and free draining as onions hate standing in water. However, they do require a lot of water and will need watering during dry conditions, particularly for eating onions as this may result in a smaller size onion, though more likely to cause onion bolting, which is where the plant runs to flower and make seed.

Onions which have bolted can still be used for eating, but they are no good for storage as they are more likely to rot.

As with most plants, onions will benefit from a regular feeding and there are specific onion fertilisers available, though most common garden fertilisers will be fine. Just avoid applying high nitrogen-based fertilisers to onions as this will cause too much leafy growth, and for eating onions, about eight to six weeks before harvesting, apply a dressing of potash which will help them to cure in readiness for storage.