You may be asking what are tree onions? Well they are like a normal onion but instead of going to a usual allium flower they have bulbils on the ends of high stalks that then bow under their own weight. When they are fully mature that weight means that they self set in the ground where the bulbils fall.
- Choose a bed that you can dig plenty of well rotted manure through. Ideally you want great drainage as tree onions can rot in the wetter months of the UK. So dig through some sharp sand. Alliums will benefit from sulphur rich soil so mix in a little gypsum (calcium Sulphate). You can buy Egyptian Walking Onions bulbils here.
- In spite of their nickname of Egyptian Walking Onions, tree onions Allium x proliferum do not need hours and hours of sunlight in the Summer months and are actually fully Winter hardy in the UK and similar zones elsewhere. However be prepared to offer some protection from really wet periods, a good mulch will do the job or a cloche. The best time to start top set onions off is between late Summer and the first frost.
- Plant each bulb two inches deep. You have two options for growing tree onions, from the big and pungent to the small and gentle chive like flavor. To achieve the larger bulbs, plant them around 6 inches apart, for the smaller ones go for around 2 inches.
- Water them in then basically relax. If you have chosen the right soil and keep an eye on waterfall levels tree onions are relatively straightforward. We plant ours in the same bed as our garlic because they love the same conditions.
- If you want the delicate green chive like taste then harvest throughout the year. However leave a few bulbs in to fully mature and then go walking. AS long as they walk where you want them they pretty much take care of themselves.
- You may like to add a bit more mulch each winter and feed them with a sulphur rich fertilizer, but other than that it is pretty simple.
- To harvest and store, just treat them as you would garlic and leave in a cool dry place for a few weeks, then plait them together and hang up in the same conditions.
- If you let the tree onions grow bulbils, which are so cute and totally worth it, then wait until they darken off. This will not be likely in the first year though and you may have to wait until the second year.
- There is a balancing act here as they are prone to topple over with their own weight and put out roots. This is great as one plant can walk to produce another 6 per year. Really the perfect version of self-seeding. When you do collect the nice dark bulbils, store them in a cool, dark place that has plenty of air circulating. You don’t want them to dry out completely but you don’t want them to rot with damp.
How To Grow Tree Onions In Pots
Your tree onions will grow just as well in pots or containers with the right mix of soil and gypsum. Ensure adequate drainage and make sure to water well. Make sure to add extra drainage holes to your pots!
How To Eat Egyptian Walking Onions
- Pickled tree onions are like little silver gems and will store really well.
- Egyptian walking onions are great in salads when they are still smaller.
- You can also put the flowers in salads for a funky looking salad, even better if you sit by the tree onions whilst eating the salad! Very much a conversation starter.
- Tree onions can be used like chives, as long as you don’t cut the entire plant down it will be a cut and come again harvest.
- The larger bulbs of the Egyptian Walking Onion can be sliced and cooked in butter or oil, a bit like you would with onions or garlic.
- The flowers of the tree onion can be used in very mature cocktails like a dirty martini.
- Roasted with other root vegetables the tree onion gives that sharp allium flavor with a really nice tone of garlic.
- In stews or slow cooker casseroles, the tree onions are a nice little addition, not too allium like in flavor but a gentle compromise with kids.
These are fun little onions to grow and actually more engaging for the kids than ‘normal’ onions. We think they are great for cooking with and hope you will agree.
If you love growing unusual herbs and vegetables we have a little list of our favorites you can find here. We are based in the UK but for growing purposes that is USDA zones 6-9. Meaning that we do have frosts but also warm Summers. So think about your garden and how tree onions may grow well there.
We also recommend growing tree onions to anyone looking to make a natural garden, as they spread and fill the space available. They will grow up inbetween existing planting very well. Making a prairie style border. We interplant the echinacea with them and allow them to naturalize the space.