Homeschool Garden Club – Onions and Shallots
Onions and shallots are very easy to grow and reward little effort with a good crop. They’re one of the most versatile vegetables in the kitchen, too. Onions are a large family with a lot of different choices from strongly flavoured to mild and sweet.
You can plant sets straight into the open soil in autumn as the ground has been adequately warmed up over summer. Bulbs will appreciate an open and sunny site.
If exposed to temperatures that are too low, there is a risk of bolting which means that plants produce flowers at the expense of harvestable bulbs. Varieties that are suited to autumn-planting are hardier to cold temperatures and less prone to bolt.
Autumn Planting Onions and Shallots
Now is the time to plant onion and shallot varieties for a crop in mid-summer next year. You will need autumn variety to do this. The advantage of these varieties is that you are planting in soil that has been naturally warmed up over the summer, so they settle well and they are set up to tolerate cold winters.
Best Varieties of Autumn-Planting Onions and Shallots
This is going to be our first year as a Garden Club to grow autumn onions so we asked for some advice. Here are the suggestions from our local allotment group. Thank you so much for a great conversation all about onions.
Onion 'Red Cross'- Produces large bulbs with deep red skin and white flesh with clearly defined red rings. Overwinters well and stores for up to 3 months.
Onion 'Radar'- Radar is loved for its mild flavour storage potential; under the right conditions it will store for about a year.
Shallot Biztro'- Spicy flavoured, strong growing shallot, with beautiful pale red flesh.
How to Plant Onion and Shallot Sets
1. In September to November plant sets pointy side up straight into the soil outdoors at 7-10cm (3-4in) intervals in a row, and space rows at 30cm (12in) apart.
2. Plant in an open, sunny site in fertile soil that is well-draining yet moisture retentive.
3. Incorporate bulky compost into the soil in the spring before to increase the soils fertility levels and create good soil texture, without it being too rich.
How to Feed and Water Autumn Planted Onions and Shallots
1. Apply bulky compost earlier in the season to planting- this will increase the fertility of the soil without it being too rich. Avoid adding freshly incorporated compost as this can create a soil which is too rich.
2. In spring, you can boost post-winter growth by applying a seaweed-enhanced feed, rich in phosphorous for stimulated root growth and encourages full and flavoursome bulbs.
3. Water at planting in autumn and reduce watering overwinter. In spring, water lightly as the weather warms but stop again once the bulbs are actively swelling.
4. A well-textured soil with incorporated bulky compost will hold on to enough moisture to see the crop through the overwintering and growing season.
How to Harvest and Store Onions and Shallots Planted in The Autumn
Harvest bulbs from early to mid-summer (June to July).
Follow these steps for harvesting shallots:
1. lift with a border fork once you notice the leaves have gone yellow.
2. Separate the clusters, clean off soil and grit, and dry in a cool light place for one to two weeks.
3. In wet weather bring into a garage by the window. In dry, sunny weather leave outdoors or in a well-ventilated greenhouse.
For onions follow these steps:
1. Lift when the foliage has wilted and yellowed.
2. Lift carefully with a border fork, dry in a cool, light place for two to three weeks before using in the kitchen.
Store in a cool place. Plaiting onions and hanging them is a space-saving way to keep them drying, and off the ground away from pests.
What should I plant?
Onions and Shallots are raised either from seed, plants or from sets (small bulbs), each has its own advantage and disadvantage. If you are really new to gardening then sets are undoubtedly the way to go this year. If you have more experience or would like more of a challenge then start by looking at the seeds and see which one you prefer.
Onion & shallot sets: Advantages: easier to grow, less prone to pests and diseases, matures earlier. Disadvantages: less choice of variety, more prone to bolting
Onion & shallot seeds: Advantages: available for all varieties, less prone to bolting, more flexible sowing times. Disadvantages: more labour, longer growing season, more susceptible to pests and diseases
Onion & shallot plants: Advantages: easier to grow, less prone to pests and diseases and have had a head-start on arrival, meaning a shorter growing season for you. Disadvantages: Less choice of variety and more expensive
Common Pests and Diseases
It’s important to be aware of the following common pests and diseases when growing onions and shallots:
Onion fly – Early signs of onion fly include the yellowing of leaves on established plants. Once this pest takes hold seedlings are often killed in patches. Any effected plants/blubs should be lifted and burnt to prevent further problems.
Bulb rot – Often occurs in warmer soil temperatures during the summer months. Plants will begin to yellow and the tips of the leaf’s will die off. The plant will have missing roots, or remaining roots will appear brown and rotted.
Smut – A fungal disease that can be identified by black blisters on the plants leaves, seedlings are often killed within a few weeks and surviving plants suffer stunted and distorted growth.
Shanking – A disease that causes leaves to yellow and shrivel up and bulbs to become soft.