You can set out plants of long-day onion varieties through January and March and expect a late-summer to fall harvest. Short day onions are planted in November through January for harvest in late-spring to early summer.
Can I plant onion bulbs in January?
Although seed is available, sets are the easiest and quickest way to grow them. They can be planting in early autumn or, more usually, in spring, for harvesting through summer and into autumn.
Month by month.
| January | February | March |
|---|---|---|
| Plant | ||
| July | August | September |
| Harvest | Harvest | Harvest |
| October | November | December |
How early can you plant onion sets?
In spring, plant onion sets outdoors as soon as the ground can be worked, usually in late March or April, when temperatures are no longer likely to dip below 28°F (-2°C). In spring, start onion seeds indoors about 6 weeks before transplanting to the ground (once the soil is at least 50°F).
What is the latest you can plant onion sets?
Temperatures should be mild enough to plant onion sets between mid-March and mid-April. You can pick up onion sets from most garden centres, or order them online. However, before you plant onion sets, you should prepare your soil so it’s an optimum growing environment for your bulbs.
Can onion sets be started indoors?
To start onion seedlings indoors in February or March, fill a container nearly to the top with a seed starting mix and then make two furrows, about 1/2-inch deep, for the onion seeds. Sprinkle seeds in the furrows and cover them lightly with more soil mix. Label the container with the name of the onion variety.
How cold is too cold to plant onions?
20 F.
Onions thrive in a variety of temperature ranges but they produce the best at 55 to 75 F. (12-23 C.) and most varieties are hardy to 20 F. (-6 C.).
Can I plant onion sets in February?
Onion sets are best planted during February to early April when the ground is frost free, workable and not too wet. Don’t worry about frost after planting (not a problem). Plant the sets 6” apart in rows 12” across or if space is limited you can grow onion sets in a block or square, but give them 8” apart each way.
Can onion sets survive frost?
Onion sets are not very sensitive to frost. Provided they are properly covered with soil, they will not be easily damaged after planting, in case of night frost.
Can you plant onion sets in winter?
It’s a little-known fact that many seasoned gardeners aren’t aware of: you can grow onions (and shallots) in the winter. These super-hardy plants can survive incredibly cold temperatures with a little protection, and provide quality bulbs even after they bolt in the spring.
How late is too late to plant onion sets?
If you wait too long, the plants will not have enough time to mature before bulbing begins. We recommend planting onion starts (transplants) or sets in the ground no later than a month before your last frost for spring plantings.
Can you plant onion sets straight into the ground?
By making a little hole for each onion set rather than just forcing them into the ground you will avoid damaging the roots. Now gather some soil around the planted onion set so that just the top tassel appears above the soil surface. Gently firm the soil down.
How deep should onion sets be planted?
1 to 2 inches deep
Sets are dormant bulbs that can be planted directly into the ground. Onion sets should be planted 1 to 2 inches deep and 2 to 3 inches apart. Then, once the plants begin to grow, thin them to 3 to 4 inches apart. Plants thinned from the row to create room can be used as green onions.
Do I need to soak onion sets before planting?
You can plant onion sets without soaking them, but soaked onions will sprout more quickly. You can also soak onion seed before planting to encourage germination. Soaking the sets in compost tea will give them added nutrition and protection from disease.
Can you start onion sets in trays?
Sow onion seed indoors as early as January, so they are large enough to plant out in spring. Sow seed in a pot or tray of moist seed compost, about 1cm apart.
How big should onion seedlings be before transplanting?
When onion greens are 5 to 6 inches tall, it’s time to transplant them into individual cells. Begin by carefully overturning the seedlings onto your hand.
Can you plant onions before last frost?
Onions are a frost hardy vegetable that can be started indoors from seed about six weeks before the last frost. Onion sets, however, offer a considerable head start on the season since they can be planted out in the garden as soon as the soil can be worked in spring.
How long do onion sets take to sprout?
7-10 days
Onion sets will sprout in 7-10 days. You should see these awesome little green sprouts coming from the tops of the onion sets you placed in soil. Of course, soil temperatures will affect this. For instance, cooler soil temperatures below 55°F will slow sprouting to 10-14 days.
Will frost hurt onions in the ground?
Onions are as hardy as they come. Frosts, freezing temperatures, and snow will not kill them. They should have steadily moist soil and even growing weather to mature at a steady pace. Otherwise, they bolt to seed or do not form good bulbs.
Can you plant onions in March?
Plant onions as soon as the ground can be worked in the spring, usually March or April. Make sure overnight temperatures aren’t forecast to drop below 20°F. Plant the bulbs about an inch deep and four inches apart. Plant no more than one inch deep, otherwise bulb formation can be restricted.
What happens if you plant onions too deep?
If you’ve planted the onions too deep, you may not be able to tell when the bulbing process begins as the onion is too deep in the ground. You’ll end up with smaller bulbs shaped similar to torpedos because the soil will restrict the plants from bulbing properly.
Can onion sets be saved for next year?
You can store onion sets for planting in much the same conditions as you would store those you plan to eat. One option for how to store onion bulbs for next year is to place the sets together in a mesh bag, or you can tie the tops of the onions and hang them.