Shallots go into the ground four to six weeks before your region’s final spring frost, giving them time to establish roots in cool soil. Knowing exactly when to plant shallots is the difference between a heavy harvest and a disappointing row of puny bulbs. This guide breaks down the timing by climate zone, planting method, and even moon phase if you are that way inclined.
You might think shallots are just small onions, but they have their own growing quirks. They are day-length sensitive and need a period of cold to trigger bulb formation. If you plant them too late, you get lots of leaf growth and almost no bulb. Too early, and a hard freeze can rot them in the ground.
Let’s get the calendar sorted for your garden.
When To Plant Shallots
The exact timing depends on where you live, but the rule of thumb is simple: plant sets (small bulbs) in early spring for a summer harvest, or plant in late fall for an early summer crop. The soil temperature should be consistently above 40°F (4°C) but below 70°F (21°C).
Shallots are hardy biennials grown as annuals. They tolerate frost surprisingly well. In fact, a light frost after planting actually helps them develop a stronger root system. The key is to avoid planting into waterlogged or frozen ground.
Spring Planting For Northern Climates
If you live in USDA zones 3 through 6, your window is narrow. You need to work the soil as soon as it is workable in the spring. That usually means late March to mid-April.
- Check the soil by squeezing a handful. If it forms a muddy ball, wait a week.
- If it crumbles when you poke it, the ground is ready.
- Plant sets 1 inch deep with the tip just showing above the surface.
- Space them 6 inches apart in rows 12 inches apart.
For northern growers, you can also plant in the fall, about four weeks before the ground freezes solid. The sets will go dormant and then take off very early in spring. This often yields larger bulbs because they get a head start.
Fall Planting For Southern And Mild Climates
Gardeners in zones 7 through 10 have the opposite problem. Your summers get too hot too fast. Spring-planted shallots will bolt (flower) and produce tiny bulbs before you can blink.
Instead, plant shallots in the fall, typically from October to November. They will grow slowly through the winter and then size up rapidly in early spring before the heat arrives. This is the preferred method for the deep south and coastal California.
In zone 9 and 10, you can also plant in very late winter (January) for a late spring harvest. Just make sure they get at least 6 hours of direct sun during the cool part of the year.
Coastal And Pacific Northwest Timing
If you live in the Pacific Northwest, you have the best of both worlds. The mild, maritime climate allows for a very long planting window. You can plant in late February or early March. You can also plant in September for overwintering.
These regions rarely see deep freezes, so the main risk is rot from excessive winter rain. If your soil is heavy clay, consider planting in raised beds or mounds to improve drainage. The sets will sit in cold, wet soil and can rot if they are planted too deep.
How To Determine Your Exact Planting Date
Stop guessing and start measuring. The soil temperature is the boss. You can buy a cheap soil thermometer for under ten dollars. Insert it 2 inches deep at 9 AM.
- If the reading is below 40°F, wait.
- If the reading is between 40°F and 55°F, plant immediately.
- If the reading is above 70°F, wait for fall or provide shade.
You can also use the “shamrock rule” in spring. When the lilacs start to leaf out, the soil is warm enough for shallots. That is a natural indicator that works across most of the US.
Another method is to count backwards from your last frost date. Your local extension office publishes this. Mark the date on your calendar. Then count back 4 weeks. That is your planting day. If a hard freeze is forecast right after planting, cover the bed with a floating row cover for the night.
Planting Shallot Seeds Vs Sets
Sets (small bulbs) are the easiest and most common way to grow shallots. They establish quickly and are less fussy about exact timing. You can plant them a bit earlier than seeds because they have stored energy.
Seeds take much longer. You need to start them indoors 8 to 10 weeks before your last frost date. They are more sensitive to cold soil. If you plant seeds directly in the ground too early, they will just sit there and may rot. For seeds, wait until the soil is consistently above 50°F.
If you are growing from sets, you have a 2-week planting window. If you are growing from seed, you have a 1-week window. So sets are more forgiving for the home gardener.
Day Length And Bulb Formation
Shallots are “long-day” plants. They need about 14 hours of daylight to trigger bulb formation. This is why timing matters so much. If you plant too late, the days are already long, and the plant will try to flower instead of making bulbs.
This is also why fall planting works so well. The plant grows roots and leaves during the short days of winter. Then, when the days lengthen in spring, it is already mature enough to put all its energy into the bulb. A young plant that experiences long days immediately will just make a single bulb with no cloves.
Regional Planting Chart For Shallots
Here is a quick reference table for the main growing regions. Use this as a starting point, but always check your local forecast.
- Zone 3-4 (Minnesota, Maine): Plant sets April 15 to May 1. Fall planting is risky but possible with heavy mulch.
- Zone 5-6 (Ohio, Pennsylvania): Plant sets April 1 to April 15. Fall planting late October.
- Zone 7 (Virginia, Tennessee): Plant sets March 1 to March 15. Fall planting November 1.
- Zone 8 (Texas, Georgia): Plant sets February 1 to March 1. Fall planting October 15 to November 15.
- Zone 9-10 (Florida, California): Plant sets January 1 to February 1. Fall planting October to December.
If you are in a high altitude desert (like Colorado), treat it like zone 5 but expect sudden temperature swings. Always keep frost cloth handy. The biggest mistake is planting too deep. Shallots like to sit high in the soil.
Preparing The Soil For Planting Time
Shallots prefer a soil pH between 6.0 and 7.0. They are heavy feeders but do not like fresh manure. If you add fresh manure right before planting, it will burn the roots and cause rot.
Work the soil to a depth of 8 inches. Remove all rocks and clumps. Add a balanced fertilizer like 10-10-10 at a rate of 1 pound per 50 square feet. Mix it in thoroughly. Do not put fertilizer in the planting hole directly under the bulb.
Good drainage is non-negotiable. If your soil stays soggy, the sets will rot before they root. Consider building a raised bed that is at least 6 inches high. You can also plant on a slight ridge or mound to keep the bulbs above standing water.
Spacing And Depth For Optimal Growth
Spacing affects bulb size. If you crowd them, you get small bulbs. If you space them too far apart, you waste garden space.
- Plant sets with the pointed end up.
- Press them into the soil so the tip is just barely visible.
- Space them 6 to 8 inches apart.
- Rows should be 12 inches apart.
If you are growing for “multiplier” shallots, they will split into a cluster of bulbs. Give them even more space, about 10 inches apart. This allows each new bulb to develop without competing for light and nutrients.
What Happens If You Plant At The Wrong Time?
Planting too early in spring leads to rot. The sets sit in cold, wet soil and simply disintegrate. You will see green shoots, but they will be yellow and stunted.
Planting too late in spring leads to poor bulb division. The plant will focus on leaf growth and then bolt to seed. You will get a single, hollow, tough bulb that is not worth eating.
Planting too early in fall causes the sets to sprout and then get killed by a hard freeze. The rule is to wait until the soil is cold (below 50°F) but not frozen. If you see green shoots in late fall, cover them with a thick layer of straw.
Frequently Asked Questions
Can I plant shallots in the summer?
No. Summer heat causes shallots to bolt. They need cool weather to establish roots. If you miss the spring window, wait for fall.
Should I soak shallot sets before planting?
Some gardeners soak them in compost tea for 15 minutes. This can help hydrate them. However, do not soak them in plain water for hours, as this encourages rot.
How long do shallots take to grow from planting?
From sets, they take about 90 days. From seeds, they take about 120 days. Fall-planted shallots are harvested in early summer, roughly 8 months after planting.
Can I plant shallots in pots?
Yes, you can. Use a pot that is at least 10 inches deep. Plant 3 sets in a 12-inch pot. Make sure the pot has drainage holes and place it in full sun.
What happens if shallots freeze after planting?
Shallots are frost-hardy. A freeze will not kill them if they are planted at the correct depth. They may look a bit floppy, but they will recover. If the ground heaves, press them back down.
Final Tips For A Successful Shallot Crop
Water deeply right after planting to settle the soil. Then do not water again until you see green shoots. Overwatering is the number one cause of failure. Once the shoots are 2 inches tall, water about 1 inch per week.
Mulch with straw or shredded leaves to keep the soil cool and suppress weeds. Shallots have shallow roots, so do not hoe aggressively near the plants. Hand pull weeds instead.
Stop watering about 3 weeks before you plan to harvest. This forces the skins to dry and improves storage life. When the tops turn yellow and flop over, gently lift the bulbs with a fork. Let them cure in a dry, shady spot for two weeks.
You can also plant a fall crop of shallots in the same bed where you grew tomatoes or peppers. They do not like to follow onions or garlic. Rotate your crops to avoid soil-borne diseases.
One last tip: save your biggest, best-shaped bulbs from the harvest to replant next year. This is called “selection” and it will gradually adapt the shallots to your specific microclimate. After a few years, you will have a strain that is perfectly tuned to your garden and your exact planting dates.
Now you have the full picture. Mark your calendar, check the soil temp, and get those sets in the ground at the right time. Your future self will thank you when you are frying up sweet, caramelized shallots in the summer.