Onions are a Cold-Season Crop
Onions are a cold-season crop, so the best time to plant them is in the fall in mild-winter areas or early spring in northern states. The onion plant initially concentrates establishing a root system. Once the root system is established in normally two to three weeks after transplanting, the cool weather will encourage them to grow tops. And as the weather warms up, that’s the time they form bulbs.
Our zip code chart (pictured to the above) has been developed by taking the last average frost date by zip code and then backing off 6 weeks which determines the best time to plant your onions. Six weeks is important since the critical period for onions to bolt comes after the sixth leaf stage. The plants are shipped usually when they have 3-4 true leaves. The time frame of development is usually:
Three weeks after planting- Roots are established
Four weeks after planting – Onion shoots their 4 or 5th leaf
Six weeks after planting – Onion shoots their 5th or 6th leaf
Bolting never occurs until after the 6th leaf stage so up until that critical stage the onion can come in and out of dormancy and not be prone to bolting. It is after this 6th leaf stage, onions become vulnerable to bolting if they are exposed to colder temperatures or stress.
Our zip code chart is used as a general recommendation since there may be micro-climates within the zip code range that may affect the date of the last average frost. We will ship the plants whenever you desire.
Order your onion plants at DixondaleFarms.com or call us at (830) 876-2430.