Row by Row Episode 119: Ultimate Guide to Planting Onions in the Garden

Ideal Time for Planting Onions

It is time to start thinking about planting onions in your vegetable garden. However, depending on your location there are certain onion varieties you should consider planting based on your zone. For short day onions, the ideal planting time is fall or late winter. The best time to plant intermediate day onions is around late winter or early spring. While long day onions work best when planted in early spring in the garden. Since onions take a little longer to germinate we recommend planting onions in seed starting trays to have better success at healthier plants. Another reason we like planting onions in a raised bed or by transplanting is that they prefer to be spaced around 6 to 8 inches apart in order to make those big onion bulbs that you want in the garden. Here in the South, we look for planting onion transplants anytime in November or early December. The best fertilizer to use on onions initially is a complete fertilizer because onions need to take up a lot of fertilizer during the vegetative phase. Once the bulbing phase starts, cut off the fertilizer to avoid any issues with blight which can happen when too much fertilizer is given to the plants.

Planting Onions: Short Day, Intermediate, Long Day

Which onion zone are you in? That is the number question to ask yourself when deciding what onion varieties you should be planting. To determine which type of onion you should grow it’s best to look at the day length in your location. When growing onions they have two different phases — vegetative and bulbing phase. Once the onion plants are ready to be planted in the garden that will start the vegetative phase. The vegetative phase is mainly just growing the foliage at the top, the bulb is not enlarging during that first phase. Once your day length hits a certain number of hours then the bulbing process will begin. With short-day onions, the bulbing phase will begin start when day length reaches around 10 to 12 hours. Intermediate day onions will start bulbing when day length reaches 12 to 14 days. While long-day onions will trigger bulbing when day length reaches 14 to 16 hours. Therefore, if you are trying to grow a long day onion variety here in the South it will never start the bulbing phase because we never experience 14 to 16-hour day lengths. Another issue that will most likely happen if you plant a short day variety in the North is as soon as you plant it in the ground it will start bulbing really quickly and you won’t have enough foliage that is needed to grow a large onion.

Show and Tell Segment

On the show and tell segment this week, Greg has a new variety to share from his microgreen project. The microgreen varieties he tried growing this week were Premium Greens Mix, Lacinato Kale, Detroit Dark Red Beet, and Ruby Fresh Swiss Chard. The microgreens are great for growing year-round on your homestead and are perfect for eating in salads or used as a garnish.

Just like last week’s show, Travis has new varieties to share this week. There are quite a few new cool-season cover crops that will be coming soon to the website once we get them to our warehouse. However, Travis does want to share some new varieties that are now on the website. The first new variety is Minuteman Cauliflower which is a hybrid that performs well in the heat for late spring and early fall production. It usually matures in just 65 to 70 days after transplant which makes it one of the earliest maturing cauliflower varieties available. Then, we have a new lettuce variety known as Brave Heart Romaine that produces large and tall heads. It is also a downy mildew resistant variety making it an excellent choice if you experience high heat and humidity in your area. Lastly, the Envy Carrot is known to produce well in clay or muck soils, unlike other carrot varieties. This variety is an imperator type that averages around 10″ to 12″ long carrots in the garden.

Viewer Questions

For the Q & A segment this week, Greg and Travis answer some popular questions from their viewers on last week’s show. The first question is whether you can grow onion transplants in the 162 seed starting trays. You certainly can grow onion transplants in the 162 trays and even drop one or two seeds in one cell and easily pull them apart when planting in the ground. When growing onions indoors you should simulate the outside day length. Once the plants get close to being ready for the ground, Greg likes to move the trays outside of the greenhouse and cut off the fertilizer and will start watering them less in order to harden the plants. By hardening off the plants it allows them to become tougher and creates better success for planting onions in the vegetable garden.

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