In a regular outdoor garden, winter vegetable gardening wouldn’t be possible. The plants and seeds wouldn’t be able to survive the harsh, cold temperatures and frost that happen during the season. But if you’re looking for vegetables to plant in December, you likely aren’t growing them outdoors! Vegetables grown in December should either be grown indoors in a home or apartment or in an indoor space like a greenhouse. There are plenty of vegetables that can be grown in an indoor environment, but some are better than others if you intend to transplant them outdoors come springtime.
One of the main things to keep in mind when you’re growing tomatoes indoors is how big the plant will get. Different varieties grow to different heights, and you may find your space is better suited for a smaller type of tomato. This is especially good to remember when potting your tomatoes or choosing what containers to grow them in. You’ll want to minimize repotting, so choosing something large enough for them to grow into will be to your benefit.
The easiest way to grow indoor tomatoes is to start with a small plant that’s already been established and plant it in a new container. However, that isn’t always possible come December, so you may have to start your plants from seed. Sow your tomato seeds in a starter mix, about a quarter inch into the soil. Seeds should be started in a 6-inch pot, so you will have to repot them at least once during their growth period. The soil should be warm and moist to encourage seed growth, and germination should happen within five to 10 days. Put them in bright light following germination, preferably in an area that isn’t drafty or cold, as that could harm the seeds and plants. Once they’re about 3 inches tall, repot them to a larger space.
Lettuces and smaller greens
Similar to tomatoes, some varieties of lettuce and greens are better suited for indoor growth than others. There are varieties that are also better for growing in winter lighting, like Arctic King and Winter Density, among others. These types will be the best ones to plant in December if you plan on growing indoors without many grow lights. However, lettuce and greens as a whole require a decent amount of light each day. So, be sure to pay attention to the needs of your specific variety and do what you need to for the individual needs.
When preparing your soil for planting seeds, you’ll want to moisten it a bit and fill the pot with roughly 3 to 4 inches of the mix. If you’re using a starter kit or system, you’ll want to put three to four seeds on every pod. Otherwise, scatter the seeds in your pot and cover with another thin layer of mix. You’ll want to place the pot in a warm space, then cover loosely with plastic wrap or a lid to help the pot retain moisture while the seeds grow. When sprouts appear, it’s time to thin them out so that each seedling is 1 inch apart. During the rest of their growth into lettuce, be sure to keep the soil moist (without overwatering).
Did you know that onions can also be grown indoors? As far as winter vegetable gardening goes, onions are a good fit because they’re inherently a crop grown in cooler weather. All you need is a container deep enough that their bulbs and roots can form. You’ll need both soil and a pot that can provide your onions with excellent drainage, as you don’t want to risk drowning the seeds or rotting the plant as it grows.
Because onions need a decent amount of light, you may find yourself wanting to purchase grow lights to help in the winter months — and this goes for any plant you attempt to grow indoors during this season. Winter days are notoriously shorter, and your plants could lose out on nutrients that they need to grow fully and properly. If you have limited space in your home and can’t get very large containers, there are onion varieties that are smaller and better suited for indoor growth as well. You’ll find this is common among many vegetables.
Even though you won’t get as large a crop as you would outdoors, growing onions in containers is fairly simple. You can start either with a whole onion or slice off the part of an onion where the roots are and plant it in the pot. In time, it will grow, and you can repeat the process as often as you wish.
The most important thing to remember when growing onions indoors in December (and any time of the year) is that each plant and every variety will have individual needs that should be met. No two onions are perfectly alike, so follow their conditions to ensure the best growth possible.
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