While you may not receive the same results as growing crops and vegetables outdoors, it is possible to grow them indoors, and this is a great option for cold weather months, or if you have limited outdoor space. This is not as easy as growing them outdoors, and you may be left with less produce come time to harvest. The biggest issues you are likely to run into will be the lack of natural light, pollination, and natural outdoor climate. However, a major plus to growing them indoors is the fact that you can control the environment, climate, and aspects of the soil such as moisture and nutrients.
General Tips for Growing Crops Indoors
Because of the difference between climate and environment, you will want to refrain from using garden soil, and instead use a high-quality potting soil blend.
The containers and pots that you use should provide adequate drainage, and be the appropriate size for the type of product that will be growing.
While plants will need as much sunlight as possible, and it may seem like a good idea to place them in a window, the fact is that they will simply not receive enough sunlight; in most cases. Because of the shorter days during winter and the positioning of the sun, you may find that you will want to invest in either a light designed for plants or a full-spectrum fluorescent light.
Don’t place your plants next to a heat source, or a drafty area of your home
Carrots
Carrots are very versatile to grow, and it would be difficult for them to not have a successful yield while doing so. Because you will be growing them in deep containers, you are taking away the hassle of digging a hole deep enough in rocky soil to accommodate.
Smaller carrot species are easier to grow indoors, as they mature fairly quickly and do not require a lot of space to grow. Because you are going to be seeding multiple plants, a large container is ideal; such as a window box. Carrots thrive in high-quality soil that is kept moist, and during the germination process, you will want to ensure the seeds do not dry out by covering them with damp peat moss. The germination period is roughly 2 weeks.
Garlic Greens
While garlic is not necessarily difficult to grow indoors, it should be noted that they do have fairly specific temperature requirements for bulbs to form. That does not mean that is the case for the tops or greens, and these can be substituted for scallions. You do not need a large container for sprouts, only needing around 4 inches maximum. Garlic greens are fairly easy to grow, and to do so you only need to plant a garlic clove one-inch deep in the soil, and water at regular intervals; they should begin to sprout in roughly 1 week.
Before harvesting, you will want to allow them to grow anywhere from 8-10 inches, and simply harvest what you need and leave the rest. Generally, you will only receive one sprout from each garlic clove, and even if you do get more than that, the quality and potency will decline.
Hot Peppers
Considered to be tropical perennials, even though peppers are very susceptible to colder climates. Both sweet or hot peppers can be grown from the seed, and you can transplant mature plants from your garden to indoors during winter. Note that you won’t get a large harvest this way, but they will bear fruit.
To plant, begin by using a container that is at least 8 inches in depth. Due to their nature, peppers require at least 10 hours of light each day (and this is where supplementing sunlight will be a huge help). Avoid over-watering, and allow the container to dry before watering again. While they are self-pollinating, you will want to aid them in this process by gently tapping the plants to release the pollen.
Lettuce and Salad Greens
Because lettuce and other greens do not have large roots, you will not need a deep container, and lettuce is quick to grow. If you continue to only harvest what you need and leave the rest to grow, it will regrow and you can continue in this way. A container that is 2-4 inches deep should suffice; fill it with damp soil, sow your seeds by lightly pressing down, and mist the seeds and soil. Within a week, you should start to see the germination process complete.
Before beginning to harvest, allow the plants to grow 4-6 inches.
Microgreens (Radish Leaves)
When we talk about microgreens, we are referring to a combination of seeds, herbs, and greens such as radishes, kale, and swiss chard. These are among the easiest crops to grow indoors, and won’t require much space or time to grow. You won’t require a lot of soil, as they will be harvested while in the seedling stage.
When planting, a shallow tray that is around 2 inches deep will suffice; simply fill with your soil mix, moisten your soil, and scatter the seeds around. You will want to avoid over-filling the soil on top of the seeds, and will also want to make sure to lightly press the seed into the damp soil. Ensure the soil is kept moist with a light spray, and within days you should begin to seed germination.
As relates to harvesting, you can begin once the seedlings have two sets of leaves. They can continue to grow after harvesting, all you need to do is snip them at soil level.
Scallions
Although bulb onions can’t be grown indoors, scallions are a great alternative. No seeds are required. Many gardeners have found that they can grow scallions simply by replanting the root side of the scallions that are purchased, even without the top parts intact. Rooting the scallions can be done in a glass of room-temperature water, and once the roots have grown you can move them into a shallow potting container with potting mix and they will continue to grow and develop. They will continue to grow after being harvested, as long as care is taken to only snip the green parts.
Tomatoes
Although tomatoes do generally die off towards the end of the harvesting season, they are considered to be tropical perennials. The mature plants are best to leave outdoors, but they can be grown indoors starting from the seed; which germinate fairly quickly. At the point that the seedlings have reached 3-4 inches in height, you can move them to a more permanent potting solution, and ensure that they are receiving at least 10 hours of sunlight a day (another reason for supplementing sunlight with artificial lighting).
After moving the seeding into its permanent pot, you may want to use an organic fertilizer; and once flowers are apparent, force the pollen to drop by lightly tapping or shaking the plant.