17 Veggies You Should Start Indoors For A More Successful Fall Garden

If you are looking to create a thriving fall vegetable garden, it is essential to know which crops you should start indoors and which ones you should directly sow. There are loads of benefits to starting your crops inside for a fall garden. Firstly, you get a head start on growth while your summer plants are still producing crops. Plus, certain seeds need a cooler environment to germinate. For example, collards and kale germinate in cool soil and may not actually grow when placed directly into the soil in warmer months. 

However, there are certain fall crops that you should not start indoors, as they do not transplant well. Root vegetables, such as carrots and parsnips, should be directly sown into the soil if the temperatures in your region allow it. Thankfully, there is a whole load of fall crops that you can start inside, such as broccoli, lettuce, leeks, and kale. By sowing them indoors at the end of summer, you can protect your seedlings from heat damage and prepare for a fall and winter harvest. 

For a fall crop, broccoli (Brassica oleracea var. italica) should be started inside in July. Although most varieties of broccoli can be grown during this time, those that have a longer growth cycle will usually fare better. This is because varieties with a longer growth cycle will form their heads in cooler weather, and therefore, avoid harm from heat. Broccoli seeds germinate when temperatures range from 45 to 85 degrees Fahrenheit and can take up to 20 days to germinate. You should transplant your broccoli out into the ground after three or four weeks of indoor growth. 

Cauliflowers (Brassica oleracea var. botrytis) are a fantastic fall crop, and you can easily start them indoors in July. They need temperatures between 45 and 85 degrees Fahrenheit to germinate, and seedlings will usually appear in a few weeks. They can be transplanted outdoors after four to six weeks inside, and it is best to place them somewhere under the full sun. When you plant your cauliflower seedlings, add some fertilizer to the soil to help them establish themselves. Give each seedling around 18 inches of space to ensure it will have enough room to mature. 

Cabbage (Brassica oleracea var. capitata) prefers the cooler months and can suffer in temperatures over 75 degrees Fahrenheit. Starting them off indoors in mid-July will give them a head start in the harsh summer heat. Cabbage seedlings can be transplanted after 4 or 5 weeks, but it is essential to harden them outdoors for a few days beforehand to avoid transplant shock. When you plant them, space your cabbage seedlings 16 inches apart and apply a liquid fertilizer. They do well when having around 6 hours of sunlight a day.

Kale (Brassica oleracea var. acephala) tolerates frost well and thrives in cooler temperatures, making it a great fall crop. Start your kale seeds indoors in June, and they will germinate in temperatures of 45 to 85 degrees Fahrenheit. They can be transplanted into your garden once the plants have four to six leaves, which is usually after five or six weeks. When your kale seedlings are ready to be planted, space them 12 inches apart. You should harden them off before taking them outside by reducing the temperature and water for a few days. 

Warm temperatures slow down the growth of collards (Brassica oleracea var. acephala), so starting them inside at temperatures of 45 to 85 degrees Fahrenheit can be beneficial. Sow them inside in July and plant them out six to eight weeks afterwards. Hardening the seedlings off will help them acclimate to the outdoors, so reduce the temperature and the amount of water you give them for a few days beforehand. Space the seedlings 8 inches apart and apply some nitrogen fertilizer. You should also feed them again two weeks later to give them a boost and help them keep growing. 

Warm temperatures can affect the growth of spinach plants (Spinacia oleracea) and cause them to flower prematurely, so it is always good to wait until the cooler season to grow them outside. You can start them off indoors during the summer for a fall harvest, ensuring the soil you are growing them in is around 45 to 68 degrees Fahrenheit. Once the seedlings have four to six leaves, they are ready to be planted out. This is usually after around six weeks of indoor growing. Space your spinach seedlings 3 inches apart and apply some nitrogen-based fertilizer. 

Brussels sprouts (Brassica oleracea var. gemmifera) are hardy, cool-weather-loving crops that you can start indoors in June. They will take around two weeks to germinate and do well when given a half-strength starter fertilizer as the seedlings first begin to appear. After four or five weeks of growth, the seedlings will be ready to be planted out in your garden for a fall harvest. Harden them off by slowly introducing them to sunlight to avoid transplant shock. Do this for several days before planting your Brussels sprouts seedlings in the soil, spacing them 24 to 36 inches apart.

Swiss chard seeds (Beta vulgaris var. cicla) can be planted indoors in June and tend to germinate best at 55 to 75 degrees Fahrenheit. Room temperature is usually fine for Swiss chard, but consider using a heating mat if your home is particularly cool. The seedlings will emerge in a week or two and can be planted outdoors once they have five or six mature leaves. They must be hardened off before being planted outside and should be spaced 6 inches apart. It does well in full sun, but Swiss chard can also be grown in partial shade. 

There are loads of varieties of lettuce seeds you can pick for a late crop in your fall garden, but most do really well in cooler temperatures. Lettuce (Lactuca sativa) germinates best at 55 to 65 degrees Fahrenheit and should be started indoors in late summer. You may also wish to start more seeds every 10 to 14 days to have an ongoing supply of lettuce throughout the fall and winter months. Transplant them outside after five or six weeks, 8 to 12 inches apart. Four weeks after transplanting, give them a small amount of nitrogen-based fertilizer.

Mustard greens (Brassica juncea) can be started indoors in midsummer in temperatures of 55 to 65 degrees Fahrenheit. Temperatures above 80 degrees Fahrenheit will affect germination, so keep an eye on them if you live in a warmer climate. After five or six weeks, you can transplant your mustard green seedlings outside, as long as the weather is cool enough. Mustard greens can really suffer in high temperatures, causing plants to go to seed or have stunted growth. Space them 3 inches apart when planting them out into your garden, and water them regularly. 

If you live in a warm climate, leeks (Allium ampeloprasum) aren't suitable for summer growing. Thankfully, you can start them off indoors for a fall crop. Sow them indoors in June for transplanting in September to avoid the summer heat. Once they are ready to go out, harden them off and then plant them deeply into the soil. Space them 5 inches apart in a spot where they will get at least 6 hours of sun a day. Leeks need to be watered regularly and do well when mulched with an organic material. 

Arugula (Eruca sativa) is another crop that can bolt (flower prematurely) in high heat, so it's perfect for a fall garden. Don't buy this vegetable garden favorite as a seedling – start seeds indoors at temperatures of 50 to 65 degrees Fahrenheit. Arugula can be transplanted up until a month before your last frost, and starting more arugula seeds every two or three weeks will ensure you get a continuous supply. Once your seedlings are a few inches tall with a few sets of leaves, they can be planted outside. Space them 6 to 8 inches apart. 

Romanesco (Brassica oleracea 'Romanesco') should be started indoors four to six weeks before you plan to plant them outside. They need to be transplanted just after the last frost, so plan accordingly. Once they are ready, plant your romanesco seedlings 18 to 24 inches apart to give them enough space to grow to maturity. They will need to be kept moist throughout the growing season, so water them regularly. Give your Romanesco seedlings some feed once or twice while they are growing to help them reach a decent size for harvesting. 

If you live in a warmer climate, sugar snap peas (Pisum sativum) can be a welcome addition to your fall garden. Start them off inside in August and plant them out 8 to 10 weeks before the last expected frost. You may need to protect the smaller seedlings from a light frost if this is expected, but they can survive this and go on to produce a plentiful harvest. Sugar snap peas will need to be kept moist throughout the season, and they are best grown in full sun. 

Certain varieties of onions (Allium Cepa), such as Egyptian onions and shallots, can be grown in a fall garden. Most varieties can survive freezing temperatures, but it is recommended to check which types are best suited to your climate to choose onions that work best for you. You can start them off inside 8 weeks before you plan on planting them out. When planting them in your garden, add some starter solution fertilizer into the soil and water them once a week. When they have five or six leaves, give them another dose of fertilizer to help with growth. 

Cilantro (Coriandrum sativum) is an easy herb to grow from seed and suits the fall as it is resistant to light frost. It can be started indoors in September and planted out once the seedlings have an established root system. To give them the best conditions, plant your cilantro seedlings in well-drained, fertile soil. Give them fertilizer a few times during their growing season to help them establish themselves. It is essential to keep watering your cilantro seedlings while they settle in. However, once they are established and healthy, they don't need that much water. 

Oregano (Origanum vulgare) is another winter-hardy herb that can be added to your fall garden. Start seedlings indoors in August and September and transplant them in October and November. Oregano does best in full sunlight, especially during the colder months. Space them out with 18 inches between each other, as oregano plants can grow pretty big. If your soil lacks nutrients, you should give your oregano some fertilizer. However, this is not always necessary. They don't need a lot of water and are drought-tolerant once they establish themselves.