Seeds Early Spring: Are you ready to start your spring garden early? Whether you’re experienced or new to gardening, learning how to start seeds indoors can bring you a head start. I’ve worked on over 15 organic farms across the U.S. and found the best seeds for an early spring harvest.
In zones 7 and cooler, starting seeds indoors is key because the growing season is short. Most vegetables and flowers should be sown indoors 4-10 weeks before you move them outside. With some plants taking 45 days to over 150 days to mature, planning your seed starting is crucial.
Key Takeaways
- Timing is critical for starting seeds indoors, with a range of 4-6 weeks to 8-10 weeks before the last frost.
- Some plants do better indoors, while others should be directly sown in the garden, about 8-10 weeks before the last frost.
- Leeks, onions, celeriac, and celery grow better when started indoors for a bigger harvest.
- Keeping the soil moist and warm is key for seeds like celery to grow well.
- Many cool-weather crops can be started indoors for an early spring garden, like lettuce, spinach, kale, and more.
Importance of Indoor Seed Starting
Starting seeds indoors has many benefits over direct sowing in the garden. It gives seedlings a strong start in a safe place. This way, they’re ready to be moved outside when the weather gets warmer. Starting seeds indoors lets you pick your crops earlier in the season, sometimes by weeks.
It also lets you grow more cool-weather crops that might not have enough time to grow if planted directly. This is great for gardeners in areas with short growing seasons. It helps them start the season early and get more from their gardens.
Benefits of Starting Seeds Indoors
- Extend the growing season by planting cool-weather crops earlier.
- Get more from your garden with multiple harvests from transplants.
- Seedlings are stronger and less likely to be eaten by pests.
- Plan your garden better, especially in small spaces, by placing transplants carefully.
Extending the Growing Season
Starting seeds indoors lets you grow sensitive plants like tomatoes, peppers, and pumpkins without worrying about early spring frost4. For cool-season crops like lettuce and broccoli, it means an earlier harvest and more crops.
Beginner gardeners should start with plants like tomatoes and broccoli indoors. Start seedlings 6-8 weeks before the last frost, which can be in mid-February in places like Glenside and Philadelphia.
Planning for Indoor Seed Starting
Getting ready for indoor seed starting is crucial. First, figure out the best sowing dates by looking at your local last spring frost date. Most seed packets tell you how many weeks before the last frost to start seeds indoors. This helps you make a seed starting calendar to keep track of when to plant each crop.
Determining Sowing Dates
When planning for indoor seed starting, think about what your cool-weather crops and warm-season vegetables need. For example, in Minnesota, you start annual flowers and vegetables like tomato, pepper, and eggplant in early spring. But, you might start cabbage and broccoli for fall crops in June or July. Some seeds, like those of alpine strawberry, should be started as early as February.
Using a Seed Starting Calendar
A seed starting calendar keeps you organized and makes sure you plant your seeds at the best time. Different plants need different times indoors before going outside, from 1-17 weeks. Also, older seeds don’t germinate as well. Using separate containers for seedlings helps avoid root injury when moving them outside.
For the best growth, start seeds on a south-facing window or under artificial lighting in Minnesota. Plants need 12 to 16 hours of light a day for good development indoors. Bottom heat helps seeds germinate faster and grow stronger roots. You can use electric heating mats for this.
Long Season Crops for Indoor Sowing
Spring gardening is best for some crops, not all. Long-season vegetables gain a lot from starting indoors early. Think of leeks, onions, celery, parsley, and many brassicas like broccoli and cabbage. These need more time to grow fully before the season ends.
Some veggies take longer to get ready, like lettuce (60-70 days), beets (50-60 days), radishes (25-30 days), spinach (25-30 days), peas (60-70 days), carrots (60-80 days), cabbage (70-120 days), broccoli (70-120 days), kale (50-60 days), potatoes (100-120 days), and turnips (40-50 days). Starting them indoors early helps them grow better and gives you more produce.
Starting these crops indoors early gives them a boost. This is key in places with short growing seasons or unpredictable spring weather. It helps ensure a big harvest in summer and fall.
| Crop | Growing Zones | Days to Maturity |
|---|---|---|
| Lettuce | 3 to 9 | 60 to 70 days |
| Beets | 2 to 10 | 50 to 60 days |
| Radishes | 2 to 9 | 25 to 30 days |
| Spinach | 3 to 9 | 25 to 30 days |
| Peas | 3 to 11 | 60 to 70 days |
| Carrots | 3 to 9 | 60 to 80 days |
| Cabbage | 3 to 9 | 70 to 120 days |
| Broccoli | 3 to 9 | 70 to 120 days |
| Kale | 3 to 10 | 50 to 60 days |
| Potatoes | 3 to 10 | 100 to 120 days |
| Turnips | 2 to 11 | 40 to 50 days |
Starting these long-season crops indoors helps you get more from your garden. It’s great for growing cool-weather crops and other early favorites.
Leeks: Early Indoor Sowing for Robust Stems
Leeks are a great choice for starting indoors early in spring, about 8-10 weeks before the last frost. They grow slowly but do well with an early start. When planting leek seeds, spread them thinly in shallow trays at 1/4 inch deep. Thin the seedlings to 1 inch apart once they grow in 7-14 days.
Planting and Care for Leek Seeds
In northern areas, start leeks 8 to 12 weeks before the last frost. In warmer places, start them 3 to 4 weeks before the last frost. Once big enough, move them outside about 4 to 6 weeks before the area is frost-free. Hardening off the seedlings for 10 days before planting helps them adapt to the outdoors.
Leeks need well-drained soil rich in nutrients. Plant them 6 inches apart in rows also 6 inches apart. Plant them deep, showing only a bit of the top above the soil. Water them twice a week for good growth. They also do well with weekly organic liquid fertilizer.
Harvest leeks when they are about two inches wide. They can be picked from fall to winter, surviving freezes with the right care. Some types like Giant Musselburgh, Blue Solaise, and American Flag can even last through the winter and grow again the next year in cold areas.
“Leeks are a biennial in the allium family, alongside onions, garlic, shallots, and chives. They’re loved for their mild taste and cold resistance.”
Starting leek seeds indoors and transplanting them at the best time gives you a big harvest in spring and winter. With the right care, you’ll get strong, tasty leek stems for many dishes.
Sweet Onions: Start Indoors for Early Harvest
Onions are great for an early start indoors, just like leeks. They take about 100 days to grow. Starting them 8-10 weeks before the last spring frost lets you enjoy fresh onions by May or June. I like to sow them in open flats or plug trays, about 1/4 inch deep, without covering them too much. Keeping them moist and warm helps them grow evenly.
Choosing Onion Varieties for Your Region
Think about your climate’s daylight when picking onion varieties. Long-day onions need 14+ hours of daylight and take 90-110 days to mature. Short-day onions need 10-12 hours and take 110 days to mature in warmer areas, or 75 days in colder areas in early spring. Day-neutral onions need 12-14 hours and take 110 days to mature, best for zones 5-6.
For keeping onions long, choose varieties known for it. Jason Kafka grew 8,000 pounds of onions from 3 1/2 ounces of ‘Ailsa Craig’ seed, showing great yield. Picking the right onions for your area and needs can make your early spring harvest big and your onions last all year.
| Onion Variety | Daylight Requirement | Days to Maturity | Recommended Regions |
|---|---|---|---|
| Long-day | 14+ hours | 90-110 days | Northern zones |
| Short-day | 10-12 hours | 110 days (warm zones), 75 days (cold zones) | Southern zones |
| Day-neutral | 12-14 hours | 110 days | Zones 5-6 |
Plant onions in bunches of four in the garden, about 6 inches apart. For eating one onion a day, plant about 400 seedlings or sets, needing 50 row feet of space. For eating two onions a week, plant a bit over 100 seedlings or sets.
Onions are easy to care for and need regular watering and weeding. Start them indoors by sowing seeds in containers with a seed starting mix. They take about a week or two to germinate.
“Melissa found that she needs to start onion seeds about 16 weeks before the last frost date to achieve the same bulb size as when buying onion sets.”
Celeriac: Preventing Bolting with Early Indoor Start
The unique and flavorful celeriac, or celery root, needs an early start indoors to avoid bolting. These slow-growing veggies should be sown 10-12 weeks before the last spring frost. It’s key to start celeriac indoors to stop it from going to seed too soon.
Starting celeriac seeds indoors can take up to three weeks. Once they grow, move them to individual pots or trays. This helps them build a strong root system before moving to the garden. Celeriac can bolt if it doesn’t have the right conditions. So, keep the soil moist and avoid stress to stop it from flowering too early.
When moving celeriac seedlings, put them 30cm (1ft) apart in rows 40–45cm (16–18in) apart. You can harvest celeriac from October to the next March. The roots get better flavor if left in the ground. Use a fork to harvest carefully to not harm the roots.
For a great celeriac crop, keep the soil moist, especially when it’s dry. Protect young plants from slugs and snails. Celeriac can get diseases like celery leaf miner and leaf spot, so check on the plants often and remove any sick leaves. By starting celeriac seeds early indoors and giving them the right care, you can enjoy this unique veggie in your garden.
“Celeriac is a versatile and underappreciated vegetable that deserves a place in every spring garden.”
Celery: Finicky Seeds Need Consistent Conditions
Celery is harder to grow from seeds than its relative, celeriac. Trying to plant celery seeds directly outside often leads to poor results. The tiny seedlings can’t handle changes in moisture and temperature well. They need steady warmth and moisture from the start.
It’s key to start celery seeds indoors 10 to 12 weeks before the last spring frost. Germination can take up to three weeks, so creating the perfect growing space is crucial. Keep the soil warm, between 70° and 75°F (21° to 24°C) during the day, and cooler at night. Keeping the soil moist is also vital, as celery seedlings dry out quickly.
When moving celery seedlings outside, timing is everything to prevent them from flowering too early. Wait for soil to warm up to at least 50°F (10°C) and nights above 40°F (4°C). Some celery types, like ‘Afina,’ can mature in 60 days. Others, such as ‘Utah 52-70R Improved,’ can grow up to 18 inches tall.
After moving celery to the garden, keep the temperature right and prevent flowering. You can build up the soil around the plants. This method can keep celery in the garden for a month. For longer storage, freeze celery stalks in half-inch pieces in airtight bags.
Celery is usually easy to grow, but watch out for pests like carrot rust flies and cucumber mosaic virus. Some celery varieties may have pesticides from the greenhouse. Be careful where you buy your seeds if this is a concern.
| Celery Cultivation Details | Data |
|---|---|
| USDA Hardiness Zone | 6-10 |
| Days to Maturity | 80-120 days |
| Plant Height | 12 inches |
| Watering Needs | 1 inch per week |
| Planting Spacing | 6-10 inches apart |
| Ideal Temperature | 55-86 degrees F |
| Sun Exposure | Full Sun |
| Common Pests | Aphids |
| Common Diseases | Blight, Circospora Leaf Spot |
| Seedling Soil Moisture | Consistently moist for 2-3 weeks |
| Ideal Seedling Temperature | 70-75°F |
| Post-Germination Seedling Temperature | 60-70°F |
| Time for First Leaves | Several weeks |
| Reduced Watering Before Transplant | 7-10 days |
| Outdoor Planting Temperature | Nights above 50°F, avoid below 55°F |
| Hot Climate Growing Temperature | Best under 85°F |
| Blanching Celery Stalks | Required for pale green or white bottoms |
“Celery is an even more finicky crop than its celeriac cousin when it comes to seed starting. I’ve had very little success direct sowing celery outdoors, as the delicate seedlings are incredibly sensitive to any fluctuations in moisture or temperature.”
Seeds Early Spring: Cool Weather Crops
As spring gardening starts, many plants love the cool weather of late winter and early spring. Leafy greens like kale and spinach, and root veggies like beets and carrots, are great for an early start. Some, like radishes and peas, can go straight into the ground. Others do better indoors before moving outside.
Starting these plants indoors lets you grow longer into the season. By sowing seeds early and moving seedlings outside, you can pick fresh produce sooner. This is especially good for broccoli and cauliflower, which need more time to grow.
- Radishes grow fast, ready in about three weeks.
- Carrots take longer but are great for early Spring.
- Broccoli is tough and does well in early Spring.
- Peas, like snow peas and sugar snaps, are perfect for early Spring and need support.
- Lettuce is ready about a month after it starts growing and can be picked early.
- Brassicas can be picked before they’re fully grown.
- Spring radishes are quick, taking only three weeks, but shouldn’t stay in the ground too long.
- Chard and beets take 50 to 65 days to mature, and their seeds start growing quickly.
- Legumes like snap peas and beans are easy to grow and perfect for beginners.
When planning your early spring garden, think about what these cool-weather crops need. The right care can lead to a great harvest, making your gardening season a success.
“The key to a thriving early spring garden is selecting the right cool-weather crops and providing them with the optimal growing conditions.” – Gardening Expert
| Crop | Sowing Indoors | Transplanting | Harvest |
|---|---|---|---|
| Kale | 4-6 weeks before last frost | 2-3 weeks after sowing | 6-8 weeks after transplanting |
| Spinach | 4-6 weeks before last frost | 2-3 weeks after sowing | 4-6 weeks after transplanting |
| Arugula | 4-6 weeks before last frost | 2-3 weeks after sowing | 4-6 weeks after transplanting |
| Beets | 4-6 weeks before last frost | 2-3 weeks after sowing | 8-10 weeks after transplanting |
| Carrots | 4-6 weeks before last frost | 2-3 weeks after sowing | 10-12 weeks after transplanting |
Adding cool-weather crops to your early spring garden extends the growing season and brings fresh, tasty produce. With careful planning and preparation, your garden can thrive and reward you with delicious results.
Broccoli and Cabbage Family for Indoor Head Start
Broccoli, Brussels sprouts, and cauliflower are great for starting indoors. They need a long time to grow, about 4-6 months from seed to harvest. Starting them inside 4-6 weeks before the last spring frost helps them grow strong for the garden.
Brassicas like cabbage and broccoli should start indoors 6-8 weeks before the last frost. This gives them enough time to become healthy seedlings before moving outside. Cabbage takes 60 to 100 days to be ready, so starting early is key for a good harvest.
When starting brassicas indoors, make sure they have the best growing conditions. The soil should be between 6 to 7 pH. Add compost, wood ash, limestone, and bone meal to make the soil rich and healthy. Keep the soil moist, as these plants don’t like drought.
Starting broccoli, cabbage, and other brassicas indoors gives you an early and bigger harvest in your spring garden. With careful planning and care, these cool-weather crops can be some of the best early-season plants.
| Crop | Optimal Sowing Time | Days to Maturity | Recommended Spacing |
|---|---|---|---|
| Cabbage | Start indoors 6-8 weeks before last frost | 60-100 days | 15-18 inches between plants, 24-30 inches between rows |
| Broccoli | Start indoors 6-8 weeks before last frost | 60-100 days | 12-18 inches between plants, 24-36 inches between rows |
| Cauliflower | Start indoors 6-8 weeks before transplant date | 60-100 days | 18-24 inches between plants, 24-36 inches between rows |
| Brussels Sprouts | Start indoors 4-6 weeks before last frost | 90-120 days | 18-24 inches between plants, 24-36 inches between rows |
“Starting brassicas indoors gives them the extra time they need to develop into robust, productive plants.”
By following these guidelines for starting brassicas indoors, you can start your spring garden early and enjoy an early harvest of these cool-weather favorites.
Microgreens and Sprouts: Quick Indoor Crops
Growing indoor seeds is a great way to quickly produce nutrient-rich crops like microgreens and sprouts. These tiny greens and seeds can be ready in just 1-2 weeks. They add fresh flavor and nutrition to your meals fast.
Microgreens are full of vitamins, minerals, and antioxidants. They have 4 to 10 times more nutrients than full-grown greens. You can grow them indoors or outside, and they come in many types. Each type has its own flavor and health benefits. Sprouting seeds like alfalfa, broccoli, or mung beans is another easy way to grow nutritious greens at home. Sprouts can boost their vitamin C by up to 700% in just 72 hours.
- Microgreens are ready to harvest in about two weeks after planting.
- Sprouts are generally ready in 1-2 days, while microgreens take a little longer to grow.
- Growing your own sprouts allows for more variety in seed types compared to store-bought options.
Growing microgreens and sprouts at home can also save you money. Organic microgreens can be over $25 per pound, and sprouts about $5 for 3 ounces. To start, consider a hydroponic microgreens starter kit or a basic tray sprouting kit. These kits have everything you need for successful indoor growing.
“Microgreens can often contain about five times higher concentrations of vitamins and cancer-protective carotenoids as their mature counterparts.”
Looking to boost your meals with nutrition or save on fresh greens? Microgreens and sprouts are perfect for indoor seed starting. They grow quickly and are packed with nutrients, making them a great addition to any spring garden plan.
Warm Season Crops: Timing for Transplanting
As the weather gets warmer, it’s time to think about moving your warm-season crops outside. This includes plants like tomatoes, peppers, and eggplants. The best time to plant these is usually from mid-May to early July.
Getting the timing right for moving seedlings from indoors to outside is key. It’s important to start your seeds inside at the right time.
Ideal Sowing Dates for Tomatoes and Peppers
Seeds for tomatoes and peppers should be started indoors in late March for a late May move outside. This early start helps the plants grow strong roots and get ready for the outdoors. Typically, these seedlings are moved outside after four to five weeks of indoor growth.
Starting small plants works best, as they adjust faster than larger ones. By summer, you can move seedlings outside in just three weeks or less.
Getting the timing right for warm-season crops is crucial. If you wait too long, you might not get a harvest or could lose your plants. Starting seeds indoors and moving them outside at the best time gives your plants a boost. This way, you can enjoy a bigger, earlier harvest.
FAQ
What are the benefits of starting seeds indoors?
Starting seeds indoors has many advantages over direct sowing outdoors. It helps create strong seedlings ready for transplanting when the weather gets warmer. This leads to earlier and more bountiful harvests. Plus, it extends the growing season, letting you grow cool-weather crops that might not have enough time to mature outdoors.
How do I determine the optimal sowing dates for indoor seed starting?
To find the best sowing dates, look at your local last spring frost date. Most seed packets tell you how many weeks before the frost to start seeds indoors. Use this info to make a seed starting calendar to keep track of when to plant each crop.
Which crops benefit the most from an early indoor start?
Long-season vegetables with a lot of days to maturity gain the most from early indoor starts. This includes leeks, onions, celery, parsley, and many brassicas like broccoli and cabbage. Starting these seeds indoors gives them the extra time needed to reach full maturity before the season ends.
How do I start leek seeds indoors?
Leeks can be started indoors early in spring, about 8-10 weeks before the last frost. Sow leek seeds thinly in shallow flats or trays at 1/4 inch deep. Thin the seedlings to 1 inch apart once they grow in 7-14 days.
What’s the best way to start onion seeds indoors?
Onions also benefit from an early start indoors. Sweet and storage onion varieties take about 100 days to mature. Start them 8-10 weeks before the last spring frost. Sow onion seeds thinly in open flats or plug trays, about 1/4 inch deep, without covering too much soil. Keep them moist and warm for even germination.
Why is an early indoor start crucial for celeriac?
Celeriac, or celery root, needs an early start indoors to avoid bolting. These slow-growing vegetables should be sown 10-12 weeks before the last spring frost. An early start is key, as cold temperatures can cause bolting, making the plant go to seed instead of developing the desired root.
Why is starting celery seeds indoors so challenging?
Celery is harder to start from seed than celeriac. Gardeners often struggle with direct sowing celery outdoors due to its sensitivity to moisture and temperature changes. If the seeds aren’t kept consistently moist and warm, they won’t germinate.
Which cool-weather crops benefit from an indoor start?
Many cool-weather crops do well with an early spring start. These include leafy greens like kale, spinach, and arugula, as well as root vegetables like beets, carrots, and turnips. Some, like radishes and peas, can be sown directly outdoors, but others do better indoors.
Why is starting brassicas like broccoli and cauliflower indoors important?
Brassicas like broccoli, Brussels sprouts, and cauliflower need a long growing season to mature. They take 4-6 months from seed to harvest. Starting them indoors 4-6 weeks before the last spring frost gives them the time needed to become strong transplants ready for the garden.
What are the benefits of growing microgreens and sprouts indoors?
Indoor seed starting is great for growing quick, nutrient-rich crops like microgreens and sprouts. These tiny greens and germinated seeds can be harvested in 1-2 weeks. They offer a fast way to add fresh flavor and nutrition to your meals.