Spring is the perfect time to get your vegetable garden started. As March begins, many cool-season vegetables can be planted to take advantage of milder temperatures before the summer heat arrives. Planning your vegetable garden now allows you to enjoy fresh produce throughout the growing season.
The best spring vegetables to plant in early March include beets, broccoli, cabbage, carrots, lettuce, onions, peas, radishes, and spinach. These hardy plants can withstand light frosts and will provide harvests before the intense summer heat arrives. Some may even be ready to eat within a few weeks of planting.
By staggering plantings and choosing the right varieties for your area, you can maximize your garden’s productivity. We’ll show you exactly when to plant each vegetable based on your location and how to give your plants the best start possible.
Understanding Your Growing Zone and Season
Knowing your growing zone and season is essential for successful vegetable gardening. These factors determine what plants will thrive in your area and when to put them in the ground for optimal results.
Determining Your Hardiness Zone
The USDA Hardiness Zone map divides North America into 13 zones based on average annual minimum winter temperatures. Most of the United States falls within zones 3-9, with each zone representing a 10-degree Fahrenheit difference. To find your zone, you can use the interactive tool provided by the United States Department of Agriculture.
Your specific location within a zone matters, too, as factors like urban heat islands, elevation, and proximity to bodies of water can create micro-climate variations.
Assessing Plant Hardiness and Planting Schedules
Once you know your hardiness zone, you can determine your growing season—the period between the last spring frost and the first fall frost. This time frame varies significantly by region.
Your growing season dictates when to plant different vegetables:
- Cold-hardy plants: Spinach, kale, peas (plant 4-6 weeks before the last frost)
- Warm-season crops: Tomatoes, peppers, cucumbers (after the danger of frost has passed)
- Fall crops: Broccoli, carrots, lettuce (8-10 weeks before first fall frost)
Create a customized planting schedule based on your zone and local frost dates. This approach ensures you maximize your growing season and harvest potential.
Preparation for Planting
Proper soil preparation, vegetable selection, and seed-starting techniques will set your garden up for success this spring.
Soil Preparation and Fertilization
Begin soil preparation as soon as the ground can be worked in early spring. For better drainage and quicker soil warming, consider creating raised beds or ridges, as these elevated areas warm faster and allow for earlier planting.
Clear all weeds and debris from planting areas, although some winter weeds can help maintain soil health, remove them before planting. Once cleared, test your soil pH and nutrient levels with an inexpensive kit from a garden center. Most vegetables prefer slightly acidic soil with a pH between 6.0 and 7.0.
Add organic matter like compost, aged manure, or leaf mold to your garden beds. This improves soil structure, drainage, and nutrient content. Work it into the top 6-8 inches of soil. Also, apply a balanced fertilizer according to package directions. For organic gardens, use fish emulsion, bone meal, or other natural amendments.
Choosing the Right Vegetables for Your Garden
Select vegetables that match your growing zone and climate, checking seed packets for specific information about growing requirements. Early spring crops include peas, spinach, lettuce, and radishes. These can be planted as soon as soil can be worked in March. Follow these with slightly less cold-tolerant vegetables like beets, carrots, dill, and cilantro a couple of weeks later.
Tall plants should be positioned where they won’t shade shorter ones, and group plants with similar water and light needs together. Consider succession planting to extend harvests. For example, instead of planting all lettuce seeds at once, plant small batches every 2-3 weeks.
Seed Starting and Transplanting Tips
- Start seeds indoors 4-6 weeks before your last expected frost date as this gives plants a head start and extends your growing season.
- Use sanitized containers with good drainage. Seed-starting trays, peat pots, or even recycled containers with drainage holes work well.
- Always fill containers with sterile seed-starting mix, not garden soil which may contain diseases or weed seeds.
- Plant seeds at a depth 2-3 times their diameter. Very fine seeds should barely be covered.
- Keep soil consistently moist but not soggy.
- Cover seed trays with plastic wrap or a humidity dome until germination occurs.
- Provide 14-16 hours of light daily once seeds sprout. A sunny window may not provide enough light, so consider inexpensive grow lights.
- Harden off seedlings by gradually exposing them to outdoor conditions for 7-10 days before planting in the garden.
Planting Techniques and Strategies
Successful spring vegetable gardening relies on proper planting methods. The right techniques help your vegetables grow strong and produce abundantly while minimizing problems along the way.
Optimal Spacing for Vegetable Growth
Vegetables need adequate space to grow properly, as crowded plants compete for nutrients, water, and sunlight, leading to smaller harvests and increased disease risk.
For root vegetables like carrots and radishes, space rows 12-18 inches apart with 2-4 inches between plants. Leafy greens like spinach and lettuce need 12-18 inches between rows and 6-8 inches between plants. Larger plants require more room. Tomatoes need 24-36 inches between plants, while cucumbers and squash need 36-48 inches of space in all directions.
Spacing Quick Guide:
- Small plants: (radishes, carrots): 2-4″ between plants
- Medium plants: (lettuce, spinach): 6-8″ between plants
- Large plants: (tomatoes, peppers): 24-36″ between plants
Companion Planting and Crop Rotation
Companion planting pairs compatible vegetables together to boost growth and deter pests. Some vegetables grow better next to certain plants while others shouldn’t be neighbors. Tomatoes benefit from basil, which improves flavor and repels flies and mosquitoes. Also, plant onions near carrots to deter carrot flies, and avoid planting potatoes near tomatoes as they can spread diseases to each other.
Crop rotation prevents soil depletion and reduces pest problems, so divide your garden into four sections and rotate plant families each season. Keep a garden journal with planting locations to help track your rotation schedule.
- Zone 1: Leafy greens (lettuce, spinach)
- Zone 2: Root vegetables (carrots, beets)
- Zone 3: Fruiting plants (tomatoes, peppers)
- Zone 4: Legumes (peas, beans)
Watering and Care for Vegetable Plants
Proper watering is crucial for vegetable growth, and most spring vegetables need about 1-1.5 inches of water weekly, either from rainfall or irrigation. Water deeply and less frequently rather than lightly every day. This encourages deeper root growth and stronger plants. Early morning is the best time to water, reducing evaporation and keeping leaves dry to prevent disease.
Use these watering techniques:
- Direct water to the soil, not the leaves
- Apply mulch (2-3 inches) to retain moisture
- Check soil moisture by sticking your finger an inch into the soil
For newly planted seeds, keep the soil consistently moist until germination, while established plants need less frequent watering but require more water per session. Different vegetables have different needs. Leafy greens need more consistent moisture, while established root vegetables can tolerate slightly drier conditions between watering.
Specific Planting Guides
Different vegetable families have unique planting requirements based on temperature needs, growing periods, and frost sensitivity. Knowing when to plant each type will help you maximize your garden’s productivity throughout the growing season.
Nightshades: Tomatoes, Peppers, and Eggplants
Nightshade vegetables are warm-season crops that thrive in hot weather and need to be planted after all danger of frost has passed. Water nightshades deeply but infrequently, and add mulch to maintain consistent soil moisture.
Tomatoes should be planted when soil temperatures reach at least 60°F, typically 1-2 weeks after your last spring frost date. Most gardeners start tomatoes indoors 6-8 weeks before transplanting outside. Space plants 24-36 inches apart to allow for proper air circulation.
Peppers are even more heat-loving than tomatoes. Plant them when nighttime temperatures consistently stay above 55°F. They grow more slowly than tomatoes, so start seeds indoors 8-10 weeks before your transplant date.
Eggplants are the most heat-sensitive of the nightshades. They need warm soil (at least 65°F) and won’t tolerate any cold snaps. Plant them 2-3 weeks after tomatoes, spacing them 18-24 inches apart in full sun.
Cruciferous Vegetables: Broccoli, Cabbage, and Kale
Cruciferous vegetables prefer cool temperatures and can handle light frosts, making them perfect for early spring planting. All cruciferous vegetables benefit from rich, well-draining soil with plenty of organic matter. They’re also heavy feeders, so consider adding compost before planting.
Broccoli grows best when daytime temperatures are 65-75°F. Start seeds indoors 4-6 weeks before the last frost, then transplant seedlings outside 2-3 weeks before the last frost date. Space plants 18 inches apart.
Cabbage is quite cold-hardy and can be planted as soon as the soil can be worked in spring. For spring crops, start seeds indoors 6-8 weeks before your last frost date, then transplant 2-4 weeks before the last frost.
Kale is exceptionally cold-tolerant and can be planted very early. Direct sow seeds 3-5 weeks before the last frost, or transplant seedlings as soon as the ground can be worked. Kale tastes sweeter after light frost exposure.
Root Vegetables: Carrots, Onions, and Radishes
Root vegetables grow best when directly sown into garden beds since they don’t re-plant well. Water root vegetables consistently but lightly, as too much water can cause splitting, while inconsistent moisture leads to woody, bitter vegetables.
Carrots should be planted 2-3 weeks before your last frost date. They need loose, stone-free soil to develop straight roots. Sow seeds ¼ inch deep and thin seedlings to 3 inches apart once they reach 2 inches tall.
Onions can be planted very early in spring, as soon as the ground can be worked. While you can grow them from seeds, most gardeners use onion sets (small bulbs) or transplants for faster results. Plant them 1 inch deep with 4-6 inches between plants.
Radishes are one of the fastest-growing vegetables, maturing in just 3-4 weeks. They can be planted as soon as the soil can be worked. Sow seeds ½ inch deep and 1 inch apart, then thin to 2 inches.
Leafy Greens: Lettuce, Spinach, and Swiss Chard
Leafy greens are perfect for early spring planting as most prefer cool weather and grow quickly. For a continuous harvest of greens, plant small batches every 2-3 weeks until temperatures warm up. Consider planting in partial shade to extend the growing season as temperatures rise.
Lettuce grows best when daytime temperatures are 60-70°F. It can be sown 2-3 weeks before the last frost date. Plant seeds just ¼ inch deep and thin leaf lettuce to 4 inches apart or head lettuce to 8 inches apart.
Spinach is extremely cold-hardy and can be planted as soon as the soil can be worked in spring. It germinates best in soil between 45-70°F and will bolt (go to seed) when temperatures rise above 75°F consistently.
Swiss Chard is more heat-tolerant than other greens, bridging the gap between cool and warm seasons. Plant seeds 2 weeks before the last frost date, ½ inch deep and 2 inches apart, then thin to 6 inches apart.
Get in touch to discuss the best options for your garden or outdoor landscape to ensure it’s healthy and low maintenance.
