What to Plant in Your Raised Bed Garden in May: Central Indiana Edition
May is an exciting time for gardeners in Central Indiana! With temperatures warming and the last frost usually behind us by mid-month, your raised bed garden is ready for a mix of cool-season crops to finish strong and warm-season favorites to kick off the summer. Raised beds warm up faster than in-ground gardens, giving you a head start. Here’s a guide to what you can plant in May in Central Indiana (Zone 6a) to maximize your harvest.
Why May is Perfect for Planting
Central Indiana’s May weather typically sees daytime highs of 70-75°F and lows around 50-55°F, with soil temperatures climbing into the 60s. Raised beds, with their excellent drainage and quicker warming, are ideal for starting seeds or transplants now. The key is timing: early May is great for cool-season crops, while late May is perfect for warm-season plants that love heat.
Cool-Season Crops to Plant in Early May
These crops thrive in the cooler temps of early spring and can still be planted in early May for a late spring/early summer harvest.
Lettuce: Sow seeds for leaf lettuce or romaine directly in the bed. Choose bolt-resistant varieties like ‘Buttercrunch’ for longer harvests. Space seeds 6-8 inches apart, and keep soil moist. Harvest baby greens in 3-4 weeks.
Spinach: Plant fast-growing varieties like ‘Bloomsdale’ for a quick crop before the heat sets in. Sow seeds 1 inch apart, thin to 4 inches, and enjoy tender leaves in about 4-6 weeks.
Radishes: These quick growers (ready in 3-4 weeks) are perfect for filling gaps. Try ‘Cherry Belle’ or ‘French Breakfast’ for vibrant flavor. Sow seeds 1 inch apart, ½ inch deep.
Kale: Start kale seeds or transplants for a nutrient-packed crop. ‘Lacinato’ (dinosaur kale) is a great choice. Space plants 12 inches apart for full growth.
Peas: If you missed April planting, early May is your last chance for sugar snap or snow peas. Choose a trellis-friendly variety like ‘Sugar Ann’ and sow seeds 1 inch deep, 2 inches apart.
Warm-Season Crops to Plant in Late May
By late May, soil temperatures are warm enough (above 60°F) for heat-loving crops. Wait until after May 15 to be safe, especially for tender plants like tomatoes and peppers.
Tomatoes: Set out transplants of determinate (bush support with cages) or indeterminate (vining support with trellis) varieties like ‘Early Girl’ or ‘Roma’. Pro tip - bury stems deep with only a few leaves above ground for strong roots. Strong roots = more fruit.
Peppers: Both sweet and hot peppers thrive in raised beds. Try ‘Bell Boy’ for sweet or ‘Jalapeño’ for heat. Space 12-18 inches apart and ensure full sun.
Cucumbers: Sow seeds or transplants of ‘Marketmore’ or bush varieties like ‘Spacemaster’ for small spaces. Provide a trellis for vining types and space 12 inches apart.
Zucchini/Summer Squash: Plant seeds of bush like compact varieties like ‘Black Beauty’ zucchini. Sow 2-3 seeds per hill, 24 inches apart, and thin to the strongest plant. Alternatively, you can go vertical with a trellising variety like the Italian Heirloom ‘Tromboncino’ to safe space in your raised bed.
Beans: Bush beans like ‘Provider’ or pole beans like ‘Kentucky Wonder’ are easy to grow. Sow seeds 1 inch deep, 4 inches apart (bush) or 6 inches apart (pole with trellis).
Basil: Start basil seeds or transplants alongside tomatoes for a classic combo. Space 8-12 inches apart and pinch back to encourage bushy growth.
Herbs and Companion Plants
May is also a great time to add herbs and companion plants to your raised bed for flavor and pest control:
Dill and Cilantro: Sow seeds directly for fresh herbs by early summer. These attract beneficial insects like ladybugs.
Marigolds: Plant these around the edges to deter pests like nematodes. ‘French Marigold’ varieties work well.
Nasturtiums: Sow seeds for edible flowers that repel aphids and add color. Space 8 inches apart. Along the edge of the bed these will provide a beautiful trailing bloomer that spills over the sides of your bed.
Tips for Success in Your Raised Bed
Soil Prep: Ensure your raised bed has well-draining, nutrient-rich soil. Mix in compost or aged manure before planting to boost fertility.
Watering: Keep soil consistently moist but not waterlogged. Raised beds dry out faster, so check daily during warm spells.
Succession Planting: For crops like lettuce and radishes, sow seeds every 1-2 weeks for a continuous harvest.
Pest Patrol: Watch for slugs and caterpillars. Hand-pick or use organic controls like diatomaceous earth.
Timing: Use a soil thermometer to confirm warm-season crops have soil temps above 60°F, especially for beans and squash.
What to Avoid Planting in May
Frost-Sensitive Crops Early in May: Avoid planting tomatoes, peppers, or basil too early if a late frost is forecast. Check local weather updates. These can go in after Mothers Day and up to the first week of June.
Long-Season Crops: Crops like Brussels sprouts or winter squash may not mature in time if started now. Save these for fall or start indoors earlier.
Final Thoughts
May is a busy but rewarding month for Central Indiana gardeners. By planting a mix of cool- and warm-season crops, you can enjoy fresh harvests from June through fall. In the fall we will mix in the cool season plants and extend the garden well into Nov/Dec. For now, take advantage of your raised bed’s fast-warming soil, and don’t forget to succession plant for a steady supply of greens. Happy gardening!
