Spring Planting Checklist by Zone: What to Plant in March, April, and May

In Zones 5-6, begin soil preparation in early to mid-March when soil can be worked without forming clumps when squeezed. Test soil temperature with a thermometer - wait until it reaches at least 40°F at 2-inch depth before working. Remove any remaining winter debris, then work in 2-4 inches of compost or well-aged manure to improve soil structure and drainage. Allow prepared beds to settle for 7-10 days before direct sowing cool-season crops like peas, spinach, and radishes.

In Zones 9-10, plant heat-tolerant vegetables like okra, Armenian cucumber, yard-long beans, and heat-resistant tomato varieties in March to establish strong root systems before intense summer heat arrives. Cool-season crops such as lettuce, spinach, and peas should also go in the ground by mid-March since they'll bolt once temperatures consistently reach the 80s. Southern peas, Swiss chard, and eggplant are excellent choices that actually thrive in the upcoming heat. Start seeds indoors now or direct sow immediately to give plants 6-8 weeks of moderate weather for optimal establishment.

Your USDA hardiness zone is based on average annual minimum winter temperatures in your area and determines which plants will survive your winters. You can find your exact zone by entering your zip code on the USDA Plant Hardiness Zone Map at planthardiness.ars.usda.gov. For your specific last frost date, check with your local county extension office or use the National Weather Service's frost/freeze data, as microclimates can vary significantly even within the same zone. Use your last frost date as a baseline, but remember that container-grown plants from Nature Hills can be planted any time the ground isn't frozen.

Cool-season crops can be planted 2-4 weeks before your last expected frost date, which varies significantly by zone. In zones 6-7, you can typically start planting peas, spinach, lettuce, and radishes in mid to late March, while zones 4-5 should wait until mid to late April when soil temperatures reach at least 40°F. These hardy vegetables actually prefer cooler weather and can tolerate light frosts. Check your local frost dates and soil temperature before planting, then sow seeds directly in well-prepared garden beds.

Yes, wait for workable soil conditions even if it pushes planting past the 6-week window. In Zones 3-4, planting in waterlogged or frozen ground damages root systems and prevents proper establishment. Container-grown plants from Nature Hills can be planted any time the ground isn't frozen, so you won't miss your planting window. Focus on soil preparation in March and begin planting hardy stock like arborvitae and fruit trees in late April when soil drains properly.

Wait until soil temperatures reach 60°F and nighttime temperatures stay consistently above 50°F before transplanting warm-season nightshades like tomatoes, peppers, and eggplant. In zones 6-7, this typically occurs in mid to late May, while zones 8-9 can often transplant by early May. These heat-loving vegetables are extremely frost-sensitive and will suffer damage or die if exposed to temperatures below 40°F. Check your local last frost date and wait 1-2 weeks beyond that date before transplanting to ensure soil warmth and stable weather conditions.

In Zones 3-6, start tomato and pepper seeds indoors 6-8 weeks before your last frost date, which typically means mid to late March for most areas. Brassicas like broccoli and cabbage need only 4-6 weeks, so start them in early April. Use a seed starting mix, maintain soil temperature at 65-75°F, and provide 12-14 hours of light daily once seedlings emerge. Check your specific last frost date and count backward to determine your exact starting dates.

The article focuses on trees and shrubs rather than vegetable planting schedules. For direct sowing vegetables like beans, corn, carrots, beets, and potatoes, timing depends on your last frost date and soil temperature reaching 50-60°F for most crops. Zone 4-5 gardeners typically wait until mid-to-late May, while zones 6-7 can often start in mid-April after soil warms. Check your local frost dates and use a soil thermometer to confirm ground temperature before planting these warm-season crops.

Wait until after your last frost date to plant warm-season annuals like marigolds, zinnias, sunflowers, and nasturtiums. In zones 4-5, this means late May to early June, while zones 6-7 can typically plant in mid to late May. Sunflowers and zinnias direct sow easily once soil warms to 65°F, while marigolds and nasturtiums can be transplanted from containers for earlier blooms. Check your local frost dates and have row cover ready if an unexpected cold snap threatens tender seedlings.

In Zones 7-8, you're likely past the ideal window for most cool-season crops like lettuce and peas, which prefer soil temperatures below 70°F. However, you can still plant heat-tolerant varieties of spinach, arugula, and Asian greens in partially shaded spots through early April. Focus your energy now on warm-season plantings like tomatoes, peppers, and summer flowering shrubs since your frost-free date has likely passed. Get these heat-lovers in the ground by mid-April to maximize their growing season before summer's peak heat arrives.