Wisconsin’s April soil remains cold, so starting vegetables indoors gives them a head start before transplanting. Finding the Best Vegetables To Plant In April In Wisconsin means choosing crops that tolerate cool weather or can be started inside. April is a tricky month here, with frost risks lingering into May, but you can still get a productive garden going.
Many gardeners feel anxious to get outside and plant. But rushing can kill tender seedlings. Instead, focus on cold-hardy greens, root crops, and indoor starts. This guide walks you through exactly what to plant and when.
Best Vegetables To Plant In April In Wisconsin
April in Wisconsin demands patience. The soil temperature often sits below 50°F, which is too cold for warm-season crops like tomatoes or peppers. However, several vegetables thrive in these conditions. Below are the top picks for direct sowing or indoor starting.
Cold-Hardy Greens For Direct Sowing
These greens can handle light frosts and germinate in cool soil. Sow them directly into the garden bed once the soil is workable.
- Spinach: Plant seeds ½ inch deep. Spinach germinates best in soil temps between 35-70°F. It bolts quickly in heat, so April is perfect.
- Lettuce: Choose leaf or romaine varieties. Sow seeds shallowly, about ¼ inch deep. Thin seedlings to 6-8 inches apart.
- Kale: A Wisconsin favorite. Kale gets sweeter after a frost. Plant seeds ½ inch deep, spacing 12 inches apart.
- Arugula: Fast-growing and peppery. Sow every 2 weeks for a continuous harvest. Seeds germinate in 5-7 days.
- Swiss Chard: Tolerates cold well. Plant seeds 1 inch deep, thinning to 6 inches apart. Harvest outer leaves first.
Root Vegetables For April Soil
Root crops prefer cool soil and can be planted as soon as the ground thaws. They don’t transplant well, so direct sow them.
- Carrots: Sow seeds ¼ inch deep in loose, sandy soil. Keep soil moist until germination (10-14 days). Thin to 2 inches apart.
- Radishes: The fastest crop. Plant seeds ½ inch deep. Harvest in 25-30 days. Sow new seeds every 10 days.
- Beets: Soak seeds overnight before planting. Sow 1 inch deep, 2 inches apart. Both roots and greens are edible.
- Turnips: Plant seeds ½ inch deep. Thin to 4 inches apart. Harvest when roots are 2-3 inches wide.
- Onions: Plant sets (small bulbs) 1 inch deep, 4 inches apart. They tolerate frost well.
Indoor Starts For Warm-Season Crops
Start these indoors in April so they’re ready to transplant after the last frost (mid-May to early June). Use seed-starting mix and grow lights.
- Tomatoes: Sow seeds ¼ inch deep. Keep soil at 70-80°F. Transplant after 6-8 weeks.
- Peppers: Slow to germinate. Sow ¼ inch deep, keep warm (80°F). Start 8-10 weeks before transplanting.
- Broccoli: Start indoors 6 weeks before transplanting. Harden off before moving outside.
- Cabbage: Sow ¼ inch deep. Transplant after 4-6 weeks. Cabbage tolerates light frost.
- Eggplant: Needs warmth. Sow ¼ inch deep, keep at 80°F. Start 8-10 weeks ahead.
Peas And Beans For April
Peas love cool weather. Plant them directly in the garden as soon as the soil can be worked. Beans wait until soil is warmer.
- Snow Peas: Plant seeds 1 inch deep, 2 inches apart. Provide a trellis. Harvest when pods are flat.
- Snap Peas: Same planting depth. Harvest when pods are plump. They’re sweet and crunchy.
- Shelling Peas: Plant 1 inch deep. Harvest when pods are full but before they dry out.
- Fava Beans: Tolerate cold better than other beans. Plant 2 inches deep, 6 inches apart.
Preparing Your Wisconsin Garden In April
Before planting, check your soil. It should be dry enough to crumble in your hand, not muddy. Working wet soil damages its structure.
Test Soil Temperature
Use a soil thermometer. Insert it 4 inches deep. For most cool-season crops, 40-50°F is fine. For peas, 45°F is ideal. For spinach, 50°F works.
Amend The Soil
Add compost or aged manure. Wisconsin soil often needs organic matter. Spread 2-3 inches over the bed and till it in. Also test pH; aim for 6.0-7.0.
Use Row Covers Or Cold Frames
April nights can drop below freezing. Protect young plants with floating row covers or cloches. This extends your season and warms the soil.
Step-By-Step: Starting Seeds Indoors
Follow these steps for successful indoor starts. Use clean containers with drainage holes.
- Fill pots with seed-starting mix. Moisten it before planting.
- Sow seeds at the depth listed on the packet. Cover lightly.
- Place pots in a warm spot (70-75°F) until germination.
- Move seedlings under grow lights or a sunny window. Keep lights 2-3 inches above plants.
- Water from below to prevent damping off disease.
- Harden off seedlings 7-10 days before transplanting. Set them outside for a few hours daily, increasing time.
Common Mistakes To Avoid
Even experienced gardeners make errors in April. Here are pitfalls to skip.
- Planting too early: Wait until soil is workable. Soggy soil rots seeds.
- Overwatering: Cold soil holds moisture longer. Water only when top inch is dry.
- Skipping frost protection: Keep row covers handy. A late frost can kill tender plants.
- Planting warm-season crops outside: Tomatoes and peppers need warm soil. Wait until May.
- Not thinning seedlings: Crowded plants compete for nutrients. Thin as recommended.
Best Varieties For Wisconsin
Some vegetable varieties perform better in Wisconsin’s short growing season. Choose these for reliability.
Tomato Varieties
- ‘Early Girl’: Matures in 50-60 days. Good for short summers.
- ‘Wisconsin 55’: Developed for the state. Disease-resistant.
- ‘Sun Gold’: Cherry tomato, very productive.
Pepper Varieties
- ‘California Wonder’: Classic bell pepper. Needs warm soil.
- ‘Jalapeño’: Tolerates cooler nights. Harvest green or red.
- ‘Banana Pepper’: Mild and fast-growing.
Carrot Varieties
- ‘Nantes’: Sweet and crisp. Good for heavy soil.
- ‘Danvers’: Tapered root. Stores well.
- ‘Little Finger’: Small, perfect for containers.
When To Transplant In Wisconsin
Wisconsin’s last frost date varies. Southern zones (Milwaukee) average May 10-15. Northern zones (Hayward) average May 25-June 5. Check your local extension office.
Transplant hardened-off seedlings after the frost date. Use a frost blanket if cold weather threatens. Water transplants well to reduce shock.
Succession Planting For Continuous Harvest
Don’t plant everything at once. Stagger sowings every 2-3 weeks. This gives you a steady supply instead of a glut.
- Lettuce: Sow new rows every 14 days.
- Radishes: Plant every 10 days until June.
- Beans: Sow every 3 weeks from late May to July.
- Spinach: Plant again in late August for fall harvest.
Dealing With Wisconsin Pests
April pests include cutworms, slugs, and flea beetles. Use these methods to protect your plants.
- Cutworms: Place cardboard collars around stems at transplanting.
- Slugs: Set out beer traps or use diatomaceous earth.
- Flea beetles: Use row covers on young plants. They love warm weather.
- Aphids: Spray with water or insecticidal soap.
Watering Wisely In April
April rain is common in Wisconsin. Check soil moisture before watering. Overwatering leads to root rot.
Water deeply once a week if no rain. Morning watering is best. It allows leaves to dry, preventing disease.
Using Raised Beds For Better Drainage
Raised beds warm up faster in spring. They also drain better than ground soil. Build beds 6-12 inches high. Fill with a mix of topsoil, compost, and perlite.
Raised beds are ideal for carrots, radishes, and lettuce. They also make pest control easier.
Container Gardening Options
If you lack garden space, use containers. Choose pots at least 12 inches deep. Use quality potting mix, not garden soil.
- Tomatoes: Use 5-gallon buckets. Provide stakes or cages.
- Peppers: 3-gallon pots work well.
- Lettuce: Shallow containers (6 inches) are fine.
- Radishes: Window boxes work great.
Fertilizing Your April Garden
Cool-season crops need less nitrogen. Use a balanced fertilizer (10-10-10) at planting time. Side-dress with compost mid-season.
For indoor starts, use a diluted liquid fertilizer once seedlings have true leaves. Avoid over-fertilizing, which causes leggy growth.
Harvesting Tips For April Plantings
Harvest greens when leaves are young and tender. Pick outer leaves first. This encourages more growth.
Radishes are ready when roots are 1 inch wide. Carrots take longer; wait until they are ½ inch thick at the top. Peas are sweetest in the morning.
Extending The Season
Use cold frames or low tunnels to push your season. These structures trap heat and protect from frost. You can plant 2-3 weeks earlier with them.
Another option is using black plastic mulch. It warms soil by 5-10°F. Cut holes for plants. This works well for tomatoes and peppers.
Frequently Asked Questions
What vegetables can I plant in April in Wisconsin?
You can plant cold-hardy greens like spinach, lettuce, kale, and arugula. Root vegetables like carrots, radishes, beets, and turnips also work. Start tomatoes, peppers, and broccoli indoors.
Can I plant tomatoes in April in Wisconsin?
No, not outdoors. The soil is too cold. Start tomato seeds indoors in April. Transplant them outside after the last frost, usually mid-May to early June.
When should I plant peas in Wisconsin?
Plant peas as soon as the soil is workable, often in early to mid-April. They prefer cool weather and will stop producing when it gets hot.
Is it too early to plant potatoes in April?
No, potatoes can be planted in April once the soil temperature reaches 45°F. Plant seed pieces 4 inches deep, 12 inches apart.
What herbs can I plant in April in Wisconsin?
Plant cold-tolerant herbs like parsley, chives, and cilantro outdoors. Start basil, dill, and oregano indoors for transplanting later.
Final Checklist For April Planting
Use this list to stay organized. Check off tasks as you complete them.
- Test soil temperature.
- Amend soil with compost.
- Direct sow cold-hardy greens and roots.
- Start warm-season crops indoors.
- Set up row covers or cold frames.
- Water only when needed.
- Thin seedlings after germination.
- Harden off indoor starts before transplanting.
April in Wisconsin is a month of preparation and early action. By focusing on the right vegetables, you set yourself up for a productive garden. The soil may be cold, but with smart choices, you can enjoy fresh greens by May. Stick to these recommendations, and your garden will thrive despite the unpredictable spring weather.