The complete visual guide to planting depths for every crop
Plant at the Right Depth for Success
Planting depth is critical for seed germination and seedling establishment. Seeds planted too shallow may dry out; seeds planted too deep may not germinate at all. This comprehensive guide shows exactly how deep to plant each crop for maximum success.
🥬 Vegetable Planting Depths
🍅 Tomatoes
Tomatoes can be planted very deep – the stem will develop roots along buried portions.
🌶️ Peppers
Don’t plant peppers deeper than they were in their containers.
🥒 Cucumbers
Direct sow after last frost. Germination is quick at warm temperatures.
🥬 Lettuce
Lettuce seeds need light to germinate. Don’t cover them completely.
🥦 Broccoli
Start seeds indoors 5-7 weeks before transplanting.
🌽 Corn
Direct sow after soil warms. Space rows 24-36 inches apart.
🌿 Herb Planting Depths
🌿 Basil
Basil loves warmth and light. Perfect for indoor starting.
🌿 Parsley
Soak seeds in warm water for 24 hours to speed germination.
🌿 Dill
Direct sow in spring. Prefers cool weather.
🌿 Cilantro
Succession plant every 2 weeks for continuous harvest.
🌿 Thyme
Tiny seeds need light. Press into soil but don’t cover.
🌿 Oregano
Small seeds. Barely cover with fine soil or vermiculite.
🫘 Legume Planting Depths
🫘 Bush Beans
Direct sow after all frost danger. Succession plant every 3 weeks.
🫘 Pole Beans
Plant around poles or trellis. Harvest throughout summer.
🫛 Peas
Cool-season crop. Plant as soon as soil can be worked.
🫘 Lentils
Direct sow in spring or fall. Drought tolerant once established.
🫘 Soybeans
Warm season crop. Plant in late spring. Harvest in fall.
🥕 Root Crop Planting Depths
🥕 Carrots
Tiny seeds need light. Keep soil moist until germination.
🥬 Beets
Each seed is actually a cluster – thin seedlings as they grow.
🌰 Radishes
Fast growers. Perfect for succession planting every 10 days.
🥔 Potatoes
Use seed potatoes. Hill soil as plants grow for better yields.
🧅 Onion Seeds
Start indoors 10-12 weeks before transplanting outside.
🥕 Parsnips
Very slow to germinate. Keep soil consistently moist.
🧅 Bulbs & Sets Planting Depths
🧅 Onion Sets
Tip should just barely show above soil. Too deep reduces bulb size.
🧄 Garlic Cloves
Plant in fall for spring/early summer harvest. Point end up.
🌷 Spring Bulbs
Tulips, daffodils, crocuses. Pointed end up, root end down.
🧅 Shallots
Plant with root end down, pointed end up and slightly exposed.
🌺 Dahlia Tubers
Plant horizontally with eye facing up. Water sparingly until sprouted.
📊 Complete Planting Depth Reference Table
| Plant Type | Seed/Bulb Depth | Spacing | Germination Time | Notes |
|---|---|---|---|---|
| Tomato Seeds | 1/4 inch | Start indoors | 5-10 days | Can bury deep when transplanting |
| Pepper Seeds | 1/4 inch | Start indoors | 7-14 days | Loves warmth, slow germination |
| Cucumber Seeds | 1 inch | 12 inches | 3-10 days | Direct sow after frost |
| Lettuce Seeds | 1/8 inch | 6-12 inches | 7-14 days | Needs light to germinate |
| Carrot Seeds | 1/4 inch | 2 inches | 7-21 days | Keep moist, slow germination |
| Bean Seeds | 1-1.5 inches | 4-6 inches | 7-10 days | Wait for warm soil (60°F+) |
| Pea Seeds | 1-1.5 inches | 2-3 inches | 7-14 days | Cool season, plant early |
| Corn Seeds | 1-1.5 inches | 12-18 inches | 7-10 days | Plant in blocks for pollination |
| Squash/Zucchini | 1 inch | 24-36 inches | 7-10 days | Direct sow after frost |
| Radish Seeds | 1/2 inch | 2 inches | 4-7 days | Fast growing, succession plant |
| Beet Seeds | 1/2 inch | 3 inches | 7-14 days | Seed clusters, thin seedlings |
| Spinach Seeds | 1/2 inch | 3-6 inches | 7-14 days | Cool season crop |
| Basil Seeds | 1/4 inch | 10-12 inches | 5-10 days | Needs warmth and light |
| Parsley Seeds | 1/4 inch | 8-10 inches | 14-28 days | Soak seeds before planting |
| Onion Sets | 1 inch | 4-6 inches | 7-10 days | Tip should show above soil |
| Garlic Cloves | 1-2 inches | 6-8 inches | N/A (Fall planting) | Plant in fall for summer harvest |
| Potato Pieces | 4 inches | 12 inches | 14-21 days | Hill as plants grow |
| Broccoli Seeds | 1/2 inch | 18 inches | 5-10 days | Start indoors 5-7 weeks early |
💡 Expert Planting Tips
📏 The 2-3x Rule
As a general guideline, plant seeds at a depth 2-3 times their diameter. A pea-sized seed? Plant it 2-3 peas deep. This ensures proper moisture while allowing seedlings to emerge easily.
💧 Moisture Matters
Seeds planted deeper require consistent soil moisture throughout the germination period. Shallow-planted seeds may dry out quickly—check daily and water gently to avoid washing them away.
🌡️ Temperature Check
Use a soil thermometer! Many gardeners plant too early. Warm-season crops like tomatoes, peppers, and beans need soil temperatures of 60-70°F minimum for good germination.
👆 The Finger Method
Your finger is a great measuring tool: First knuckle ≈ 1/2 inch, second knuckle ≈ 1 inch, full finger ≈ 3 inches. Use this for quick, consistent planting depth.
🏜️ Soil Type Adjustment
Clay soil: Plant slightly shallower (heavy soil resists emergence)
Sandy soil: Plant slightly deeper (retains less moisture)
☀️ Light-Sensitive Seeds
Some seeds like lettuce, celery, and dill need light to germinate. Press them into the soil surface but don’t cover completely. A light dusting is acceptable.
🌱 Firm the Soil
After planting, gently firm the soil over seeds with your hand. Good seed-to-soil contact can improve germination rates by 30-50%!
📅 Seasonal Adjustments
Early Spring: Plant slightly deeper to reach warmer soil
Late Summer: Plant slightly shallower as surface soil is warm
🔍 Troubleshooting Common Problems
Possible Causes:
- Seeds planted too deep (most common issue)
- Soil temperature too low for warm-season crops
- Old seeds with low viability
- Soil too dry or waterlogged
- Seeds washed away by overwatering
Solutions: Check planting depth, verify soil temperature, test seed viability, maintain consistent moisture, and use a gentle spray for watering.
Possible Causes:
- Seeds planted too deep – seedlings exhaust energy reaching surface
- Insufficient light after emergence
- Too much nitrogen fertilizer
- High temperature combined with low light
Solutions: When transplanting, bury stems deeper (tomatoes especially), provide more light, reduce nitrogen, improve air circulation.
Possible Causes:
- Inconsistent planting depth
- Uneven soil moisture
- Variable soil temperature across bed
- Mixed age or quality of seeds
Solutions: Use a dibber or planting tool for uniform depth, water evenly, level your soil bed, purchase fresh seeds from reputable sources.
🛠️ Helpful Tools for Accurate Planting
✋ Your Hand
Free and always available! Use finger joints for measurements, or make a fist to create shallow furrows for larger seeds.
📏 Marked Dibber
A pointed stick with depth marks. Perfect for transplants and making uniform holes. Make your own by marking a dowel with permanent marker.
🌱 Seed Tape
Pre-spaced seeds on biodegradable tape. Lay in shallow trench at correct depth. Great for tiny seeds like carrots and lettuce.
🔧 Hoe Handle
Use the hoe handle to create straight furrows at consistent depth. Drag it along string line for perfectly straight rows.
📐 Ruler or Tape Measure
Keep one in your garden toolkit. Double-check depths when planting new-to-you crops for best success.
🌾 Bulb Planter
Cylindrical tool that removes soil plugs. Many have depth markers. Excellent for bulbs, transplants, and large seeds.
🗓️ Seasonal Planting Depth Adjustments
🌱 Early Spring
Adjustment: Add 1/4 inch to standard depth
Soil is cool near the surface. Planting slightly deeper helps seeds reach warmer soil layers for better germination.
☀️ Late Spring/Summer
Adjustment: Use standard depth
Soil is warm throughout. Standard depths work perfectly. Focus on maintaining consistent moisture.
🍂 Late Summer/Fall
Adjustment: Reduce by 1/4 inch
Surface soil is still warm while deeper soil cools. Shallower planting promotes faster germination for fall crops.
❄️ Winter Sowing
Adjustment: Standard depth in containers
For winter sowing outdoors in milk jugs, use standard depths. Seeds will naturally germinate with spring thaw.
🌱 Ready to Start Planting?
Now that you know the correct planting depths, explore our other helpful resources to ensure gardening success!