To sow seeds in a square-foot bed, prep Mel’s Mix, mark a 12×12 grid, plant at packet depth, and space by the SFG chart.
Square-foot gardening keeps planting tidy, fast, and productive. You work with a 12×12-inch grid. Each box holds a set number of seeds or transplants. Follow the seed packet for depth, match spacing to the grid, and refill each square with compost after harvest. The result is dense growth and quick cleanup.
Plant Seeds In A 1-Foot Grid: Step-By-Step
Build Or Prep The Bed
Use a raised frame at least 6–8 inches deep. Fill with the classic SFG blend called Mel’s Mix: one third fluffed peat or coco coir, one third coarse vermiculite, and one third mixed composts. Water the bed so the mix is evenly moist. Lay a firm grid on top: wood lath, PVC, or taut string in 12-inch squares.
Plan Each Square
Every crop has a plant count per square. Leafy greens go 4, 9, or 16 per square. Big fruiting plants use a whole square and often need a trellis on the north side. Root crops fit by the seed count. Stagger sowing dates to keep harvests steady.
Follow Depth And Spacing
Most seeds go about two to three times their width deep. Small seed often needs just a dusting of mix over the top; larger seed gets a finger-length hole. Keep depth even so germination stays uniform. After sowing, mist well to settle the mix around each seed.
Water, Label, And Cover
After you plant, label each square with the crop and date. Water with a gentle rose or a fine wand. A lightweight cover holds in moisture and deters birds.
Quick Spacing And Depth Guide (Common Crops)
The chart below shows typical counts per square and starting depths that match packet guidance for many home gardens. Adjust to your variety and local conditions.
| Crop | Per Square | Typical Depth |
|---|---|---|
| Carrot | 16 | 1/4 in (6 mm) |
| Radish | 16 | 1/2 in (12 mm) |
| Beet | 9 | 1/2 in (12 mm) |
| Turnip | 9 | 1/2 in (12 mm) |
| Lettuce (leaf) | 16 | 1/8 in (3 mm) |
| Spinach | 9 | 1/2 in (12 mm) |
| Kale | 1 | 1/2 in (12 mm) |
| Swiss Chard | 4 | 1/2 in (12 mm) |
| Bush Bean | 9 | 1 in (25 mm) |
| Pea | 8 | 1 in (25 mm) |
| Cucumber (trellis) | 2 | 1 in (25 mm) |
| Tomato (indeterminate) | 1 | Transplant |
| Pepper | 1 | Transplant |
| Zucchini | 1 | 1 in (25 mm) |
| Onion (from seed) | 16 | 1/4 in (6 mm) |
Soil, Light, And Grid Setup Tips
Mix That Holds Water And Air
Mel’s Mix gives seeds firm contact with moisture and still drains well. Blend with several compost types for balanced nutrition. If you use coco coir, rinse and buffer if needed. Replenish each square with a trowel of compost after every harvest.
Sun And Trellis Placement
Put tall crops like peas, pole beans, or indeterminate tomatoes on the north edge so they don’t shade shorter plants. Install a trellis before you sow. As vines climb, tie loosely and prune to keep the square accessible.
Grid That Stays Put
Make the grid permanent so placement is obvious each season. A rigid grid keeps spacing true and speeds sowing. If you favor string, retension it at the start of spring and mid-season.
Timing: When Each Seed Goes In
Warm-season crops like tomato, pepper, cucumber, and squash wait until nights are mild and frost risk is past. Cool-season crops like peas, lettuce, and radish can go in sooner. Use your local last frost date as the anchor and count back or forward per packet guidance. Start heat lovers indoors and move them out after a short hardening period.
Find Your Local Frost Dates
Use a frost-date tool for your location, such as the frost dates calculator. Then build a small calendar for each crop so you’re sowing into the right soil temperature and light.
Succession For Non-Stop Harvests
Split a square into halves or quarters and stagger sowing every one to two weeks. After you pull one crop, add compost and replant that day. Mix early, mid, and late varieties to stretch the window.
Step-By-Step: Sowing A Single Square
1) Pre-Water And Mark Holes
Water the square until the top few inches are evenly moist. Press a dibbler, pencil, or your finger to make uniform holes at the correct spacing pattern for that crop. Keep each hole the same depth.
2) Place Seeds
Drop one seed per hole for large seed types. For small seed, pinch a few and thin after emergence. If your packet lists low germination, double-sow and snip extras later.
3) Cover And Firm
Backfill holes with loose mix. Press lightly to ensure seed-to-soil contact. Finish with a gentle mist; avoid puddles.
4) Protect And Check Daily
Lay down row fabric or a clear humidity dome to hold moisture. Peek daily for sprouting and moisture level. Vent if condensation beads persist through midday.
Watering, Thinning, And Early Care
Keep Moisture Steady
Seeds need steady moisture until roots reach deeper layers. Test with a finger: if the top half-inch feels dry, water. Early morning is best. A simple drip line along each grid line saves time and prevents splash.
Thin With Scissors
When seedlings show true leaves, thin to the target count.
Feed Lightly
With rich compost in the mix, seedlings seldom need heavy feeding. If leaves pale, drench with a mild compost tea or fish-and-seaweed blend. Keep salts low and rinse the foliage after feeding.
Troubleshooting Germination
Slow Or Patchy Sprouts
Check depth first. Over-deep sowing delays or stops emergence. A common rule is to plant seeds about 2–3× their width. Next, check temperature. Cool soil slows beans and squash; warm soil slows lettuce. Use a soil thermometer, and re-sow shallowly if needed.
Crusty Surface
If a hard cap forms after rain, sprinkle a thin layer of fine compost or vermiculite over the square. That keeps the surface from sealing and helps seedlings break through.
Pests At Emergence
Slugs, birds, and flea beetles love tender greens. Use row fabric from day one of growth. Beer traps and hand picking work on slugs. Keep mulch off tiny seedlings until stems toughen.
Crop-By-Crop Notes For The Grid
These quick notes help you plant and manage a few favorites in tight spacing.
Leafy Greens
Sow shallowly. For cut-and-come-again harvests, seed 16 per square. Harvest outer leaves often to keep air moving.
Root Crops
Carrots, beets, and turnips like friable mix with no clods. Water the day before you sow. Thin early and keep moisture steady to prevent forks and cracks.
Beans And Peas
Sow beans once soil warms. Trellis peas at the north edge. In small beds, lean toward bush beans and snap peas to make care simple.
Tomatoes, Peppers, And Squash
Start indoors, harden, then transplant one per square spot. Use a cage or trellis. Prune lightly so light reaches neighbors. Mulch after the soil has warmed.
Season Extensions For More Squares Per Year
A simple cover can add weeks to each shoulder season. Cold frames, domes, or a low tunnel raise night temps and block wind. Start cool greens earlier and run fall carrots late. Add shade cloth during heat spikes so lettuce and spinach keep growing.
Second Table: Mini Planting Calendar By Frost Date
Use the ranges below as a quick planner for common beds. Confirm dates with your packet and local frost data.
| Crop | Direct Sow Or Transplant | Timing Vs. Last Frost |
|---|---|---|
| Pea | Direct sow | 4–6 weeks before |
| Lettuce | Direct sow or transplant | 2–4 weeks before |
| Carrot | Direct sow | 2–4 weeks before |
| Beet | Direct sow | 2–3 weeks before |
| Bush Bean | Direct sow | 1–2 weeks after |
| Cucumber | Direct sow or transplant | 1–2 weeks after |
| Tomato | Transplant | 2–3 weeks after |
| Pepper | Transplant | 2–3 weeks after |
| Zucchini | Direct sow | 1–2 weeks after |
| Spinach (fall) | Direct sow | 6–8 weeks before first frost |
Pro Tips That Save Time
Make A Sowing Board
Drill holes in a thin board to match patterns: 16-hole for carrots, 9-hole for beets, 4-hole for chard. Press, sow, and cover in seconds.
Label Once, Reuse Often
Print weatherproof labels for common crops and reuse them square after square. You’ll track timing and harvests at a glance.
Safety And Cleanliness In A Small Bed
Keep paths mulched so you never step on the mix. Wash hands and tools after working with raw compost. Rotate crop families by square to reduce disease carryover.
What To Do After Harvest
Snip plants at soil level and leave roots to feed soil life unless the plant was diseased. Smooth the square, add a trowel of compost, and replant. In hot spells, shade new seed with a board for a day to lock moisture in.
Frequently Missed Details
Depth Creep
As you work down a row of holes it’s easy to go deeper. Set a stop mark on your dibbler so holes match.
Skipping Hardening
Transplants need a gradual move to sun and wind. Start with a few hours in bright shade, then add more outdoor time daily for a week or so. Move to full sun near the end and plant after a mild evening.
Ignoring Seed Age
Old seed can waste space. If a packet is two or three seasons old, run a quick germination test on a paper towel and adjust your sowing rate.
Wrap-Up: A Fast, Orderly Way To Sow
With a fixed grid, simple depth rules, and square-by-square cleanup, planting seeds in a compact bed stays calm. Stick to counts per square, water with care, and top off each square with compost. You’ll harvest more from small space with less guesswork, and you’ll enjoy the tidy look the grid delivers.