How do I find my USDA hardiness zone?

The USDA Plant Hardiness Zone Map at planthardiness.ars.usda.gov lets you enter any U.S. ZIP code and returns your zone (1a through 13b) based on the average annual extreme minimum temperature over the past 30 years. Each zone covers a 10-degree-Fahrenheit band, with the 'a' and 'b' subdivisions covering 5-degree increments. The 2023 update shifted roughly half the country one half-zone warmer than the 2012 map, reflecting decades of warming winter lows. Your zone determines which perennials, shrubs, and trees can survive the coldest expected winter night where you live; for annual vegetables, your first and last frost dates matter more than the zone itself. Always cross-reference your zone with the local Cooperative Extension service, which publishes microclimate-aware planting guides tied to your county.

How much soil do I need for a 4x8 raised bed?

A 4-by-8-foot raised bed filled to 12 inches deep needs 32 cubic feet of soil: 4 ft x 8 ft x 1 ft = 32 cu ft, or 1.19 cubic yards. At standard retail bagged-soil sizes that converts to about 22 bags of 1.5 cu ft, 16 bags of 2 cu ft, or roughly one and a quarter cubic yards from a bulk landscaping supplier. Bulk delivery is almost always cheaper per cubic foot for beds this size — bagged soil typically runs $5-$8 per cubic foot, while bulk topsoil mixes sit around $30-$60 per cubic yard delivered ($1.10-$2.20 per cubic foot). For raised beds, fill with a blended mix: roughly one-third compost, one-third topsoil, and one-third aeration material (coco coir, vermiculite, or perlite). Pure topsoil compacts and drains poorly in a contained bed.

When should I start seeds indoors?

Count backward from your local last-frost date, which you can look up via the National Centers for Environmental Information or your county Cooperative Extension. Tomatoes, peppers, and eggplants need 6-8 weeks of indoor growth before transplanting, so for a May 15 last-frost date you would start them indoors around March 20-April 1. Brassicas (broccoli, cauliflower, cabbage) need 4-6 weeks indoors and tolerate transplanting 2 weeks before the last frost. Lettuce, spinach, and other cool-season greens need only 3-4 weeks indoors and can go out 4 weeks before the last frost. Direct-sown crops like beans, corn, squash, cucumbers, carrots, and radishes skip indoor starting entirely — their roots dislike being disturbed by transplanting. Use a heat mat for warm-season seeds (tomatoes germinate fastest at 75-85 degrees Fahrenheit) and a grow light kept 2-4 inches above seedlings to prevent legginess.

What pH does my garden need?

Most vegetables thrive in slightly acidic soil with a pH of 6.0-6.8. At this range nitrogen, phosphorus, potassium, calcium, and magnesium are all readily plant-available. Tomatoes, peppers, beans, corn, cucumbers, squash, and most leafy greens fall squarely in this band. Blueberries are the major outlier — they require highly acidic soil, pH 4.5-5.5, and will yellow and starve at neutral pH because iron becomes locked up. Asparagus, by contrast, tolerates slightly alkaline soil up to pH 7.5. Test your soil with a $15 home kit, a digital meter, or — for serious accuracy — a $20-$30 lab analysis through your state Cooperative Extension. To raise pH (sweeten acidic soil), apply garden lime in fall at 5-10 pounds per 100 square feet. To lower pH (acidify alkaline soil), apply elemental sulfur or aluminum sulfate, retest after one full season, and adjust again. pH changes slowly — plan amendments months ahead of planting.

How do I succession-plant lettuce?

Succession planting means sowing the same crop in small batches every 1-3 weeks so you harvest continuously rather than all at once. For lettuce, sow a new 2-3-foot row every 14 days from 4 weeks before your last frost through late spring, then pause during midsummer heat (lettuce bolts above 80 degrees Fahrenheit), and resume in late summer for a fall harvest. A typical schedule for a Zone 6 garden with a May 15 last frost: sow April 17, May 1, May 15, May 29, June 12 — then skip July and August — then resume August 21, September 4, September 18, with the last sowing roughly 8 weeks before your first fall frost. Each batch matures in 45-60 days for heading types or 30-45 days for cut-and-come-again varieties like 'Black Seed Simpson' or 'Salad Bowl.' Pair early-season lettuce with late-planted bush beans or summer squash in the same bed — by the time the warm-season crops need the space, the spring lettuce has finished.

Garden Planner Calculator

Calculate soil volume, mulch coverage, and material costs for your garden beds.

Last reviewed: May 2026

Built and maintained by Shannon Patterson · Last updated May 2026

Garden Length

Garden Width

Bed Depth

inches

Mulch Depth

inches

Plant Spacing

inches

Soil Cost per Cu Ft

Mulch Cost per Cu Ft

Garden Area

32 sq ft

8 ft x 4 ft raised bed

Soil Volume

0 cu ft

0 cu yd

Soil Bags (1.5 cu ft)

0 bags

Mulch Volume

0 cu ft

Mulch Bags (2 cu ft)

0 bags

Plants That Fit (Grid Spacing)

0 plants

0 per row x 0 rows at 12" spacing

Total Soil Cost

$0.00

Total Mulch Cost

$0.00

Total Material Cost

$0.00

Important Disclaimer: This calculator is for informational and educational purposes only. Plant spacing, frost dates, and material requirements vary by region, microclimate, soil type, and cultivar. Always consult your local Cooperative Extension service, the USDA Plant Hardiness Zone Map, and seed-packet directions for site-specific guidance before purchasing materials or planting.

This garden planner calculator computes the four numbers that drive most raised-bed projects: total square footage, soil volume in cubic feet and bagged units, mulch coverage, and the number of plants that fit on a regular grid at a chosen spacing. Enter your bed dimensions above; the sections below walk through how each figure is derived, how to translate seed-packet spacing recommendations into row counts, and how to layer succession planting, companion planting, and frost-date timing on top of the raw geometry.

What This Calculator Does

At its core the garden planner turns five inputs — length, width, bed depth, mulch depth, and plant spacing — into the practical numbers a first-year gardener actually needs at the hardware store: how many bags of soil to buy, how many bags of mulch, how many seedlings or transplants will fit, and how much the whole bill will run.

Seed Spacing and Row Counts

The plant-spacing math is straightforward grid geometry. For a 4-foot-wide bed at 12-inch spacing, the calculator places one plant every 12 inches along the width: floor(48 inches ÷ 12 inches) + 1 = 5 plants per row. The same logic runs along the length for the row count. A 4-by-8-foot bed at 12-inch grid spacing therefore holds 5 plants per row × 9 rows = 45 total plants. Tighten spacing to 6 inches and the bed holds 9 × 17 = 153 plants — the spacing input is the single biggest lever on plant density.

Succession-Planting Schedules and Frost Windows

The calculator also helps you reason about succession planting — sowing the same crop in waves every 1-3 weeks so harvest is continuous rather than concentrated. The arithmetic is simple: divide the row count by the number of successions you want. A 9-row lettuce bed split into three sowings becomes three rows planted two weeks apart, giving you a fresh head every couple of weeks for two months rather than 45 heads simultaneously. The frost-date piece of the puzzle is regional and requires looking up your local last-frost (spring) and first-frost (fall) dates via the National Centers for Environmental Information or your county Extension service; the calculator's outputs feed directly into the days-to-maturity figure printed on every seed packet to tell you the latest safe sowing date for a given crop.

Raised-Bed Soil and Mulch Volume

Soil volume is length × width × depth, with depth converted from inches to feet. A 4-by-8-foot bed filled 12 inches deep takes 32 cubic feet — exactly one tidy pickup-truck load of bagged soil at 22 bags of the standard 1.5-cu-ft size, or about 1.19 cubic yards from a bulk delivery. Mulch coverage uses the same formula at a shallower depth: 3 inches over 32 square feet is 8 cubic feet, or four 2-cu-ft bags. The cost figures multiply volume by your per-unit prices to produce a hardware-store total before you load the cart.

How to Use It

Step 1 — Enter Bed Dimensions

Start with the physical footprint of your bed in feet. A standard cedar raised-bed kit ships in 4-by-4-foot, 4-by-8-foot, or 2-by-8-foot sizes; in-ground rows can be any length but a 4-foot maximum width lets you reach the center from either side without stepping into the bed and compacting soil. Bed depth of 10-12 inches works for shallow-rooted crops like lettuce, herbs, radishes, and most flowers; deeper-rooted crops like tomatoes, carrots, parsnips, and potatoes prefer 18-24 inches of loose soil.

Step 2 — Pick a Crop and Spacing

Every seed packet prints two spacing numbers: spacing between plants within a row, and spacing between rows. The calculator uses a single spacing value and applies it equally in both directions — the square-foot gardening pattern. Use the within-row figure from the packet for most crops. Common defaults: lettuce 6 inches, bush beans 4 inches, carrots 2 inches, tomatoes 24 inches, peppers 18 inches, broccoli 18 inches, onions 4 inches, basil 8 inches, marigolds 6 inches. For square-foot gardening shortcuts: 1 large plant per square (tomato, broccoli), 4 medium plants per square (lettuce, chard, parsley), 9 small plants per square (onion, beet, spinach), or 16 tiny plants per square (carrot, radish, scallion).

Step 3 — Read the Sowing Date and Plant Count

The total-plants result tells you how many transplants or seeds to buy. For direct-sown crops, multiply that by 1.2-1.5 to allow for germination failures and thinning. The soil and mulch outputs translate directly to a shopping list: round up to the next whole bag, and add 5-10% on bulk soil deliveries to allow for settling after the first watering.

Worked Example: 4×8 ft Raised Bed with Tomato, Basil, and Onion

Bed dimensions: 4 ft × 8 ft = 32 sq ft
Bed depth: 12 inches
Soil volume: 32 sq ft × 1 ft = 32 cu ft (1.19 cu yd)
Mulch depth: 3 inches → 8 cu ft total
USDA zone: 6b (example: central Pennsylvania)
Last frost date: May 5 (averaged)
First fall frost: October 14
Growing season: 162 days

Step 1 — Plan the Layout

Reserve the center 4-by-4-foot section for tomatoes at 24-inch spacing. That gives floor(48 ÷ 24) + 1 = 3 plants per row × 3 rows = 9 tomato positions, of which we use the 4 corner squares — leaving the 5 interior positions open for basil. The remaining two 4-by-2-foot strips along the long edges hold onions at 4-inch spacing border-row style: floor(96 ÷ 4) + 1 = 25 onions per edge × 2 edges = 50 onions total.

Step 2 — Compute Crop Totals

Tomatoes: 4 plants (one in each corner of the central 4×4 area). Basil at 8-inch spacing slotted between the tomatoes serves as a companion planting: 5 basil plants in the interior gaps. Onions along both long edges at 4-inch spacing: 50 onion bulbs. Total 59 plants in a 32-sq-ft bed. At commodity prices (transplant tomatoes $3 each, basil $2 each, onion sets $0.10 each) the plant cost is $12 + $10 + $5 = $27.

Step 3 — Stage the Harvest Calendar

Onions go in first as sets, 4 weeks before last frost (April 7 for our example). Tomatoes and basil are both warm-season — transplant after May 15, two weeks past the average last frost, when soil temperatures reliably exceed 60°F. Onions harvest in mid-July when tops yellow and fall over. Tomato harvest peaks August through early October. Basil is cut continuously from late June through first frost. The bed produces three distinct harvest waves rather than one chaotic glut.

Step 4 — Materials Cost

32 cu ft of bagged soil mix at $0.50/cu ft = $16.00. 8 cu ft of mulch at $0.30/cu ft = $2.40. Total material cost: $18.40. With plant cost the all-in budget is roughly $45 for a bed projected to yield 30-50 lbs of tomatoes, a quart-jar's worth of dried basil, and 50 storage onions — a yield-to-cost ratio that justifies the planning effort.

Top-down layout: four tomatoes anchor the corners of the central 4×4 zone, five basil plants slot between them as pest-disrupting companions, and 50 onions form a continuous border row down both long edges. This single-bed polyculture produces three distinct harvest waves from May through October.

Common Use Cases

First-Year Garden Planning

A new gardener with no soil-test results, no compost pile, and no track record of frost dates is the calculator's most natural audience. Start with a single 4-by-8 raised bed, fill it with a commercial bagged mix to skip the soil-testing question entirely for year one, and plant a small set of forgiving crops: bush beans, leaf lettuce, cherry tomatoes, zucchini, basil, and marigolds. The calculator's plant-count output lets you buy exactly enough transplants without the rookie tendency to crowd the bed.

Square-Foot Gardening

Mel Bartholomew's 1981 system maps onto the calculator perfectly: enter your bed dimensions, then pick the spacing that produces the per-square density you want (12 inches for 1 plant per square, 6 inches for 4 per square, 4 inches for 9 per square, 3 inches for 16 per square). The grid output is the count for the whole bed, not per square — divide by the number of squares to confirm per-square density.

Succession Planting Lettuce and Radish

Both lettuce (45-60 day maturity) and radish (25-35 day maturity) are textbook succession crops. Use the calculator to size a small bed (2×4 ft, 8 sq ft) for continuous harvest: at 6-inch lettuce spacing the bed holds 5 × 9 = 45 plants; split into 3 sowings of 15 plants spaced 14 days apart and you eat a salad every other day for two months.

Companion Planting

The tomato-basil-marigold trio is the most-cited companion combo. Marigolds at 6-inch spacing around the bed perimeter discourage root-knot nematodes (genuinely demonstrated in research) and may repel some flying pests; basil between tomato plants disrupts pest oviposition (modestly supported); both share the warm-season, full-sun, even-moisture care profile of tomatoes. The calculator's grid output lets you reserve specific positions for each species without overcrowding.

Greenhouse-to-Outdoor Transplant Timing

Tomatoes, peppers, eggplants, and brassicas all benefit from 4-8 weeks of indoor or greenhouse growth before transplanting. The plant count from the calculator tells you how many cell-pack seedlings to start. A standard 72-cell tray plants four 4×8 beds at 24-inch tomato spacing — buy by the tray, not the six-pack, once your needs exceed 20 plants.

Fall Garden Planning

The same bed that grew summer tomatoes can host a fall crop of broccoli, kale, lettuce, spinach, garlic, or cover-crop rye. Count backward from your first fall frost: a crop with 60 days to maturity needs to go in 60 + 14 (frost-tolerance buffer) = 74 days before first frost. The calculator's plant count multiplies by your fall-crop choice to size the second planting.

Edge Cases and Climate Reality

USDA Hardiness Zone Awareness

The USDA Plant Hardiness Zone Map (updated 2023) divides North America into 13 zones based on average annual extreme minimum temperature. Zone 1 in northern Alaska sees winter lows below -50°F; Zone 13 in tropical Puerto Rico stays above 60°F year-round. Most of the continental U.S. falls between Zones 4 and 9. Zones tell you which perennials and shrubs can survive your worst expected winter night, but for annual vegetables your last-frost and first-frost dates matter more. A Zone 6 garden in coastal Maine and a Zone 6 garden in interior Missouri share a zone but have very different growing-season length and humidity profiles.

Sun Exposure

"Full sun" on most seed packets means 6 or more hours of direct sun per day; "partial shade" means 3-6 hours; "shade" means under 3 hours. Fruiting crops (tomatoes, peppers, squash, beans, corn, cucumbers) almost universally require full sun to produce reliable fruit. Leafy crops (lettuce, spinach, kale, chard) and root crops (beets, carrots, turnips, radishes) tolerate partial shade — in southern climates, afternoon shade actually extends their season by suppressing bolting. Walk your potential bed location at 9 AM, noon, and 3 PM on a sunny day to confirm direct sun hours before construction.

Soil pH

Most vegetables prefer slightly acidic soil at pH 6.0-6.8. Blueberries are the famous outlier at pH 4.5-5.5; potatoes do well slightly more acidic at 5.5-6.5; asparagus tolerates slightly alkaline soil up to pH 7.5. A $15 home pH meter is accurate enough for amendment decisions. Raise pH with garden lime (5-10 lbs per 100 sq ft); lower with elemental sulfur (1-2 lbs per 100 sq ft); both take months to take effect, so amend in fall for spring planting.

Frost-Date Variability

"Average last frost" is exactly that — an average. Real frost dates vary by 2-3 weeks year-to-year in most U.S. regions. Add a 14-day buffer for warm-season crops (tomatoes, peppers, basil, squash) and watch the 10-day forecast before transplanting. Cold-tolerant crops (peas, spinach, lettuce, broccoli, onions, garlic) can go in 2-4 weeks before the average last frost without losing the entire planting to a late freeze.

Microclimates

South-facing brick walls, paved courtyards, and sheltered urban yards can run a full USDA zone warmer than the regional average. North slopes, cold-air-drainage pockets at the bottom of a hillside, and exposed coastal sites can run a zone colder. A protected south wall in Zone 6 can sometimes overwinter Zone 7 perennials; a low spot in Zone 5 can lose Zone 5 perennials to cold-air pooling.

Container vs In-Ground Spacing

Container plants typically need 25-50% more spacing than in-ground or raised-bed plants to allow root systems to develop without competing for the limited container volume. A tomato that fits at 24-inch spacing in a raised bed wants a 30-36-inch container of its own; a basil at 8-inch in-ground spacing needs a 1-gallon container. Container plants also dry faster and require daily watering in midsummer heat.

Behind the Horticulture

The Square-Foot Gardening Movement

Mel Bartholomew published Square Foot Gardening in 1981 after retiring from civil engineering and watching neighbors waste row-garden space. The book reframed home gardening as a precision exercise in volume and spacing, codified the 4×4 grid, and proposed "Mel's Mix" (equal parts compost from at least five sources, peat moss, and coarse vermiculite) as a universal soil that skipped local soil testing entirely. The method exploded in popularity through the 1980s and 1990s, has sold over two million copies, and remains the default introduction to raised-bed gardening for most U.S. beginners.

Biointensive Gardening

Alan Chadwick brought the French intensive and biodynamic traditions to UC Santa Cruz in the 1960s, training a generation of small-farm advocates including John Jeavons. Jeavons's How to Grow More Vegetables (1974, now in its ninth edition) systematized biointensive methods: 24-inch double-dug raised beds, hexagonal close planting, heavy composting, and an explicit calorie-yield target per square foot. Biointensive practitioners produce 2-4x the yield per square foot of conventional row gardens, at the cost of significantly more soil-building labor in the first two seasons.

Indigenous Three Sisters Polyculture

The Three Sisters intercrop — corn, beans, and squash grown together — predates European contact by at least 1,000 years and was practiced across much of pre-Columbian North America. The system works because each plant covers a weakness of the others: corn provides a vertical structure for beans to climb, beans fix atmospheric nitrogen that feeds the heavy-feeding corn, and squash's broad leaves shade the soil to suppress weeds and retain moisture. Modern research has confirmed the yield-per-acre advantage of the polyculture over corn monoculture in low-input conditions.

Companion-Planting Science vs Folklore

The companion-planting literature is a mix of demonstrated science and cherry-picked tradition. Solidly supported: French marigolds (Tagetes patula) suppress root-knot nematodes through alpha-terthienyl exudates; nasturtiums function as trap crops for aphids; legumes fix nitrogen via Rhizobium root nodules. Modestly supported: tomato-basil pest disruption; carrot-leek mutual pest masking. Largely folklore: "improves flavor" claims for most pairings, the more elaborate guild charts in older companion-planting books. Treat companion planting as a low-risk hypothesis worth trying, not a substitute for crop rotation, soil care, and proper pest management.

Permaculture Food Forests

Bill Mollison and David Holmgren coined "permaculture" in 1978 to describe perennial polyculture systems modeled on natural forest ecosystems. Food forests stack seven layers — canopy trees, understory trees, shrubs, herbaceous perennials, ground cover, root crops, and vines — to produce a self-maintaining food system that requires minimal annual labor after establishment. Food forests are a long-horizon project (5-10 years to maturity) and a poor fit for the annual-vegetable focus of most raised-bed gardens, but the layering principle informs how to fit more crops into less ground space.

Limitations of This Calculator

Geometry Is Not Horticulture

The grid math the calculator performs assumes uniform spacing across the entire bed. Real gardens are rarely uniform: corner positions, edge positions adjacent to a path, and positions next to a south-facing wall all behave differently from interior positions. The calculator's plant count is an upper bound assuming optimal uniform conditions, not a guarantee.

Soil Tests Beat Formulas

The soil-volume figure is accurate; the assumption that 32 cubic feet of "soil" is fungible is not. Sandy soil drains too fast for most vegetables; pure clay holds too much water and starves roots of oxygen. The right answer for a raised bed is a custom blend (roughly one-third compost, one-third topsoil, one-third aeration material like coco coir or vermiculite). For in-ground beds, a $20-$30 lab soil test through your state Cooperative Extension is the most cost-effective gardening investment you can make — it tells you exactly what to amend rather than guessing.

Weather Is Unpredictable

Frost dates, rainfall, and summer heat-stress windows all vary year-to-year by significant margins. A "normal" growing season is a 30-year average that any individual year can miss by weeks. Build slack into your schedule: start more seedlings than you need, plant in waves rather than all at once, and keep frost cloth on hand for the late-spring and early-fall edges of the season.

Pest Pressure Varies

The same crop in two adjacent yards can have wildly different pest outcomes based on local insect populations, neighbor gardens, prevailing winds, and the previous year's pest load. The calculator says nothing about pest management — that requires walking the bed daily, learning to identify the half-dozen pests common to your region, and intervening early (hand-picking, row cover, biological controls) rather than reaching for sprays after damage is visible.

Frequently Asked Questions

The USDA Plant Hardiness Zone Map at planthardiness.ars.usda.gov lets you enter any U.S. ZIP code and returns your zone (1a through 13b) based on the average annual extreme minimum temperature over the past 30 years. Each zone covers a 10-degree-Fahrenheit band, with the 'a' and 'b' subdivisions covering 5-degree increments. The 2023 update shifted roughly half the country one half-zone warmer than the 2012 map. Your zone determines which perennials, shrubs, and trees can survive the coldest expected winter night; for annual vegetables, your first and last frost dates matter more. Cross-reference with the local Cooperative Extension service, which publishes microclimate-aware planting guides tied to your county.

Square-foot gardening (SFG) is a raised-bed method popularized by Mel Bartholomew's 1981 book of the same name. The technique divides a 4-by-4-foot raised bed into a 16-square grid, then assigns each square a planting density based on mature plant size: 1 tomato per square, 4 lettuces, 9 onions, or 16 radishes. The result is higher yield per square foot than traditional row gardening, with much less weeding. SFG also calls for "Mel's Mix" — equal parts compost (from at least five sources), peat moss or coco coir, and coarse vermiculite — designed to skip in-ground soil testing entirely.

Basil's strong volatile oils — eugenol, linalool, and methyl chavicol — appear to repel or confuse common tomato pests including thrips, whiteflies, and tomato hornworm moths. A 2002 study in HortScience found yields modestly higher in tomato-basil intercropped plots than in monoculture controls, though effect sizes were small and varied by cultivar. Both plants share nearly identical sun, water, and warm-soil requirements, making them practical bedmates regardless of pest dynamics. The myth that basil "improves tomato flavor" has no laboratory backing, but the pest-disruption and shared-care benefits are real enough to make the pairing a sensible default.

A 4-by-8-foot raised bed filled to 12 inches deep needs 32 cubic feet of soil: 4 × 8 × 1 = 32 cu ft, or 1.19 cubic yards. That converts to about 22 bags of 1.5 cu ft, 16 bags of 2 cu ft, or roughly 1.25 cu yd from a bulk landscaping supplier. Bulk delivery is almost always cheaper per cubic foot — bagged soil runs $5-$8 per cubic foot while bulk topsoil sits around $30-$60 per cubic yard delivered. Fill with a blended mix: roughly one-third compost, one-third topsoil, one-third aeration material (coco coir, vermiculite, or perlite). Pure topsoil compacts and drains poorly in a contained bed.

Count backward from your local last-frost date. Tomatoes, peppers, and eggplants need 6-8 weeks of indoor growth, so for a May 15 last frost start them around March 20-April 1. Brassicas (broccoli, cauliflower, cabbage) need 4-6 weeks indoors and tolerate transplanting 2 weeks before the last frost. Lettuce and spinach need only 3-4 weeks indoors and can go out 4 weeks before the last frost. Direct-sown crops like beans, corn, squash, cucumbers, carrots, and radishes skip indoor starting entirely — their roots dislike transplanting. Use a heat mat for warm-season seeds (tomatoes germinate fastest at 75-85°F) and a grow light 2-4 inches above seedlings to prevent legginess.

Leafy and root vegetables can produce respectable yields with as little as 3-4 hours of direct sun, but fruiting vegetables generally cannot. Lettuce, spinach, kale, chard, arugula, mustard greens, scallions, beets, radishes, turnips, parsley, cilantro, and mint all tolerate partial shade — in hot southern climates, afternoon shade actually extends their season by preventing bolting. Fruiting crops like tomatoes, peppers, eggplant, squash, cucumbers, melons, beans, and corn need 6-8 hours of direct sun to set fruit reliably; less than that produces leggy plants and sparse blossoms. If your only spot gets fewer than 6 hours, plan a leaf-and-root garden rather than fighting biology.

Most vegetables thrive in slightly acidic soil with a pH of 6.0-6.8. At this range nitrogen, phosphorus, potassium, calcium, and magnesium are all readily plant-available. Tomatoes, peppers, beans, corn, cucumbers, squash, and most leafy greens fall squarely in this band. Blueberries are the major outlier — they require highly acidic soil, pH 4.5-5.5, and will yellow at neutral pH because iron becomes locked up. Test your soil with a $15 home kit or a $20-$30 lab analysis through your state Cooperative Extension. To raise pH, apply garden lime in fall at 5-10 pounds per 100 square feet. To lower pH, apply elemental sulfur, retest after a season, and adjust again. pH changes slowly — plan months ahead.

Succession planting means sowing the same crop in small batches every 1-3 weeks so you harvest continuously rather than all at once. For lettuce, sow a new 2-3-foot row every 14 days from 4 weeks before your last frost through late spring, then pause during midsummer heat (lettuce bolts above 80°F), and resume in late summer for a fall harvest. A typical Zone 6 schedule with a May 15 last frost: sow April 17, May 1, May 15, May 29, June 12 — skip July and August — then resume August 21, September 4, September 18. Each batch matures in 45-60 days for heading types or 30-45 days for cut-and-come-again varieties like "Black Seed Simpson" or "Salad Bowl." Pair early lettuce with late-planted bush beans or summer squash in the same bed — by the time the warm-season crops need the space, the spring lettuce has finished.

Quick reference

Garden Planner Calculator Quick Reference
Plant Type	Spacing (inches)	Water Needs	Soil pH
Tomatoes	24-36	1-2 inches/week	6.0-6.8
Herbs (Basil)	12-18	1 inch/week	6.0-7.0
Carrots	3-4	1-1.5 inches/week	5.5-6.5
Lavender	12-18	1 inch/week	6.5-7.5
Peppers	18-24	1-2 inches/week	6.0-6.8
Radishes	2-3	1 inch/week	5.5-6.5