Growing Guide
Why Sun Hours Matter More Than You Think
Sources: USGS 3DEP terrain + buildings, NAIP-CHM leaf-on canopy model (U-Montana), pvlib solar geometry, Konarska (2013) seasonal transmissivity
Full Sun
6+ hours
Direct daily light
Partial Sun
4-6 hours
Moderate exposure
Full Shade
< 2 hours
Limited direct light
How much sun does your yard get?
Enter an address for a quick read on peak-season sun hours and tree canopy — estimated from sky irradiance, terrain, and a national tree-canopy layer. It’s a fast first look; your full report casts the sun through your parcel’s exact terrain, buildings, and leaf-on canopy.
The single biggest factor most growers underestimate
Soil gets the attention. Frost dates get the headlines. But sun exposure is the factor that separates a productive garden from a disappointing one — and it's the hardest to estimate by eye. The human eye adapts to brightness, making a spot that receives 4 hours of direct sun feel "sunny." Plants don't adapt the same way.
A tomato plant in 4 hours of sun will set 60-70% fewer fruit than the same variety in 7 hours. Not because it dies — it looks healthy. It just doesn't produce. The grower blames the variety, the soil, the fertilizer. The real answer was overhead: not enough sun.
See YOUR sun exposure
Get a solar heat map of your property — every spot measured in hours of direct sun.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Sun categories: What the numbers mean for plants
Full Sun: 6+ hoursRequired for tomatoes, peppers, squash, melons, corn, and most fruiting crops. Also needed for lavender, rosemary, and sun-loving perennials. The more hours above 6, the better the yield.
Partial Sun: 4-6 hoursSuitable for leafy greens (lettuce, spinach, kale, chard), most herbs (parsley, cilantro, chives), root vegetables (carrots, beets, radishes), and many berries. Productive gardening is absolutely possible here.
Shade-tolerant vegetables (arugula, some lettuce varieties), woodland herbs (mint, lemon balm), and many native understory plants. Not ideal for food production but excellent for specific niches.
Too little for most food crops. Focus on shade-loving ornamentals, ground covers (hostas, ferns, native woodland species), and mushroom cultivation. Not a limitation — a different kind of garden.
How we measure sun exposure on your parcel
Growable Ground reads the sun on your land by casting it through a three-part model of your parcel — the ground, the buildings, and the trees — the way light actually reaches a growing bed.
Terrain and buildings
We start with USGS 3DEP: a bare-earth elevation model for your land’s slope and aspect, plus LiDAR-classified building footprints where 3DEP LiDAR has been flown. Both are solid — they block the sun completely. Where LiDAR hasn’t been flown, a seamless national elevation floor keeps every parcel covered.
Tree canopy, in leaf
Tree shade is the hard part, because it changes with the season. We read canopy height from NAIP-CHM — a leaf-on model the University of Montana builds from 0.6-meter summer aerial imagery. It’s modelled, not laser-measured: a neural network estimates how tall the trees stand in full leaf, which is what actually shades a bed in July. Where NAIP-CHM has gaps, the 1-meter Meta/WRI canopy model fills them in.
Casting the sun — and letting some through
We ray-march the sun’s path across all three layers using pvlib for sun position, sampling 8 representative days across the four seasons, hour by hour. Unlike a building, a leafy canopy lets some light through — so instead of treating trees as solid, we apply measured seasonal transmissivity (Konarska et al., 2013): dense summer leaf blocks nearly all direct sun, while bare spring branches let much of it pass. That’s why the same trees read sunnier in spring than at midsummer.
We checked the canopy read against NEON airborne LiDAR at 8 sites across the US — agreement is within about 3 meters of height, best over dense stands and least certain around a single open-grown yard tree. So this reads most reliably over a stand of trees; for a lone tree, a midday walk of the spot confirms where its shade actually falls.
Why sun exposure varies within a single property
Walk around your property during the day and you'll notice: some spots get morning sun but afternoon shade. Others are shaded until noon then bake all afternoon. This isn't random — it's geometry.
- Buildings: Your house, garage, and neighbors' structures cast shadows that sweep across the property as the sun moves. In winter, when the sun is low, these shadows extend much further.
- Trees: A mature oak can shade 1,500+ square feet at midday. Deciduous trees shade less in spring before leaf-out — which is why early-season crops (peas, lettuce) can succeed under trees that shade out summer tomatoes.
- Terrain: South-facing slopes receive more direct sun per hour than flat ground. North-facing slopes receive less. In hilly terrain, aspect (the direction a slope faces) can create a full sun-category difference within 50 feet.
- Season: The sun's arc changes dramatically between June and December. A spot with 8 hours of sun in summer may get only 3 in early spring — which matters for cool-season crops you're starting in March.
The shade garden opportunity
Shade isn't a limitation — it's a different growing context. Some of the most productive and beautiful gardens are deliberately shade-focused:
- Leafy greens actually prefer partial shade in hot climates — they bolt (go to seed) faster in full sun during summer heat.
- Woodland natives like trillium, ferns, and wild ginger are ecologically valuable understory plantings that thrive where nothing else will.
- Mushroom cultivation — shiitake, oyster, and wine cap mushrooms need shade and moisture, making otherwise "unusable" areas highly productive.
- Pollinator habitat — many native pollinators depend on shade-edge environments for nesting and forage.
Growable Ground's crop engine includes shade-tolerant species and scores them specifically for your sun conditions. A parcel with 3 hours of sun isn't a bad parcel — it's a shade garden waiting to happen.
Pro TipSee YOUR sun exposure
Get a solar heat map of your property — every spot measured in hours of direct sun.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Frequently Asked Questions
How many hours of sun do vegetables need?
Most fruiting vegetables (tomatoes, peppers, squash) need 6-8 hours of direct sun — classified as "full sun." Leafy greens (lettuce, spinach, kale) tolerate 4-6 hours ("partial sun"). Root vegetables fall between. Below 4 hours, focus on shade-tolerant herbs and select leafy greens.
How does Growable Ground read sun and shade?
We cast the sun across a three-part model of your parcel: bare-earth terrain and buildings from USGS 3DEP, and tree canopy from a leaf-on canopy-height model — modelled from summer aerial imagery, not a laser scan. Using pvlib for sun position, we ray-march 8 representative days across the seasons and let some light filter through leafy canopy, so the same trees read sunnier in spring than at midsummer.
Why does sun exposure vary so much within one property?
Buildings cast shadows that move throughout the day. Mature trees create shade patterns that change seasonally. Terrain slope and aspect affect how directly sunlight hits the ground. A spot receiving 8 hours of sun in June may get only 4 hours in March. These variations mean different parts of the same parcel suit different plants.