Shade Level Reference
Measured light level → shade category → suitable plants → spacing at mature size → weekly watering → toxicity, for every plant the shade plant selector knows about, in one table. Every column below is computed by the same functions the calculators on this site use — nothing here is a separate, hand-maintained copy.
How to read a measured light level
These three readings are real output from the light level calculator, one representative lux-and-hours reading per shade tier, so you can see roughly what a phone light-meter app would show for each category before it ever reaches a plant decision.
| Shade tier | Example reading | Daily Light Integral | Foot-candles |
|---|---|---|---|
| Partial shade | 12,000 lux × 6h | 4.8 mol/m²/day | 1114.8 fc |
| Full shade | 6,000 lux × 5h | 2 mol/m²/day | 557.4 fc |
| Deep shade | 2,000 lux × 4h | 0.53 mol/m²/day | 185.8 fc |
A phone light meter is indicative, not lab-grade — see our guide to lux, foot-candles, and Daily Light Integral for what these units actually measure and how much to trust a reading.
Plant reference: light, spacing, watering, toxicity
| Plant | Light levels suited | Moisture | Mature height | Spacing (triangular) | 10×10 ft bed fits | Weekly water (loam) | Toxicity |
|---|---|---|---|---|---|---|---|
| Hosta Hosta spp. Zone 3–9 | partial, full, deep | medium, wet | 10–36 in | 23 in | 39 plants (0.39/sq ft) | 0.4 in Water once or twice this week. | ⚠ Toxic to pets Contains saponins that make it a risk to dogs, cats and horses. Fine around people. If a pet eats it, contact a veterinarian. |
| Christmas fern Polystichum acrostichoides Zone 3–9 | partial, full, deep | medium | 12–24 in | 18 in | 56 plants (0.56/sq ft) | 0.4 in Water once or twice this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Astilbe Astilbe spp. Zone 4–8 | partial, full | medium, wet | 12–36 in | 24 in | 33 plants (0.33/sq ft) | 0.55 in Water once or twice this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Lenten rose Helleborus x hybridus Zone 4–9 | partial, full | medium | 12–18 in | 15 in | 85 plants (0.85/sq ft) | 0.55 in Water once or twice this week. | ⚠ Toxic if eaten All parts are poisonous if eaten, and the sap can irritate skin — wear gloves when dividing, and site it away from children and pets. If any part is eaten, contact Poison Control (people) or a veterinarian (pets). |
| Japanese painted fern Athyrium niponicum Zone 5–8 | partial, full, deep | medium, wet | 12–18 in | 15 in | 85 plants (0.85/sq ft) | 0.4 in Water once or twice this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Coral bells Heuchera spp. Zone 4–9 | partial, full | medium | 8–18 in | 13 in | 105 plants (1.05/sq ft) | 0.55 in Water once or twice this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Lungwort Pulmonaria spp. Zone 3–8 | full, deep | medium, wet | 8–12 in | 10 in | 175 plants (1.75/sq ft) | 0.4 in Water once or twice this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Solomon's seal Polygonatum biflorum Zone 3–8 | partial, full, deep | medium | 18–36 in | 27 in | 27 plants (0.27/sq ft) | 0.4 in Water once or twice this week. | ⚠ Toxic if eaten The blue-black berries are poisonous if eaten. Site away from children and pets. If any part is eaten, contact Poison Control (people) or a veterinarian (pets). |
| Foamflower Tiarella cordifolia Zone 3–8 | partial, full, deep | medium, wet | 6–12 in | 9 in | 216 plants (2.16/sq ft) | 0.4 in Water once or twice this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Bigroot geranium Geranium macrorrhizum Zone 4–8 | partial, full | dry, medium | 12–20 in | 16 in | 72 plants (0.72/sq ft) | 0.28 in Water lightly once this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Siberian bugloss Brunnera macrophylla Zone 3–8 | partial, full | medium, wet | 12–18 in | 15 in | 85 plants (0.85/sq ft) | 0.55 in Water once or twice this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
| Lily-of-the-valley Convallaria majalis Zone 2–7 | partial, full, deep | medium | 6–12 in | 9 in | 216 plants (2.16/sq ft) | 0.4 in Water once or twice this week. | ⚠ Seriously toxic Every part is seriously poisonous, and the bright red berries are exactly the kind small children pick. Keep it out of gardens used by children or pets; the water from cut stems is unsafe too. If any part is eaten, contact Poison Control (people) or a veterinarian (pets). |
| Sweet woodruff Galium odoratum Zone 4–8 | full, deep | medium, wet | 6–12 in | 9 in | 216 plants (2.16/sq ft) | 0.4 in Water once or twice this week. | ⚠ Toxic if eaten Contains coumarin and is unsafe to eat in quantity despite its use as a flavouring. Site away from children and pets. If any part is eaten, contact Poison Control (people) or a veterinarian (pets). |
| Wild ginger Asarum canadense Zone 4–8 | full, deep | medium | 6–8 in | 7 in | 350 plants (3.5/sq ft) | 0.4 in Water once or twice this week. | ⚠ Toxic if eaten Not related to culinary ginger and not edible — it contains aristolochic acid. Site away from children and pets. If any part is eaten, contact Poison Control (people) or a veterinarian (pets). |
| Barrenwort Epimedium spp. Zone 4–9 | partial, full, deep | dry, medium | 8–12 in | 10 in | 175 plants (1.75/sq ft) | 0.2 in Water lightly once this week. | None reported No significant toxicity reported for people or pets. That is not a promise that every part is safe to eat. |
Spacing and bed-fit figures use each plant's mature height as a practical spacing proxy on a fixed reference bed, and watering figures assume loam soil with no recent rainfall — use the plant spacing calculator and watering-in-shade calculator directly for your own bed's exact dimensions and soil type.
How these numbers are derived
Nothing in the table above is a hand-maintained copy of the calculators — every column is computed by calling the same underlying functions the six calculators on this site run. "Light levels suited" comes from actually running the shade plant selector's own filtering logic for each of partial, full, and deep shade, using the plant's own zone and moisture so only the light input varies. Spacing and bed-fit figures come from the plant spacing calculator's triangular-layout math, given a spacing distance drawn from the plant's real published mature-height range. Weekly watering comes from the watering-in-shade calculator, using the deepest shade tier a plant is suited for and a water-need class bridged from its moisture preference.
Toxicity comes straight from the shade plant selector's own label for each plant, the same label the selector shows next to its results, so the two pages cannot disagree. It is plant-tag labelling, not medical advice: no symptoms or treatment, only a pointer to Poison Control or a veterinarian. "None reported" means no significant toxicity is commonly reported for that species, not a guarantee that every part of every plant is safe to eat.
Frequently Asked Questions
How are the "light levels suited" for each plant worked out?
By actually running the shade plant selector for that plant three times — once each for partial, full, and deep shade — using the plant's own zone and moisture so only the light filter can vary the result. A light tier only appears in the table if the selector genuinely returns that plant for it, the same way it would for you on the shade plant selector page.
Where does the spacing number come from, if the data only tracks a plant's height?
The spacing figure uses the midpoint of the plant's published mature height range as a practical spacing proxy, then runs that through the same triangular-layout math the plant spacing calculator uses. This is a reasonable working default for mounding, clump-forming perennials, where height and spread track closely — it's a looser approximation for spreading groundcover, which stays low but spreads further sideways than its height alone suggests.
Why is the watering figure the same for several different plants?
Weekly watering is derived from two inputs: a water-need class bridged from the plant's moisture preference (dry → low, medium → medium, wet → high), and the deepest shade tier the plant is suited for. Plants that share both of those — the same moisture preference and the same deepest suited tier — will show an identical watering figure, computed by the real watering calculator, not because the table repeats a number.
Does the shade plant selector itself track toxicity?
Yes. Every plant in the selector carries a toxicity label (none, toxic to pets, toxic if eaten, or seriously toxic) and a short siting note, and this table shows that same label, so the two pages always agree. The selector can also be set to show only plants with no reported toxicity. Neither page gives symptoms or treatment; if a plant has been eaten, contact Poison Control or a veterinarian.
Educational reference only, not a substitute for professional horticultural, medical, or veterinary advice. Invasive status varies by region — this reference does not certify any plant as safe to plant everywhere; check your local or regional invasive-species list before planting. If a person or pet may have eaten a toxic plant, contact Poison Control or a veterinarian directly rather than relying on this page.
Use it with
- Light Level & Lux Guide — take the actual reading this reference's light tiers are built from.
- Shade Plant Selector — filter the full curated list by your own zone, light, and moisture rather than the fixed examples above.
- Plant Spacing Calculator and Watering-in-Shade Calculator — run the spacing and watering math for your own bed's real dimensions and soil.
- From a Light Reading to a Plant List — the guide version of this pipeline, with its own worked example.