holywood
Guaiacum sanctum · Zygophyllaceae
holywood (Guaiacum sanctum) is a perennial tree in the Zygophyllaceae family. It is native to North America. USDA records it as hardy in zone 10 and warmer, down to about 36°F.
At a glance
| Type | tree Derived |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 30 ft USDA |
| Growth rate | slow USDA |
| Soil pH | 6–8.5 USDA |
| Bloom | March–May USDA |
| Flower color | Blue USDA |
| Hardiness zones | 10 and warmer USDA |
| Guild layer | understory Derived |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
Its drought tolerance is rated medium. It is recorded on soils from pH 6 to 8.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 10.
Size and growth
At maturity it reaches about 30 ft, making it a substantial woody plant. It grows slowly.
Bloom period
USDA records a bloom period of March through May. Flowers are blue.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, medium in texture. Its flowers are conspicuous. Its fruit or seed heads are conspicuous, extending interest past flowering. Its active growth period is spring. Its winter foliage is dense, which makes it useful for year-round screening.
What the site needs to provide
USDA records it across sites receiving 34 to 60 inches of annual precipitation. It needs at least 365 frost-free days to finish its season. It roots to at least 36 inches. Fertility requirement: medium.
Propagating it
Seed is the only propagation method USDA lists. Division and cuttings are not listed as options. USDA records no cold-stratification requirement, so seed should germinate without a chilling period.
Resilience and wildlife
Browsing animals rate it barely palatable — the sourced basis for calling it deer-resistant. Its fire tolerance is rated medium.
Role in a guild
Understory. In a layered planting this is the layer beneath the canopy, tall enough to hold structure but shaded from above. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Guaiacum
- lignum-vitae Guaiacum officinale
Similar role and hardiness
- Indian mulberry Morinda citrifolia
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol GUSA, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Bloom, Bloom end, browse palatability, cold stratification, Drought tolerance, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, Growth rate, Hardiness zones, Lifecycle, Mature height, Minimum temperature, Native status, Nitrogen fixation, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, Soil pH, Soil pH (upper), Tolerance of wet soil.
- Derived by a fixed rule from those columns: Guild layer, Type.
Read our full data sources and methodology.
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