Q1: Why do some white flowers stay closed during the daytime?
A1: Species such as Ipomoea alba and Epiphyllum oxypetalum conserve delicate moisture and protect nectar stores by closing their petals against drying midday sun and high heat. Opening exclusively at dusk targets their primary mutualists, moths and nocturnal beetles, while preventing theft by daytime insects that do not pollinate them.
Q2: How does light pollution from streetlights affect a moon garden?
A2: Artificial light pollution suppresses flower fragrance production and interferes with pollinator navigation. High-lux municipal lighting disrupts the flight-to-light instincts of hawk moths, exhausting them before they find the blossoms. Shielding garden spaces behind dark evergreens or tall fencing helps maintain the darkness these plants require.
Q3: Can night-blooming cereus survive cold winter temperatures outdoors?
A3: No. Epiphyllum oxypetalum and related cereus species are tropical epiphytes native to Central and South America, winter-hardy only in USDA Zones 10 through 12. In colder climates, grow them in hanging baskets or containers that move outdoors for summer and return indoors before autumn temperatures fall below 50°F (10°C).
