Illustration
Lemon Star
Thunbergia alata 'Lemon Star'
Lemon Star blooms from June through October.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Lemon Star
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 10–11. Expect it to reach about 6.5 ft tall and 1.5 ft wide at maturity, in roughly 1 year (a house reading).
Pets
- No toxic listing found for dogs and cats in the sources we check.
Lists differ and none is complete. If a pet eats a plant and seems unwell, call a veterinarian or a pet poison helpline.
No toxicity note is on file for Lemon Star. That is not a clearance: check its safety for people and pets before planting.
What was checked
Nine facts were checked against named botanical sources, each recorded beside the sources that carried it: mature height and spread, hardiness zones, sun, water, bloom months and color, the trait tags, and years to mature size, which rests on a recorded house rule where no publisher states one and is marked so. Soil, diseases, pests, toxicity and the plant's own names have not yet been read for this plant, and its trait tags are the ones a feature uses rather than every word a page prints. Each fact above carries its own mark. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Lemon Star
Lemon Star sits in a nearly frost-free range (zones 10 to 11): plant it in the cool season, fall through late winter, and let the mild months settle its roots. On the calendar that means October or November, or January or February. Once settled, it blooms from June to October.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 10, the middle of this plant's hardy range, start with zone 10 in January. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Lemon Star get?
6.5 fttall5 ft 7 inan adult1.5 ftwideSee Lemon Star in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Lemon Star
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Lemon Star about 1.5 ft apart, center to center, so each plant has room to reach its full width.
Add Lemon Star to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Lemon Star's height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 8 published sources on October 20, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- Proven Winnersheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- Plant Addictswater and bloom months and color
- The Morton Arboretumbloom months and color and trait tags
- University of Wisconsin HorticultureUniversity of Wisconsin-Madison Extensionsun and bloom months and color
- ballfloraplant.comBall FloraPlantheight and spread
- Missouri Botanical Gardensun and water
- NC State Extensionwater and trait tags
- plants.natorp.comNatorp'sbloom months and color
How the checking works, and what each standard covers, is on the verified plants page.
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