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World of CitrusWorld of CitrusMarumi Kumquat
University of California, Riverside — Citrus Variety Collection
https://citrusvariety.ucr.edu/crc3237 (opens in a new tab)
Accessed
alexFortJames · YouTube · 2026-03-07
https://www.youtube.com/watch?v=4EeJomXg76Y (opens in a new tab)
Summary from transcript: English automatic captions reviewed 0:00–17:45 of 17:48. All tasting samples had been refrigerated through winter; raw timestamped capture is retained in the Thomasville citrangequat research archive.
Accessed
The Mulberries · YouTube
https://www.youtube.com/watch?v=PUO9SEdTW9I (opens in a new tab)
Summary from transcript: Native English auto-generated captions reviewed across the 43:47 video. At 4:17–5:18 the presenter identifies a Marumi grown from a tree sourced from Madison Citrus Nursery; no site or rootstock is stated. At 6:43–7:03 three fruits are spoken as 5.4g, 5.15g, and 5.4g; presenter gives an approximate reported value of 5.5g. At 11:50–13:08 aroma is described as deeper and pimento-like. At 15:42–18:26 the presenter describes variable/limited seeds, very small fruit, little juice for a pH test, and soft poorly defined interior. At 19:17–20:57 he describes occasional seeds, unpeelability and juiciness. Tasting at 23:12–25:15: acidic orange/marmalade notes, tart but not very sour, no bitterness, sweet but not very sweet. A matching Mulberries Marumi scorecard prints 5.5g and the same test's qualitative ratings; it is the companion for this sample, not an independent test or second fruit sample. The card image is archived at https://themulberries.org/wp-content/uploads/2026/01/Marumi-kumquat-1-724x1024.png. No Brix or pH measurement was obtained for Marumi.
Accessed
Heinrich · Tropical Fruit Forum · 2018-04-28
https://www.tropicalfruitforum.com/index.php?topic=27976.0 (opens in a new tab)
Thread started by Heinrich on Apr. 28, 2018; reviewed both pages (26 posts through Jan. 9, 2025). Heinrich reports a Marumi crop in Bavaria, zone 6: about 30 fruits on his plant, largest fruit up to 35 mm, most seedless, and flowering/fruit at multiple stages after winter in a cold house. Later taste preferences are unscored and explicitly limited by few fruits, no direct comparison, and different seasons. In an October 2020 reply he identifies Poncirus trifoliata as the rootstock; the post does not date the grafting itself. No measured hardiness event or threshold.
Accessed
6b Steve · Houzz
https://www.houzz.com/discussions/4466432/marumi-kumquats-for-up-north (opens in a new tab)
The opening post quotes Nature Hills/TyTy retail claims that Marumi is undamaged at 10°F and may lose leaves and regrow at 0°F, then asks whether the claims are accurate. Follow-up replies discuss C-35 and Flying Dragon rootstocks. The original poster says he planned to test the claims; later he recommends a frame/floorless tent for protection. The thread provides no dated exposure, measured minimum, duration, or documented Marumi damage or survival result.
Accessed
Boisefruit (@Boisefruit) · YouTube
https://www.youtube.com/watch?v=mRyXyzZ4Otw (opens in a new tab)
Summary from transcript: The presenter records a tasting on Jan. 20, 2025, comparing one Marumi fruit with one Meiwa fruit; the Marumi grows in a 7-gallon pot in a greenhouse. He describes the Marumi as juicier than the Meiwa, orange-like inside, tarter than an orange, with sweet skin, a citrusy taste, and a strong aftertaste. These are uncalibrated descriptions from a one-fruit comparison; the auto-captions render “tartter.” He also reports greenhouse winter temperatures around 45–50 degrees (units unstated) and Marumi leaves yellowing then greening as temperatures warm. This is not a measured hardiness threshold.
Accessed
The Mulberries · YouTube
https://www.youtube.com/watch?v=urj0CU0p5gY (opens in a new tab)
Summary from transcript: The presenter points out a Marumi kumquat with what they describe as an unusually large number of flowers (0:08–0:18). They say this will be their first year trying its fruit and repeat hearsay that it is “supposed to be one of the heartiest kumquats” (0:31–0:37). No fruit is tasted and no winter outcome or measured hardiness is reported.
Accessed
Seattle Figs (@SeattleFigs) · YouTube
https://www.youtube.com/watch?v=Gywg1j3ZL0s (opens in a new tab)
Summary from transcript: The speaker harvests greenhouse-grown Marumi fruit for a second crop after a summer crop; the exact count is unclear. They describe flowers through much of the year and the largest crop in spring/summer, though the auto-captioned wording is imperfect. In tasting, the speaker says the skin is edible and sweet, the flesh is sour but “not extremely sour,” and the fruit has a few seeds; they consider the skin its best part. These are qualitative observations, not measured intensity scores. The title says fall 2019, but the captions’ “October 30th” does not establish the harvest year.
Accessed
Growing Fruit · 2023-07-13
https://growingfruit.org/t/meiwa-kumquat-tree/55576 (opens in a new tab)
Post 15 (Gkight, September 19, 2023) reports a second bloom on their Marumi, with fewer flowers than their Meiwa. This is a single grower’s seasonal observation, not a general flowering pattern.
Accessed
Skandiberg · Tropical Fruit Forum · 2025-11-27
https://www.tropicalfruitforum.com/index.php?topic=60062.msg571327#msg571327 (opens in a new tab)
Reply 35 reports one Marumi fruit from the author’s plant. The author judged it ripe after it detached with a gentle touch and reports five developed seeds, two empty seed coats, and a reading of 7 °Bx. This is a single-fruit grower report, not a cultivar-wide measurement.
Accessed
Skandiberg · Tropical Fruit Forum · 2026-02-23
https://www.tropicalfruitforum.com/index.php?topic=60062.msg576517#msg576517 (opens in a new tab)
Post 73 contrasts received Marumi fruit with fruit from the poster's own small plant, which had died during winter. The post does not give the plant's site, rootstock, death date, temperature, exposure duration or cause; it does not establish a hardiness threshold.
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