That deep purple, triangular leaf that folds up at night like a resting butterfly—Oxalis Triangularis is a houseplant obsession that spreads fast once you see it. But the online bulb market is packed with dried-out corms that never push a single sprout, leaving you staring at bare soil for weeks.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I study grower reviews, compare bulb freshness across suppliers, and analyze germination success rates so you don’t waste a season on dead corms.
After sorting through hundreds of verified owner reports on size, sprout speed, and package count, I’ve narrowed the field to the five packs that actually deliver on the promise of a best oxalis plum crazy experience in your home or office.
How To Choose The Best Oxalis Plum Crazy Bulbs
The “Plum Crazy” look you’re after is that deep wine-purple foliage with three heart-shaped leaflets per stem. Reaching that depends on three factors that beginner buyers often overlook.
Bulb Freshness & Size
Oxalis corms are small, dry, and light—they don’t look impressive out of the bag. But a fresh corm shows a tiny pinkish tip or a hint of a root nub. Bulbs that have sat in a warehouse for two seasons arrive shriveled and rarely germinate. Larger corms generally store more energy for the first push of leaves.
Packed Count vs. Actual Germination
One pack boasts “25 bulbs,” but growers report soft rot before planting. Another advertises 10 corms and buyers frequently receive 16–19 extras that all sprout. The number of live sprouts that emerge weeks later matters more than the advertised count on the label.
Iron Cross vs. Purple Shamrock
Iron Cross Oxalis produces green leaves with a purple center cross, plus pink flowers—not solid purple. If you want the deep purple triangle look, you need Oxalis Triangularis, often sold as “Purple Shamrock.” Read the “about this item” text carefully before clicking add to cart.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Lucky Leaf Shamrock Bulbs (10 Bulbs) | Iron Cross | Best Overall Count & Germination | 16–19 bulbs received vs 10 advertised | Amazon |
| Oxalis Triangularis 10 Bulbs | Purple Shamrock | True Plum Crazy Foliage | Solid purple triangular leaves | Amazon |
| Oxalis Triangularis Bulbs (10 Bulbs) | Purple Shamrock | Indoor Windowsill Display | Magenta underleaf, deep purple top | Amazon |
| Purple Shamrock Bulbs (5 Bulbs) | Purple Shamrock | Budget Try-Before-You-Commit | 5 corms only, mixed germination reports | Amazon |
| Iron Cross Flower Bulbs (25 Bulbs) | Iron Cross | High-Volume Outdoor Color | 90% germination on large 5/6 cm corms | Amazon |
In‑Depth Reviews
1. Lucky Leaf Shamrock Bulbs for Planting (10 Bulbs)
This pack from CZ Grain is the standout for one simple reason: buyers consistently report receiving 16 to 19 bulbs when they ordered 10, and nearly every one germinates. One verified review noted sprouts pushing through in just 10 days—far faster than the 4 to 10-week window listed on the instructions. That kind of over-delivery builds immediate trust.
The variety is Iron Cross Oxalis, so the leaves are green with a deep purple cross in the center rather than solid purple. If you want that exact “Plum Crazy” look, this isn’t it—but if you want a dense, healthy clover that also produces rosy pink summer flowers, these bulbs deliver exceptional value. Growers on the hot East Coast reported success both in pots with daily water and in ground beds with no supplemental water.
The downside: the foliage isn’t the solid purple you may have pictured. Multiple buyers mentioned they purchased expecting the Triangularis purple look and were surprised by green leaves with purple centers. Read the description closely. The package count alone, however, makes this the most reliable buy for your money.
What works
- Buyers often receive nearly double the advertised bulb count
- Some corms sprout in 10 days instead of 4–10 weeks
- Thrives indoors and outdoors with minimal care
What doesn’t
- Iron Cross produces green leaves, not solid purple foliage
- Bulb size varies and smaller corms may lag in growth
2. Oxalis Triangularis 10 Bulbs – Purple Shamrock
This is the true Oxalis Triangularis—the one with the dark purple triangle leaves that buyers describe as looking like little butterflies. One verified reviewer planted 8 out of 10 corms and got 8 successful sprouts, even after accidentally leaving the bag unplanted for days. Tiny roots had already pushed through the plastic, proving the corms arrived alive and eager.
The growing instructions are straightforward, and multiple owners mentioned the plant was forgiving of neglect. The leaf color stays a deep wine-purple in bright indirect light, which matches the “Plum Crazy” aesthetic perfectly. Some packs even arrived with more than 10 corms, though that’s not guaranteed. The year-round blooming period means you’ll see those purple flags open repeatedly indoors.
Not every corm germinated for every buyer—one report of zero sprouts exists, with the user suspecting the bulbs had already started to sprout and then shriveled in storage. That risk exists with any live bulb order. But the overwhelming majority of reports show 8/10 or 10/10 germination with fast growth once planted.
What works
- Deep purple triangular leaves match the Plum Crazy look exactly
- Forgiving planting window—corms survived days in the bag
- Year-round blooms with moderate watering
What doesn’t
- A small percentage of corms can arrive shriveled and fail to sprout
- Full sun is recommended but indoor windowsill light may not be sufficient for robust growth
3. Oxalis Triangularis Bulbs (10 Bulbs) – Purple Shamrock
A second CZ Grain entry, this pack also sells true Oxalis Triangularis, but buyers describe a slightly different color payoff: deep purple on the top surface and a magenta shade on the leaf underside. One thrilled owner reported all 10 bulbs sprouted, with one corm producing three separate stems and two corms producing two stems each. That kind of branching density fills a pot quickly.
The compact growth habit is ideal for windowsills, desks, and small shelves—the plant stays low and bushy rather than leggy. In bright indirect light, it maintains that rich pigmentation throughout the year. The brand’s reputation for bulking up orders also applies here, although not as aggressively as the Lucky Leaf pack. Buyers consistently praise CZ Grain’s packaging and shipping speed.
The primary complaint: some users report the plant goes dormant quickly after the first flush of bloom, especially if the pot isn’t filled with enough corms to create a full look. One reviewer noted the shoots came up “frail” and recommended buying a larger order to achieve a dense display. For a small solo pot, this works beautifully. For a broad planter, consider two packs.
What works
- Magenta undersides add a second color dimension to the purple leaves
- Compact growth fits small indoor spaces without outgrowing the pot
- Multiple stems per corm leads to a fuller look faster
What doesn’t
- Some corms produce thin stems that look sparse in large containers
- Dormancy can hit quickly after the first growth cycle
4. Purple Shamrock Bulbs – 5 Bulbs to Plant
This entry-level 5-bulb pack from CZ Grain is the smallest commitment in the roundup, and it shows in the mixed owner feedback. While one buyer reported beautiful pairing with green Oxalis in a mixed container, several others reported zero germination after two attempts over three months, even while following the included instructions exactly.
The low bulb count increases the stakes: if a few corms arrive dried out, you have almost no margin for error. With 10-bulb packs, you can afford to lose two or three and still get a decent pot. With 5, one bad batch leaves you with nothing. Multiple 1-star reviews describe the same experience—no sprouts, no blooms, just dormant soil.
On the positive side, the price point is the lowest in this list, making it a low-risk trial for someone who wants to test Purple Shamrock before investing in a larger pack. If you have good conditions and get live corms, the deep purple foliage is unmistakable. But given the frequency of failure reports, it’s worth spending a few dollars more for a bigger, more reliable pack.
What works
- Bare minimum investment for testing Purple Shamrock indoors
- Surviving corms produce the classic deep purple triangular leaves
What doesn’t
- Multiple reports of zero germination after two planting attempts
- 5 bulbs is too few to fill even a small pot with confidence
5. Iron Cross (Oxalis) Flower Bulbs – 25 Bulbs per Pack
Holland Bulb Farms delivers the largest pack by count with 25 Oxalis Iron Cross corms, sized 5 to 6 cm each—noticeably larger than typical CZ Grain offerings. Buyers report a 90% germination rate with very rapid sprouting and blooming within two weeks. That’s unusually fast for Oxalis, which typically takes 4 to 10 weeks to show its first leaves.
The green-pink-purple bicolor foliage works beautifully in large outdoor containers and borders in USDA zones 8 through 10. The rosy pink summer flowers add a second seasonal show after the purple-centered leaves establish. The corms are organic and perennial in warm climates, meaning they’ll come back year after year if left in the ground.
The trade-off: this is Iron Cross, not Purple Shamrock, so you won’t get solid purple foliage. And some buyers noted that the pack arrived shabbily packaged and unlabeled—the bulbs themselves were excellent, but the unboxing experience was sloppy. The 25-bulb count is impressive on paper, but several corms may go dormant quickly after the first bloom cycle, as noted in one 3-star review.
What works
- 25 large corms offer the best per-unit count and fast germination
- Pink flowers appear within 2 weeks of planting
- Perennial in zones 8–10 for repeat seasons
What doesn’t
- Iron Cross has green leaves with purple centers, not solid purple
- Some bulbs bloom briefly then go dormant without reblooming
Hardware & Specs Guide
Bulb Size & Freshness
Oxalis corms range from 1 to 6 cm in diameter. Larger corms (5–6 cm) hold more energy for faster leaf push and thicker stems. Fresh corms show a pinkish tip or a small root nub—avoid packs where bulbs look papery or crumble when squeezed.
Light & Moisture
Oxalis Triangularis needs bright indirect light to maintain its deep purple pigment—full sun can scorch leaves, while low light turns them green. Moderate watering is key: let the top inch of soil dry out between waterings to prevent corm rot, which is the leading cause of failure reported in buyer reviews.
Iron Cross vs. Triangularis
Iron Cross (Oxalis deppei) produces green four-leaf clovers with a dark purple center splotch and pink summer flowers. Triangularis (Oxalis triangularis) produces solid purple three-leaf triangles and is the variety that matches the “Plum Crazy” look. The product name and description are the only way to tell them apart.
Dormancy Cycle
All Oxalis experience a natural dormancy period after active growth and blooming. Leaves may yellow and die back, but the corm remains alive underground. Reduce watering during dormancy and resume when new growth appears—typically after 4 to 8 weeks. Some growers mistake dormancy for plant death and discard live bulbs unnecessarily.
FAQ
How long does it take for Oxalis Triangularis bulbs to sprout indoors?
Can I keep Oxalis Plum Crazy alive year-round indoors without a dormant period?
What is the difference between Purple Shamrock and Iron Cross Oxalis?
Final Thoughts: The Verdict
For most gardeners, the best oxalis plum crazy winner is the Oxalis Triangularis 10 Bulbs because it delivers the exact solid purple triangle foliage you’re picturing, with reliable germination and fast growth indoors. If you want a dense pot with the best bulb count per dollar, grab the Lucky Leaf Shamrock 10 Bulbs—just remember the green leaves with purple crosses aren’t the Plum Crazy look. And for high-volume outdoor color in beds or large containers, nothing beats the Holland Bulb Farms 25-Pack Iron Cross for rapid bloom and perennial return in warm zones.