Oxalis Iron Cross is also known as the Good Luck plant or Oxalis Tetraphylla, it is native to Mexico and it is one of the easiest plants to grow. The best part about this plant is that it will grow well both in full sun or partial shade. Oxalis Iron Cross is grown both for its foliage and its flowers as well, its foliage is predominantly green with dark purple-ish triangles which looks like an iron cross, its flowers are pink or red depending in what kind of soil it is grown.
The special characteristic of this plant is that its leaves close up during the night, and open up in the morning. The Oxalis Iron Cross is a perennial plant usually grown from bulbs, the bulbs are rather small and relatively cheap so you can easily plan a beautiful flower border with them. If you want to grow some alliums as well then check out my recent article Allium Mount Everest ( Allium Stipitatum Mount Everest ).
Characteristics: Perennial Bulb
Hardiness Zone: Zone 7-10
Sun Requirements: Full Sun. Shade
Height And Width: Height 5″- 12″ ( 12cm-30cm ), Width 3″-6″ ( 7cm-15cm )
Flowering Period: June – August
Planting: Easy
Propagation: Dividing Bulbs, Seeds
Deer Resistance: Yes
Pet Friendliness: No
Pests: Slugs, Aphids
Indoor Care: Easy
Soil Type And PH: Clay, Sand, Loam, Acidic, Alkaline, Neutral
Water Requirements: Moderate
Invasive: No
Pots And Containers: Yes
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Oxalis Iron Cross Characteristics
This plant is usually grown from bulbs which tend to multiply once they are established. It is a mostly carefree plant, as you do not even have to deadhead them, but you will have to separate the bulbs once every 5 years or so. Once the bulbs have clumped up due to new bulbs forming some of them might die off if you do not divide them. The Oxalis Iron Cross tends to bloom for a relatively long time, and it will thrive in any type of soil.
Oxalis Iron Cross Hardiness Zone
The Oxalis Iron Cross is a perennial plant only between Zone 7-10 and an annual plant in the rest of the zones. This means that between Zone 7-10 you can leave it in the garden during the winter, but you have to dig the bulbs up and store them in a cool dark environment if you are not in Zones 7-10. The Oxalis Iron Cross will do well from Zone 7-10, as it is originally from Mexico it will thrive in areas with somewhat hotter climates. Even though I am in Zone 6 I still have no problems growing this plant, and it comes up every year without a problem.
In case your area has fairly humid winters and your soil doesn’t drain well then you might want to plant the bulbs in an area where the extra moisture will not rot the bulbs away.
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Oxalis Iron Cross Sun Requirements
The Oxalis Iron Cross can grow both in full sun and in partial shade as well. Just keep in mind that these plants come from a relatively hot environment, so they will have no problem growing in partial shade in the south but in the northern parts of the country, you should grow them in full sun. If your Oxalis Iron Cross doesn’t flower in partial shade then you should relocate it to a full sun area and it should flower.
Oxalis Iron Cross Height And Width
The Oxalis Iron Cross is a relatively short plant, its height is between 5″- 12″ ( 12cm-30cm ) and its width is around 3″-6″ ( 7cm-15cm ). If it is grown in full sun then it will be shorter and wider, in partial shade, it will grow tall and thinner.
Oxalis Iron Cross Flowering Period
Generally speaking, the Oxalis Iron Cross will bloom from June to August, although in the southern parts of the country it could bloom even during October. In colder climates, the flowering period can be cut short if the nights tend to be fairly cold. The color of the flowers are usually pink, but sometimes they can come up as red, it all depends on the local climate and of the soil composition.
Oxalis Iron Cross Planting
Planting the Oxalis Iron Cross is extremely easy, just dig a small hole that is 3 times deeper than the size of the bulb and place the bulb with the pointy tip up. Fill in the hole with garden soil or with some kind of compost. You can also mulch the area with wood chips, compost, hay, and so on as the Oxalis Iron Cross bulbs will have no problem growing right through the mulch. The best time to plant the bulbs is during the autumn, generally speaking around 6-7 weeks before your first frost date.
Oxalis Iron Cross Propagation
The Oxalis Iron Cross is extremely easy to propagate, and the best part about it is that it can easily do it by itself. The bulbs tend to multiply, which can either be left alone or divided for more plants. In addition to this the Oxalis Iron Cross can also be a fairly reliable self-seeder in some areas, and collecting the seeds is extremely easy.
Oxalis Iron Cross Deer Resistance
For the most part, the Oxalis Iron Cross is deer resistant, although if the deer are hungry enough they will eat it.
Oxalis Iron Cross Pet Friendliness
Unfortunately, the Oxalis Iron Cross is not pet friendly as it is poisonous to pets, its leaves contain oxalic acid which when ingested could cause serious problems. If you have pets that tend to dig up your bulbs or eat some of their leaves then you should avoid planting this plant.
Oxalis Iron Cross Pests
The Oxalis Iron Cross has two main pests, slugs and aphids. Generally speaking, the slugs will eat the first shoots coming out of the bulb, which can stunt the growth or outright kill the plant. Once the weather is hot enough for the Oxalis Iron Cross to push through the surface you should either use slug pellets or place a plastic bottle on top of it for extra protection. Once the plant is mature enough the slugs will mostly stay away from it.
The second most common pest for the Oxalis Iron Cross are aphids, which tend to attack once the plant has matured. You can remove them by hand or by using pesticides for aphids.
Oxalis Iron Cross Indoor Care
The Oxalis Iron Cross can actually be grown indoors, make sure to use high-quality potting soil and place it next to a window where it gets plenty of sunlight. This plant will do fine in partial shade, but it will struggle indoors if it is not getting direct sunlight for at least a couple of hours a day. In case it doesn’t get enough sunlight the plant will simply not flower.
Oxalis Iron Cross Soil Type And PH
The Oxalis Iron Cross will grow well in, clay, sand, or loam soils. If you have compacted clay soil then you need to loosen up the soil while planting. The Oxalis Iron Cross can grow in alkaline, acidic, and neutral soil, so do not worry about your soil PH. As long as things are growing in the area where you are planting them, then it should do well.
Oxalis Iron Cross Water Requirements
The Oxalis Iron Cross has a relatively moderate water requirement, as this plant is native to Mexico it can be somewhat drought tolerant as well, especially if it is growing in partial shade. Usually what tends to kill this plant is overwatering, which often can lead to the bulbs and roots rotting.
Is The Oxalis Iron Cross Invasive?
No, the Oxalis Iron Cross, is not an invasive plant, although if you plant hundreds of bulbs then you might want to thin them out once every couple of years.
Can Oxalis Iron Cross Be Grown In Pots And Containers?
Yes, the Oxalis Iron Cross can be grown in pots and containers, especially as the plant tends to be relatively short with shallow roots. If you are planting them in pots and containers outside then make sure to give them enough water as these containers tend to dry out relatively fast. As a general rule, you should avoid plastic pots and containers, but any other container will do well. You can even get away by using a small container if you are planting only one bulb, but the more bulbs you plant the bigger the container should
Can I Grow Oxalis Iron Cross In My State?
The Oxalis Iron Cross can be grown in every US state, even if your local USDA hardiness zone is above or below zones 7-10 you can still grow it as an annual, which means that you have to dig up the bulbs in the autumn and replant them in the spring. If you don’t know your hardiness zone then you can check it USDA Hardiness Zones.
| State | Hardiness Zone | Can I Grow It? |
|---|---|---|
| Alabama | 7a to 9a | Yes, In The Entire State |
| Alaska | 1a to 8b | Yes, In Zones 7-8 |
| Arizona | 4b to 10b | Yes In Zones 7-10 |
| Arkansas | 6b to 8a | Yes, In Zones 7-8 |
| California | 5a to 11b | Yes, In Zones 7-10 |
| Colorado | 3a to 7a | Yes, In Zone 7 |
| Connecticut | 5b to 7a | Yes, In Zone 7 |
| Delaware | 7a to 7b | Yes, In The Entire State |
| Florida | 8 to 11 | Yes, In The Entire State |
| Georgia | 6a to 9a | Yes, In Zones 7-9 |
| Hawaii | 9a to 13a | Yes, In Zones 9-10 |
| Idaho | 3 to 7 | Yes, In Zone 7 |
| Illinois | 5a to 7a | Yes, In Zone 7 |
| Indiana | 5b to 6b | Yes, As An Annual Plant |
| Iowa | 4b to 5b | Yes, As An Annual Plant |
| Kansas | 5a to 6b | Yes, As An Annual Plant |
| Idaho | 1a to 8b | Yes, In Zones 7-8 |
| Kentucky | 6a to 7a | Yes, In Zone 7 |
| Louisiana | 8 to 9 | Yes, In The Entire State |
| Idaho | 1a to 8b | Yes, In Zones 7-8 |
| Maine | 3 to 6 | Yes, As An Annual Plant |
| Maryland | 5b and 8a | Yes, In Zones 7-8 |
| Massachusetts | 5a to 7b | Yes, In Zone 7 |
| Michigan | 4a to 6b | Yes, As An Annual Plant |
| Minnesota | 3a to 5a | Yes, As An Annual Plant |
| Mississippi | 7b to 9a | Yes, In The Entire State |
| Missouri | 5b to 7a | Yes, In Zones 7 |
| Montana | 3a to 6a | Yes, As An Annual Plant |
| Nebraska | 4b to 5b | Yes, As An Annual Plant |
| Nevada | 4a to 10a | Yes, In Zones 7-10 |
| New Hampshire | 3b to 6a | Yes, As An Annual Plant |
| New Jersey | 6a to 7b | Yes, In Zones 7 |
| New Mexico | 4 to 9 | Yes, In Zones 7-9 |
| New York | 3b to 7b | Yes, In Zone 7 |
| North Carolina | 5b to 8b | Yes, In Zones 7-8 |
| North Dakota | 2b-6a | Yes, As An Anual Plant |
| Ohio | 5b and 6b | Yes, As An Annual Plant |
| Oklahoma | 6a to 8a | Yes, In Zones 7-8 |
| Oregon | 4b to 9b | Yes, In Zones 7-9 |
| Pennsylvania | 5b to 7a | Yes, In Zone 7 |
| Rhode Island | 5b and 7a | Yes, In Zone 7 |
| South Carolina | 7a and 9a | Yes, In Zones 7-9 |
| South Dakota | 3b to 5b | Yes, As An Annual Plant |
| Tennessee | 5b to 8a | Yes, In Zones 7-8 |
| Texas | 6a to 9b | Yes, In Zones 7-9 |
| Utah | 4a to 9a | Yes, In Zones 7-9 |
| Vermont | 3b to 5b | Yes, As An Annual Plant |
| Virginia | 5a to 8a | Yes, In Zones 7-8 |
| Washington | 4a to 9a | Yes, In Zones 7-9 |
| West Virginia | 5a to 7a | Yes, In Zone 7 |
| Wisconsin | 3b to 5b | Yes, As An Annual Plant |
| Wyoming | 2a to 5b | Yes, As An Annual Plant |
In Conclusion
As you can see the Oxalis Iron Cross is relatively easy to care for and I highly recommend it even to beginner gardeners. This plant tends to bloom for a relatively long time, and if the soil conditions are good then you can see blooms even at the end of autumn.
