How to Grow and Care for Blood Flower

Blood flower—known by many other names including tropical milkweed, Mexican butterfly weed, and scarlet milkweed—is a striking species of milkweed, attracting pollinators with its bright, orange flowers that bloom in summer through fall. Perennial in warmer areas, blood flower is usually grown as an annual and thrives in full sun and in nutrient-rich, well-draining soil.

Note that this species can actually be harmful for monarch butterflies. Blood flower can bloom at a time that can disturb migration patterns, and it plays host to a common monarch parasite. Monarch butterfly populations are struggling. Additionally, blood flower is toxic to people and pets.

Blood Flower Care

Blood flower is a low-maintenance plant that is very easy to grow. Here are the main care requirements for blood flower:

• Choose a sunny spot that gets at least six hours of direct sunlight per day.
• Prepare nutrient-rich, well-draining soil.
• Water consistently, though blood flower can handle a bit of drought.
• Additional fertilization is not needed when growing as an annual.
  

Light

Blood flower grows best in full sun but can tolerate partial shade when grown outdoors. When choosing a spot in your garden for blood flower, select a location that receives plenty of direct sunlight throughout the day. When potted plants are moved indoors, they demand a very sunny location.

Soil

Blood flower is able to grow in a variety of different soil types and generally isn't picky about where it grows. Above all else, make certain that well-drained soil is provided, as blood flower does not like to be waterlogged.

Water

Blood flower is considered drought-tolerant but will do best when consistent moisture is provided. Supplement regular rainfall with occasional watering if you notice that the plant is drying out significantly between rainfalls. 

Temperature and Humidity

In most areas, blood flower is treated as an annual, although they are evergreen perennials in tropical climates—zones 9 to 11. Blood flower can tolerate both humid and dry environments but thrives in humid climates, such as the coastal areas of the deep south and southeast.

Fertilizer

Blood flower prefers nutrient-rich soil, but if you are growing it as annual, it won't need much additional feritlization. If you are starting blood flower from seed, you may wish to fertilize the seedlings once they have become established to give them a boost at the beginning of the growing season.

Types of Blood Flower

The pure species of this plant has red-orange flowers with yellow hoods and grows to about 3 feet tall. Various cultivars of A. curassavica have been developed to improve the flower color and create shorter, more manageable plants.

• A. curassavica 'Silky Gold' features large clusters of golden-yellow flowers.
• A. curassavica ‘Silky Deep Red’ is a cultivar with strong red flowers.
• A. curassavica ‘Red Butterfly' is another red option, featuring flowers that are darker red.
• A. curassavica ‘Apollo Orange’ is a cultivar with pure orange flowers.
• A. curassavica ‘Apollo Yellow’ has pure yellow blossoms.

Pruning

Due to the fact that blood flower can interfere in the natural migratory pattern of monarch butterflies, it's best if they are not allowed to go to seed and spread, especially when grown in states without harsh winters to kill them off. Cut back the plants at ground level in the fall to ensure they don’t go to seed. When grown in areas with mild winters, blood flower should be cut back every couple of weeks to ensure it does not flower year-round.

Propagating Blood Flower

Vegetative propagation through stem cuttings is fairly easy with this plant, though it's not commonly done since the seeds germinate and sprout so easily. However, the vegetative method may be the best option if you are growing one of the named cultivars and want to ensure an exact duplicate of the parent plant:

1. During a period of active growth, snip a 6- to 8-inch long tip off a growing shoot, preferably without flowers or buds. Take care not to touch the milky sap, as this can cause skin irritation.
2. Strip off the lower leaves, then plant the cutting in a small pot filled with commercial potting mix.
3. Place in a bright, warm location and keep the potting moist until the cutting develops roots and new growth is evident.
4. Once roots are established, the cutting can be transplanted into the garden. Don't wait too long, as the plant will not transplant well once it develops a sizable tap root.
5. Pinching back young plants will cause them to be bushier and produce more flowers.

How to Grow Blood Flower From Seed

For spring planting, start the seeds indoors eight to 10 weeks before the last frost. You can use commercial seeds or seeds collected from the mature seed pods of garden plants.

1. Soak the seeds for 24 hours before planting.
2. Sow them in small pots filled with seed starter mix or ordinary potting soil, and keep them in a bright, room-temperature location until they germinate. This normally takes two to three weeks.
3. The seedlings can then be moved to a sunny location and kept moist (but not wet) until planting time.
4. Note that seedlings transplant fairly easily, but established plants develop a long taproot that makes transplanting a tricky matter.

This plant self-seeds very readily, and volunteer seedlings can easily be dug up and transplanted into other areas in the garden.

Overwintering

When grown as a perennial in its established hardiness range, this plant requires no special winter protection. In colder zones where it is grown as an annual, mature plants should be cut off or pulled from the ground and discarded before they set seed.

Potting and Repotting Blood Flower

Blood flower is a fairly easy plant to grow in containers, and because it is evergreen in warm climates, potted plants are sometimes moved back and forth between indoor and outdoor locations with the changes in season. When moved indoors for the winter, these plants will need the sunniest location you can offer.

Use a fairly large, deep container to provide room for the deep taproot, and fill it with ordinary commercial potting mix, preferably mixed with some extra perlite or vermiculite to improve drainage. Plants will need to be watered somewhat more frequently when grown in containers.

Common Pests

Pests are more likely to be problematic in warmer regions where blood flower grows as a perennial. In these regions, aphids often colonize on the leaves and stems, sometimes leading to sooty mold that develops on the honeydew excretions of the aphids. Aphids are best handled by simply spraying the plants with strong blasts of water to dislodge the insects.

Avoid pesticides, as these are likely to also kill the desirable butterflies and their larvae, as well as other pollinators. Pests are less troublesome in colder climates where the plants die back each winter.

How to Get Blood Flower to Bloom

As long as they're planted in a sunny spot and in generally good health, blood flower plants should bloom readily and offer a colorful show.

Bloom Months

This plant usually blooms from late spring or early summer into fall, depending on your location.

What Do Blood Flower Blooms Look and Smell Like?

This milkweed species offers clusters of bright orange blooms with yellow centers. The flowers have a light, sweet smell.

How to Encourage More Blooms

To extend the bloom period, start seeds indoors eight to 10 weeks before the last frost date. Shady conditions may hinder flower development, so grow your blood flower plants in the sunniest spot you can.

Caring for Blood Flower After It Blooms

Once blood flower is done blooming, prune it back to remove the spent flowers, preventing the plants from self-seeding and spreading.