Getting it to bloom

Why won't my Showy Milkweed bloom? (and how to make it flower)

Also called showy milkweed, Greek milkweed (Asclepias speciosa).

More about showy milkweed

About Showy Milkweed

Asclepias speciosa · also called showy milkweed, Greek milkweed · flowering

Showy milkweed is a robust North American native prairie perennial grown as a monarch host and nectar plant. It produces star-shaped pink-mauve flower clusters and velvety grey-green leaves on upright stems. Tough and drought-tolerant once established, it spreads by rhizomes to form colonies and thrives in full sun and lean, well-drained soil.

Plant type: flowering

Watch for — Oleander aphids: Bright yellow aphids cluster on stems and buds; blast off with water or tolerate them, since insecticides also harm monarch larvae feeding on the plant.

The reasons showy milkweed isn't blooming

Almost every non-blooming showy milkweed traces back to one of these, roughly in order of how common they are:

Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
The plant has not been deadheaded, so it stops flowering once it sets seed.
Irregular watering — drought or waterlogging at the budding stage makes buds abort.
It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding showy milkweed a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get showy milkweed to flower

Maximise sun. Give showy milkweed the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for showy milkweed and get the feeding right with the showy milkweed fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Showy Milkweed flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full showy milkweed care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Showy Milkweed blooming — frequently asked questions

Why won't my showy milkweed flower?

Showy Milkweed blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make showy milkweed bloom?

Give showy milkweed the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does showy milkweed normally bloom?