Getting it to bloom

Why won't my Red amaranth bloom? (and how to make it flower)

Also called Red amaranth, Purple amaranth, Blood amaranth, African spinach (Amaranthus cruentus).

More about red amaranth

About Red amaranth

Amaranthus cruentus · also called Red amaranth, Purple amaranth · flowering

Red amaranth is a vigorous, heat-loving annual grown for both its dramatic plum-red or crimson flower plumes and its highly nutritious edible leaves and seeds. Tolerant of drought and poor soil, it performs best in full sun with moderate fertility. Its architectural stature makes it a striking border plant and excellent dried flower.

Plant type: flowering

Watch for — Aphid infestations: Dense colonies of black or green aphids, especially on new growth and flower plumes. Blast off with a strong jet of water or apply insecticidal soap. Companion-plant with nasturtium as a trap crop.

The reasons red amaranth isn't blooming

Almost every non-blooming red amaranth 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 red amaranth 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 red amaranth to flower

Maximise sun. Give red amaranth 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 red amaranth and get the feeding right with the red amaranth 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

Red amaranth 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 red amaranth care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Red amaranth blooming — frequently asked questions

Why won't my red amaranth flower?

Red amaranth 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 red amaranth bloom?

Give red amaranth 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 red amaranth normally bloom?