Getting it to bloom

Why won't my Dahlia 'Thomas Edison' bloom? (and how to make it flower)

Also called Thomas Edison dahlia, purple dinner plate dahlia (Dahlia 'Thomas Edison').

More about dahlia 'thomas edison'

About Dahlia 'Thomas Edison'

Dahlia 'Thomas Edison' · also called Thomas Edison dahlia, purple dinner plate dahlia · flowering

Dahlia 'Thomas Edison' is a vintage dinner-plate dahlia with huge, fully double rich royal-purple blooms up to 20 cm across on tall sturdy stems. A robust tuberous perennial, it flowers from midsummer to frost, thrives in full sun and fertile soil, and reaches around 1.2 m, making a bold border centrepiece and statement cut flower.

Plant type: flowering

Watch for — Stem flop without staking: Heavy dinner-plate blooms snap or splay unsupported stems; stake at planting and tie in as the plant grows.

The reasons dahlia 'thomas edison' isn't blooming

Almost every non-blooming dahlia 'thomas edison' 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 dahlia 'thomas edison' 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 dahlia 'thomas edison' to flower

Maximise sun. Give dahlia 'thomas edison' 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 dahlia 'thomas edison' and get the feeding right with the dahlia 'thomas edison' 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

Dahlia 'Thomas Edison' 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 dahlia 'thomas edison' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Dahlia 'Thomas Edison' blooming — frequently asked questions

Why won't my dahlia 'thomas edison' flower?

Dahlia 'Thomas Edison' 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 dahlia 'thomas edison' bloom?

Give dahlia 'thomas edison' 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 dahlia 'thomas edison' normally bloom?