Getting it to bloom

Why won't my Rhododendron 'Blue Peter' bloom? (and how to make it flower)

Also called Blue Peter Rhododendron, Lavender Rhododendron (Rhododendron 'Blue Peter').

More about rhododendron 'blue peter'

About Rhododendron 'Blue Peter'

Rhododendron 'Blue Peter' · also called Blue Peter Rhododendron, Lavender Rhododendron · flowering

Rhododendron 'Blue Peter' is a classic, floriferous hybrid bearing conical trusses of lavender-blue flowers with purple-spotted throats in late spring. A robust and free-flowering cultivar with attractive glossy foliage. AGM holder from the RHS. All parts are highly toxic to pets and humans if ingested.

Plant type: flowering

Watch for — Rhododendron leafhopper / bud blast: Leafhoppers introduce the fungus that kills flower buds (bud blast). Control leafhoppers in late summer with a systemic insecticide to break the cycle.

The reasons rhododendron 'blue peter' isn't blooming

Almost every non-blooming rhododendron 'blue peter' 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 rhododendron 'blue peter' 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 rhododendron 'blue peter' to flower

Maximise sun. Give rhododendron 'blue peter' 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 rhododendron 'blue peter' and get the feeding right with the rhododendron 'blue peter' 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

Rhododendron 'Blue Peter' 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 rhododendron 'blue peter' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Rhododendron 'Blue Peter' blooming — frequently asked questions

Why won't my rhododendron 'blue peter' flower?

Rhododendron 'Blue Peter' 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 rhododendron 'blue peter' bloom?

Give rhododendron 'blue peter' 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 rhododendron 'blue peter' normally bloom?