Getting it to bloom

Why won't my Penstemon 'Stapleford Gem' bloom? (and how to make it flower)

Also called Stapleford Gem beardtongue, lilac-mauve penstemon (Penstemon 'Stapleford Gem').

More about penstemon 'stapleford gem'

About Penstemon 'Stapleford Gem'

Penstemon 'Stapleford Gem' · also called Stapleford Gem beardtongue, lilac-mauve penstemon · flowering

A semi-evergreen, clump-forming border penstemon prized for lilac-mauve, white-throated tubular flowers held on upright spikes from June into autumn. It draws bees and hummingbird-like pollinators, rewards deadheading with months of bloom, and thrives in a sunny, free-draining spot. RHS Award of Garden Merit holder, reliably hardy in milder UK gardens.

Plant type: flowering

Watch for — Floppy, sparse flowering: Caused by too much shade or over-rich soil. Move to full sun and ease off nitrogen feeds for stronger, more upright spikes.

The reasons penstemon 'stapleford gem' isn't blooming

Almost every non-blooming penstemon 'stapleford gem' 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 penstemon 'stapleford gem' 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 penstemon 'stapleford gem' to flower

Maximise sun. Give penstemon 'stapleford gem' 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 penstemon 'stapleford gem' and get the feeding right with the penstemon 'stapleford gem' 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

Penstemon 'Stapleford Gem' 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 penstemon 'stapleford gem' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Penstemon 'Stapleford Gem' blooming — frequently asked questions

Why won't my penstemon 'stapleford gem' flower?

Penstemon 'Stapleford Gem' 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 penstemon 'stapleford gem' bloom?

Give penstemon 'stapleford gem' 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 penstemon 'stapleford gem' normally bloom?