Getting it to bloom

Why won't my Spencer Waved sweet pea bloom? (and how to make it flower)

Also called Spencer Waved sweet pea, Spencer sweet pea (Lathyrus odoratus 'Spencer Waved').

More about spencer waved sweet pea

About Spencer Waved sweet pea

Lathyrus odoratus 'Spencer Waved' · also called Spencer Waved sweet pea, Spencer sweet pea · flowering

Spencer Waved sweet peas are the classic exhibition and cutting-garden sweet pea group, producing large, wavy-petalled, intensely fragrant flowers in a wide colour range on long, straight stems. Vigorous climbers reaching 1.8 m or more, they bloom prolifically in cool conditions from late spring through summer if deadheaded faithfully.

Plant type: flowering

Watch for — Bud drop (flower abortion): Buds fail to open and drop off in dry soil conditions, water stress, or sudden heat. Keep soil consistently moist with deep weekly watering and a thick mulch. Water in the evening in warm weather.

The reasons spencer waved sweet pea isn't blooming

Almost every non-blooming spencer waved sweet pea 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 spencer waved sweet pea 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 spencer waved sweet pea to flower

Maximise sun. Give spencer waved sweet pea 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 spencer waved sweet pea and get the feeding right with the spencer waved sweet pea 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

Spencer Waved sweet pea 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 spencer waved sweet pea care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Spencer Waved sweet pea blooming — frequently asked questions

Why won't my spencer waved sweet pea flower?

Spencer Waved sweet pea 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 spencer waved sweet pea bloom?

Give spencer waved sweet pea 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 spencer waved sweet pea normally bloom?