'White Supreme' Sweet Pea Plants

• Variety: White Supreme
• Type: Spencer
• Colour: Pure white
• Scent: 3/5 (Parsons) — light and fresh, noticeable up close
• Flowers: Large, well-waved blooms with good substance. Typically 4 blooms per stem
• Stems: Long, strong, and upright — reliable for cutting
• Height: 2m (6–7ft) with support
• Flowering: Late spring to early autumn with regular picking
• RHS AGM: No
• Bred by: Unwins
• Sold as: Jumbo plug plants, hand-sown by us
• Plant outdoors: After last frost
• Delivered: March to May by next-day courier

White Supreme – Clean, Hard-Working, and Oddly Underrated

White sweet peas divide people. Some gardeners find them bland — all that effort for a flower without colour. Others, usually after a year or two of growing mixed varieties and ending up with clashing vases, come round to the view that a good white is the most useful plant in the cutting garden. White Supreme sits firmly in the second camp's corner. The blooms are a true, clean white without the cream undertones you get from varieties like Jilly, and without the slight grey cast that can creep into some whites during cool, overcast spells.

The flowers are well-waved Spencers with decent substance — they hold their shape in the vase rather than flopping after a day. Four blooms per stem is typical, occasionally three early in the season when the plant is still finding its stride. Stems are long and straight enough for cutting without being exhibition-grade, which is an honest distinction worth making. This is a garden and vase variety, not a show bench contender.

The Case for Growing White on Purpose

Most people who grow White Supreme are not growing it alone. They are growing it because they have learned, usually the hard way, that a handful of white stems transforms a mixed bunch from a cheerful muddle into something that looks intentional. White acts as a visual pause between colours. It stops a vase of deep purples and hot pinks from looking like a disagreement.

There is a practical consideration too. White sweet peas photograph well. If you grow flowers for the house and occasionally post the results online, white is the colour that makes your phone camera behave. Darker varieties — gorgeous in person — tend to photograph as indistinct blobs. White Supreme in a jam jar on a windowsill looks exactly as good on screen as it does in life. We mention this because a surprising number of our customers have told us so.

White Supreme is not the variety you grow nose-first. The fragrance is there — a clean, light sweetness — but it sits in the background rather than demanding attention. Think of it as the visual anchor in a mixed planting: the scent comes from whatever you grow it with, and White Supreme makes everything around it look better in return.

Pairing Ideas

White Supreme is at its best as a supporting player. Pair it with Heathcliff for a stark, dramatic contrast — deep maroon against clean white, the sort of combination that looks deliberate even if you threw it together in thirty seconds. For something softer, Anniversary (pale pink that deepens as the blooms age) makes a gentle, romantic pairing.

Outside the sweet pea range, White Supreme works beautifully alongside cosmos in the cutting garden. Something like Purity or Daydream from our cosmos collection gives you a second tier of white and blush flowers that overlap with the sweet peas through July and August. The cosmos keep going after the sweet peas tire in September, so you extend the season without a gap.

Honest Notes on Performance

White Supreme is not faultless. In very hot summers, the petals can scorch slightly at the edges — a faint browning that is more obvious on white than it would be on a coloured variety. Regular picking helps because it is the older, fading blooms that show it most. In a typical British summer, with its mix of warm days and overcast stretches, this is rarely a problem. It tends to be an issue only during sustained heatwaves, and even then mostly on south-facing supports with no afternoon shade.

The variety can also look a little wan during prolonged grey weather. All whites suffer from this to some degree. The blooms are still perfectly good, they just lack the luminous quality they have in sunshine. This is not a fault of White Supreme specifically — it is the nature of growing white flowers in a climate that does not always cooperate.

For detailed planting and growing advice, including support options and feeding schedules, see our sweet pea growing guide.

Why Buy Your Sweet Pea Seedlings from Ashridge?

We have been growing sweet peas in Somerset since the early 2000s. The seed - which we collect - is hand-sown at two seeds per plug and the weaker seedling is removed. Every plant is then pinched out to encourage bushy growth and hardened off before dispatch. What you are buying are sturdy, garden-ready jumbo plug plants that have had the best possible start.

We send your sweet peas out by next-day courier between March and May, packed in purpose-designed recycled cardboard packaging. The moment they arrive, they are ready to go into the ground or a container. If anything is not right, we have real people on the phone in Somerset who will sort it out. We hold a Feefo Platinum Service Award and have been named a Which? Best Buy plant supplier — endorsements that came from our customers, not our marketing team.

Frequently Asked Questions

What colour is White Supreme exactly?

A clean, true white. Not cream, not ivory — properly white. The buds can have the faintest green tinge as they develop, but the open flowers are white without visible undertones. In low light or on overcast days they can appear slightly cool-toned, but in sunshine they are bright and clear.

Is White Supreme good for cutting?

Yes, and it is one of the more practical choices for mixed arrangements. Long stems, good form, and a neutral colour that works with everything else in the vase. Pick when the first flower on the stem has just opened fully. Stand them in cool water straight away and keep them out of direct sun indoors. They last well — a week is realistic if you refresh the water regularly.

How fragrant is White Supreme?

Gently scented. You will catch it when arranging a bunch or leaning in to pick, and a large handful in a bedroom is pleasant. It is not a powerhouse — this is a variety chosen for its clean colour, reliable stems, and the way it lifts everything else in the vase.

Can I grow White Supreme in a pot?

Yes, and container-grown whites look particularly striking on a terrace or by a doorway. Choose the biggest pot you can manage — a tall, narrow container suits the deep roots better than a shallow bowl. The non-negotiable is watering: pots dry out far faster than borders, and once a sweet pea gets thirsty it sulks. Feed every couple of weeks with a potash-rich liquid from first bud.

Do sweet peas come back every year?

No. Sweet peas are annuals. They germinate, flower, set seed, and die in a single season. Not to be confused with the perennial everlasting pea, which does return each spring but trades away the scent and delicacy that make annual sweet peas worth growing. Everything in our sweet pea collection is annual Lathyrus odoratus — one glorious season, then you start again.