Windsor Sweet Pea Plants

• Variety: Windsor
• Type: Spencer
• Colour: Deep maroon-claret, rich and velvety
• Scent: Medium. A warm, sweet fragrance with depth
• Flowers: Large, waved Spencer blooms. 3–4 per stem, deep colour
• Stems: Long and straight, good for cutting
• Height: 2m (6–7ft) with support
• Flowering: Late June to September with regular picking
• RHS AGM: No
• Show class: Spencer — NSPS Class 5
• 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. Collection from Castle Cary also available

Windsor – Deep Maroon with Velvet Depth

Windsor is a maroon-claret Spencer with a depth of colour that comes from genuine pigment richness rather than dark muddiness. The tone is warm: closer to a glass of good Burgundy than to a blackberry. In overcast light the blooms look almost black; in sunshine the claret warmth shows through and the petals have a soft, velvety sheen. The kind of colour that looks distinguished against a pale background and dramatic against green foliage. Unwins bred it, and whatever else they did, they got the colour exactly right.

The flowers are large, well-waved Spencers on long straight stems, 3–4 blooms per stem, and the colour holds well from first opening to last petal. The scent is medium, warm and sweet with a depth that complements the visual weight of the flower. Windsor grows to about 2m with support and flowers from late June through September with regular picking. In a mixed planting it anchors the colour scheme the way a bass note anchors a chord. Every row of sweet peas benefits from a dark variety, and Windsor is one of the best.

Dark Flowers, Bright Garden

Dark sweet peas absorb light. That sounds like a problem, but it is the key to using them well. A planting of only pastels can look washed out, especially in the strong midday sun of a British July. Add a dark variety and everything around it gains contrast. The pinks look pinker, the whites look cleaner, the blues look deeper. Windsor does this job reliably because the colour is dark without being dull. The claret undertone keeps it warm even in shade.

In a cottage garden, Windsor on a hazel wigwam or bamboo cane obelisk brings an instant sense of richness. The deep colour reads well from across the garden in a way that pale varieties cannot. It is also a fine cut flower: a vase of Windsor alone on a dark wooden table has an old-fashioned grandeur, and the warm maroon looks as good by candlelight as by daylight. For full growing and support guidance, see our sweet pea growing guide.

Windsor in Good Company

White Supreme (pure white Spencer) is the classic contrast. The maroon and white together look timeless and deliberate, like a colour scheme chosen rather than assembled at random. Pink Pearl (soft shell-pink Spencer) bridges warm and dark and softens the effect. Our Harry (deep lavender-blue Spencer) adds a cool note, and the three on one support give you a planting with real range: dark, light, and cool.

In a wider garden scheme, Windsor on a wall or fence with honeysuckle nearby makes a strong summer picture. A late-flowering honeysuckle like Serotina (dark red buds opening to cream) echoes the maroon-and-cream theme of a Windsor-and-white-sweet-pea planting, and the honeysuckle's evening scent fills the gap when the sweet peas close for the night. Both climbers attract the same pollinators, so the garden benefits as much as the gardener.

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 ourselves, is hand-sown at two seeds per plug. After germination, 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. They arrive ready to plant from the moment you open the box. 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, both earned by doing this properly, one parcel at a time.

Frequently Asked Questions

What colour is Windsor?

A deep maroon-claret with a warm, velvety quality. In overcast conditions it reads as very dark, almost black at a distance. In direct sun the claret undertone warms up and gives the petals a rich, Burgundy-wine glow. The colour holds well throughout the life of each bloom without fading to a tired purple.

How does Windsor compare to Black Knight?

Both are dark sweet peas but they come from different backgrounds. Black Knight is a Victorian Grandiflora with smaller, open-faced flowers and a stronger scent. Windsor is a modern Spencer with larger, waved blooms but slightly less fragrance. Windsor's maroon is warmer and more claret-toned; Black Knight's is cooler and more purple-black. If you want drama with scent, choose Black Knight. If you want large, formal blooms in a warm dark tone, choose Windsor.

Is Windsor fragrant?

Windsor carries a warm, sweet fragrance at medium strength. You will notice it from a cut bunch and in the garden when you lean close. It is not one of the heavily perfumed heritage varieties, but the warmth of the scent suits the warmth of the colour. For a dark variety with more fragrance, Heathcliff (deep burgundy-maroon Modern Grandiflora) rates a Parsons 4.

When should I plant sweet pea plugs outside?

After the last frost in your area, usually mid to late May in most of England. If you receive your plugs earlier, keep them in a cold frame or sheltered spot and harden them off gradually over a week before planting out. Sweet peas tolerate cool weather but young plants will not survive a hard frost. Our plugs arrive already pinched and hardened, so they are tougher than a windowsill-raised seedling.

Is Windsor an annual?

All sweet peas are annuals, and Windsor is no exception. It gives you one season of deep maroon flowers from late June to September, then it is finished. At the end of the season, cut the stems at ground level and compost them, but leave the roots in the soil. Sweet pea roots harbour nitrogen-fixing bacteria that improve the ground for whatever follows. For fresh plants each spring, browse our sweet pea collection.