As September arrives in the UK, many gardeners begin to feel the change in the air. The summer blooms may be fading, and the longer days are giving way to cooler evenings. It’s a time for reflection and a fresh opportunity to prepare for the future. Although it’s generally too late to sow most flowering plants for blooms this year, September offers exciting possibilities for those willing to plan ahead.
For those looking to enhance their indoor environment, September is an excellent month to explore houseplants. Moreover, while many outdoor sowings may be wrapping up, the preparation for next year’s blooming season can start now. By selecting the right plants to sow in September, you can lay a solid foundation for a stunning garden in the coming months. So let’s dive into the best flowering plants to consider this month, ensuring your growing journey continues with vibrancy and joy!
Cactus (Houseplant)
- Flowering Months: Throughout the Year
Cactus houseplants are fantastic for those looking to bring a touch of the desert indoors. These hardy plants thrive in bright light and require minimal watering, making them ideal for busy lifestyles and those new to gardening. Cacti come in various shapes and sizes, from small, round varieties to tall columnar types. Their unique features, including spines and occasional vibrant flowers, serve as striking focal points in any home decor. Just ensure they are planted in well-draining soil and placed in a sunny spot to flourish. Cactus houseplants offer a quirky charm that brightens your living space while demanding little care.
Coleus
- Flowering Months: June to October
Coleus is a captivating foliage plant celebrated for its vibrant, multicoloured leaves. Growing to 30 to 60cm, this plant thrives best in rich, well-drained soil and prefers partial to full shade. Its striking patterns and a wide range of colours—from deep reds and purples to bright greens and yellows—make it a standout choice for borders, containers, and hanging baskets. While its flowers are often inconspicuous, the foliage brings an element of interest that lasts throughout the growing season. Coleus is relatively low-maintenance and can easily adapt to various garden conditions, adding lively colour wherever it grows.
Cyclamen Hederifolium
- Flowering Months: October to December
Cyclamen hederifolium, or ivy-leaved cyclamen, is a delightful perennial that brings charm to gardens in late summer and autumn. Typically growing to 15 to 20cm tall, this plant flourishes in well-drained, humus-rich soil and loves partial shade. Its heart-shaped leaves often sport attractive silver patterns, enhancing the visual appeal even when not in bloom. The lovely flowers, which come in shades of pink, white, and purple, appear above the foliage, creating a cheerful display. Ideal for woodland gardens and shaded spots, cyclamen hederifolium is both low-maintenance and a reliable source of seasonal colour.
Forget Me Not
- Flowering Months: April to June
Forget Me Not, scientifically known as Myosotis, is a perennial favourite renowned for its charming small blue flowers. Growing to 15 to 30cm tall, this hardy plant thrives in moist, well-drained soil and prefers partial shade. Blooming in early spring, forget-me-nots create a delightful carpet of colour with clusters featuring distinctive yellow centres. Perfect for borders, cottage gardens, or naturalising under trees, they add a nostalgic touch to any landscape. With their ability to self-seed, forget-me-nots will return year after year, brightening your garden with their lovely blooms in the warmer months.
Poppy (Perennial)
- Flowering Months: April to July
Perennial poppies, such as Papaver orientale, are magnificent flowers known for their large, colourful blooms. Typically growing to 60 to 90cm heights, these hardy plants thrive in well-drained soil and prefer full sun. Perennial poppies in late spring to early summer showcase vibrant colours ranging from fiery reds to soft pinks and whites, often with a contrasting black centre. Their lush foliage adds texture, making them a stunning addition to borders and cut flower arrangements. With relatively low maintenance needs, perennial poppies bring dramatic beauty to gardens while attracting pollinators.
Potentilla
- Flowering Months: June to September
Potentilla, commonly known as cinquefoil, is a robust perennial that adds colour and resilience to gardens. Typically reaching 30 to 60cm, this versatile plant flourishes in well-drained soil and thrives in full sun. From late spring to autumn, potentilla boasts charming, cup-shaped flowers in vibrant shades of yellow, orange, and red. Its deeply lobed foliage provides a lovely green backdrop, complementing the bright blooms. Ideal for borders, rock gardens, or as ground cover, potentilla is low-maintenance and attracts beneficial insects, making it a practical choice for enhancing your garden’s vibrancy.
Sensitive Plant
- Flowering Months: June to September
The Sensitive Plant, or Mimosa pudica, is a captivating perennial known for its unique ability to respond to touch. Typically growing 30 to 60cm tall, this tropical plant thrives in warm, well-drained soil and prefers partial shade. Its delicate, fern-like leaves fold up when disturbed, creating a fascinating spectacle for curious observers. In summer, it produces soft pink, fluffy flowers that add an attractive touch. The Sensitive Plant is engaging and easy to care for, making it an excellent addition to your garden or a fun houseplant for indoor enjoyment.
Strelitzia
- Flowering Months: February to May
Strelitzia, the bird of paradise plant, is a striking perennial that brings a tropical vibe to any garden. Typically reaching 1 to 2 metres, this bold plant thrives in well-drained soil and enjoys full sun exposure. Known for its large, banana-like leaves, Strelitzia creates a lush backdrop for its unique, bird-like flowers that showcase vibrant orange and blue hues. Blooming from late spring to autumn, this plant is a dramatic focal point, perfect for enhancing garden aesthetics. With moderate care, Strelitzia can thrive in warm climates with winter frost protection, providing stunning visual interest year after year.
Check out the RHS page here.
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From Darren’s Patch
September is one of my favourite months in the garden. There’s a calmness to it — a chance to slow down, reflect, and plan. While many think the sowing season is over, I see it as a time full of promise. I always set aside time this month to tuck in seeds like cyclamen and forget-me-nots, knowing they’ll reward me with colour when I need it most. Indoors, I love dotting a few quirky cacti around the windowsills — they bring such character to the home with barely any fuss. And coleus? I can never resist their showy foliage — they beautifully brighten up those in-between spots in the garden. Gardening in September feels a bit like writing a letter to your future self — and I can promise, the blooms that come from it are well worth the wait.
