Flowers You Should Plant by Month in UK

What Flowers Can You Plant Now? Flower Planting Calendar UK

Discover the best time to plant each type of flower for year-round blooms.
Learn how to align your planting with the UK’s seasonal weather.
Find out which flowers thrive in spring, summer, autumn, and winter.
Create a vibrant window box display that changes with the seasons.
Get expert advice on planting techniques for healthier, more colourful flowers.

Flowers are an incredible way of spicing up your garden, making it the envy of others. As an avid gardener, you might be wondering when to plant flower seeds in the UK so that your garden remains beautiful throughout the year. In fact, some of the best planned gardens are those which offer variety all year round - irrespective of whether this comes in the shape and form of flowers, foliage or even berries. In this post, we’ll offer you a comprehensive flower planting calendar for the UK, which will show you when to plant flower seeds and what flowers you can plant now.

January

When it comes to the question of what flower seeds you can sow now, this when to plant flowers calendar is ideal for you. Starting with January, it can be acknowledged that this is usually a fairly quiet month in the garden so it is time to start raising plants from seed.

Some of the options you might consider include:

Begonias
Plant begonias indoors in early January in peat-free, multi-purpose compost. And once March comes around, move them outdoors.
Geraniums
Lightly bury your Geraniums seed in a small tray containing seed compost and 10 percent vermiculite. Then sprinkle a dust of vermiculite over the spot where the seeds lay. They should remain barely covered. Keep the container in a room with temperatures between 24-27°C (75-80°F). While waiting for the seeds to germinate give them a proper amount of light. The germination itself will take around 14 days. Move Geraniums outside between April and May.
Lobelia
Sow lobelia seeds in mid January in trays or pots filled with good seed sowing compost. Seal the pots with a polythene bag and place them somewhere warm. This will help the seeds propagate. When the lobelia plants have grown big enough and the risk of frost has passed, start acclimatising them to the outdoor conditions. This should be done for around a week.
Sweet peas
Sow your sweet pea seeds 6 cm deep in 7 cm pots in a mixture of seed compost plus 10% grit. Keep them in an unheated greenhouse or a cold frame, where the temperature is around 12°C. Germination usually takes about 2 weeks. Sweet peas flower from May till August.

February

Wondering when to plant flowers in February? February usually gets busier than January and it’s time for gardeners to make early sowings of many summer bedding plants.

These include:

Petunia
Lightly bury your Petunia seed in a small tray containing seed compost and 10 percent vermiculite. Then sprinkle a dust of vermiculite over the spot where the seeds lay. They should remain barely covered. Keep the container in a room with temperatures between 24-27°C (75-80°F). While waiting for the seeds to germinate give them a proper amount of light. The germination itself will take around 14 days.
Impatiens (busy lizzie)
Sow your Impatiens seeds in a propagator on a windowsill or inside a greenhouse in finely sieved moist compost. Keep the temperature between 18-20°C(65-68°F) and shade the seeds from direct sunlight - you must not allow the compost to dry out. Germination takes between 10 and 21 days.
Nicotiana
Sow your nicotiana seeds in late February, under cover. Move the young hardened plants outside only once the risk of frost has passed.
Perennials
There are many perennial plants that can be sown in February. Some of these include: Lupins, Globe thistles, Japanese anemones and Acanthus.

March

March is usually considered the peak for sowing flower seeds as most summer bedding varieties can be sown.

Here are some of them:

Cosmea
Sow your cosmea seeds in a seed tray or small pot filled with sieve or multi-purpose compost. Once placed on top of the compost, cover the seeds with about 3 mm of sieve compost or vermiculite. Cover the pot with a clear plastic bag and wait for the seeds to propagate. Once you notice seedlings with two pairs of leaves popping out, it’s time to transplant your Cosmea plants into their own individual 7cm pots. Make sure to keep the transplanted plants indoors. When May comes around you can move the plants outdoors where they will flower beautifully.
Gazania
Annual gazanias can be sown from seed in March in pots or trays filled up with seed compost. Since the seeds require heat to germinate, you will need to place them either in a heater propagator or wrap the pots in a clear plastic bag(seated on a warm windowsill). Once the gazania seedlings have grown big enough to handle, you can transplant them into individual pots and leave them to hard off outdoors during the warmer days. Planting them outside should be done after the last frost, the earliest.
Marigold
Marigolds need to be sown in March in order to flower in Summer. The seeds can be sown directly into the ground, however, make sure you have removed any weeds prior to sowing. Make small holes - around 12mm (one-half inch) deep and space them 30cm (12 inches) apart. Sprinkle the seeds before covering them with the soil. Apart from gracing you with their bloom, the marigolds petals are edible too and would make a great addition to your salad.
Dahlia
Since Dahlias are not hardy, when planting them make sure that all risks of frost have passed. It'll take around six weeks for the plant to emerge from the soil, and the top growth will be delicate. You can plant them under glass or place a cloche over them to avoid late frost damage. However, if your growing conditions are not too favourable in March, you can always start growing Dahlias in a container until May and then bring them outside once the time’s right.

April

To the question “when to plant flower seeds”, especially in April, it’s definitely time to sow some half-hardy flowers. Do this under cover for some, while others can be sown indoors or outdoors.

Rudbeckia
Annual rudbeckias are ideal to sow in April. Seeds should be sown in pots and trays of sowing compost. The perfect temperature they will thrive in would be 20-25C. (68-77F). The plant will need to be hardened (placed in a cooler temperature for some time). When large enough to handle, you can plant them out 30 cm (12 inches) apart.
Clarkia
Clarkia seeds can be sown straight into the soil outdoors. Just make sure that the area in which you’ll be sowing the seeds is weed-free and well watered. Make 5mm deep holes for the seeds and space them 15 cm apart. Once the seeds are in the hole, cover them up with soil. Make sure to water clarkia seedlings plenty during dry weather.
Lagurus
Also known as bunny's tail grass, Lagurus will thrive healthily if sown outdoors from April onwards. It's an annual grass with fluffy blooms, which can be dried and used for decor or bouquet filler.
Monarda
This red flowering perennial can be sown in April in moist but well-drained soil. Preferably, sow the seedlings in a pot so they can establish proper rooot and then plant out in a sunny spot. Also known as "bee balm", this annual flower needs to be protected from drought during hot summer days.

May

With the soil warming up, it’s the perfect time for sowing seeds. You can sow some of them by simply pushing them into damp compost or directly into the ground.

Here are a few examples:

Primrose
Sow your seeds in May in a tray filled with moist planting medium. Place the tray in the fridge for three to four weeks and then take it out and keep at a temperature of 20-21°C for 3-6 weeks until the seeds germinate. Move your seedlings outside around September when the soil outside is still kind of warm, but the weather is cooler.
Cornflowers
Cornflower seeds are best sown in late spring in outdoor containers, with the seeds being spaced about 5 cm apart from each other. The seeds should also be buried just a 1 cm deep into the soil. Sowing cornflowers in May will give you nice blue flowers during summer between July and October.
Sweet William
Sweet Williams can be sown from late May til the end of August. Sow them in a tray and keep it indoors. Sweet Williams germinate at 7-19°C so they won’t need a warm greenhouse or anything, normal room temperatures will do the trick.
Nasturtium
Sow Nasturtium seeds outdoors directly into the soil and they will flower from summer to autumn. Weed the area where the seed will go in, poke 20mm deep holes which are spaced at least 30cm apart. Sprinkle the seeds into the holes and cover them with a thin layer of topsoil.

June

June flowers to sow outdoors include:

Alstroemeria
Sow alstroemeria at the beginning of June directly into your garden’s soil. Pick a place where the plant will be reasonably sheltered while also getting a reasonable amount of sunlight. Alstroemeria seeds should be spaced around 60 cm from each other.
Achillea
Achillea seeds should be sown in early summer for overwintering. Sow the fine seed on the surface of plugs or trays filled with free draining compost. Cover the seed with a fine layer of vermiculite and then cover the trays with polythene in order to retain moisture and increase the chances of germination. Germination of Achillea takes around a week and during that time the trays need to be kept at 15 to 20°C. Once the Achillea seedlings are big enough to handle, transplant them in separate 3-inch pots.
Arabis
You can sow arabis seeds in early June in a cold frame or directly into the ground. Sow the seeds on the surface of good quality compost and lightly sprinkle some vermiculite over them. Keep the temperature of the soil at around 20°C. Germination normally takes around 2 weeks.
Canterbury bells
Like other bellflower plants, Canterbury bells are best propagated by seeds. Simply sow your seeds in a garden bed or directly into the outdoor soil during June and leave the rest to nature.

Coreopsis
June is the last month during which you can sow coreopsis outdoors. A great species of this plant is the “Incredible Dwarf Mixed” which produces absolutely amazing and cheery flowers.
Erigeron
Sow erigeron seeds in June on the surface of well-drained seed compost. Place the pot or tray in which the seeds are close to a window as the soil needs to be around 15-20°C for the seeds to germinate. Germination itself takes 14-30 days. Once large enough Erigeron seedlings can be transplanted into 8cm pots. Slowly acclimatise the plant for the outdoors once it becomes 2-3 cm tall.
Limnanthes
This lovely white and yellow blooming annual grows in moist and well-drained soil no matter if it's chalk, clay or loam. Also known as the "poached egg plant", this hardy flower needs very little attention and will look amazing at your garden’s front end borders.
Night-scented stock
This is an easy plant to maintain and will thrive well without any attention. It should be plated in early spring and no later than April. You can start growing your evening stock indoors for two months, before transferring them out. Keep the soil moist yet well-drained.

July

There is a wide variety of flowers you can sow in July, while making sure you’re prepared for planting in the autumn. Here are some examples:

Foxglove
Sow foxglove seeds in late July when they are ripe in good quality seed compost. Lightly press the seeds into the compost without covering them as they require only light germination. Water the seeds with tap water after sowing them into the pot and then allow the pot to properly drain. Once the seeds have germinated, move the seedlings into individual 9 cm pots. When the plant has gotten big enough, you can plant it into the ground in autumn or the following spring (if they aren’t big enough).
Forget-me-nots
Sow forget-me-not seeds directly outdoors in July.
Pansies
Sow your pansies in early July to ensure gorgeous spring blooms. They're one of the most preferred flowers by gardeners as they create colourful borders, hanging baskets and pots. They do best in peat-free potting compost and when placed in sun or partial shade.
Wallflowers
Wallflowers seeds are usually sown in July, but if your climate is favourable, you can sow them in May as well. They prefer full sun, well-drained and alkaline soil. Once sown, make sure to water regularly, especially during a drought and when they're flowering vigorously.

August

For colourful pot plants indoors and to ensure you use the right flower seeds to sow in August, sow the following:

Cactus
Fill a pot with moist, gritty, free-draining compost and gently sow cacti seeds under the surface of the dirt. Sprinkle a layer of vermiculite over the seeds in turn covering the whole surface of the compost. Cover the pot with a plastic bag and leave it by a warm windowsill for germination. Seedlings normally develop within a few weeks and can be transplanted the following spring into individual pots.
Coleus
Fill a seed tray or small container with good quality, well-draining potting mix. Place your seed on top of the soil and press them in gently without covering them in dirt, as coleus seeds need light to germinate. Cover the tray with plastic and place it on a warm windowsill, coleus seeds require a consistent temperature of 21-23°C to germinate. Keep the potting mix moist using a spray bottle to water. Seeds normally take 7-14 days to germinate.
Feverfew
Sow feverfew seeds outdoors in August into prepared seed beds.
Siberian wallflower
Sowing this plant from seed in late summer will give off spring flowering the following year. Surface sow seeds outdoors into moist well-drained seed compost. Then cover the seeds with a fine layer of vermiculite and keep the area moist (but not wet). The ideal temperature for germination is 20°C and the process itself takes between 7-10 days.

Cyclamen hederifolium
Plant Cyclamen dry corms in August outside. Preparation for sowing dry corms is extremely important. Start off by digging the planting area in order to remove weeds and other rubbish. Then improve the soil by feeding it with decent garden compost or leaf mould. Avoid burying the corms deeply. Shallow sowing is best so make sure the top of the corms ends up just below the soil’s level. And last but not least make sure the planting site is well drained. Cyclamen plants die quickly when the ground is constantly wet.
Potentilla
Sow Potentilla seeds outside in August, 20 to 45 cm apart. Choose a sunny spot in your garden that has partial shade in the afternoon. Bear in mind that Potentilla plants prefer sandy soil that is slightly acidic but can also grow in plain old back garden soil.
California poppies
This plant requires no attention and thrives well in neglected conditions. It is drought tolerant but will die at the end of the season. That's why many gardeners prefer to pull them out and plant new seeds during the following growing season. Although California poppies are short-lived, their blooms will brighten your garden until their end.
Wild carrot
The wild carrot's seeds germinate better in winter, and that's why they should be sown in autumn. The plant itself looks like an umbrella and has white blooms and feathery leaves. Sow seeds directly outside and cover them with a thin layer of soil. It takes two years for the plant to flower, so if you want a continual display, sow seeds each year.

September

There are two ways to plant seeds this month. For the outdoors, flower seeds to sow in September include:

Calendula
Sowing calendula in September will result in seedlings a few inches high by the winter, however below the surface, the plant’s root ball will continue to grow. This exact root ball will zap lots of nutrients up into the plant come early spring and boost the plant’s growth substantially.
Nigella
Sow Nigella seeds straight outdoors in September to get a bloom between May and June, the following year. Firstly mix compost and organic matter into the planting area before sowing the seeds into the seedbed.
Poppy
Sow poppy seed directly into your garden in September for flowers to pop up in the first season.
Wildflowers
Wildflower seeds are best sown in September directly into the ground outdoors for quicker germination. Seeds sown in autumn tend to flower in early spring as they are dependent on the winter ground frost to kick start their germination.

October

Despite the shorter nights and the increasingly cooler weather, you can still sow this month. Some flower seeds to sow in October include:

Oxalis
Never plant oxalis in soggy soil as they need a well-drained but yet moist one. These flowers can be planted directly in the garden but still will need some protection in cooler climates. However, if you live in a warmer climate, make sure that your Oxalis will have some afternoon shade. You can expect the foliage to emerge in 3-4 weeks after the planting, while the blooms can take up to 10 weeks.
Aquilegia
Aquilegias are hardy plants and require almost no attention once established. They love and thrive well in light soil and sunny spots. Since aquilegias are tall, plant them out on the border by leaving at least 40cm between them.
Phacelia
This annual is one of the best pollinators and very beneficial for bees. It's not a plant native to the UK but will survive the robust winter and emerge with lavender-blue flowers in summer. It suits most soil types but needs complete darkness in order to germinate.
Cowslips
This cup-shaped and yellow blooming plant is one of the best spring flowers and thrives on dry and chalky soils. It loves partially shady spots and germinates in spring when it becomes an early source of nectar for various insects, especially bees.

November

November is the month of variety. You can make early sowings of:

Plus nemesia
Nemesia flowers need to be planted in soil with good drainage and rich in organic matter. These plants love the full sun but grow better when temperatures are more cooling. Nemesias are perfect for both pot and garden growing as they can be bushy or compact.
Bare root roses
They'll benefit from planting between November and April during dormancy as they need time to establish and prepare for blooming. Make sure you're leaving enough space between each root as they can compete with each other for nutrients.
Sea holly
This architectural and spiny perennial looks astounding, especially in rocky gardens. It's a carefree plant and blooms in summer and early autumn. Note that sea holly, also known as Eryngium, doesn’t like to be disturbed. That's why choose your spot carefully and never transplant the plant.
Bugle
An UK native plant that can be found as ground covering in damp areas like meadows. It has dark green leaves and bright purple blooms arranged at the top of its stem.

December

Contrary to popular belief, you can still sow flowers in December. Some of the flower seeds to sow in winter this month are:

Cyclamen
Growing cyclamen in your garden is surprisingly easy if the plant gets the needed amount of sunlight. When choosing the seeds, we recommend you use the seeds of a large-blooming flower. It is essential to know the right deepness when planting cyclamens, as too deeply planted ones may not flower. Make sure to plant the flowers 3-5 cm deep when they’re in root growth as that will help them establish more quickly.
Laurentia
This plant has a trailing habit and looks amazing in hanging baskets and borders. It's best planted in chalky soil with good drainage. You can sow Laurentia seeds under glass in a bright area, so they receive full sun.
Snapdragon
Snapdragon is a very easy to grow but short-lived perennial. It is frost tolerant and blooms vigorously in the spring. Sow snapdragon seeds in December under a bright light until they establish.

In this post, we’ve offered you a wide variety of flower options to plant throughout the year in the UK. With these tips, we hope you see your garden blooming all year round. It doesn’t matter which month it is, you can always sow different types of plants and see your garden blossoming, enriched with colour and various nuances.

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