How to grow Ranunculus

Ranunculus, the Rose of the Spring…

Ranunculus, called the ‘Rose of Spring’, will provide gorgeous blooms throughout the start of the season giving you an abundance of flowers long before the Roses wake up…

How to grow Ranunculus

What to do when they arrive…

When they arrive, they are dormant in a dried and dehydrated state.

Your parcel of little sea urchin like Ranunculus corms will be in a dormant state, dried and dehydrated. This does make them fragile so the first thing to do is to re-hydrate them, this ‘starts’ them!

If saving some for the Spring then leave them in this dehydrated state.

Starting Ranunculus

Once rehydrated they need to be pre-spouted straight away so I tend to do this in batches…

How to grow Ranunculus How to grow Ranunculus

You can keep the rest of your corms cool and dry before ‘starting them’ (no lower than 4 degrees).

You can plant your Ranunculus either in the Autumn or the Spring.

We find that Autumn grown plants bloom up to 6 weeks earlier than Spring grown corms but we do give them a cloche or grow them in the polytunnel to give added protection from the worst of the winter weather. They are a little more tender than Anemones and will need covering if temperatures dip.

Why not stagger your corms and do a trial to see what works best for your location?

We soak our corms at room temperature for around 3 hours

(a full step by step ‘soak along’ will be starting on Instagram stories once you have received your order)

The advice is to ‘leaving the water running just slightly during the process to help provide extra oxygen’ we don’t do this as we don’t like to waste water and find that just adding a splash more water to the bowl once or twice has not caused any problems.

How to grow Ranunculus How to grow Ranunculus

As the corms soak, you will be thrilled to notice that they plump up to 2-3 times their original size and now resemble a ‘fat’ little octopus!

Now these precious corms (along with Anemones) are like caviar to Squirrels and Mice so we pre-sprout ours indoors rather putting out a ‘Hamper’ for the wildlife!!

Presprouting the corms before planting will also give plants a jump start (just like Sweetpeas) and you’ll have flowers a few weeks earlier.

To presprout, fill a flat-bottom seed tray halfway full of moist compost or as I prefer to do use the large 15 cell Plant Trays.

I plant one corm to each cell, this is just my personal preference so I don’t have to rush to move them to their final planting position and I often ‘over winter’ in these trays…

Leave labelled tray’s in a cool place (4-10 degrees is ideal) where rodents can’t reach for 10-14 days.  Be careful that you don’t overwater at this stage.

You are most likely to lose them if you over water so keep the soil moist but not wet.

Once plants show signs of growth you can move them to their final positions or leave them to develop in their trays. – I prefer to do this as it further insures against the rodents!


Soil should be prepared to a good loamy tilth and weed free, chickweed for example can smoother plants so hand weeding may be required from time to time…

I like to add a good multipurpose fertiliser to the soil ahead of planting (for more information on click here for my resource on Planting)  

Plant 20-22cm apart. Plants are shallow rooted so will do well in a pot if given the same spacing. I’ve found that reducing their room to grow results in smaller blooms.

A properly spaced crop produces 10 stems per plant with some really bumper flowers!

Weather protection is helpful especially for an Autumn started crop. Neil’s growing frames have proved ideal to give you an idea.

How to grow Ranunculus

Spring started crops need less protection as they bloom as once the weather improves but we have found that slight shading during hot spells really helps, despite their looks these are ‘cool weather flowers’

If leaving them in their trays for an extended period apply a seaweed feed when the plants are actively growing.

Once temperatures plunge the plants will stop growing and suspend until the Spring.

During very cold periods where the temperature dips below freezing, cover the plants with a caterpillar tunnels and a layer of Horticultural fleece (frost cloth), don’t water them.

Keep an eye on those planted in Tunnels (Hoops Houses) the temperature can soar on fine days and they don’t have the benefit of rain so open doors whenever the conditions allow to give ventilation. Hot dry weather can cause the corms to become dormant, which looks a bit like they are dying but actually just shutting down for high summer.

How to grow Ranunculus

Autumn planted corms flower in early spring (April for us) and continue steadily for approx 8 weeks.

How to grow Ranunculus

Pests and Diseases

Ranunculus seem to be delicious to everyone so we recommend using an organic bug and fungus control. This one (click) is from the Royal Horticultural Society and they promise

‘Safe to use around the whole family, including children, pets, wildlife and bees. Edible crops can be eaten within hours of application.’ Always read instructions before use.

If you prefer, a Multi purpose Rose spray has the correct ingredients. We like to use organic products so I add this a preventative to head off any issues before they arise.

Spring planted Ranunculus normally starts to flower about 90 days after planting.

Ranunculus have a brilliant vase life often exceeding 10 days!

How to grow Ranunculus

Brides love them in their bouquets, giving that round Rose shape before the Roses flower.

They also score highly for personal flowers that need to last out of water such as Buttonholes and Flower Crowns.

How to grow Ranunculus

Harvest stems at ground level being careful not to damage immature bud’s. Cut when buds are at the marshmallow stage, fully coloured up but not fully open for the longest vase life.

Pick in the early morning before the flowers open in the daylight and move to cool shed. Brides love them in their bouquets!

For home gardeners (often myself included) don’t worry too much and just pick when they look ‘pretty’ you have a vase to do, even an open flower lasts ages getting bigger and bigger as it ages!

Lots of love

Zoe x

Zoe Woodward, Swan Cottage Flowers © Ferri Photography

For step by step videos and fun growing along in real time follow us on Instagram 

2 Comments Add yours

  1. Alison Clarke says:

    Hi Zoe
    I’ve just recently purchased some ranunculus corms from you and wondered if you could offer some advise.
    I’m just in the process of setting up an allotment with raised beds in Derbyshire (heavy clay with poor drainage in the winter – although I’ve put a lot of work in this year to improve the soil condition – for my daughter who is a young and eager florist (Arbutus and Ivy near Bakewell) keen to have some flowers that haven’t travelled halfway across the planet and that the local flower markets can’t offer.

    I noted you grow on in 15 cell trays after pre-sprouting and wondered what size each module is – I’ve just spotted some very sturdy 15H modular trays (7cm x7cm and deep) from a company called containerwise (apparently used by Charles Dowding) but they are a bit of an investment

    After pre-sprouting and potting on the corms I am thinking of keeping in the unheated greenhouse until the worst of the weather is over rather than plant out due to the soil conditions and as it is probably a little colder than you up here. The greenhouse is insulated with bubble wrap, has a slimline waterbutt for thermal mass and I am intending placing onto trays on top of a hot bed (containing stable litter) to help keep the frost at bay – any suggestions and thoughts you could offer would be extremely welcome. My only thought would be how long could the plants remain in the modules before the need to plant out as I’m thinking of starting them soon.
    As you will guess I am new to propogating and growing on but we all have to start somewhere!
    Kind regards

    1. Swan Cottage Flowers says:

      Hi Alison

      We are not planting any of our Autumn Sown Corms out into the garden (they are planted in the Polytunnel in mid January). Garden grown corms will be started at the end of January.

      My best advice is to follow along on my Instagram account and find the Video Highlights on Ranunculus and Anemones. You will find there are already hundreds of short videos to answer all of your questions. Maybe Start with ‘Q&A Time’

      In addition there are more highlights for the ‘Kit I use’ where I’ve even recorded the sizes with a tape measure. I have not ever used Containerwise.

      Happy gardening


      Zoe xxx

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