These little shrivelled corms look unpromising but come spring, serve up in buckets!
And they need to; unscented, they are reliant on their soft mille-feuille like, billowing layers of petals that unfurl over days and days giving vase life like no other, let alone this early in the season.
They aren’t hard plants to grow but they do need some attention throughout the coldest season. Just when we aren’t motivated to be there with them. They aren’t great in a border either, I’d suggest growing as a ‘crop’ in the way you probably wouldn’t grow lettuce among your winter scented shrubs.
All these things seem to result in plants that are universally admired but somehow considered ‘not for me’ to grow.
But they are.
Here are my top tips on growing them.
Soaking and pre-sprouting
Like the seed that isn’t sown, the corm that isn’t soaked is unlikely to produce a flower.
From September onwards, soak them in warm water. In a few hours they turn from shrivelled little corms into plump bunches of potential! You see after they have flowered, the plants die back and dry up over the summer. This is why they don’t grow so well if left in position. They are a ‘Goldilock’ plant - they need not too much, not too little moisture, rehydrating in order to sprout. Too much and they rot, too little and they don’t receive the nod to start again.
I used to rehydrate over night but now I only leave them for about 4 hours. That seems to be enough. If you have hungry mice looking for a meal, add a couple of drops of tea tree oil, the scent and taste will send them off packing.
Presprouting
Before planting in their final position, like a ranunculus preschool, until they produce a sprout.
The swollen corms are then pushed into old compost, in trays, almost touching each other. Or better still, I take my time; half fill trays of modules with compost, place a corm and top with more compost. These make very beautiful plugs.
I have used sand, perlite and vermiculite to sprout them in. All of them work but I prefer compost now that I try to plant into modules.
I’ve usually watered the corms whilst sprouting with a homemade comfrey feed or this to give them a boost before planting.
Once I see a strong sprout and some little white roots, they are ready to go. The white roots will emerge through the holes in the bottom of the trays. This might take 10 days or so. They are good to go into their final position now.
Planting
Inside, under cover or outside, under cover!
I plant out in my 1.2m wide beds, in 5 rows. Or about a hand widths apart. The soil is clear of large deep rooting weeds like mallow and dandelion that we have here and large stones. A good mulch of homemade compost too.
A great way to plant ranunculus is under polythene ensuring protection from heavy rain, frost and snow. Monitor watering with drip tape and feed.
I have meant to make caterpillar tunnels (this video is the O.G.) but never got around to it. But I have made tunnels like this with environmesh. These work really well for me - I don’t usually have to water them over the winter, they protect the plants from hungry birds and offer some frost protection. Not that they really need it.
I have covered them with fleece to protect from frost but these are winter growing plants. They just don’t need it and flowered well after -8 degrees for over a week.
However they will not enjoy water logged soil and worse, frozen water logged soil. This is what we had last year, -12 degrees for a week after heavy rain. No fleece or polythene will protect much in those conditions.
Instead, I had another go in February and planted out in late March for May flowering plants.
This year -
I planted the first batch in October directly outside in beds, expecting flowers from late March and through out April.
I am planting a couple of hundred in my polytunnel now to provide the earliest flowers, protected from the worst of the winter and given warm conditions to thrive on.
And will do a final batch in February, planted outside that will flower in late spring.
Ranunculus flower for about 6 weeks altogether and over that time send about 6 or 7 flowers up. Grown undercover, you must water well and the stems will be tall. Outside, the first stems are stout but I find much stronger. Wherever planted, feed when you spot a bud emerging from the leaves.
End of the Season
At the end of their flowering, usually by late May or early June for Ranunculus, the flowers dry up and the stems shrivel.
The corms do exactly the same. They hibernate under ground during the hottest months. Then, as the temperatures reduce, and the soil is moist in October, the corms should naturally swell and rehydrate to reflowed. The trouble is, it’s a fine line between the come rehydrating and sprouting and rehydrating and rotting before it sprouts. I have tried both ways.
In our soil and conditions, Ranunculus do swell and come back. But it’s hit and miss.
Rather than leave plants in, I find it a better use of space, better soil health and ultimately better flowers, to lift and dry corms. Each year I usually save the best corms and buy in fresh stock. Then in September, only about 14 weeks later, I start again.
Have you grown Ranunculus? When do you start yours?
I do love them but they do drive me crazy each year . Last year sprouted well and got off to a great start in the poly then when they flowered in late March every stem I picked just kind of wilted/rotted near the flower rendering them totally unusable grrr. Nonetheless as a glutton for punishment I’m trying again this year 😊
Hi Anna, so lovely to read about my favourite flower. Are they corms or are they claws? I grow under cover in the poly tunnel and have had great success every year. Your article has prompted me to try growing outside in February. Do you ever have stems that look like they have fused together?