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Do Ranunculus Spread



Ranunculus grows to heights of 1 to 2 feet with a similar spread. Light and Temperature Requirements. Ranunculus prefers full sun but does not like the heat. In fact, it prefers temperatures between 55 and 70 degrees. Temperatures above 70 degrees will cause ranunculus to slow or cease blooming. Ranunculus (pronounced as ran-un-kew-lus) comes in a variety of colors. Shades of orange, yellow, peach, pale pink, hot pink, red and white ranunculus flowers can be seen. The word ranunculus is derived from the Latin word ‘rana’ which means frog, this is so because these flowers grow in wet areas. Naturalizing bulbs is a terrific way to brighten up lawns. A surprisingly large number of perennial bulbs do well in grass, such as snowdrops (Galanthus), crocuses (Crocus), squills (Scilla), checkered lilies (Fritillaria meleagris) and plenty others charming bulbs. How to Plant Ranunculus Bulbs. Planting ranunculus couldn’t be any easier. They come as bulbs (or corms) and are typically mail-ordered or picked up at a garden center — look for large, healthy-looking bulbs that will grow and support large, healthy plants with lots of blooms.

Creeping buttercup, a King County Weed of Concern, is a low-growing perennial with creeping stolons that's found in rural and urban areas throughout King County, such as pastures, farmlands, natural wetlands, city gardens, and lawns. Stems reach one foot tall. Leaves are dark green with pale patches, divided into 3 toothed leaflets. Leaves and stems are both somewhat hairy. March-August, produces bright yellow, glossy flowers with usually 5 (up to 10) petals. Reproduces by seed and vegetatively via long, branching stolons that root at the nodes. Stolon growth starts in spring, peaks in late summer. This plant is extremely aggressive and toxic to grazing animals.

Legal status in King County, Washington

Creeping buttercup is not on the Washington State Noxious Weed List. However, in King County, this non-native invasive buttercup species is classified as a Weed of Concern. For more information see Noxious Weed Lists and Laws.

The King County Noxious Weed Control Board recommends the prevention of spread of this species to uninfested areas and its control in protected wilderness areas, natural lands that are being restored to native vegetation, and in pastures that are being grazed.

Identification

Do Ranunculus SpreadRanunculus season
  • Perennial with short swollen stems and creeping stolons that root at the nodes
  • Can be distinguished from other buttercup species such as tall buttercup (Ranunculus acris) by the creeping stolons
  • Can grow up to one foot tall but are often shorter in mowed areas
  • Leaves are dark green with light patches and are divided into three toothed leaflets, the central leaflet on a stalk
  • Pale patches on the leaves distinguish creeping buttercup from similar looking plants such as hardy geraniums
  • Basal leaves have long petioles (stalks), leaves higher up the plant have shorter or no petioles
  • Leaves and stems are somewhat hairy
  • Flowers usually have five (sometimes ten) glossy, bright yellow petals and grow singly on long grooved stalks
  • Bloom time is usually from March to August
  • Fruits are clusters of 20-50 achenes on globe-shaped heads. Achenes have a short hooked beak and are light brown to blackish brown when mature with an unevenly pitted surface

Impacts

Creeping buttercup's competitive growth crowds out other plants, especially in wet soils. One plant can spread over a 40 square foot area in a year. Creeping buttercup also depletes potassium in the soil and so can have a detrimental effect on surrounding plants. Because creeping buttercup can tolerate heavy, wet soils, it can be a particularly bad problem on well-watered lawns, wet meadows and poorly drained pastures. In addition to invading wet grassy areas, creeping buttercup is reported as a weed of 11 crops in 40 countries.

Fresh buttercup plants are toxic to grazing animals, who can suffer from salivation, skin irritation, blisters, abdominal distress, inflammation, and diarrhea. Fortunately, buttercup has a strong, bitter taste so animals generally try to avoid it if more palatable forage is available. Also, the toxin protoanemonin is not very stable and loses its potency when dry, so buttercup is not generally toxic in hay. Unfortunately, livestock occasionally develop a taste for buttercup and consume fatal quantities. It is safest to keep populations of buttercup under control on grazed pastures and offer plenty of healthy forage.

Growth and reproduction

Creeping buttercup spreads by seed and by long branching stolons that root at the nodes, forming new plants. In more established woodland and grassland communities, this plant increases mostly through stolons unless the soil is disturbed. In dry conditions, flowering and seeding is more prevalent and in wet conditions, stolons are more plentiful. Seeds can germinate and seedlings can grow under water-logged conditions.

Ranunculus Propagation

One of the reasons creeping buttercup is so competitive is that its stolons respond to the environment. Under favorable conditions, plants form more stolons through branching. However, when nitrogen is limiting, stolons tend to be longer and unbranched allowing longer distance “sampling” of a number of potential sites until more suitable locations are found. When favorable conditions are discovered, stolon branching resumes, allowing rapid local colonization to take advantage of the available resources. In general, short stolons are produced in dense turf and much longer ones appear in open fields or woodlands.

Depending on the temperature, creeping buttercup either overwinters as a rosette or dies back to ground level. In either case, the nutrients stored in the short swollen stem produce rapid growth in spring, between April and June. Stolons grow from the leaf axils in spring and summer and growth peaks in late summer. Stolons connecting parent and daughter plants usually die off in fall.

Flowers can appear from March to August with seeds soon after. Each plant produces from about 20 to 150 seeds. Seeds can remain viable in the soil for at least 20 years, and up to 80 years, especially under acid or water-logged conditions. Seeds are dispersed by wind, water, birds, farm animals, rodents, and other animals by adhering to them with the hooked seeds.

Creeping buttercup grows particularly well in moist or poorly drained situations, although it will also colonize sandy and gravel-based soils with sufficient moisture. Creeping buttercup also has some tolerance to salinity and is found along beaches, salt marshes and the margins of tidal estuaries. In woodlands, this buttercup is mainly restricted to clearings, forest margins and paths. It is frost tolerant and will survive moderate droughts. Creeping buttercup is tolerant of trampling, compacted soils, and grazing.

Control

Be sure to have a long-term plan to ensure success, protect native and beneficial species while doing the control, and start in the least infested areas first and then move into the more heavily infested areas.

Prevention and cultural control

  • In lawns and pastures, promote healthy grass by overseeding, fertilizing as needed, and not over-grazing. Adding lime can improve grass health and keep buttercup from re-establishing. However, lime won’t control buttercup that is already well-established.
  • It also helps to improve soil drainage. Reduce compaction by aerating and avoid trampling when soils are wet.
  • Clean mowers and other equipment to avoid spreading buttercup seeds to un-infested areas.

Manual

  • Dig out with a sharp trowel or fork-type tool, removing all of the runners, roots and growing points. Digging is most effective from fall to spring while the soil is moist and roots won’t break off as much.
  • Cultivating or incomplete digging may increase the buttercup population because it can sprout from nodes along stem and root fragments.
  • Disturbance of the soil can increase seed germination. Seeds stay viable for 20 years or more and the number of seeds in infested soils can be immense compared to the number of plants present, especially in long-term pastures and woodland ecosystems.

Mechanical

  • Creeping buttercup’s growing point is at soil level, so plants resist mowing and quickly re-sprout when cut.
  • Regular cultivation can kill the buttercup but plants buried by cultivation can grow back up through deep soil and re-establish themselves and long-lived seeds in the soil can germinate and re-infest the area once cultivation ceases.

Chemical

  • Herbicides can be used if allowed and appropriate for the site and land use. Follow all label directions to ensure safe and effective use.
  • Glyphosate (e.g. Roundup, Aquamaster) can be applied to actively growing plants before they seed. Keep spray off of grass and other plants. Re-seed or re-plant bare areas after removing buttercup to keep it from re-infesting the area.
  • Broadleaf herbicides can be applied over grassy areas infested with creeping buttercup to selectively kill the buttercup and not the grass. Products containing the active ingredient MCPA are most effective on buttercup. Metsulfuron (Escort, Ally) is also effective but can harm some grasses. Follow label directions on timing and rates.
  • It will probably take at least two or three applications to eradicate creeping buttercup because of the seed bank and because some mature plants will generally recover.
  • Monitor the treated area for re-growth and pull up any new seedlings before they establish runners.

Additional information on creeping buttercup (Ranunculus repens)

  • Oregon State University Extension Bulletin (external link)
  • Photos and Distribution from the University of Washington Burke Museum (external link)
  • Alaska Natural Heritage Program (external link)
  • USDA-NRCS Plants Database (external link)
  • Down Garden Services : Creeping Buttercup Control (external link)

What to do if you find this plant in King County, Washington

Because creeping buttercup is so widespread, property owners in King County are not required to control it and we are not generally tracking infestations. We can provide advice on how to control creeping buttercup, but there is generally no legal requirement to do so.

Creeping buttercup photos

I have big dreams of growing ranunculus here in my zone 6b/7 climate. Ranunculus are my all time favorite flower and even though they don’t typically overwinter in my zone, I am determined to give it a shot.

The tricky thing about ranunculus is that they are cool season flowers, but they don’t tolerate freezing temperatures.

Here in Utah County we get temperature extremes of freezing cold to boiling hot, even within one day. Our spring doesn’t last long before the temperatures jump up meaning our growing window for ranunculus is very short (especially if you have plant them late winter/early spring).

This doesn’t allow a lot of time to get a harvestable crop from the ranunculus. (Same goes for anemones which have similar grow conditions.)

After quite a bit of research, I’ve discovered some flower farmers that grow ranunculus in zone 7 by planting in the fall and providing overwinter protection from the cold.

Spread

Being an urban flower farmer, my options are pretty limited. Ideally, a minimally heated hoop tunnel would be my first choice for overwintering the ranunculus. However, that is just not feasible in my suburban grow space.

Instead, I will be constructing a low tunnel for overwintering the ranunculus and anemones (a much more affordable and space conscious alternative to a hoop house). I am building a mix between this farmer and this farmer.

The cost of a four foot by thirty foot low tunnel is around $200. Add that to the cost of my ranunculus corms and anemones (around $225 for 500 corms) and you get quite the costly gamble. Therefore, I will be planting half my corms this fall and half in the late winter/early spring to compare results.

Plus praying for a mild winter.

Where to source corms?

If you are growing for market, I highly recommend getting your corms from a wholesaler for cost effectiveness. I ordered all my corms from Gloeckner. (They sell out so be sure to check their purchasing calendar to get your order in at the right time. I ordered mine in the summer.)

Side note: If you want to order just a few for some beauty in the garden, then I would order from Easy to Grow Bulbs online and I would actually just plant in the late winter/early spring rather than overwintering.

Before ordering, I researched the different varieties of ranunculus to know which ranunculus series and variety would be the most hardy for my zone. Some series and varieties are less cold tolerant or don’t get tall enough stems for cut flowers.

After a lot of research, I found that most flower farmers in similar conditions found the La Belle ranunculus series to be the best option.

Now, different colors within a series also have different grow results. Some color varieties within a series are more productive than others. With that in mind, I decided to put most of my investment in the La Belle Champagne variety. I will also be planting smaller amounts of La Belle Whites and La Belle Salmon.

Finally, you will want to consider the size of corms. Knowing that I am asking a lot of my ranunculus to overwinter in a zone that they are not fond of and knowing I want them for market production (meaning I want the max number of stems as tall as possible), I chose the largest size corms (5/7 ).

The same process applied when ordering anemones for overwintering. My research pointed to the Galilee series of anemones in their largest corm size. I particularly wanted to grow the black and white (or panda) variety.

Unfortunately, Gloeckner canceled my order of the galilee series due to a crop shortage and subbed the Marianne series in the panda variety. I was super bummed, but hopefully, this Marianne series performs ok.

What to COnsider Before the Pre-SprouT?

Knowing my corms were scheduled for delivery the first week of October, I quickly began gathering everything I would need for pre-sprouting.

Below is a list of the materials I gathered:

  1. A pre-sprouting medium (half peat moss & half perlite – I got two large bags for mixing from Home Depot)
  2. A tub for mixing the medium and some tubs for planting the corms for pre-sprouting (I found some kitter litter-sized tubs from Walmart)
  3. Misting bottle for keeping the pre-sprouting medium slightly damp during the pre-sprouting process
  4. Mesh bags for the pre-soak (sourced from the dollar store)
  5. A clean bucket for the pre-soak
  6. Electronic temperature gauge to make sure the corms stayed as close to 50 degrees as possible (sourced from Home Depot)
  7. Waterproof labels to place in the mesh bags during the pre-soak and in the tubs during pre-sprouting

Some growers use different types of potting soil mixes for the pre-sprout medium, but after a bit of research I decided to go with my half and half mix of peat moss and perlite. Vermiculite is listed as an acceptable medium as well and potting soil.

I chose not to do an anti-fungal soak in favor of keeping the process as simple and affordable as possible.

Do Alstroemeria Spread

My next big consideration was where I was going to pre-sprout my corms. Ideally, the corms should be kept as close to 50 degrees fahrenheit as possible, but I did not have a root cellar or basement like all the other flower farmers seemed to have.

I considered keeping the corms in an extra bathroom with the heating vent blocked and the window cracked, but when I tested it out, the house heat seemed to kick on more frequently.

I ended up deciding that my partially insulated garage was the next best thing. (The walls and garage door are insulated, but we have not gotten to the rafters yet.) I am hoping this environment isn’t too cold since my corms will rot if they freeze.

Ranunculus Tubers

I need this to work out as it is my only option…our garage tends to be about ten degrees warmer than the outside temperatures. Unfortunately, while our fall days tend to be around mid fifties, the nights are dipping down to 27 degrees. As an extra precaution, I placed a small space heater in the garage that should kick on if the temperature drops too far. (I hate the added expense of doing that, but the pre-sprout process should only take ten days.)

The Pre-Sprout Process:

  1. Pre-soak: When my corms arrived I unpacked them and inspected them for any signs of rot or mold. Everything looked great so I started placing the corms in their respective mesh bags with waterproof labels. I filled my bucket with cool to room temperature water and placed the bags of corms inside, making sure all the corms were submerged. I then placed the bucket in a bathroom tub with the water trickling to allow air flow. I left my corms soaking for three hours which was plenty of time for them to plump up without risking rotting them.
  2. Prepping the medium: While the corms are soaking, you can prep the pre-sprouting medium and work station. I had a fold out table set up in my garage. I got out my large tub and mixed one bucket or peat moss with one bucket of perlite (one-to-one ratio). The best way to do this is with your hands so you can break up any big chunks of the peat moss and discard any large twigs. (This is a great time to include your little helpers that love getting their hands in the “dirt.”) Once it was all mixed, I used a watering can to sprinkle water on the medium until it was slightly damp but not saturated like you would with seed starting. The best way to do this is to add water gradually. Set the medium aside and prep your pre-sprout tubs (I used a black sharpie to mark the inches on my tubs for easy measuring). Make sure all your materials are pre-cleaned because you don’t want to introduce fungus or bacteria.
  3. Planting the corms for pre-sprouting: Once your three hour soak is complete, bring your corms to your prepped workstation. I let my corms drip dry by pulling the mesh bags out of the water and placing them on my table. Drip dry does not mean you should wait until the corms are actually dry, just get them out of the water and let the excess water drip off. To plant the corms in the tubs for pre-sprouting, you will be layering the growing medium with the corms like a lasagna. Start with a one inch layer of the growing medium on the bottom of the tub, then a layer of corms (just spread out the corms so they are close but not touching). Then cover the corms with another inch of the growing medium (don’t press the medium down). Repeat this process until your corms are all planted or tubs are full. I kept my varieties in separate tubs and placed the waterproof labels inside. Once the corms were all tucked in for pre-sprouting, I placed them on a shelf in my garage with the lids partially off to allow air. Every day I check on the corms to (1) make sure no mice got inside, (2) no mold is growing from a rotted corm that needs removed, and (3) that the growing medium is still damp. If the medium seems dry, I have been using a misting spray bottle to re-dampen it. I am hoping for a lovely batch of pre-sprouted ranunculus and anemone corms after ten days!

Update: My corms sprouted after 14 days (they took a few extra days because my garage was chilly). I had outstanding germination on the La Belle Champagne. Only one was rotted out of 100. I was really worried that my corms were too dry or osmething because I saw nothing happening. Then suddenly boom! They all sprouted out of no where. The anemones had no rot, but had pretty low sprouting in comparison (around 60 percent). I would probably soak the anemones twice as long next year. I planted all of them anyway since I saw no rot.

While I am waiting for the corms to pre-sprout, I am prepping the outside area for planting. This involves double digging my row, getting a quick soil sample, fertilizing/amending the soil, and building my low tunnel.

Do Ranunculus Flowers Spread

My tulips, daffodils and peonies should be arriving for planting this week too, plus my dahlia tubers are ready and waiting to be dug up for storing. It is a bit overwhelming!

Are Ranunculus Annuals

Stay tuned for the second part of overwintering ranunculus and anemones. I will also be sharing my process for constructing my low tunnel and planting my other fall planted bulbs.

If you like incredibly detailed instructions (like me) then keep following along here or on my Instagram.Both flower farmers and hobby gardeners are welcome!