Dr. Roberto Lopez and his lab assistants have been working on understanding flowering mechanisms of ranunculus. Tater and I had the pleasure of having Dr. Lopez and his crew out to the farm on multiple occasions, and they all asked what are some production pain points for us is. And I gladly gave him an earful about winter ranunculus production! How challenging it is to schedule when we don’t understand the mechanisms that induce flowering. It makes succession planning challenging.

 

I am thrilled that Dr. Lopez and his team took our feedback to heart and went to work on this! They postulated that a combination of temperature, vernalization, and photoperiod can reduce crop time and make successions more uniform. I am so proud to be an MSU alum, shout out to Dr. Lopez and his lab for taking this on!

 

Here is the summary of their research on the Influence of Vernalization Duration and Temperature and Photoperiod on Ranunculus Cut Flower Production. You can read the full experimental protocol HERE. Below is a summary of their findings that Dr. Lopez wrote for GrowerTalks. 

 

Methods Summary
 

- Corms of Amadine Black, La Belle White and Butterfly Artemis ranunculus corms were soaked for 8 hours in 68F, then transplanted into plug trays. 

 

- After soaking and transplanting, corms were put in a cooler for “presprouting” at 42F under LEDS providing  µmol·m–2·s–1 for 12 hours. 

 

- After the presprouting treatment, trays were moved to coolers for a vernalization treatment with a set point of 38F, 41F or 46F for zero two or three weeks of vernalization with the same lighting treatment as the “presprouting” treatment.  
 

- Following the vernalization treatments, the ranunculus were planted into bulb crates at a spacing of 26 plants per 10 sq. ft. Day temperatures averaged 55F and plants received a photo period of either 12, 14 or 16 hours with a target daily light integral of 12 mol·m–2·d–1.
 

Above shows the effect of providing no vernalization or two weeks of vernalization to sprouted ranunculus corms at 38F or 46F and greenhouse forcing under 12, 14 or 16 hour photoperiod. 

The Results

 

- Vernalized ‘Artemis’ butterfly ranunculus corms flowered 12 or 18 days faster compared to nonvernalized corms, regardless of temperature treatment.
 

- Vernalized La Belle White ranunculus corms flowered 13 days faster compared to nonvernalized corms, regardless of temperature treatment.
 

- All three ranunculus varieties were delayed from four to ten days when plants were forced under a 12- or 14-hour photoperiod. Results indicate that these ranunculus cultivars are facultative long-day plants. 
 

- All three cultivars had the longest stems when presprouted, vernalized and forced under a 12-hour finishing photoperiod. 
 

- Time to harvest was hastened when plants were grown under short days for four to five weeks to allow for vegetative growth prior to forcing under long days. 

 

On behalf of flower farmers everywhere, thank you, American Floral Endowment and the Association of Specialty Cut Flower Growers (ASCFG) for funding this! It is truly an exciting time to be a flower farmer. And the more we understand the flowering mechanisms of our elusive crops, the more profitable we can become, strengthening the American flower industry. Fingers crossed there is more research like this in the mill for ranunculus, because this is just the tip of the iceberg.

• Tunnel-grown lisianthus are better quality, with higher bud count and stem length. However, field-growing lisianthus is entirely possible. If you decide to grow lisianthus in the field, Dave advises against growing frilly variety lisianthus since they are more prone to botrytis, due to rain. 
 

• Dave states tunnel grown lisianthus will pay for the tunnel in the first year. When grown well, they command the real estate. 
 

• Dave recommends group 2 and 3 for field growing. If you plant group 2 and 3 on the same day, they will automatically stagger their bloom period. It may only be a ten-day window, but it will allow you to have flowers over a longer period.

 

• Lisianthus are one of the most challenging plants to from seed, with plugs taking 12-13 weeks to grow to transplant size. You will be tied to your propagation house. You are better off buying your lisianthus plugs from a professional. 

 

• Some lisianthus seeds cost 7 to 8 cents per seed; by the time you factor your time, heat and material you are better off buying in the plugs. Some lisianthus varieties are not offered as plugs, so if you want a specific variety you have to grow your own. But Ball offers something like 275 lisianthus varieties in plugs, so there is a good chance you can find what you want. 

 

• If you stress lisianthus plugs at any point, they will rosette and stagnate all summer. You need to plant your lisianthus plugs right away. Do not wait more than 5 or 6 days after receiving your plugs to plant them. And they need to be babied for the first 2 or 3 weeks. Hand-water them and allow them to establish. According to Dave, Rosetting is caused by heat stress, root-bound plugs, lack of water, or any other stress that happens to the plugs. Some varieties are more resistant to resetting, such as the ABC series. Rosetting is a major production challenge for lisianthus growers. The folks at Ball Tagawa offer a chilled lisianthus plug, which reduces heat stress in the plug tray, so the plants are less likely to rosette. This is a good option when growers plant lisianthus in July and August in hopes of a fall lisianthus crop. They won't be as tall as their spring counterparts, but it is a saleable option. 

 

• When succession-planting lisianthus, it is important to understand the different group numbers. Lisianthus group numbers are different than snapdragons! The groups are based on how quick they bloom. Lisianthus flower initiation is based on the number of leaf nodes. For example, group 1 flowers faster, since it takes fewer leaf nodes (approximately 12) for flower initiation. Which usually means group 1 lisianthus flower at a shorter height. Dave does not usually recommend group 1 varieties. Compare them to group 3 lisianthus, which start flower initiation at 18 leaf nodes, meaning plants are taller before they even think about flowering. Dave outlines the different group numbers below:

 

Group 0 - winter growing, bud initiation at 8 leaf nodes.

Group 1 - bud initiation at 12 leaf nodes

Group 2 - bud initiation at 15 leaf nodes

Group 3 - bud initiation at18 leaf nodes. Much taller plant. 

 

• Dave stressed that lisianthus like a cool start. You should plant your first field succession two to three weeks before your last spring frost. If there is a hard freeze you will need to protect them, but they can withstand frost. According to Dave, you should plant tunnel-grown lisianthus four weeks before your last frost. Cool spring soil is the key to a successful lisianthus crop. If you are planting later in the spring, white plastic can be an invaluable tool to keep the soil cool. Make sure black is on the back side of the plastic to make sure the weeds die.

 

• You can stretch the plug cost by reflushing your lisianthus. When you harvest your first cut, you only leave two to four leaves on the plant. This will ensure longer stems on your second flush. Dave encourages folks to water and fertilize them throughout the season to encourage a quality reflush. It usually takes four to six weeks for a rebloom. 

 

• Be sure to net your lisianthus, which is also great for spacing. You can plant eight plants per square foot, which boils down to two plants per square (if you have six-inch square netting). Close spacing encourages plants to grow taller. 

 

• To pinch or not to pinch? You can pinch lisianthus, although Dave didn't pinch his lisianthus crops in the past. The benefit of pinching is you can get more stems per plant, but the stems are shorter. If you want shorter stems for mason jar bouquets, that’s an option. But Dave does not recommend pinching on purpose. 

 

• Some growers deadhead the first bloom. Most growers wait for secondary set of buds to open before harvesting. You want two or three open stems on the stem before cutting.

 

• Dave doesn’t recommend holding lisianthus stems for more than two weeks. The longer you keep them in the cooler the shorter the vase life to the customer. And you want the best experience possible for your customer. 

 

• You can overwinter lisianthus in your tunnel. You will get tall, breathtaking lisianthus the following spring. Make sure to keep the plants moist and feed them during the winter. “Don’t expect them to live on last year’s food,” Dave says. You will receive four to five stems per plant and will bloom two to three weeks earlier. You might not get a second flush off of these overwintered plants. 

To be eligible you need to meet the following criteria:
 

- Must be actively pursuing a degree in horticulture or floriculture. 
- Must be a citizen of the U.S. or Canada or be enrolled in an accredited college in the U.S. or Canada.

- Have a minimum of 2.0 grade point, although some AFE scholarships may require a different GPA. 

 

Students can apply for up to six scholarships. You’ll need to complete the online application, two letters of recommendation, and submit your resume and transcripts. Here is the LINK. Applications are due May 1.

Tater and I have yet another PSA for you: It's time to presell your Easter Flowers! Easter has gained some traction as a floral holiday over the last few years. It’s not the same caliber as Mother’s Day and Valentine’s Day, but it is still presents a marketing opportunity.

 

 Easter is April 20 this year. This is a great opportunity to try to presell your early spring flowers. You’ve got four weeks to engage your followers and customers. Even if Easter isn’t your thing, you can still use this time to market your early spring flowers. And now is the time to start introducing the idea of buying local spring flowers. 

 

As you begin to strategize your social media and email marketing strategy, let me introduce you to the Marketing Rule of Seven. According to the University of Maryland, the Marketing Rule of Seven asserts that potential customers need to encounter a brand’s marketing messages at least seven times before they make a purchase decision. Meaning that one pretty picture on a social media post isn’t going to presell your crop. Customers need to see your message at least seven times before they will be inclined to make a purchasing decision. There is a psychological and emotional aspect of selling your flowers. You are selling your farm, your mission and your brand. It’s not just 10 stems of tulips for $25.

 

If you want to take a deep dive into the Marketing Rule of Seven, check out this ARTICLE from Illumination Marketing. Tater and I encourage you to take the time this week to outline a marketing plan to engage your customers. We’re going to start getting our customers excited about Easter this week and we hope you will do the same!