Target Grade Level / Age Range:
9th – 12th
Use this document to convert the lesson into a virtual learning module for your students. Use the steps outlined to create the different elements of a Google Classroom or other online learning platform. You can also send the steps directly to students in a PDF, present them in a virtual meeting, or plug them into any other virtual learning module system.
Students will explore how lavender production (including soil preparation, propagation techniques, row spacing, establishment of plants, irrigation techniques, fertilization, weed control, pest and disease management, and harvesting techniques) can lead to providing value-add products.
- Post-It notes or other piece of paper
- Writing utensil
Essential Files (maps, charts, pictures, or documents)
- Loam – a soil with roughly equal proportions of sand, silt, and clay.
- Propagation – the breeding of a plant by natural processes from the parent stock.
- Aromatherapy – a holistic healing treatment that uses natural plant extracts to promote health and well-being.
- Value-Add - A change in the physical state or form of the product (such as milling wheat into flour or making strawberries into jam). The production of a product in a manner that enhances its value.
Background – Agricultural Connections
Lavender is a small, aromatic shrub used in the fragrance, specialty-food, and alternative medicine industries. Like most herbs, lavender has very few insect pests. A few fungal diseases attack lavender, but because there are no known remedies for them, chemical applications are rarely used on the plant. Lavender ranks high as a sustainable crop because it does not rely on pesticides and fertilizers. It does not require much fertilization, although in hot climates irrigation may be necessary.
Lavender can be compared to grapes in the sense that temperature, days of sunshine, rain and growing season all impact lavender’s scent and bounty. A dry summer might produce stunted plant growth, but very fragrant oil and intense flowers which translate into a spectacular essential oil. Growing altitude also impacts lavender’s fragrance. As a general rule of thumb, the higher the elevation the greater the difficulty in harvesting or wild crafting the lavender, and the more precious and pricey the resulting oil.
For the purpose of this lesson we discuss organic and in-organic. Organic is related to or derived from living matter. Organic mulch includes things like wood chips, leaves, needs, and other compost. In-organic is non-living. Things like gravel and rocks would be considered inorganic or non-organic. In lavender processing, organic solvents are those are carbon based chemical compounds. All living things have carbon which is one of the defining characteristics of organic chemistry. These terms in no way refer to the food classification of 'organic' from USDA.
Interest Approach – Engagement
Write the word ‘value-added product’ on a large surface. Ask students to describe what they think it means. After a few minutes of discussion, provide the USDA definition: A change in the physical state or form of the product. The production of a product in a manner that enhances its value. Ask students to come up with some examples of value-added products (for example milling wheat into flour or making strawberries into jam).
Give students two minutes to write down as many value-added products on a post-it not or piece of paper as they can. Students should work silently and quickly to come up with their lists. After two minutes ask all students to stop and stand up. Go around the room and ask each student to share one value-added product that they wrote down (one that hasn’t been said by another student). If other students had the same item, ask them to cross it out. Go around the room multiple times until all value-added items have been shared. If a student runs out of items on their list (they all get announce and/or crossed out) have the student sit down. The last student standing ‘wins’. Congratulate the winning student with a round of applause.
Explain to students that today you will be discussing value-added products from lavender as well as discussing how lavender is grown and harvested.
- Use the PowerPoint slides 1-13 and walk students through the information. Have students capture notes in their notebooks. Encourage students to ask questions.
- Lavender: This pretty plant known for its soothing scent stars at farms throughout the Midwest.
- Native to hot, dry, Mediterranean climates.
- Hardy small shrub adapts to the challenging growing conditions of the Midwest
- Needs plenty of sunshine
- Needs room to spread and perfect drainage; lavender rots when planted in soil that holds too much moisture.
- Lavender must have well-drained soil, with a pH of 6 to 8.
- If soil is too alkaline, add sulfur to lower the pH.
- If soil is too acidic, add lime to raise the pH.
- Lavender does best in sandy loam soil that provides good drainage.
- If the soil becomes saturated with water the result is root rot disease that will kill the lavender plants.
- Many lavender growers use raised growing beds to improve water drainage.
- Tips for Growing
- Plant in full sun. Lavender likes at least eight hours of sun a day.
- Prepare 8-12 inches of well-draining soil for your plants.
- Lavender doesn't like the clay soils of the Midwest, which trap moisture.
- Prepare an ideal soil that drains well with one-third garden soil, one-third sand or pea gravel and one-third organic compost.
- A mounded bed also helps provide drainage.
- Without good drainage, lavender will rot.
- Plant in spring for best results.
- Provide room to grow.
- Space their plants 3 feet apart on mounded rows of well-draining soil.
- The extra space allows better air circulation to keep the plants healthy and improve production.
- Use inorganic mulch.
- Mulch plants with white limestone pea gravel.
- The gravel mulch "sweetens" the soil, making it slightly alkaline (which lavender prefers) and reflecting light and warmth up into the plants.
- Use organic mulch only when first preparing the soil for new plants.
- Wood mulch holds too much moisture and may promote mold growth.
- Water until the roots take hold.
- Water new plants when they're dry to the touch.
- Once lavender is growing well, the plant is extremely drought-tolerant and doesn't need pampering or fertilizer.
- Growers propagate from cuttings rather than from seed
- This ensures plants are consistent in quality, color, and oil production
- Producing lavender from cuttings guarantees the new plants will be exact clones of the parent plants.
- New growers can purchase their plants from wholesale growers, then take cuttings from these “mother” plants.
- Selecting the best species
- 30 species of lavender – hundreds of varieties
- 3 species widely grown by commercial growers
- Lavendula augustifolia, or English lavender,
- Cold-hardy species that does well in climate zone 5 to 9, with mild summer heat and long hours of daylight.
- The sweet fragrance of the true lavenders is ideal for culinary use, and the aroma and quality of the essential oil they produce.
- Several varieties are popular landscaping plants, and are also used for fresh and dried bouquets.
- Lavendula x intermedia.
- Cross between L. augustifolia and L. latifolia, called lavandins.
- Produce large plants, with more long floral spikes
- Many varieties grown solely for essential oil production, (as much five times oil as English lavenders).
- Lavandula stoechas, topped lavender, or Spanish lavender
- Easy to recognize, with a cylinder-shaped flower head topped by leafy extensions that resemble rabbit ears.
- Earliest to bloom and produce flowers all through the season
- Less hardy, with most varieties only suitable for zones 7 to 10.
- Popular for fresh cut flowers.
- Harvesting and drying
- Lavender may bloom its first year, but it takes three years for plants to mature.
- Harvest spikes of mature plants as soon as they bloom.
- Cut just above the leaves.
- Cut a lot of spikes; harvesting will promote new growth and keeps the plants from becoming leggy.
- Harvest on a dry day, or after a series of dry days.
- This will mean less moisture on the plant.
- Late morning, after dew has evaporated, is an ideal time.
- Dry in bundles.
- Tie six to 12 lavender spikes together and hang upside down on poles or hooks in a dry, dark place.
- Good air circulation will prevent the lavender from becoming moldy. It should dry in about a month.
- Lavender as a business
- Small growers tend a few dozen plants in their backyard and can make a few hundred dollars.
- Larger operations on acreage can bring in hundreds of thousands, especially if they also produce and sell value-added products.
- Purple Haze Farms, in Sequim, Washington, routinely grosses over a million dollars a year with about 8 acres of lavender.
- Fresh lavender bouquets are a very profitable way to sell lavender.
- Most growers sell direct to the retail public - garden or at the local farmer’s market.
- Lavender bunches can sell for $6 each.
- A 20′ x 20′ growing area can produce around 300 bunches each year, worth $1,800.
- A quarter-acre can produce about 3,000 bunches, worth $18,000.
- Unsold lavender bunches can be dried and sold to crafters and florists, who use the bunches for dried floral arrangements.
- The flower buds can be removed from the bunches and sold or used to make sachets and other value-added products.
- Other lavender products, such as lotions and soaps, bring 500% or more markups from the price of the basic ingredients.
- Value-add products
- There are dozens of lavender products that are easy to make and increase the value of raw lavender by up to 1,000%.
- Proven products include:
- Lavender bags. After lavender flowers are harvested and dried, the flower buds can be removed from the stems and used to make a sachet, used for dryer bags, bath bags and pet bags.
- Aromatherapy oil. Lavender oil is one of the most used essential oils in aromatherapy. It has a calming, soothing effect when it’s scent is inhaled.
- Lavender soap. The basic affordable lavender soap bars are the consistent best-sellers. Best of all, soap is another repeat product, with many customers using several bars a month.
- Making Lavender Oil
- Hydro distillation – water and plant material are boiled together creating a hydrosol
- Steam distillation – dry steam vaporizes and extracts oil
- Solvent extraction – organic solvents extract oils
- Supercritical extraction – carbon dioxide under extremely high pressure extracts oils
- Pass out the Estimating Value worksheet to students. Work through the first problem together as a class. Then assign the students to complete the rest of the worksheet on their own.
Did you know? (Ag facts)
- The name Lavender comes from the Latin verb, "lavare," which means to wash
- Lavender comes from the same family as mint
- Over 2500 years ago, lavender was used in ancient Egypt during the mummification process
- Back in the Elizabethan times, when baths weren't common practice, lavender was used to perfume clothes and bed linen
- The scent of lavender deters mice, flies, mosquitoes and other pests from the area
- Lavender oil can be used to soothe aching muscles and joints, reduce anxiety and stress, and to induce sleep
- It is a commonly used ingredient in potpourri
- Nectar from lavender plants are used to make high quality honey
- In the language of flowers, lavender can mean devotion, luck, success, happiness or distrust
- Lavender plants don't produce seeds; propagation is done by cutting or root divisions
- Most lavender plants are blue or purple, but there are some varieties that come in pink and yellow
- Have students make soy-based lip balm with lavender essence. https://agclassroomstore.com/soy-wax-lip-balm/
Suggested Companion Resources
Iowa Agriculture Literacy Foundation
Agriculture Literacy Outcomes
- T2.9-12.b. Compare similarities and differences between organic and inorganic nutrients (i.e., fertilizer) on plant growth and development; determine how their application affects plant and animal life
- T2.9-12. d. Evaluate evidence for differing points of view on topics related to agricultural production, processing, and marketing (e.g., grazing; genetic variation and crop production; use of fertilizers and pesticides; open space; farmland preservation; animal welfare practices; world hunger)
Iowa Core Standards
- HS-LS2-1. Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.
- HS-LS2-5. Develop a model to illustrate the role of photosynthesis and cellular respiration in the cycling of carbon among the biosphere, atmosphere, hydrosphere, and geosphere.
- Social Studies
- SS-Econ.9-12.14. Use cost-benefit analysis to argue for or against an economic decision.