Plant Name: Lavender, Pinnata
Common Name: Fern leaf lavender
Botanical Name: Lavendula multifida, “Pinnata”
Origin: Native to Europe.
Height/Physical Description: This variety grows 18 to 24 inches in height and width. The leaves are green and fern-like. The plant has dark blue flowers on 4 to 6-inch stems that bloom continuously starting in late Spring.
Special Attributes: Fern-like leaves that are beautiful in pots and window boxes. The reviews are mixed with regard to the fragrance. Some say it resembles a skunky smell. Others say lemony. Not the lavender prized for fragrance but appearance only.
Purchasing: Easy to find in local nurseries.
Planting Requirements: Plant in Spring after danger of frost or in the Fall. Lavenders require good drainage. If soil is mostly clay, amending and aerating the planting area will ensure better success. Planting in a dome is another way to promote good drainage and keep your lavender from sinking down in clay soil. The preferred mulch at the base of the plant is gravel or a thin layer of compost. Do not use wood or leaf mulches as this contributes to root rot.
Repotting and transplanting: To determine your lavender is hardy and ready to repot or transplant, check the bottom of the container for vigorous roots coming out of the drainage holes. This is a sign of good health.
Watering: Water at base of plant only. Lavenders do not like overhead spray. Use of a drip system is best. Put on a drip line with plants that have similar water needs to avoid overwatering. Lavenders rot very easily when overwatered. To avoid this, allow the soil to dry out moderately before next watering.
Fertilizing: Lavenders are hillside plants that thrive in rocky, good draining soil that is somewhat alkaline (pH of 6.5 to 7.5). Lavenders do not require a great deal of fertilizer as they prefer neutral soil. Since this is the case, use of compost or compost tea is all that is needed.
Blooming Time/Harvesting: Flowers bloom continuously starting in late Spring.
Pruning: Lavenders can live up to 25 years if well maintained. The time to prune is after the flush of flowers. The flowers and stems should be gently pruned so the plant is the shape of a ball. Consider it a haircut not a severe pruning. Removing the flowers in this manner allows the plant to regenerate foliage and avoids it from becoming “woody.”
Note: If the plant has become woody, it cannot be reversed. It will live but will not have the original full shape that it had at the beginning.
Pruning underneath the plant is another way to keep the plant healthy as this promotes good air circulation which prevents root rot.
Pests: Spittle bugs, grasshoppers, gophers, moles.
Diseases: Root rot.
Hardiness: zones 9-11
Additional Comments: This variety is not hardy in either extreme cold or heat. Usually used as an annual.
Plant Name: Lavender, Provence
Botanical Name: Lavandula x intermedia, “Provence.” The “intermedia” lavender varieties are cross breeds. This means they are a cross between two varieties of lavenders: L. angustifolia and L. latifolia. Intermedias are also known as “lavandins”. These plants tend to grow larger, produce numerous long flower stems, have a high oil content and are hardy.
Origin: Alpenglow Gardens, North Surrey, British Columbia, mid-1950’s.
Height/Physical Description: This plant variety is 48 to 60 inches in height, 60 to 72 inches wide, green leaves, light purple flowers. The flower stem length spans 24 to 30 inches.
Special Attributes: The flowers are very fragrant, has a high oil content and is an excellent variety to use for distilling essential oil. The flower buds are sweet and good to use for culinary purposes. It is both cold and heat hardy which makes it a perfect choice for arid Southern California farms and gardens.
Purchasing: Easy to find at local nurseries as it is hardy and grows quickly.
Planting Requirements: Plant in Spring after danger of frost or in the Fall. Lavenders require good drainage. If soil is mostly clay, amending and aerating the planting area will ensure better success. Planting in a dome is another way to promote good drainage and keep your lavender from sinking down in clay soil. The preferred mulch at the base of the plant is gravel or a thin layer of compost. Do not use wood or leaf mulches as this contributes to root rot.
Repotting and transplanting: To determine your lavender is hardy and ready to repot or transplant, check the bottom of the container for vigorous roots coming out of the drainage holes. This is a sign of good health.
Watering: Water at base of plant only. Lavenders do not like overhead spray. Use of a drip system is best. Put on a drip line with plants that have similar water needs to avoid overwatering. Lavenders rot very easily when overwatered. To avoid this, allow the soil to dry out moderately before watering next.
Fertilizing: Lavenders are hillside plants that thrive in rocky, good draining soil that is somewhat alkaline (pH of 6.5 to 7.5). Lavenders do not require a great deal of fertilizer as they prefer neutral soil. Since this is the case, use of compost or compost tea is all that is needed.
Blooming Time/Harvesting: Light purple flowers once in early summer. Harvest when flowers first pop open.
Pruning: Lavenders can live up to 25 years if well maintained. The time to prune is after the flush of flowers. The flowers and stems should be gently pruned so the plant is the shape of a ball. Consider it a haircut not a severe pruning Removing the flowers in this manner allows the plant to regenerate foliage and avoids it from becoming “woody.”
Note: If the plant has become woody, it cannot be reversed. It will live but will not have the original full shape that it had at the beginning.
Pruning underneath the plant is another way to keep the plant healthy as this promotes good air circulation which prevents root rot.
Pests: Spittle bugs, grasshoppers, gophers, moles.
Diseases: Root rot.
Hardiness: zones 5-9. Provence thrives in dry summer climates. In wetter climates, this lavender is more prone to root rot.
Additional Comments: When considering Provence for a residential garden, be sure to allow plenty of room as it is a very large plant.