Manage Soil Moisture For Proper Irrigation Of English Lavender

There are several popular species of lavender, including Spanish lavender (Lavandula stoechas), English lavender (Lavandula angustifolia), and Lavandin (Lavandula x intermedia). Spanish lavender is typically grown in southern areas of the U.S., because it is considered to be more tolerant of heat and humidity. English lavender is one of the more winter hardy species of lavender. It is hardy to Zone 5 or 6, compared to Zone 8 for Spanish lavender. English lavender is a popular landscape plant that is grown for its attractive form and flowers, and it is also used as an aromatic herb.

 

 

 

 

Because lavender is native to Mediterranean climates, it is recommended that plants be allowed to dry between watering. According to the “Ball Red Book,” English lavender has an intermediate difficulty level in regards to growing. One challenge with growing this plant is managing soil moisture. While it is typically recommended to grow plants in dry substrates, it is unknown if additional moisture would benefit plants, or how much drought plants can tolerate. For example, other Mediterranean plants, such as rosemary, prefer well-drained soils, but die when exposed to drought.

Two Cultivars Tested For Response To Various Moisture Levels

Our goal was to determine how English lavender plants would respond to a range of irrigation levels, including drought and normal moisture. We worked with two cultivars of Lavandula angustifolia, ‘Munstead’ and ‘Hidcote.’ ‘Munstead’ has been the industry standard in Maine for cold-hardiness for many years. ‘Hidcote’ is a cultivar that has rich, deep-purple flowers.

The plants in the experiment were maintained at relatively constant soil moisture. However, moisture contents ranged from near the permanent wilting point (very dry) to close to container capacity (quite moist). We used soil moisture sensors (5-TM, Decagon Devices) to measure soil moisture and maintain very dry or moist substrate moisture levels. These sensors measure volumetric water content, which is the ratio of the volume of water to the volume of soil (units = m3•m-3).

For the substrate, we used a peat-lite mix. Very dry substrates were irrigated when substrate volumetric water content fell to 0.10 m3•m-3. On the other hand, moist substrates would be irrigated at 0.40 m3•m-3. Using this approach, we were able to observe the response of English lavender to a broad range of soil moistures. During the course of this experiment (54 days), we applied a range of 0.5 (low soil moisture or 0.10 m3•m-3) to 3.5 gallons (0.40 m3•m-3) of water to English lavender.

‘Munstead’ Lavender Responds Well To Drought Conditions

Both cultivars of lavender were generally larger when they were grown with more water (Figure 1, Figure 2, see slideshow). Plants were taller, and had greater overall size. When ‘Munstead’ and ‘Hidcote’ were grown drier, there were fewer flowers on each plant. This would impact quality, because consumers are more likely to purchase larger plants with more flowers. ‘Munstead’ plants grown in the driest soils did not flower at all. The plants grown at the highest or intermediate soil moisture levels did not exhibit any signs of stress or disease.

Many ‘Hidcote’ lavender plants died when they were grown in the driest soils (0.10 m3•m-3). By comparison, ‘Munstead’ plants survived even the driest conditions. They were generally larger and more vigorous when compared to ‘Hidcote.’ Based on this information, it appears that ‘Munstead’ may be a more drought-tolerant cultivar than ‘Hidcote.’

English Lavender Prefers Slightly Moist, Well-Drained Soils

Overall, we found that English lavender may not be as drought tolerant as we previously thought. It may be a good approach to grow plants in a well-drained soil, but avoid allowing plants to dry out completely. This would be particularly true for cultivars such as ‘Hidcote’ that are not particularly vigorous. If you prefer to grow lavender dry, ‘Munstead’ would be a good cultivar to select for production because of the two cultivars we researched, it was the more drought tolerant. One new, promising lavender cultivar is ‘Phenomenal.’ While we did not research this cultivar, it would be a good one to consider for in-house trials because it is hardy to Zone 5 and grows to a maximum height of four feet.

If you wish to use sensors to measure water in your greenhouse, you have a few approaches to consider. The sensors that we used can be connected to a hand-held datalogger called a Pro-Check (Decagon Devices). This datalogger allows for instantaneous readings of soil moisture that may provide more information for making irrigation decisions. Several sensors could also be connected to a datalogger (EM50 or similar, Decagon Devices) to provide continuous monitoring.

This work was supported by the American Floral Endowment and is based upon research supported in part by Hatch Multistate Grant ME0-31401. The authors thank the Fafard Corporation for providing substrate to support their work. 

Topics: ,

Leave a Reply

One comment on “Manage Soil Moisture For Proper Irrigation Of English Lavender

  1. Have you also measured pH and EC level during this test ? – as saltstress in drier soils could more easily occur and also effect growth and/or dying of plants….

More From Production...
Triathlon BA container shot

May 24, 2016

OHP’s Triathlon Biofungicide Now Listed By The Organic Materials Review Institute

Triathlon BA is a broad-spectrum preventative biofungicide that provides control of many foliar and soilborne diseases in ornamentals and herbs.

Read More
Pythium On Chrysanthemum

May 20, 2016

How To Prevent Pythium In Fall Garden Mums

Avoid profit loss in fall garden mums due to pythium root rot with good drainage and integrated pest management practices that reduce risk factors.

Read More
Agro-K

May 19, 2016

Agro-K Expands Distribution In New England Through Partnership With Northeast Agricultural Sales

Agro-K, which manufactures conventional and organic foliar plant nutrients, will distribute its full line of foliar fertilizers and soil biological products through NEAG.

Read More
Latest Stories
Triathlon BA container shot

May 24, 2016

OHP’s Triathlon Biofungicide Now Listed By The Organic …

Triathlon BA is a broad-spectrum preventative biofungicide that provides control of many foliar and soilborne diseases in ornamentals and herbs.

Read More
Pythium On Chrysanthemum

May 20, 2016

How To Prevent Pythium In Fall Garden Mums

Avoid profit loss in fall garden mums due to pythium root rot with good drainage and integrated pest management practices that reduce risk factors.

Read More
Agro-K

May 19, 2016

Agro-K Expands Distribution In New England Through Part…

Agro-K, which manufactures conventional and organic foliar plant nutrients, will distribute its full line of foliar fertilizers and soil biological products through NEAG.

Read More
Stained poinsettia foliage from high iron

May 19, 2016

Minimize Build-up In Your Water Pipes

This article is the third in a series of case studies designed to help growers reduce, remediate, and recycle irrigation water as part of a multi-state research grant (CleanWateR3.org).

Read More
pond water management

May 16, 2016

Pinpoint Toxicity In Your Pond Water

This article is the second in a series of case studies designed to help growers reduce, remediate, and recycle irrigation water as part of a multi-state research grant (CleanWateR3.org).

Read More
MSU Guide To Attracting Pollinators

May 14, 2016

New Online Guide Offers Tips On Enhancing Pollinators I…

The guide, produced by a team of researchers from Michigan State University and elsewhere, includes information on plants that attract pollinators and offer an ideal habitat.

Read More
Two-spotted spider mites, adults and eggs

May 11, 2016

SePRO Launches Summer Insecticide Management Program Fo…

The program is designed to help growers use SePRO’s insect management tools to prevent plant damage from a variety of pests.

Read More
Mum With and Without Ammonium Toxicity

May 5, 2016

How Nitrogen Influences The pH Of Your Growing Medium

In standard greenhouse fertilizers, nitrogen is supplied as ammonium, nitrate, or urea. Each of these three nitrogen sources, when taken up by plant roots, produces different chemical reactions with differing effects on the growing medium pH.

Read More
As the pots continue around the carousel, bark is pushed into the pots and settles around the roots, which helps to avoid compaction in the growing media

May 5, 2016

Three Factors That Can Impact The pH Of Growth Media

Water alkalinity, fertilizer, and plant species can each play a role in the pH of your growth media.

Read More
Small Aphid Colony on Calibrachoa

May 2, 2016

How To Stop Aphids In The Greenhouse

When untreated, aphids damage ornamental crops and act as vectors for disease. Integrated Pest Management combined with vigilant scouting can help you stay ahead of the problem.

Read More

April 28, 2016

Holistic, Integrated Approach To Pest Control Rooted In…

Greenhouse growers have been practicing integrated pest management for decades, but it’s becoming increasingly more important with the continued scrutiny of conventional pest control by a number of “regulators” — government, retail, and consumers. I just returned from Meister Media Worldwide’s Biocontrols USA 2016 Conference, in Monterey, CA, at the beginning of March this year, which served 450 attendees and 50 exhibiting supplier companies. It’s clear from the presentations and the growing attendance at this specialized event — now only in its second year — that use of biocontrols in IPM will continue to be adopted widely, as more growers get past their personal hurdles of doubt and intimidation, and embrace a new way to approach pest and disease control. Many growers think of using biocontrols as an all-or-nothing approach, but ultimately, IPM is about balance. Growers will need to continue to focus on IPM, integrating chemistry with biology, because […]

Read More
Drip irrigated citrus liner

April 27, 2016

Unclog Drip Emitters In Your Greenhouse

This is the first article in a series of case studies designed to help growers reduce, remediate, and recycle irrigation water as part of a multi-state research grant (CleanWateR3.org).

Read More
Fine Americas Website Feature Image

April 26, 2016

Fine Americas Offers A Digital Resource For Plant Growt…

The blog section of Fine America’s website is updated regularly, with input from both technical managers and independent researchers

Read More
Cicada (Greg Hoover, Penn State)

April 26, 2016

Cicadas Set To Emerge In Several Eastern States This Sp…

While there’s no immediate cause for alarm, experts say the cicada’s egg-laying process can damage woody ornamentals and make them vulnerable to diseases.

Read More
Parisitic Wasp Aphidius colemani

April 25, 2016

Plant Growth Regulator Use Can Affect Biological Pest C…

The use of plant growth regulators may negatively influence the outcome of biological control programs, according to researchers at North Carolina State University.

Read More
Beneficial Insectary Orius insidiosus

April 22, 2016

Beneficial Insectary Increasing Production Of Three Bio…

The company is now producing Orius insidiosus, Dalotia coriaria, and Dicyphus hesperus at its California facility, reducing the transit time of perishable biocontrols between producer and grower.

Read More

April 21, 2016

Nutrient Supply Makes A Difference In Soil Media Testin…

Research from the University of Massachusetts highlights the differences approaches to soil media testing, and when to use them.

Read More

April 21, 2016

Michigan State University Offers Tips On Greenhouse Soi…

Improper pH and higher than adequate nutrient levels are among the many reasons for regular soil testing.

Read More
[gravityform id="35" title="false" description="false"]