Lavender in pots – Gardener Report

Lavender 'Provence' (Lavandula x intermedia) is an perennial plant that can live up to 15 years with the right care and regular pruning. 'Provence' is a hybrid of Portuguese lavender (Lavandula latifolia) and English lavender (Lavandula angustifolia) that combines the hardiness and longevity of the English lavenders and the longer flowering season of the Portuguese lavenders. As 'Provence' retains the cold hardy characteristics of English lavender, it can withstand cold damaging Winter weather and will grow again the following year whereas the less hardy Portuguese, French and Spanish lavenders can not tolerate freezing temperatures which is why they are regarded as annuals in some climates, although, like all lavenders they are actually perennials. Lavender 'Provence' will come back each Winter and bloom for as many as 15 years and possibly longer as long as it has the right care. Ensure Perennial Lavender 'Provence' Grows back each Year In Temperate climates (such as Washington, Oregon and the UK) French, Spanish and Portuguese lavenders are often treated as annuals as they often die in Winter due to freezing temperatures. English lavenders and Hybrids such as 'Provence' will survive snow, ice and freezing Winters if the are cared for properly and pruned every year. The most important aspect of ensuring lavender 'Provence' survives Winter is to plant the lavender in the right potting mix. Lavenders of all varieties do not like wet soil at any time of year as this will lead to the fungal disease root rot. Diseases that affect lavender are more prevalent in Winter as soils stay moist for longer due to the lower levels of evaporation. Lavender 'Provence' will die in wet, cold soils if the soil profile has not been amended with horticultural sand or grit. Sand for amending soil. When you are potting your lavender or preparing garden soil for planting, make sure that you add roughly 1/3 of the soil mix as sand or grit and 2/3's with potting soil or compost. The high proportion of sand will ensure that the soil drains very quickly and it won't hold moisture for long periods. This will keep roots dry and healthy during Winter, protecting the roots of the lavender and avoiding disease. 1/3 sand or grit may seem an excessive amount but consider that lavenders are native to the sandy soils of the Mediterranean coast where they thrive in the dry conditions. By adding sand to the soil mix we as gardeners are emulating the conditions of the lavenders native environment. The more dry and fast draining the soil is, the stronger the scent and more flowers that lavender 'Provence' will display which is a great incentive to prepare the soil properly! For more information on preparing soil read my guide on the optimal soil mix for lavenders in pots. Prune 'Provence' Every Year for Longevity The second most important step to ensure that your perennial 'Provence' lavender lasts more then a year is to prune the lavender in the Fall, for three reasons: Pruning lavender every year helps to reduce the woody growth from the base of the plant and encourages new growth which will support more flowers.Pruning lavender will increase the life span significantly and prevent the lavender from becoming leggy.Pruning the plant to a nice mound shape will ensure consistent flowering and prepare the lavender for Winter. Prune lavender 'Provence' in the Fall after flowering ('Provence' typically flowers from mid summer till Fall). The goal with pruning should be to achieve a rounded shape as this will prepare the lavender for Winter. A mounded shape can better resist the affects of weather (such as snow and ice) which can cause the relatively fragile woody base of the lavender to split. Pruning also increase the longevity of lavenders in the same way that pollarding a tree will increase its life span. Prune roughly the top third of flexible growth of the lavender and avoid hard pruning down to the woody base. For a visual guide watch this YouTube video of how to prune lavenders: https://www.youtube.com/watch?v=9PyoWgXAf2w Other Factors Influencing Lavender 'Provence' life span Other factors that will ensure your perennial lavender 'Provence' lasts more then a year are... Whether it is planted in full sunWatering the appropriate amountSoil pH (lavender require a soil pH of between 6.5-8) To get the best out of your lavender 'Provence' you will need to replicate the conditions of the mediterreanean where lavenders thrive. Lavender will produce a stronger fragrance and more flowers if they are in full sun. Lavenders with less then 6 hours of sun tend to grow leggy with few flowers and often do not live for very long. Always plant lavender 'Provence' in full sun and in an area that receives some airflow, rather then an enclosed corner of the garden. When established lavender 'Provence' rarely requires any watering and in temperate climates will likely attain all the moisture it requires from rainfall. Lavenders thrive in coastal areas of Southern Europe with infrequent rainfall and therefore they are drought resistant in almost all climates. If there has been no rainfall for more then two weeks during the growing season (Spring till Fall) then give the lavender a good soak, preferably in the morning and do not water lavender during the Winter. The only time your lavender 'Provence' requires significant watering is after planting. Read more about how to water lavender in all conditions in my article how often should you water lavender? Lavenders of all varieties prefer soil to have a pH between 6.5 and 8. This ranges from slightly acidic to alkaline. Therefore perennial lavender may only last a season if your soil is too acidic. Most garden soil is around pH 6-7 (which is slightly acidic to pH neutral). If plants such as azaleas, rhododendrons, camellias, blueberry plants and roses are thriving in your garden, and yet lavenders are dying after the first year as an annual would, then it is possible that your soil is too acidic to support lavenders. However you can still grow lavenders in pots, containers and raised beds as you can control the soil profile and add 1 tablespoon of horticultural lime or half a cup of wood ash to the soil to raise the pH so that it is alkaline. You can also measure the soils pH with a soil gauge, which are easy to use without and specialist knowledge and available for a great price on amazon. (Read my article for more on measuring soil pH and growing lavenders in acidic soil). Key Takeaways: Lavender 'Provence' (Lavandula x intermedia) is a perennial plant that can live up to 15 years with the right conditions.Amend the soil with sand or grit for better drainage to prevent root rot and improve soil structure.,Prune 'Provence' every year in the Fall to prepare the lavender for Winter.Plant the lavender in full sun, and only water occasionally even in hot weather.Lavenders don't live very long in acidic soils ('Provence' prefers soils between pH 6.5-8). Plant 'Provence in pots if you have acidic soil and amend the soil with horticultural lime or wood ash (both of which are alkaline) if necessary.