lavender dying in container – Gardener Report

The reason your lavender in a pot is dying is usually because: Lavender has been planted in the wrong type of pot. Lavender pots need to have drainage holes in the base and measure 16 inches across otherwise lavenders die of root rot. The soil mix is not well draining which causes the lavender's roots to rot. Lavender soil needs to be amended with sand or gravel to balance nutrients and improve soil drainage. Watering potted lavender too frequently. Lavenders are drought-resistant and established lavender only needs watering once every two weeks. Too much water causes root rot and can cause the lavender to die. Lavender isn't receiving enough light. Lavenders do best in full sun and will die in shade. Move your pot to the sunniest part of your garden Wrong lavender for your climate. Some species of lavender are cold hardy whilst others will die in cold winters. Pots also provide less insulation for the roots from the cold and dry quickly in summer. Keep reading to find out exactly why your potted or container lavender is dying and what you can do to solve it... 1. The Wrong Pot for Growing Lavender Perhaps the most common reason that I see for potted lavenders dying, is because they are planted in an inappropriate pot. The ideal pot for growing lavender should measure at least 16 inches across and have drainage holes in the base. If the lavender pot does not have drainage holes in the base then water will simply collect in the pot and saturate the soil. (Read my article Which is the best pot for lavenders? for more information). Lavenders are drought-resistant plants that have adapted to living in dry sandy soil which does not hold much moisture. If excess water cannot escape out of the pot then the roots will rot and the plant will die. In this situation, the first signs of stress will be the lavender foliage turning brown and the plant will likely have a drooping appearance. The excess water causes the fungal disease root rot which is one of the few diseases that lavender is particularly susceptible to. The only solution to this is to immediately transplant the lavender into a new pot with drainage holes in the base and let your lavender dry out for two weeks, by which time it may show signs of recovery, however, this will depend on how long the roots have been in the saturated soil. If the lavender does show some signs of recovery then water once every two weeks and ensure that it does not receive any additional water from rainfall. Occasionally I see a lavender in a pot or container that is either indoors or on a patio that has a drip tray underneath the pot. This will mimic the effect of having a pot without drainage holes in the base and the plant will die of root rot. If the plant is indoors and you are trying to prevent the water from pouring out over your window sill then I would recommend placing a paper towel under the pot whilst you water as a temporary measure, or just move the pot elsewhere whilst watering. 2. The Wrong Soil Mix for Pots Using the wrong soil mix is a very common reason why lavenders in pots and containers die. Lavenders grow their best in soil that is sandy, alkaline, and well-draining with low to medium fertility. To ensure that your lavenders are healthy, and produce lots of flowers and fragrance you must create a soil mix for your pot that recreates the soil conditions of lavender's native environment. The most frequent problem with the soil mix is that it does not drain fast enough. Lavenders require fast-draining soil so that their roots can dry out between watering. Rich organic soil that is unamended with sand or gravel will hold onto too much moisture which causes root rot. The plant's foliage will turn brown and droop in appearance and if it is not transplanted into well-draining soil the plant will die. Lavenders have adapted to sandy or gravelly soils that are relatively low to medium in nutrients in their Mediterranean home range. If you plant lavender in high fertility soils or feed the lavender then the plant will grow lots of foliage and produce fewer flowers. Nitrogen-based fertilizers will cause the lavender foliage to turn yellow and grow leggy. Lavenders can grow in soil that is anywhere between pH 6.5-7.5 but lavenders prefer slightly alkaline soil. If the soil is over acidic (less than pH 6.5) then the lavender will likely die or not live for very long. The great thing about planting lavenders in pots is that you have complete control over the soil that you use, rather than trying to amend your garden soil to suit lavenders. Fortunately, the solution to lavenders in pots dying because of the wrong soil is very easy to solve. Take the lavender out of the offending soil and discard it. Replant the lavender into soil that is at least 30% sand (or gravel) and 70% organic compost or store-bought potting soil. Add a tablespoon of agricultural lime (which will be available from any good gardening store) into the mix before planting as this will increase the pH of the soil from acidic to alkaline. The added sand or gravel will drastically improve the soil structure so that water drains more effectively and the roots will have a chance to dry out after watering which will decrease the chance of root rot. The minerals also do not contain high levels of nutrients so they will balance out the organic compost and recreate the lavender's preferred, low to medium fertility soil conditions where it thrives in countries such as France, Italy, and Spain. The soil mix is one of the most important aspects to get right when it comes to growing lavenders in pots and containers, which is why I have an article detailing how to create optimal soil conditions for growing lavenders in pots. 3. Watering Potted Lavender Too Frequently Established potted lavenders will only need watering once every two weeks in the growing season (spring and summer). Lavenders will not need any watering at all during winter if they are left outside, however indoor lavenders or lavenders that are brought indoors over winter for protection from the cold only need watering once every 4 to 6 weeks. (For full details on winter potted lavender care, read my article, will lavender survive in pots over winter?) If you water your lavender in a pot or container too frequently it will likely die from root rot. Watering potted lavenders can be confusing as the signs of stress from an overwatered lavender may superficially look like an underwatered plant. Do not make this mistake! If the lavender foliage is starting to look brown and the lavender stems are starting to droop in appearance then the problem will be that the lavender is overwatered. Lavenders are drought-resistant plants that live in relatively harsh, dry conditions with blazing sunshine so it is unlikely the plant will be underwatered unless it is kept indoors and hasn't been watered for months. If your lavender is exhibiting the signs of stress of an overwatered plant then scale back the watering to once every two weeks and shelter it from rainfall and it may revive. This should be done in conjunction with ensuring that the lavender is planted in a pot with drainage holes in the base and well-draining soil that has been amended with sand or gravel. Lavender in pots grows best with a soak and dry style of watering where they receive enough water so that it trickles out the bottom of the pot (which is also a sign that the soil is well draining). You need to give outdoor potted lavender the opportunity for the soil to dry out before you water it again so if there has been excessive rainfall in the two weeks since you last watered then you can skip watering for a few days until the soil feels dry to a fingers depth. It should be noted that watering lavender that has just been planted is different from watering established lavender. Read my guide on watering lavenders in pots to learn when to water lavenders at different stages of growth. 4. Not Enough Sun Light Lavenders produce the most flowers and best aromas when they are in full sun and they will not live for very long in the shade. Even in their winter dormancy lavenders will benefit from as much sun as possible. The more sun they receive the stronger the fragrance and the more blooms the plant will produce. Try to find an area for your potted lavender that sees at least 6 hours of sun per day (morning sun is better) although more is preferred. Lavenders with too much shade will exhibit poor growth, with fewer flowers, and produce less oil, so move the pot to the sunniest area of your garden or patio as soon as possible and the lavender should produce more fragrance and blooms in the following season. 5. Wrong Potted Lavender for Your Climate The reason you potted lavender is dying could be because the lavender species is not suitable for your climate. English lavenders (Lavandula angustifolia) popular varieties include, Munstead and Hidcote are the hardiest lavenders and will tolerate frosts and winter temperatures that drop as low as 14°F (-10°C) and they are considered hardy up to USDA zone 4. Whereas Spanish and French species of lavender are not cold hardy and will die in winter frosts and cold temperatures. French and Spanish lavenders are only hardy in USDA 7-9 which makes them unsuitable for pots growing outdoors in many temperate climates. So if your lavender looks as though it is suffering and the weather is cooler then check which species your variety of lavender is to see whether it is cold hardy. It should be noted that the effects of excessively hot and cold can be more pronounced for potted lavenders as pots leave lavender roots more exposed to the cold with less insulation and more susceptible to the drying effects of hot weather as the pot can heat up in blazing sunshine, hence the importance of planting lavender in a pot that measures 16 inches across so it can contain more soil to protect the lavender. If you live in a colder climate that experiences frosts, English lavenders are the best option as they produce lots of flowers, have the finest fragrance, and can live for up to 15 years with the right care. English lavender is also the most versatile species as it can tolerate drought-like conditions as well as cold. It is possible to grow French and Spanish lavenders in cooler climates if you are prepared to bring the pots indoors as soon as the temperature starts to drop before winter. I have written an article on the exact steps of how to care for potted lavenders in winter which covers French, Spanish, and English lavenders for more information. Key Takeaways: The reason lavenders in pots are dying is usually because they are planted in the wrong type of pot. The pot needs to have drainage holes in the base to allow excess water to escape, otherwise, the pot will fill with water and the lavender will develop root rot. Drip trays placed underneath the pot to catch excess water will also have the same effect and the soil will become too moist for the lavender's roots. Soil mix is just as important as the right type of pot. The potting mix needs to be amended with sand or gravel so that the soil is well-draining and does not retain much water. Lavenders are adapted to be drought resistant and grow best in dry conditions with sandy soils that are medium to low in nutrients. If the soil is too fertile the lavender's foliage will turn yellow and the plant will grow leggy with few flowers. The soil should contain roughly 30% sand or gravel to 70% organic soil to provide the optimal structure and level of nutrients in the soil. Pots do provide favourable drainage conditions for lavenders however established lavender should still be only watered once every two weeks in the growing season and do not water outdoor potted lavender in winter. If you are watering your lavender too frequently then the foliage will turn brown and the lavender's stems will have a drooping appearance. Scale back the water to once every two weeks and the plant may revive. Lavender pots and containers should be in full sun to achieve the best results in terms of aromas and blooms. Lavenders do not grow well in the shade so move your pot to the sunniest part of your garden or patio. English lavenders are cold hardy and can survive frosts whereas French and Spanish lavenders are only hardy in USDA zones 7-9 and will die in cold temperatures. Bring French and Spanish lavenders indoors over winter for protection or only grow English lavender varieties such as Munstead and Hidcote which are both cold-hardy and drought-resistant and produce the finest scents and spectacular blooms.