Lavender

In general lavender is excellent for hot, dry conditions. It will survive in sandy soil and it doesn’t require a lot of water. It benefits from a trim after flowering. This will keep the plant neat and compact and will reward you with a second, third maybe a fourth flush of flowers. Trim into the new growth to help stop it going woody. Do not cut back into the old wood, it’s unlikely to grow back.

Lavandula angustifolia.

This type of lavender is probably the most common type. It grows to around 1m high and 1m+ wide and is reasonably compact. Its flowers, which are pale to deep purple on long stems appear in June through to August. Angustifolia is commonly used by lavender farmers. Probably the 2 most common varieties are ‘Hidcote’, commonly used for hedging, and ‘Munstead’, has paler flowers and is a little smaller than previous variety. These two grow to about 60cm in both directions. ‘Little lady’ is a smaller variety, growing to around 48cm. A couple of “monster” varieties, growing to 5ft wide and up to 3ft high, ‘Twerkle Purple’ and ‘Royal Purple’. While at the other end of the scale, ‘Little Lottie’ grows to around 30cm. Most lavender flowers are pale purple to near blue. However there are varieties that flower white, ‘Artic white’ and ‘Nana Alba’, and pink, ‘Rosea’-aka Jean Davis- and ‘Ellagance Pink’.  I must mention the variegated ‘Platinum Blonde’.  Its grey foliage is edged with a yellow that radiates gold, the flowers are bright blue. Can grow up to 50cm high and the same wide. A beautiful variety.  

Lavandula latifolia, aka Spiked and Broad Leaved lavender.

Flower spikes, up to 6cm (2.5in), of Pale lilac (blue/Lilac) on leafless stems up to 50cm (20ins) from June to September, depending on the weather. Has a stronger fragrance as well as longer and broader leaves than angustifolia.  ‘Corbieres’- has a purple flower, unfortunately this variety is not generally available. As with some types/varieties of lavender this is available to buy as seed but is difficult to come to find.

Lavandula x intermedia, commonly known as lavadin.

This is a naturally occurring hybrid (cross) between angustifolia and latifolia and can withstand heavier soils. It is generally a larger and more robust type than angustifolia. It has a longer flower stem, which makes it useful in flower arranging. It’s also widely grown commercially for its oil as it’s among the lavenders with the strongest fragrance. It generally comes into flower after the angustifolia type. Probably the most commonly seen, and used, variety is ‘Grosso’ which has rich purple flowers. It grows to 90cm (36in) high including flowers on longer stems. The variety ‘Edelweiss’ has pink buds that open white and has an intense fragrance. As with all intermedia varieties the flowers are on long stems. It reaches a height 0f 90cm (36in). The last variety for this type, ‘Grappenhall’, is named after a small town in Cheshire in early 1900. It has light blue 5in long flowers that are on stems up to 40cm long. The stems give it an overall height of 90cm. The foliage of this variety is more green grey than the more familiar grey.

Lavandula dentata, aka Fringed lavender.

This gets its name from the square teeth on its leaves, is a tender type, needs a mild climate, therefore usually grown in pots so it can be brought in during the winter month. It needs excellent drainage, so clay/heavy soils are a big no. In areas that have clay soils it may benefit from a raised bed or a rockery. This is a bushy, compact type of lavender and therefore can be used for topiary. The flower spikes, which appear in mid to late summer, are of lavender/mauve and are on short sems. Can grow to 1m high and 70cm across.

Varieties of L. dentate, 'Pure Harmony' has white flowers, ‘Candicans’ has pale purple flowers topped with short pale purple bracts, ‘Royal Crown’  has small purple flowers topped with pale purple bracts and has been awarded the RHS AGM (Award of Garden Merit). Which basically means that it’s a good garden performer.

Lavandula stoechas, aka Butterfly Lavender.

Probably more commonly known as French Lavender but here’s where it gets confusing, it’s also known as Spanish and Italian lavender. Perhaps it should be called the European lavender instead. It’s one of the earliest types to flower, mid to late spring. The flowers are about 2-3cm on stems that can be as long as 30cm (12in). At the top of the flowers are bracts (a modified leaf), sometimes called ears or flags. This type is less frost tolerant than angustifolia and won’t grow in the shade.

A popular variety of stoechas is ‘Anouk’. This is a dwarf variety, growing to about 30cm (12in) high. The silvery green foliage helps the stunning purple flowers and lilac bracts standout. An eye catching variety. This variety, ‘Tiara’, is another eye catcher. With its purple blue (looks more blue), 3 to 4cm long flowers topped with creamy white 1cm long bracts. It grows to about 60cm high and can be the same wide. Wouldn’t mind this one myself. True blue is not a common colour in the world of flowers, this, in my opinion, comes close to sapphire blue. The last stoechas variety I’ll mention is ‘Kew Red’. The deep pink to red flowers topped by pale pink bracts, which fade to white as they mature appear from mid to late spring and, if treat right, go on to late summer. It grows to around 50cm high and the same wide.

With the flowers of this variety mostly bicoloured the colour palette of this type is vast. There are white varieties of which ‘Madrid White’ aka ‘Bee Cool’ is one.

Lavandula multifida, aka Fern Leaf.

Trouble is, two other types are also known by the same alternative name. The only way to tell the difference is by foliage colour. L. multifida has grey green leaves with a fragrance similar to oregano. The leaves have a soft feel and are divided making them look like ferns. In summer it produces violet blue spikes up to 3in long. . It only grows to about 60cm (24in) and is short lived, 2-3yrs. Much divided. Has an architectural value both with its foliage and flowers.  

‘Spanish Eyes’, ‘Blue Wonder’, ‘Blue Torch’, ‘Minty Ice’. I believe these varieties are all available to grow from seed. The reason for this being that, in the UK, you’re better off treating this type of Lavender as an annual. That’s not to say they won’t survive for several winters. If you’re wanting to keep them I’d suggest to put them in a container that you can move to frost free place before the first frost. With our winters getting warmer I’d certainly chance them outside. They all can grow to around 60cm (24in) high and wide. I assume that’s if they survive the winter. The latter two varieties are new introductions for 2020.

The following types of lavender are judged too tender for our climate. L. pinnata buchii (Tenerife Lavender), L. canariensis (Canary Island Lavender), L.pinnata (Fernleaf Lavender), L. rotundifolia (Cape Verde Lavender). They’re best grown in pots in all areas of the UK and over wintered in a protected position.

Lavender seems fairly pest and disease resistant, which isn’t to say they don’t suffer from anything because they do.

Alfa Mosaic Virus: with this the leaves get patches of yellow and then start to curl and contort. This is spread by aphids and us. If you have a few lavender and only one is affected, use something that can be disposed of to handle the plant and remove the affected plant, then, if you can burn it and anything used to handle it. If you’re unable to burn it, bag and bin it. Do NOT recycle or compost. Also weed thoroughly and remove any debris in the area. The good news is that this disease is rare in Britain.

Wet Feet, strictly not a pest or a disease. If the soil around the roots of lavender get to wet it’ll suffer from this, especially over the winter. Rot sets in, bark comes off easily from the base. Slightly twist and pull the stem and it’ll come off. Large plants will struggle on for a while, only delaying the inevitable.

Cuckoo Spit, more unattractive than a nuisance. However the Capsid Bug inside will have its first meal of sap from the lavender. However it’ll do little or no damage so not really worth bothering with. If there are too many they may cause the leaves to contort, but that about as bad as it gets. To remove Cuckoo Spit a simple blast of water should be enough. No chemicals required.

Whitefly, are attracted to Lavender but not in great numbers, very rarely to the point where they can be fatal to the plant. If your lavender does become infested growth will become stunted and turn yellow. As there is no effective pesticide available so you’ll need to use your hands. A blast of water will remove the adults.

Aphids, may visit lavender but rarely cause any damage. The rarer but far more serious disease caused by aphids is below.

Lavender Shab Disease (Phomopsis lavandula), is a fungus. The clearest sign your lavender has this is the shoots suddenly wilting for no reason. If you look at it closely and I do mean closely, you’ll need a good magnifying glass. You’re looking for black shapes (pycnidia) cruelling from the bark. Best course of action is to burn it. If you’re unable to burn it, bag and bin it. Do NOT recycle or compost. Also weed thoroughly and remove any debris in the area. The good news is that this disease is rare in Britain.