The “Lavatera” is a popular plant genus, well known for its vast array of long-flowering garden plants. There are around 25 species in this heavily blooming collection, all of which are stunning. Let’s take a closer look into their world and find the perfect plants for your own garden.
The Lavatera genus is alternatively known as the “Tree Mallow” or “Rose Mallow”. It’s comprised of annuals, biennials, herbaceous perennials, and semi-evergreen, soft-wooded shrubs. Although these come in a wide range of differing plant forms, the flowers are the same throughout the genus. In fact, the luscious blooms are what grab our undivided attention.
All of these plants belong to the Malvaceae plant family. They’re native to Northern America, Australia, Asia, and the Mediterranean.
There are few plant families out there that can beat Lavatera’s prolific flowering. You can expect a continuous run of the prettiest trumpet-shaped blooms from late spring right through until late autumn. Truly, these are some of the most beautiful you’re likely to see within the horticultural world.
Impressed? Indeed, I am. This is a plant that just keeps on giving.
Varieties
Below are a few of my favorite selections from the 25 or so available.
Let’s start with the Lavatera x clementii “Rosea”
This is a wonderful hybrid cross of the renowned Lavatera olbia and Lavatera thuringiaca. It’s a semi-evergreen shrub that’ll soon be a sure staple for the back of your garden border.
This humble hybrid is a vigorous grower with an erect form and a mature height of 6–8 feet. As such, it’s a perfect backdrop for both smaller sub-shrubs and summer perennials alike. It features velvet textured, maple-leaf foliage and abundant deep-pink trumpet-shaped flowers from early summer, right through to fall. You can understand why it has gained so much respect.
This variety is suitable for outdoor growing all year around in zones 7–9, and is half-hardy in all other areas.
Lavatera arborea
A native British “tree mallow” that isn’t fully frost hardy in colder areas, but commonly naturalised in many U.K. coastal districts. This biennial species will mature to a height of around 4 – 6 feet, and grows with an upright, stout, sturdy habit.
The Lavatera arborea’s palmately lobed, mid-green leaves are textured like soft velvet, and arranged spirally on woody stems. In summer, it produces beautiful pale purple-veined flowers, around 2 inches across, on leafy panicles, each reaching 2–3 feet long.
There’s also a variegated variety that has white-mottled leaf markings and deep red flowers. It’s definitely worth taking a look at.
This one’s suitable for outside growing all year round in zones 7–9, and half-hardy in other areas.
Lavatera assurgentiflora
Now classified as the “Malva assurgentiflora”, this Lavatera is known as the “Royal Mallow”. It’s endemic to areas throughout Southern California, U.S.A. It’s a sprawling, semi-evergreen shrub with twisted glaucous stems and grey-green foliage. Generally, it grows to a maximum height of anywhere between 1.5 and 4 metres.
Its large, hairy, deeply lobed leaves play backdrop to a mass of cerise pink flowers that appear in mid summer. Each flower petal has a distinctly rectangular shape, often reaching up to 4.5 cm in length.
This is a popular shrub for cultivating wildlife gardens and natural landscaping projects.
Lavatera trimestris “Mont Blanc”
A really special specimen is the “Mont Blanc”. It’s a compact and bushy annual form with plentiful snow white, trumpet-shaped blooms. Although small in stature, its growing rate is vigorous and it quickly reaches a height of approximately 24 inches and spreads to 18 inches.
This hardy annual has dark green, oval-shaped leaves. They’re deeply lobed, making it a gorgeous mainstay for a herbaceous border and annual garden. It’s an extremely versatile, prolific choice, with a long flowering period and large, cup-shaped blooms.
Frost hardy in zones 8–10, but commonly used as a substantial annual bedding plant.
Lavatera trimestris “Silver Cup”
The “Silver Cup” comes from the same genus as the “Mont Blanc” above. It’s another dwarf, bushy variety with a similar growing height and form. This vigorous branching annual has long stalks, and an early summer showcase of open-trumpet shaped, rose-pink flowers, right through till autumn.
Each silky bloom is heavily veined in a deep red-purple, with deep purple centres. This old-fashioned Lavatera is perfect for the cutting garden or herbaceous beds. It’s also guaranteed to bring a host of wildlife interest into your garden.
Frost hardy in zones 8–10, and regarded as a sought-after annual bedding plant.
Another interesting variety to take a look at is the Lavatera trimestris “Loveliness”, which has prolific trumpet-shaped deep rose-pink blooms.
Lavatera maritima
I think this variety has one of the prettiest blooms of all. The L. maritima has purple-veined, trumpet-shaped white flowers, each with a magenta-purple throat.
This is a fast-growing, semi-evergreen shrub, reaching a size of 1.5 metres tall x 1 metre in width. Native to South Western Europe and Northern Africa, the “maritima” is a half-hardy specimen shrub with a typical upright, sturdy form and branched woody stems.
It’s a popular and seriously long-flowering species, with abundant flowers produced in terminal clusters. These literally smother the branches from spring through till autumn time.
This variety will continue to bloom lightly throughout the rest of the year if kept in optimum conditions. It’s also suitable for outside planting all year round in zones 6–8. Alternatively, this is a good shrub for pot-growing and over-wintering in the greenhouse.
As with all of these wonderful species, the Lavatera maritima prefer to be sited in a sheltered spot. It’ll bring a host of wildlife into your garden, eager to sample its nectar-rich blooms.
Further Interesting Varieties
If you’re a fan of the species listed above and are looking for more inspiration, check out these shrub-forming varieties. They may be just what you’re looking for!
- “Barnsley” – Deep pink blooms with a bright red heart
- “Burgundy Wine” – As the name suggests, blooms are deep burgundy-pink
- “Bredon Springs” – An unusual variety with mauve-pink flowers
All the above are slightly frost-tender shrubs, suitable to be grown in a pot and over-wintered indoors. Alternatively, they can be planted outside in zones 7–10 for a stunning floral garden.
How to Get the Best from your Lavatera
Planting
Site and Soil Requirements
As a genus, Lavatera are quite unfussy plants. They’re happy to be sited in many different soil types, from acid to alkaline and neutral. Just remember that your plants will always perform better in a well-drained, loamy soil.
Heavy clay is possibly the only soil in which your plant will suffer. This has nothing to do with the excessive alkaline, but more to do with the soil’s heavy, waterlogged nature.
When planting out in the garden, always dig a good-sized hole. If you do have heavy soils, incorporate some lighter, free-draining mediums into it such as grit, sharp sand, or small gravel before you plant. Well-rotted manure or other organic matter will also help to improve the soil’s structure.
If you live in a cooler area, plant your Lavatera into a sizeable pot and keep it in a sunny outdoor spot throughout the flowering season. Choose a good quality, loamy compost, (with a large soil base, and not peat). Adding a good handful of slow-release granule fertilizer will ensure a good nutrient base from the start.
I recommend planting your Lavatera in a sunny, sheltered site. It will achieve a greater floral show throughout the summer months, and the risk of wind damage will be much reduced. In a windy site, your shrubs’ woody stems are vulnerable to snapping off, and many flowers will be blown away.
Temperature Requirements
Many species aren’t fully frost hardy, but can be lifted at the end of the season, or pot grown and over-wintered indoors. Take a good look at the care instructions when buying your plants. Doing so can ensure you have the right plant for the right spot.
In my “Besties List”, I’ve made a note of which zones are appropriate for each species.
Starting Seeds
I just love growing plants from seed. It gives me a huge sense of enjoyment and satisfaction to know I’ve created plants from scratch. The best time to start your Lavatara seeds is in the spring: so, March, April, and May.
These seeds are pretty easy to grow: just grab yourself a seed-tray and some fine compost, and get started.
Once you’ve filled your seed-tray with fine compost, give it a light water with a fine watering can. Next, place your seeds on the damp soil and cover lightly with either horticultural grit, or more of that fine compost.
Place your seed tray indoors, maintaining a temperature of around 21C/70F. You’ll see your sprouts in around 15–20 days.
Alternatively, you can also direct-sow annual varieties when the chances of a hard frost have passed. Each plant will need room to grow, so thin weaker seedlings when they’re around 4 inches tall, and leave an 18-24″ gap between plants.
General Maintenance
Watering
Once your Lavatera plants are established, they’ll be quite drought tolerant. This is beneficial if you’re away for a week or two, but try to include them in your watering schedule during long hot, dry weather spells. You’ll know when your plant is too dry as the flowers will start to fall prematurely.
Mulching
Regardless of species, I always mulch my plants in late autumn. For floriferous species such as these superb Lavatera, it’s especially important to put nutrients back into the soil for the next season. This will give your plant all the essential nutrients for strong green growth, and promote better flowering.
Use good, weed-free organic matter, or well-rotted farmyard manure. Only mulch once a year around your mallow plants. Excess nutrients can create too much green growth in this species, which will cut down on the flowers produced.
Fertilizing
Potted plants will always need to be fertilized throughout the growing season. This is simply because they have a limited amount of soil nutrients available to them. Over time, composts lose both their structure and nutrient value, so always re-pot with fresh compost and extra slow-release feed granules once a year.
Garden-planted mallows shouldn’t need extra feed if they’ve been mulched in the autumn. If not, use a well-diluted, balanced feed once a month. Just be aware that excess nutrients may cause unnecessary green growth.
Pruning
It’s important to deadhead your flowers regularly to promote continued blooming for the season. Just be sure to leave the last blooms on your plant near the end of the season, so it can re-seed.
Pruning a Shrubby Lavatera
Prune your shrubby mallow back quite hard in mid spring, once the risk of frosts has passed.
New flowering shoots, (for the coming season), will grow from the plant’s base, so all old wood can be cut back to around 12 inches tall. Any dead, dying or diseased wood can be taken right down to the base. I know this may sound a little harsh, but trust me: a hard prune will promote strong vigorous growth, bringing abundant blooms throughout the next flowering season.
Annuals will die down once the cold weather arrives, so replace these next season.
Propagation
Popagate your perennial Lavatera, sub-shrub and shrubby species by taking softwood cuttings in early spring or summertime.
Annuals and biennial plants can be grown from seed in springtime or early autumn.
These plants grow vigorously and have huge flowering potential. The downside is that they have a relatively short life expectancy of about 5 years. It’s worth taking cuttings from an established mother plant to allow for this loss. Then, just replace spent plants with young propagated softwood cuttings.
Pests and Diseases
Pests
This hardy plant family doesn’t really have great pest problems. That said, there are a couple of critters to be aware of.
Aphids
These common, sap-sucking insects create more mess than major problems. Their sticky residue can attract black sooty mould to grow, and they can cause distorted and weakened growth. This can be remedied by washing your infected plants with a suitable insecticidal soap available from a garden center or plant store.
Red Spider Mite
This is another nasty, sap-sucking insect that takes a liking to tender plant juices, and can cause plant deformity and insipid, yellow-looking leaves. The mites are too small to see with the naked eye, but form tiny webs in a plant’s leaf axis. Once you notice these webs, your plant is already infested.
Remove the mites, and their webs, by washing your plant with an insecticidal soap from your nearest garden center or plant store.
Diseases
Foliage Rust
Being a close descendant of the hollyhock species, the Lavatera genus is susceptible to foliage rust on its leaves and stems. You’ll first notice this as raised, orange, spore-bearing pustules, which will turn brown in time. This disease is non-fatal to your plant and can be treated with a suitable fungicide, should your infection be extensive.
Prevention is probably your best course of action, so here are a few pointers to be aware of:
- Rust is most prominent in the spring and autumn, when the weather is damp
- Keep your plants free from weeds and dead leaves, and give them enough space for good ventilation
- Water your plants early in the morning, so the leaves can dry out throughout the remainder of the day
- Cut off all infected leaves as you see them
- When your plant has finished flowering, cut right back down to the ground, removing and destroying any infected parts
- Your plant will re-grow invigorated!
Bacterial Leaf Spot
This is scientifically known as Pseudomonas cichorii and is a disease that affects plants in the “Mallow” family. As such, it affects Hollyhocks, Hibiscus, Lavatera, etc. Tell-tale signs to look out for are both light and dark spotting on the upper sides of the leaves.
You’ll also find black and brown lesions, and sometimes spots with circular rings around them. If the disease is left untreated, leaves from the plant will turn yellow and eventually fall off.
Precautions can be taken to avoid this disease, these being:
- Always water your plant at the roots to avoid wet foliage
- Do not overcrowd your plants, leave enough room for good air circulation
- Keep planting areas clean and free from weeds and debris
Soil-borne Fungal Disease
When soil becomes waterlogged, which is especially typical of heavy soils, there is a soil-based fungal disease called “Phytophthora blight”. This attacks the plant’s vascular system, affecting its foliage and flowers. It can be easily spotted by the wilted and sickly-looking foliage and sad looking blooms.
Bad drainage and siting of your plant is likely to cause this problem. To avoid this disease, it is imperative to choose your site carefully: plant your mallow in well-draining soil, on a sunny site. As discussed, Lavateras are relatively drought tolerant and perform better in drier soils.
Stem Rot
Avoid this problem by ensuring that any mulch is kept a little distance away from the stems.
Companion Plants
I like the colour combination between deep purple lavender plants and Lavatera pinks. As a result, lavender is one of my favourite companion plants. They also have the same site requirements, and enjoy the same well-drained soil—preferably on the dry side. Other good mixtures are shrubs such as the Choisya ternata, Cistus and those in the Ceanothus species.
Herbaceous plants such as dahlias continue with the big bloom theme. Additionally, if deadheaded regularly, they’ll continue to provide a huge range of flowers for the whole summer through. The tall and leggy Verbena bonariensis is also a favourite of mine, which adds movement to a mixed border.
