Lavender is often described as an easy plant. It can be, but that description assumes a sunny site and soil where winter rain can drain away. A lavender planted into a damp, shaded border may struggle no matter how carefully it is watered. Getting the position right at planting is more important than finding a special fertiliser.
For most UK gardens, hardy English lavender is a safer choice for a permanent outdoor border than less hardy French or Spanish types. Those can look spectacular in pots through summer but may need additional shelter from winter wet and cold. Read the label so you know which plant you have.
Pick the plant before choosing its home
English lavender, including cultivars of Lavandula angustifolia and some Lavandula × intermedia, is commonly grown as a hardy garden shrub. French lavender, often sold with distinctive tufted flowerheads, is usually more vulnerable in cold or wet conditions.
Check the mature height and spread. A neat little nursery pot can grow into a rounded shrub much wider than the space you left for it. Spacing plants too tightly in a hedge may produce a dense patch of foliage that remains damp after rain.
Choose a plant with plenty of firm, grey-green growth and no blackened patches around the stem base. Avoid specimens sitting in soaking wet compost or already showing severe dieback. An established but overgrown lavender will not necessarily respond well to hard cutting into old, bare wood.
Look for sun, air and drainage
Lavender wants a site with good sunlight. The RHS describes sunny, well-drained chalky or sandy soil as a good fit. A gravel garden, raised border or warm edge of a patio can work well if roots can drain freely.
Heavy clay is the main difficulty. Digging a small hole, filling it with gritty compost and planting lavender in the middle may create a sump if water still cannot escape into the surrounding ground. Improve drainage over a wider area or make a raised bed rather than relying on a little gravel at the bottom of the hole.
Try to avoid places where roof water discharges or paving channels rain towards a border. A south-facing wall can provide warmth, but check that overhanging eaves do not leave the roots bone dry during establishment.
When should lavender be planted?
Spring is a practical planting season for UK lavender, especially in colder gardens. Soil is warming and the plant has a growing season to establish before its first winter. Early autumn can also work in mild, free-draining places.
Avoid planting when soil is frozen, saturated or baking dry during a heatwave. Choose a day when you can water the plant in properly without immediately exposing the rootball to extremes.
Lavender bought in full summer flower may look irresistible, but a very hot spell is a difficult time to establish a new shrub. If you must plant then, be especially attentive to moisture while roots spread, without keeping the ground wet.
Prepare the bed without overfeeding it
Remove weeds, especially perennial roots that will be difficult to reach once the lavender is established. Dig or fork the planting area to check drainage and break up compacted ground where possible.
Do not treat lavender like a hungry vegetable. Excessively fertile, damp conditions often produce soft growth rather than a robust, well-shaped shrub. On suitable soil, a modest improvement to structure is usually enough.
If you're planting a row, lay the plants out in their nursery pots first. Allow for the mature size shown on the label, not the spacing required to make a finished hedge instantly. Good air movement around the plants helps foliage dry after rain.
How to set the plant in the ground
Water the nursery pot if the rootball is dry. Dig a hole wide enough to receive the roots comfortably and approximately as deep as the compost in the pot.
Slide the plant out carefully. If the outer roots are tightly circling, loosen them gently; avoid wrenching apart a small, fragile rootball. Set the top of the rootball level with the surrounding soil rather than burying the woody crown under extra earth.
Backfill with the prepared soil and firm gently. Water enough to settle soil around the roots. Standing puddles after that first watering should prompt another look at drainage rather than a decision to add yet more water.
Plant lavender successfully in pots
Lavender can thrive in containers if the pot has generous drainage holes and stands where it gets plenty of sunshine. Choose a stable pot slightly larger than the rootball, with enough room for growth but not a huge volume of perpetually wet compost.
Use a suitable open, free-draining peat-free compost. A proprietary mix for Mediterranean plants or a well-structured multipurpose compost amended appropriately for drainage can work. Do not place stones in a sealed decorative pot and assume they solve the absence of drainage.
Raise the container if needed to prevent the drainage holes becoming blocked against paving. Empty saucers after rain. A pot in an exposed corner may require more watering during summer but better protection from winter saturation.
Watering during establishment
A newly planted lavender still needs water while it builds new roots, even though a mature shrub is drought tolerant. Water thoroughly when the root zone begins drying rather than sprinkling the foliage every evening.
Inspect below the surface. A dry top centimetre does not necessarily mean the whole rootball is dry, and a heavy clay bed can stay damp long after a shower. Container plants may dry faster than plants in the border.
As establishment progresses, reduce unnecessary watering. Persistent wetness around the crown is a more common enemy of lavender than a missed watering of an established plant in ordinary British weather.
Pruning after planting
Do not cut a newly planted, stressed lavender back hard to bare woody stems. Let it settle, and shape only as appropriate for the cultivar and growing stage.
Once established, most lavenders benefit from trimming after flowering to keep a compact dome and prevent a build-up of bare, leggy wood. The exact timing and severity vary with type, so follow appropriate guidance for English or French lavender.
Avoid severe late pruning that removes healthy growth immediately before cold weather. Lavender often refuses to reshoot from old woody material, which is why regular moderate trimming works better than waiting years before trying a drastic rescue.
Troubleshooting plants that turn brown
Sudden browning at the base in soggy ground may indicate root or stem damage from poor drainage. Stop watering blindly and check the soil. A lavender sitting in saturated compost may need a better-drained growing position, not plant food.
A plant wilting in a small pot during hot weather may be too dry, particularly soon after purchase. Water the root zone, let excess drain away and reassess. Browning after severe frost is a different situation from browning after weeks of wetness.
When a border lavender fails, look carefully at the conditions before buying an identical replacement. Choosing a sunnier raised position or a more suitable cultivar can change the outcome far more than changing the brand of compost.