← All guides · Species & planting · Updated August 2026

The aftercare mistake that kills more new hedges on Thanet than bad soil or bad weather.

I plant hedges across CT7 to CT12 every autumn and winter. The failures I come back to fix in August are almost never about bad planting: the spacing was right, the species was right, the hole was right. They die because of what happens in the six weeks after May, when the chalk and Thanet Sand dries out faster than anywhere else in England and the new roots haven't anchored far enough to find moisture on their own. The mistake is almost always the same one: a light daily watering that feels conscientious but builds a surface root system that a dry June kills overnight.

The mistake most Thanet hedge owners make

Plant in autumn (good). Water in generously on the day (also good). Then water a little every day or every other day through spring, because it feels like regular care. By May, the plants look fine. By late June, especially on the coastal strip from Westgate-on-Sea CT8 through Cliftonville CT9 to Birchington CT7, they start going brown from the tips. By August, half the run is dead.

This is the little-and-often mistake. It feels right because it mirrors how you'd water a pot plant. It is wrong for a hedge, and it is especially wrong on Thanet's geology.

Why Thanet's soil makes this worse than anywhere else

The Isle of Thanet sits on the Margate Chalk Member, overlaid in many areas by Thanet Sand formation: a free-draining, silty sand that holds almost no moisture once the surface dries out. On the chalk-and-sand profile that underlies most gardens from Margate CT9 through Broadstairs CT10 to Ramsgate CT11 and CT12, water applied in small amounts at the surface evaporates or drains away before it reaches root depth. The roots that did develop during autumn and winter are clustered in the top 10 to 20 centimetres, where the daily light watering briefly appeared.

Then June arrives. Kent is consistently the driest county in England, and Thanet sits at the exposed eastern tip of it. The coastal NE and SE winds from the North Sea and the English Channel increase transpiration stress on new plants further. A week without rain, which is routine in Thanet in June and July, desiccates a surface root system completely. A plant with roots running down 40 centimetres into the chalk would survive that same week without watering. A plant with roots sitting at 10 centimetres does not.

What you were told that wasn't wrong, exactly

Most nursery guidance says "keep well watered in the first year." That is true. The error is in interpreting "well watered" as "watered frequently." These are not the same thing, and on free-draining chalk they produce opposite results.

Frequent light watering encourages roots to remain near the surface, where the water is. Infrequent deep watering forces roots downward to find moisture. A hedge with deep roots survives a Thanet summer. A hedge with surface roots does not, regardless of how reliably it was watered through April.

Bunny Guinness, a UK garden designer with over fifty years of professional hedge-making across the country, covers this principle directly in her video "Top Tips to establish a Happy Healthy Hedge" (YouTube, July 2025): deep, infrequent watering is the correct approach for establishment, not the daily light touch most gardeners default to. The principle applies everywhere, but on Thanet chalk it is the difference between a hedge that establishes and one that fails.

The grass and weed competition mistake

The second mistake I see almost as often: leaving the grass or lawn growing right up to the base of new hedging plants. Grass is an aggressive competitor for moisture and nutrients in the root zone, more so than most people realise. On chalk-and-sand soil, where available moisture is already limited, grass growing at the base of a new escallonia or hornbeam run will take a significant share of what water does reach root depth.

The standard recommendation is to keep a clear, weed-free strip at least 30 centimetres wide on each side of new hedging, maintained for a minimum of two years. On Thanet chalk I would say three years for bare-root stock and two years for pot-grown, because the chalk limits rooting depth and bare-root plants start from essentially zero established root structure.

In practice this means removing all grass and weeds from the planting strip, not just trimming them back. Trimmed grass re-establishes within weeks. Pulled or killed grass (a light layer of cardboard under a mulch works well) stays clear long enough to matter.

Mulch: not optional on Thanet chalk

A 7 to 10 centimetre layer of bark chip or well-rotted compost mulch over the cleared weed-free strip does two things: it suppresses weed regrowth without you having to maintain a constant pulling regime, and it significantly reduces evaporation from the soil surface. On free-draining Thanet Sand and chalk, that second function is critical. Mulch is what keeps moisture in the top 20 centimetres long enough for deep watering to reach the root zone before it drains away.

Keep mulch away from the actual stems of hedging plants (a gap of about 5 centimetres around each stem). Mulch piled against stems creates the conditions for collar rot, which is a separate failure mode. The mulch ring should cover the root zone, not the plant base.

What the correct aftercare programme actually looks like

For bare-root hedging planted October to February on Thanet chalk:

• Water in on the day of planting. Soak the full planting strip, not just around individual plants. Aim for water penetrating to 30 centimetres. This is the one moment where volume matters more than anything else.
• Mulch immediately. Bark chip, well-rotted compost or even cardboard under wood chip. 7 to 10 centimetres deep across the cleared strip either side of the plants.
• Clear grass and weeds. Remove, not trim, everything in a 30-centimetre strip each side of the planting line before it competes for the first spring moisture.
• Water deeply and infrequently through April to September. In dry conditions, 5 to 10 litres per metre of hedge run, twice a week. Not a light daily sprinkle. Direct water to the base of the plants, not the foliage. The goal is soil damp to 30 centimetres, checked by pushing a stick or finger into the soil after watering.
• Continue into the second year. On Thanet chalk, particularly for beech, hornbeam, cherry laurel and escallonia, establishment watering should continue through the second summer as a safety measure. Roots will be deeper by then, but chalk limits ultimate rooting depth and the risk does not disappear after twelve months.
• Do not feed heavily. A light application of a balanced granular fertiliser in spring of year two is reasonable. Heavy nitrogen feeding in year one encourages lush top growth that the shallow root system cannot support in a dry summer. The plant puts on leaves faster than it roots; then the first dry spell strips those leaves and the plant has nothing in reserve.

A note on species differences

All hedging species need establishment care, but some are more forgiving on Thanet's chalk-and-salt conditions than others. Hawthorn and blackthorn (the backbone of native mixed hedges from Minster to Sarre) are deep-rooters that establish more readily on chalk than most formal hedging species. They still need the first-summer watering, but they have more margin for error.

Escallonia and griselinia, the dominant species on the salt-belt coastal strip from Westgate through Cliftonville to Ramsgate, are tougher once established but are more vulnerable than people expect in the establishment phase. The salt wind adds to transpiration stress on top of the chalk drainage issue. These are the species I most often have to go back and replace.

Cherry laurel (Prunus laurocerasus) establishes well on chalk once it gets through year one, but has large leaves that lose moisture quickly in exposed conditions. On a Westgate-on-Sea CT8 coastal boundary, a newly planted laurel run needs more attention in the first summer than the same species planted in a sheltered CT10 Broadstairs garden.

Beech (Fagus sylvatica) and hornbeam (Carpinus betulus), often chosen for inland Thanet gardens in the areas around CT7 Birchington and inland CT9/CT10, have naturally shallow root systems on chalk. Both are unforgiving of the little-and-often watering mistake: they respond more visibly than most species to surface-root stress in a dry summer, and recovery from near-drought stress is slow.

Sources: RHS Hedges Planting Guide (rhs.org.uk/plants/types/hedges/planting); Ashridge Nurseries, "Hedge Aftercare Guide: First Year Care and Maintenance" (ashridgetrees.co.uk); Hopes Grove Nurseries, "Looking After Your New Hedge" (hopesgrovenurseries.co.uk); Bunny Guinness, "Top Tips to establish a Happy Healthy Hedge," YouTube, 11 July 2025 (youtube.com/c/bunnyguinness); Wildlife and Countryside Act 1981, section 1; British Geological Survey: Margate Chalk Member and Thanet Sand Formation mapping for the Isle of Thanet.