Autumn Planting in Ireland: A Month-by-Month Guide
Autumn is the single best planting window of the Irish gardening year. The soil has been warming since May and still holds that heat through September and well into October, the rain arrives without you having to lift a hosepipe, and roots carry on growing underground long after top growth has shut down — so an autumn-planted hedge or border comes into spring already anchored, a full season ahead of the same plant put in during April. This guide covers exactly what to plant in September, October, November and December in Ireland, with 19 container-grown packs from €50.95 to €155.95, planting densities per square metre, and honest advice about the month when you should stop planting altogether.
Met Éireann's 1991–2020 national average puts Irish rainfall at 1,288mm a year, and the wetter half of that total falls between August and January. In most of Europe, autumn planting is a bet on rain arriving. In Ireland it is close to a certainty. That single climatic fact is why the continental gardening calendar — which tends to treat spring as the main planting season — understates how good an Irish autumn is for getting plants into the ground.
Why is autumn the best time to plant in Ireland?
Autumn planting works in Ireland because soil temperature lags air temperature by several weeks, so the ground stays warm long after the weather has turned. Three things line up at once between early September and the end of October: soil that is still warm enough for active root growth, rainfall that is reliable rather than hoped for, and top growth that has stopped demanding water. A plant put in during those weeks spends three or four months doing nothing visible above ground while quietly extending its root system into the surrounding soil.
Compare that with spring. A plant set out in April has to build roots and leaves at the same time, from a standing start, and then meet its first warm, drying spell within weeks — often before it has enough root to supply the leaves it has just produced. That is why spring-planted stock so often sulks through its first summer while the autumn-planted equivalent is away. The gain is roughly a full growing season.
There is a second, quieter advantage. Everything we ship is container-grown, not bare-root. Bare-root hedging and shrubs are only lifted while fully dormant, which restricts them to a narrow window from about November to March, and they have to go straight into the ground once they arrive. Container-grown stock carries its own root ball and an intact root system, so it can go in during the warm soil of September and October when establishment conditions are genuinely at their best — and it will wait a few days in a sheltered spot if the weather turns before you get to it.
What should you plant in September in Ireland?
September is the month for hedging, evergreen structure and anything that needs to make a lot of root before winter, because the soil is at its warmest of the entire planting year. Anything you want established and self-sufficient by next summer — a boundary hedge, a bank of ground cover, a new perennial border — benefits most from going in now rather than in six weeks' time.
Hedging and evergreen structure
Evergreen hedging is the classic September job in Ireland. Small evergreen hedging plants have proportionally small root systems, so they need the warmest soil you can give them, and they repay it by knitting together far faster than a spring-planted run. For a low, clipped hedge or a formal edge, allow 3 to 5 plants per metre in a single row; for a denser screen, plant a staggered double row.
6x Euonymus fortunei 'Emerald 'n Gold'
Ilex crenata 'Jenny' is the practical answer to box blight in Irish gardens: the same tiny dark leaf and the same tolerance of hard clipping, without box's disease problems. Euonymus japonicus 'Green Spire' is the tougher, faster option for exposed and coastal sites. For a longer boundary run, the 60-plant Green Spire pack at €155.95 covers roughly 12 to 20 metres of single-row hedge, and the full range sits in our hedge plants collection.
Perennials and border planting
September is also the moment to plant — or divide and replant — hardy herbaceous perennials. They have finished flowering, the soil is warm, and they will spend the autumn putting on root rather than leaf. Plant them now and they come up in spring as established clumps rather than nervous new arrivals.
Geranium macrorrhizum is the most forgiving perennial we sell — aromatic, semi-evergreen, happy in dry shade under trees where almost nothing else will carpet, and effectively self-maintaining once established. Sedum 'Herbstfreude' is an upright border sedum, 40 to 60cm tall, whose rust-pink plates feed late bees and then stand through winter as frost sculpture; do not expect it to carpet. Salvia nemorosa 'Ostfriesland' gives you a solid block of deep violet in June and again in late summer if you cut it back, and it is one of the best pollinator plants for a sunny Irish border.
What should you plant in October, and why is it the best month of all?
October is the single best planting month of the Irish gardening year. The soil still carries September's warmth, the autumn rain has properly arrived, and top growth has stopped — which means a plant put in now spends every ounce of its energy on roots and none on leaves. If you only plant once this autumn, plant in October.
Ground cover
Ground cover is the category that gains most from October planting, because the whole point of it is to knit into a closed carpet before weeds get a chance. Plant in October and the plants spend autumn and winter spreading roots sideways, then explode into cover in their first spring. Allow 5 to 7 plants per square metre for mat-formers such as creeping thyme, and 3 to 5 per square metre for vigorous spreaders that fill out quickly on their own.
Cotoneaster dammeri is the workhorse for a bank or slope: fully evergreen, rooting as it runs, holding soil on ground that is otherwise a mowing nightmare, and carrying red berries into winter. Thymus serpyllum wants the opposite conditions — sharp drainage, full sun, gravel rather than clay — and rewards you with a fragrant, bee-covered mat you can walk on. 'Biokovo' sits between the two, tolerating a wide range of Irish soils and smothering weeds with dense lobed foliage. There is far more in the ground cover and landscaping collection.
Ornamental grasses
Ornamental grasses are at their best in October, which makes it the ideal month both to plant them and to see what you are buying. Grasses planted now settle in over winter and come away strongly in spring, and evergreen sedges in particular hold their structure right through the coldest months of an Irish winter.
Calamagrostis 'Karl Foerster' is the one grass we would plant in an exposed Irish garden without hesitation: its stems are stiff and vertical, so it does not flop after heavy rain the way softer grasses do, and its buff seed heads stand from July until you cut them down in February. Carex morrowii 'Ice Dance' is evergreen and genuinely shade-tolerant, which makes it useful under trees and along north-facing paths. Browse the rest in the ornamental grass collection.
Can you still plant in November in an Irish garden?
Yes — November still works for hardy container-grown stock, as long as the ground is neither frozen nor waterlogged. The soil has cooled and root growth has slowed, so establishment takes longer than it would have in October, but plants put in now will still be ahead of anything planted next spring. November is the month to prioritise the toughest, most reliable things on your list and leave anything borderline until March.
The test is simple and physical. Dig a spade-full and look at it. If it crumbles, plant. If it glistens, slumps and smears, the soil is saturated and planting into it will smear the sides of the hole into a waterproof lining — wait for a drier week. If the top few centimetres are frozen solid, wait too.
Hedera hibernica — Irish or Atlantic ivy — is the most useful November plant in this list. It will climb a north-facing wall, carpet dry shade under a beech, or hold a bank together, and it is as close to unkillable as garden planting gets in this climate. Euonymus fortunei 'Minimus' gives you the same evergreen persistence at a much smaller scale, for edging and tight gaps. Liriope muscari 'Big Blue' is the exception that flowers late: strap-like evergreen leaves with violet spikes in September and October, holding its shape all winter in shade where most perennials disappear.
What should you do in the garden in December?
In most Irish gardens, December is not a planting month — and it is more useful to say so plainly than to pretend otherwise. By December the ground is commonly either waterlogged from a month of rain or frozen in the top layer, and both conditions do real damage: planting into saturated soil compacts and seals it, and planting into frozen soil leaves roots in an air pocket they cannot grow out of. December's real jobs are structure, containers and planning.
What still works in December is planting into containers, where you control the compost and the drainage entirely, and where a pair of clipped evergreens either side of a door does more for a winter garden than anything in open ground. It is also the month to look honestly at your garden with the leaves gone, see where the eye falls on nothing at all, and note the gaps for next autumn.
A pair of Ilex crenata balls in matching pots is the simplest structural gesture in a winter garden, and it reads from the road on the darkest afternoon of the year. Carex morrowii 'Irish Green' and Luzula nivea both stay green through an Irish winter and give containers something to do between December and March — Luzula in particular thrives in the dry shade beneath trees where nothing else looks alive.
How many plants do you need, and which pack size should you buy?
Work out the area first, then let the density figure choose the pack size. For ground cover, multiply your square metres by 5 to 7 for mat-formers and by 3 to 5 for vigorous spreaders; for a low evergreen hedge, multiply your metres of run by 3 to 5. That number tells you immediately whether you are in 6-pack or bulk-pack territory, and it is a far more reliable guide than guessing.
| Pack size | Typical price | Ground cover it plants | Best for |
|---|---|---|---|
| 6-pack | €45–€68 | About 1m² | Filling a gap, trialling a plant, small borders |
| 24-pack | €72–€107 | 3–5m² | A whole border, a front garden, a short hedge run |
| 48-pack | €129–€190 | 7–10m² | Banks, driveways, larger domestic projects |
| 60-pack | €152–€233 | 9–12m² | Landscaping jobs and full boundary hedges |
Under-planting is a false economy. At the low end of each density range you save on plants and then spend two seasons weeding the gaps; at the high end the carpet closes in a single growing season and the weeding largely stops.
What about bulbs, compost and mulch?
Autumn advice columns always tell you to plant bulbs and spread mulch, and both are good advice — but neither is something we supply, so here is the honest version. Spring-flowering bulbs are best planted from September to November in Ireland, at roughly two to three times their own depth, pointed end up, in ground that drains; you will find them in any Irish garden centre at this time of year. What we supply, through a direct partnership with European growers, is container-grown plants — not bulbs — and we would rather say so than point you at something we do not stock.
The same goes for the bagged goods. We sell the plants, not the bags. Compost, grit, bark mulch, topsoil and membrane are heavy, low-value items that cost far more to ship than to buy, and a builders' merchant or garden centre near you will supply them by the bulk bag for a fraction of what delivered small bags would cost. Buy them locally, get them onto the ground before you plant, and spend your online budget on the plants themselves.
Mulching itself is worth doing. A layer of organic mulch 5 to 8cm deep, spread over damp soil in late autumn and kept clear of plant stems, holds moisture, suppresses annual weeds and slowly feeds the soil as it breaks down — which matters far more on thin or compacted ground than any autumn feed does.
What should you plant in each autumn month?
The short version: September for hedging and structure, October for everything, November for hardy evergreens only, December for containers and planning. The table below is the whole guide in one place.
| Month | Soil & conditions | Best to plant | Leave until later | Example pack |
|---|---|---|---|---|
| September | Warmest soil of the planting year; rain returning | Hedging, evergreen structure, perennials, divisions | Nothing — this is the widest window | 24x Green Spire €77.95 |
| October | Still warm, reliably wet, top growth stopped | Ground cover, perennials, ornamental grasses, hedging | Tender or borderline-hardy plants | 24x Creeping Thyme €72.95 |
| November | Cooling and often wet; frost possible inland | Hardy evergreen ground cover, ivy, tough hedging | Grasses, late-flowering perennials, anything marginal | 24x Irish Ivy €77.95 |
| December | Frequently waterlogged or frozen at the surface | Containers only — clipped evergreens, sedges | All open-ground planting until conditions improve | 2x Ilex Ball XL €77.95 |
Most Irish planting calendars are written around bare-root stock, which is only available from roughly November to March and must be planted immediately on arrival. Every plant on this page is container-grown through a direct partnership with European growers, so it arrives with an intact root ball and can be planted from early September onwards — through the warmest, most favourable soil of the year, months before the bare-root season even opens.
Frequently Asked Questions
Explore More Guides
- Rockery Plants for Irish Gardens: What Actually Survives — why winter wet, not winter cold, is what kills plants here, and how to build drainage that works.
- Ground Cover for Dry Sunny Banks & Gravel Gardens — the planting solution for slopes and gravel that never need a hosepipe.
- The Best Ground Cover Plants for Irish and European Gardens — Cotoneaster, hardy Geranium and the rest, compared side by side.
- Hedge Plants — the full evergreen hedging range behind the September section.
- Ornamental Grasses — every grass and sedge in this guide, plus the rest of the collection.
Plant this autumn, month by month
- Last chance: plant spring bulbs now for a spectacular Spring 2027 — timing, depth, and which bulbs suit Irish soil
- Best plants to buy in October (Ireland)
- What to plant in November in Ireland
Ready to plant? Browse the full flower bulb range — tulips, daffodils, crocus and naturalising bulbs, all in stock now.
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