Planting before the Ice Saints: what can go out early

They often miss the best planting window as a result.

In many gardens, the traditional cold spell in May is treated almost like a stop sign. Anyone planting too early worries about losing everything in the bed. A closer look, however, reveals that only some plants are genuinely sensitive. Many species much prefer the cool conditions of early spring to soil that has heated up by late May.

What the Ice Saints really mean – and what they do not

The term Ice Saints refers to a period in mid-May when cold nights and ground frost can return after a mild spell. Meteorologists regard it as a statistical pattern rather than an unbreakable rule.

“The Ice Saints are a weather guide – not a strict ban on planting until mid-May.”

The main risk concerns plants originating in warm regions, or those that have so far been kept indoors or in a heated greenhouse. Their cells are full of water and they are barely accustomed to changes in temperature. Even a brief frost can destroy leaves and shoots.

Hardy plants adapted to European winters respond very differently. They cope with low temperatures, develop a degree of frost protection and often fare better in cool spring soil than in hot, dry ground later in May.

Ornamental plants that can be planted out early

Flowering favourites that cope easily with cold

Anyone tired of colourless beds by late March or April can confidently choose several reliable species. They add colour and cope without difficulty with chilly nights.

• Pansies: A classic choice for window boxes and beds; they tolerate light frosts and flower for months.
• Primroses: They thrive in the cooler part of the year and tend to retreat during summer, so early planting does them no harm.
• Ranunculus: More sensitive to persistent wetness than cold, while producing exceptionally vivid colour.
• Wallflowers: Strongly scented and suitable for bed edges and raised wall ledges; they handle cool conditions well.

For a longer-lasting garden display, choose robust perennials and shrubs that are happy to be planted in their final position early on:

• Aster species: They benefit from a spring start, allowing them to form strong clumps by autumn.
• Japanese anemones: They favour free-draining soil and are more sensitive to waterlogging than cool temperatures.
• Helleborus (Christmas roses and Lenten roses): True winter specialists that are scarcely affected by being moved in spring.
• Ornamental cherries: Often planted early so they can establish roots before summer arrives.
• Box: A compact evergreen that copes far better with cold than with dry heat.

“Planting perennials and hardy ornamental shrubs early usually gains you a whole growing season of growth.”

Fruit trees and berry bushes – timing pays off

For many fruit trees and shrubs, early spring is actually the ideal time to plant. Their roots have weeks to settle into the still-moist, cool soil before summer brings drier conditions.

Fruit varieties suitable for early planting

• Apple: Tolerates cold nights and prefers deep soil that does not dry out too readily.
• Pear: Slightly more demanding regarding soil, but unaffected by cool spring temperatures.
• Cherry: Develops stronger roots when planted early and fruits more reliably later on.
• Berry bushes such as raspberry, blackcurrant or blackberry: Produce more vigorous new growth following an early planting date.

Stone fruits are somewhat trickier:

• Peach and apricot: Their blossom is easily damaged by late frost. They should be grown against sheltered house walls or in mild locations, and are best not planted during the frost-prone heart of spring.

In harsher areas, it is worth using small-scale climate tricks: south-facing walls retain warmth, hedges slow cold winds, and a gently sloping bed allows cold air to drain downhill.

Vegetable beds: what can go out now, and what must wait?

Hardy vegetables for an early start

The distinction is especially clear in the vegetable garden. Some crops enjoy cool temperatures and quickly become tough or bolt in the height of summer.

Suitable for an early start	Benefit
Peas	Germinate well in cool weather and benefit from spring moisture
Broad beans	Tolerate light frost and provide an early harvest
Carrots	Form fine roots in cool soil
Radishes	More tender when grown in spring than when ripened in high summer
Potatoes	Tubers remain protected underground, while foliage can be earthed up during frost
Onion sets, garlic, shallots	Early planting encourages rapid growth and an early harvest

“Many traditional vegetables are more ‘cool-weather fans’ than frost victims – they suffer more from summer heat than from spring cold.”

These warmth-loving crops need patience

The genuinely delicate crops are those that originally come from tropical or subtropical regions. They barely tolerate temperatures only just above freezing.

• Tomatoes
• Courgettes and other cucurbits
• Melons
• Peppers and chillies
• Aubergines

They should not be moved into the garden until night-time temperatures remain reliably above freezing. Anyone unwilling to wait needs proper protection: a heated greenhouse, a polytunnel, thick horticultural fleece, or at least the option to bring containers back indoors at short notice.

Herbs: which can go outside and which should stay on the windowsill?

A clear contrast also appears among culinary herbs. Some are remarkably tough, whereas others react badly even to a cool draught.

• Parsley: Tolerates cool temperatures and even prefers fresh conditions.
• Mint: Vigorous and hardy, almost invasive, and happy outdoors early in the season.
• Rosemary: Depending on the variety, it is hardy; it prefers drier sites and can be planted out early if it has overwintered.
• Chives: A classic early starter that quickly sends up new growth after winter.

Basil, by contrast, behaves very differently. This herb can lose leaves and rot after even a single degree below zero. It is better kept on a warm windowsill, in a greenhouse or beneath thick horticultural fleece until nights become noticeably milder.

How to acclimatise young plants safely to outdoor conditions

Much spring damage is caused not only by frost, but by abrupt change: from a constant 20°C to blazing sunshine, wind and cool nights. Professional gardeners therefore take a gradual approach.

• First place young plants outdoors during the day in a shaded, sheltered spot.
• Extend their time outside a little each day.
• After several days, move them first into light partial shade and then into full sun.
• If frost is forecast overnight, bring containers back inside or cover plants with horticultural fleece.

“The gradual acclimatisation process protects sensitive leaves from sun scorch and cold shock – often more effectively than one additional day in a warm living room.”

Protection tips for anyone who cannot wait

Those who like to get started early can greatly reduce the risk with simple measures. Loose, well-prepared soil retains heat more effectively and drains water away, preventing roots from sitting in wet ground during cold weather.

Useful protective measures include:

• Horticultural fleece over beds or window boxes to provide a few extra degrees overnight.
• Small polytunnels over rows containing more sensitive crops.
• A cold frame or unheated greenhouse as an intermediate stage between the living room and the open garden.
• A mulch layer of straw, leaves or grass clippings to buffer the soil against sharp temperature changes.

Container plants are particularly flexible: place them on the patio during the day, then move them back beside the house wall or into the hallway overnight. This makes it possible to bring forward the planting date without putting the entire season at risk.

Why planting early is often worthwhile

Anyone relying solely on the mid-May calendar date loses several weeks when the soil is moist, air temperatures are moderate and weed competition remains low. Hardier plants reward an early start with stronger root systems, sturdier shoots and often an earlier harvest.

A simple rule of thumb is useful: a plant’s origins and growth habit set the pace. Plants with thick, soft leaves and tropical roots need protection and patience. Species from mountains, steppes or temperate regions can be planted out considerably earlier if they are gradually acclimatised to wind and sun.

Knowing these differences allows gardeners to make far better use of spring – with colourful beds, an early-planted vegetable patch and herbs by the kitchen door, while others are still waiting for that supposedly magical date in May.