Your Complete Guide to Spring Gardening in the UK

A guide with practical focus on greenhouse growing

Spring is the season when UK gardens truly come alive. After months of grey skies and bare borders, longer days and warmer sunshine bring the promise of growth, colour and fresh harvests. But with unpredictable frosts, heavy rain and blustery winds still part of the forecast, success in a British spring garden is as much about preparation as it is about planting. Whether you’re sowing seeds in a greenhouse, refreshing soil in raised beds, or pruning shrubs back into shape, the steps you take now will set the tone for the whole gardening year ahead.

In this guide we cover general spring gardening tips but also the jobs needed in the greenhouse.

Spring at a glance:

We are going to take you through all the jobs you need to do in both your garden and greenhouse for the exciting Spring season. We've also made monthly guides too, which you can see below.

March

Clean, mulch and start sowing under cover. Vent the greenhouse on bright days, close before dusk, and keep fleece handy for late frosts.

Read our March gardening guide

April

Prime greenhouse month. Pot on tomatoes and peppers, train cucumbers, and plan succession. Directly sow carrots, beetroot and radish as soil warms.

Read our April gardening guide

May

Crank up ventilation, harden off in batches, and plant out frost-tender crops after local last frost. Keep sowing salads and herbs for continuity.

Read our May gardening guide

First step, take a walk

At the end of February, grab a clipboard, notepad or device and take a short walk around your greenhouse and garden; it's time to assess how it fared during the winter months. A short walk round now will shape your whole season. Note down what winter left behind and set priorities before you sow.

Winter weather damage checklist

• Inspect foliage for frost burn or blackened tips on tender perennials and shrubs

• Test drainage in formerly waterlogged areas and mark any pooling

• Prune storm-broken or crossing branches cleanly above a bud

• Firm in plants lifted by freeze–thaw and top up with compost

• Check lawns for compaction, moss and bare patches

• Examine frames, fences, trellises and raised beds for repairs

Know your local frost window

Before deciding on your planting, it's worth bearing in mind when the last frost of the season is likely to happen. Frost is devastating to some new and established plants so it's important to protect them. Approximate last frosts vary by region, so treat calendar dates as guides, not rules.

Track local weather forecasts and use microclimates. South-facing walls, courtyards and urban gardens often run a few degrees warmer than open plots. If there is an unexpected frost in the forecast, it's worth covering sensitive plants with frost protection such as fleece or frost bags.

• Light frost 0 to −2°C
  A single fleece layer suffices for most seedlings.

• Moderate frost −2 to −4°C
  Double fleece or fleece plus cloche.

Soil preparation and garden setup

Healthy soil makes everything easier. A simple test now prevents guesswork later.

Step-by-step soil refresh

1. Clear and assess
   Remove weeds, stones and debris. Squeeze a moist handful. If it stays smeary, you have more clay; if it falls through your fingers, more sand.

2. Test pH and nutrients
   Most veg prefer pH 6.0 to 6.8. A basic kit guides your amendments.

3. Add organic matter
   Spread 5 to 7 cm of well-rotted compost or manure across beds.

4. Incorporate or no-dig
   Either fork through the top 20 to 30 cm, or lay mulch on the surface and let worms do the mixing.

5. Level and settle
   Rake, water lightly and give beds 2 to 3 weeks to settle before heavy planting.

UK soil challenges and fixes

• Heavy clay soils -Clay is nutrient-rich but prone to waterlogging in winter and cracking in summer. Improve it by adding organic matter and coarse grit to open the structure, and use raised beds where drainage is poor. Always avoid working clay when it’s wet, or it will compact.

• Sandy soils - Sandy soil warms quickly in spring but loses water and nutrients fast. Boost fertility with plenty of compost, mulch early to retain moisture, and water deeply but less often to encourage strong root growth.

• Chalky soils - Chalky soils drain freely but often lack nutrients and are naturally alkaline. Add organic matter to improve water retention, feed regularly, and grow acid-loving plants in containers with ericaceous compost.

• Loam (the goal) - Loam is the ideal soil: crumbly, moist yet free-draining, and full of organic life. Regular additions of compost can gradually bring most soils closer to this perfect balance.

Pruning in the Spring

Spring is the perfect time to refresh many plants after the winter. As sap starts to rise and new buds form, pruning encourages strong growth, shapes shrubs and trees, and helps prevent disease.

Shrubs and climbers: In early spring, prune summer-flowering shrubs such as buddleia, hydrangea, and roses to promote healthy shoots and more flowers later in the season. Certain clematis varieties also benefit from a hard cut back now (check which pruning group your clematis falls into).

Fruit trees and bushes: Remove any dead, damaged or crossing branches from apple, pear and gooseberry plants. Open up the centre of the plant to allow light and air to reach developing fruit.

Ornamental grasses and perennials: Cut back dead foliage left over winter to make way for fresh new growth. This tidies borders and reduces the risk of pests hiding in old stems.

General tip: Always use clean, sharp tools to avoid tearing stems or spreading disease, and prune on a dry day so wounds can heal quickly.

After pruning, give plants a feed of slow-release fertiliser or mulch with compost. This supports recovery and powers the flush of new shoots.

Plants to prune in the Spring

Plants NOT to prune in the Spring

Growing under glass: your greenhouse in the Spring

Spring sunshine can push greenhouse temperatures high even on cool days, so balance warmth with airflow. Even when the outside air feels chilly, the glass traps heat quickly and can create a stifling environment for young plants. Regularly opening vents or doors prevents overheating, reduces the risk of fungal diseases, and ensures seedlings develop into sturdy, healthy plants rather than weak, leggy ones.

Core spring gardening checklist for your greenhouse

• Deep clean glazing, frames and staging to remove algae and pests

• Check heater, auto vents and door runners

• Place a thermometer at plant height; aim for 18 to 21°C by day for most seedlings

• Fit shading or shade cloth ahead of hot spells

• Sterilise pots, trays and labels; set up seed racks and shelving

• Keep a water butt close by and stage capillary mats or reservoirs for steady moisture

Keep an eye out for pests in the greenhouse

Monitor for early greenhouse pests such as aphids, whitefly and red spider mite. Regularly check the undersides of leaves and use yellow sticky traps or biological controls before problems escalate. Good airflow, clean tools, and removing old leaves quickly all help to keep disease at bay.

Sowing Seeds and Hardening Off

Starting Heat-Loving Plants

Heat-loving plants, such as tomatoes, peppers, and aubergines, require special care when starting from seed. These plants thrive in warm conditions and benefit from an early start in a controlled environment.

Timing

• Begin sowing seeds in mid-spring, Typically, this falls between late March and early April, depending on your local climate

Optimal Growing Conditions

• Provide consistent warmth (around 18-21°C )

• Aim for strong, direct light for 12-16 hours daily

Potting On

As seedlings grow, they require progressively larger containers to accommodate their developing root systems for several reasons. 

Firstly, the expanding root network necessitates additional space to prevent root binding, which can impede nutrient uptake and overall plant health.

Secondly, larger containers provide increased soil volume, ensuring an adequate supply of nutrients and water to support the plant's growth. 

Thirdly, a more spacious environment allows for proper aeration of the root zone, promoting optimal oxygen exchange and preventing the accumulation of harmful gases. 

Furthermore, larger containers facilitate better drainage, reducing the risk of waterlogging and associated root diseases.

Lastly, the increased container size enables the plant to establish a more robust and extensive root system, which is crucial for supporting the growing above-ground biomass and enhancing the plant's ability to withstand environmental stresses.

Process

1. Start seeds in small cells or trays
2. Once true leaves appear, transplant to slightly larger pots
3. Continue this process as plants grow, gradually increasing pot size

Hardening Off

Hardening off is the crucial process of acclimating indoor-grown (or greenhouse grown) seedlings to outdoor conditions.

Steps

1. Begin by opening greenhouse doors for a few hours daily

2. Move plants to a cold frame, increasing exposure time each day

3. Place plants outside for short periods, starting with 1-2 hours

4. Progressively increase outdoor time and exposure to elements

Key Considerations

• Protect plants from strong winds and direct sunlight initially

• Bring plants indoors or provide cover during frost warnings

• Monitor soil moisture closely, as outdoor conditions may dry soil more quickly

Final Planting

After the hardening off process is complete, plants are ready for their permanent outdoor locations.

Timing

• Plant out after all risk of frost has passed, typically late spring to early summer, depending on local climate

Use Cold Frames as stepping stones

As we mentioned earlier, Cold frames bridge indoor comfort and outdoor reality. They are ideal for toughening salads, early brassicas and bedding, and for squeezing an extra fortnight at both ends of the season.

Make the most of early spring

Cool-season crops are your allies now. They grow fast in low heat and shrug off light frost.

Crop Rotation

Rotating your crops each year helps keep soil healthy and reduces the risk of pests and diseases building up. Many common problems, such as clubroot in brassicas or carrot fly in carrots, are far worse if the same plant family is grown in the same soil repeatedly. By moving crops around, you break the cycle and give the soil a chance to recover.

A simple three- or four-bed rotation works well in most gardens:

• Brassicas (cabbage, kale, broccoli, sprouts) → Legumes (peas, beans) → Roots (carrots, beetroot, parsnips, onions) → Potatoes and other heavy feeders.

• Between rotations, always add compost or well-rotted manure to replenish nutrients.

If you don’t have space for a formal system, even alternating where you grow tomatoes and potatoes each year will help. Raised beds, containers, and grow bags also make crop rotation easier, as you can refresh the soil more quickly.

A simple cool-crop sequence

• Early March
  Direct sow peas and plant out hardened broad bean modules.

• Mid to late March
  Sow lettuce, spinach and radish in prepared beds; plant onion sets.

• April
  Continue salad successions every 2 to 3 weeks.

In parallel, prepare for warm-season veg that will wait for frost-free soil. Tomatoes, courgettes and French beans prefer soil above 10°C and settled nights. Sow under cover in March and April, then plant out after your local last frost.

A typical spring rhythm looks like this: prepare beds and start hardy modules in late winter, sow peas and salads in March, pot on tomatoes and peppers in April, harden off and plant out through May while keeping greenhouse successions rolling.

Essential maintenance

Weeds and Wildlife

Spring weeds emerge quickly and can take over if left unchecked. Hoe lightly on dry days, cutting weeds off just below the soil surface before they can re-root. Mulching bare soil with compost, bark, or straw helps suppress weeds by blocking out light. Raised beds and containers are easier to keep weed-free, but it’s still important to stay on top of them early in the season.

At the same time, don’t be too tidy. Some so-called “weeds” such as dandelion, dead-nettle, and clover are vital early nectar sources for bees and hoverflies. Leaving a patch of wild growth or a strip of lawn uncut in spring can support pollinators and beneficial insects that will, in turn, help control pests in your garden.

Encourage wildlife by:

• Planting early-flowering perennials such as pulmonaria, primroses, and wallflowers for pollinators.

• Providing water with a bird bath or small pond.

• Creating log piles or leaving leaf litter for hedgehogs, frogs, and beetles.

Balancing weed control with wildlife support keeps your garden healthy, productive, and buzzing with life throughout the season.

Spring lawn care the easy way

• First cut when grass reaches 5 to 7 cm, set the mower high, and never remove more than one third in a single pass.

• Scarify to lift thatch and moss, then overseed bare patches and water lightly during dry spells.

• Aerate compacted areas with a fork or hollow tines.

Organic pest management that works

• Use ferric phosphate pellets sparingly around high-value plants.

• Apply nematodes once soil sits at 5°C or above for a steady biological check on slugs.

• Encourage predators. A small wildlife pond supports frogs and toads; log piles suit hedgehogs.

• Fit copper tape to containers and use gritty mulches round stems.

• Reduce hiding places and improve drainage where slugs congregate.

Weather protection and adaptation

Rainy spells

Heavy spring rain can quickly saturate beds and containers, leading to root rot and fungal problems. Improve drainage by mixing grit into heavy soils, raise pots on bricks or pot feet, and avoid overhead watering late in the day when foliage might stay damp overnight. In greenhouses, keep gutters clear so water doesn’t pool around the base and check staging trays for standing water. Hopefully you already have a water butt plumbed in and you're capturing some of the rainwater; you'll likely need it when summer takes hold!

Wind

Spring winds can strip moisture from soil and snap tender stems. Use hedges, fences or mesh windbreaks to soften gusts without blocking airflow completely. In exposed gardens, group pots together in sheltered corners. If you have a greenhouse, now is the time to use it. Bring in potted plants which might get damaged by the winds.

Frost

As mentioned, late frosts remain one of the biggest risks in March, April and even May. Keep horticultural fleece or cloches ready to cover outdoor seedlings overnight, and use your greenhouse or cold frame as a temporary shelter for tender plants. Remember to remove covers in the morning so plants still receive light and airflow.

Map your microclimates

Every garden has its own warmer and cooler spots. South-facing walls, patios and raised beds warm up earliest, making them perfect for tomatoes, peppers or basil, while low-lying areas trap cold air and suit hardier veg. A greenhouse effectively creates its own microclimate, extending your season and shielding crops from the worst of Britain’s unpredictable spring weather.

Spring planting snapshots

• Under cover now
  Lettuce, rocket, spinach, brassicas, tomatoes, peppers, celery, celeriac, peas and broad beans. Basil, coriander, parsley, chives and dill. Cosmos, zinnia, nasturtium, marigold, sweet peas, begonias and geraniums.

• Direct sow as soil allows
  Radish for quick wins; carrots, beetroot and turnip for roots; ongoing salad rows; beans and sweetcorn from May in warm ground.

• Tubers and vines
  Chit early potatoes and plant in late March or April, including grow bags. Sow pumpkins and squashes in pots for post-frost planting. Train cucumbers vertically under glass.

Conclusion and next steps

Gardening during spring in the UK is about timing, preparation and flexibility; especially in the UK. A tidy, ventilated greenhouse and nourished soil give you the margins you need when the weather swings. Plan successions, protect in cold snaps, and keep sowing little and often.

If you are weighing up protected growing, remember that even a compact greenhouse or a well-sited cold frame can transform your season. Review last year’s notes, sketch this year’s layout, order seeds you trust and line up fleece, canes and compost. Your best harvests start with the groundwork you do now.