As the days get warmer and longer, there’s no better time to get stuck into the garden—and your greenhouse is the perfect place to start. Whether you’re a seasoned grower or just beginning your greenhouse journey, spring is the season to clean, prep, and plant.
In this post, we’ll walk you through everything you need to do to set up your greenhouse for the months ahead—from essential maintenance tips to a handy guide on what to sow and grow in April, May, and June.
Let’s get your greenhouse blooming!
Why Spring Is the Best Time to Get Your Greenhouse in Shape
Your greenhouse has likely had a bit of downtime over the winter, and before you fill it with fresh seedlings, it’s worth giving it a proper refresh. This helps create a healthy environment for young plants and stops pests or mould from becoming an issue down the line.
Think of it as your greenhouse’s spring clean—quick, easy, and totally worth it.
7 Easy Spring Greenhouse Maintenance Tips
1. Give it a thorough clean
Start with the glazing—inside and out. Use warm, soapy water and a soft cloth or sponge to wipe away algae, dirt, and dust. Clean panels let in more light, which is exactly what your seedlings need.
2. Check for any damage
Inspect the frame, doors, and glazing for cracks or loose bits. Replace any damaged panels and tighten bolts or screws that may have worked loose during winter.
3. Ventilation is key
Clear debris from vents and make sure they open and close properly. Good airflow keeps humidity balanced and reduces the risk of fungal diseases.
4. Pest-proof your space
Look out for signs of slugs, snails, aphids, or red spider mites. Clean any pots, staging, or trays you plan to reuse with a mild disinfectant.
5. Tidy and reorganise
Remove any dead plants or old compost and organise your tools, seed trays, and watering cans. It’s much easier to manage your crops when everything has its place.
6. Check your watering system
If you use an irrigation system or hosepipe, test it now to avoid surprises later. Clean out water butts and make sure any taps or timers are working properly.
7. Replace or refresh soil and compost
Used compost can be tired and low in nutrients. Top up beds and pots with fresh compost or soil conditioner to give your plants a great start.
What to Grow in Your Greenhouse This Spring
Now that your greenhouse is looking sharp, it’s time to start planting! The best part about a greenhouse is that it extends your growing season, meaning you can get a head start on crops that would struggle outdoors in early spring.
Here’s a simple guide to what you can plant each month:
April: Get a Head Start
April is perfect for sowing seeds indoors or directly in your greenhouse.
Tomatoes – Start them in pots for transplanting later.
Peppers & Chillies – Need warmth, so perfect for the greenhouse.
Lettuce & Rocket – Fast growers and great for early salads.
Herbs – Basil, coriander, and parsley all do well now.
Courgettes & Cucumbers – Start indoors, then move to growbags or containers.
->Keep the greenhouse ventilated on sunny days and consider using fleece overnight to protect young plants from chilly nights.
May: Time to Plant in Earnest
May is when everything really kicks off. With the risk of frost behind us, you can get growing more confidently.
Aubergines & Melons – May is the sweet spot to get these going in warmth.
Runner Beans & French Beans – Sow in pots to plant out later.
Sweetcorn – Start in modules now for transplanting into beds or containers.
Flowers – Sunflowers, nasturtiums, cosmos, and marigolds all thrive in greenhouses early on.
Make sure your plants are spaced well to avoid overcrowding and improve airflow.
June: Maintain & Enjoy
By June, your greenhouse should be thriving with life.
Harvest – Lettuce, spinach, radishes, and early tomatoes may be ready for picking.
Succession sow – Keep planting little and often to ensure a continuous crop.
Support taller plants – Use canes, trellises, or string to support tomatoes, beans, and cucumbers.
Shade cloths – Consider adding shade nets if it’s getting too hot inside.
Don't forget to water regularly, especially in the mornings, and keep vents open to avoid overheating.
Top Tip: Think Vertical
If space is tight, use tiered shelving or hanging baskets to grow upwards rather than outwards. This works especially well for herbs, strawberries, and compact leafy greens.
Looking to Start or Upgrade Your Greenhouse?
Whether you’re after a compact walk-in greenhouse or a spacious polytunnel setup, MonsterShop has everything you need to turn your garden into a grower’s paradise.
Our greenhouse collection includes:
- Sturdy polycarbonate and steel frame greenhouses
- Walk-in designs with shelving for maximum storage
- Weather-resistant materials to handle the UK climate
- Easy assembly and great value for money
Browse now and find the perfect greenhouse for your garden:
Shop Greenhouses at MonsterShop
Spring is the season of new beginnings, and your greenhouse is the perfect place to start. With just a bit of cleaning and clever planning, you can enjoy a bountiful, low-stress growing season all the way into summer and beyond.
So roll up your sleeves, grab your gloves, and get growing—you’ll be reaping the rewards in no time.