If you love gardening but don’t have much space, a small greenhouse could be just what you need. These compact structures let you grow plants all year round, even in a modest Essex garden. This guide will help you pick the perfect small greenhouse and make the most of every inch.
Why Choose a Small Greenhouse?
A compact greenhouse protects your plants from unpredictable British weather. Spring frosts, summer storms, and autumn winds can all damage delicate seedlings. A greenhouse keeps them safe and warm.
You can also start growing earlier in the year. While outdoor beds might still be frozen in March, your greenhouse will be warm enough to sow seeds. This means you can harvest vegetables weeks earlier than your neighbours.
Best of all, a small greenhouse doesn’t need much space. Even a structure measuring 6 feet by 4 feet can produce an impressive amount of food.
Choosing the Right Size
Small greenhouses come in various sizes. Here are the most popular compact options:
| Greenhouse Size | Floor Space | Best For |
|---|---|---|
| 4ft x 4ft | 16 sq ft | Seedlings, herbs, small salads |
| 6ft x 4ft | 24 sq ft | Tomatoes, peppers, plus seedlings |
| 6ft x 6ft | 36 sq ft | Mixed vegetables, year-round growing |
| 8ft x 6ft | 48 sq ft | Full production, multiple crops |
If you’re just starting out, a 6ft x 4ft greenhouse is a brilliant choice. It’s big enough to grow a decent crop of tomatoes or peppers, whilst still leaving room for seed trays on shelving.
For very small gardens or patios, a 4ft x 4ft mini greenhouse works well. You won’t grow huge amounts, but you can still raise seedlings, grow salads, and keep herbs going through winter.
What to Grow in a Small Greenhouse
Start your growing season in February or March by sowing seeds indoors. Tomatoes, peppers, and chillies all need an early start. You can also sow courgettes, cucumbers, and French beans to plant outside later.
Hardy vegetables like lettuce, onions, and peas can go straight into the greenhouse borders. They’ll be ready to harvest weeks before outdoor crops.
Summer is when your greenhouse really earns its keep. Even a small greenhouse can produce dozens of tomatoes from just two or three plants. Choose cordon varieties (tall, single-stem types) to make the most of vertical space. Peppers, chillies, and cucumbers all thrive in greenhouse warmth.
Don’t let your greenhouse sit empty in winter. You can grow salad leaves, spinach, and oriental greens right through to spring. Winter is also perfect for growing herbs like parsley, coriander, and chives.
Setting Up Your Greenhouse
Pick a spot that gets plenty of sunlight, ideally facing south or southeast. Avoid placing it under trees or in constant shade. Make sure the ground is level before you start. A wonky greenhouse will leak and might even blow over in strong winds.
Ventilation is crucial. On a sunny day, temperatures can soar to over 40°C within hours. The Royal Horticultural Society recommends that roof vents should equal 15 to 20 per cent of your floor space.
Many small greenhouses come with one roof vent, which often isn’t enough. Consider adding a second vent or fitting automatic vent openers. These clever devices open and close vents automatically as the temperature changes.
Potting Sheds: An Alternative Solution
If you want somewhere to grow plants but also need storage space, consider a potting shed. These hybrid buildings combine a garden shed with a greenhouse section, giving you the best of both worlds.
A potting shed typically has a solid shed on one side for storing tools, with a glazed section on the other for growing plants. This design works brilliantly in small gardens because you get two buildings in the space of one.
At Poulton Portables, we build potting sheds to order in any size you need. We can also create bespoke buildings that combine features from different structures.
Making the Most of Limited Space
In a small greenhouse, every inch counts. Use vertical space by growing climbing plants like tomatoes and cucumbers up strings or canes. Add shelving on the sides for seed trays and young plants.
Grow in containers. Pots and growing bags are perfect for small greenhouses. You can move them around and replace spent compost easily.
Choose compact varieties. Many vegetables now come in dwarf or patio versions. Look for “compact” or “mini” on seed packets.
Corner Buildings for Awkward Spaces
If you have an awkward corner in your garden, a corner building might be the perfect solution. These angled structures fit neatly into spaces where a standard rectangular greenhouse won’t work.
Corner buildings can serve as mini greenhouses, potting areas, or covered seating. Because they’re made to measure, you can specify exactly what you need.
Heating and Insulation
Most Essex gardeners don’t need to heat their greenhouse in summer, but a bit of warmth in winter extends the growing season significantly. Even a frost-free environment (around 2 to 3°C) will protect tender plants and keep salads growing.
Electric heaters are the easiest option, but they’re expensive to run. A better choice is bubble wrap insulation. Fix it to the inside of your greenhouse glass in October, and remove it in April. This simple trick can keep temperatures several degrees warmer without any running costs.
Common Mistakes to Avoid
Don’t cram in too many plants. Overcrowding causes problems. Plants compete for light, water, and nutrients. Give each plant the space it needs.
Always open vents and doors on warm days. If you’re away during the day, automatic vent openers are essential.
Plants in pots and growing bags use up nutrients quickly. After about six weeks, start feeding them weekly with liquid fertiliser. Without it, growth slows and yields drop dramatically.
When summer crops finish, clean your greenhouse thoroughly. This kills overwintering pests and diseases that would attack next year’s crops.
Is a Small Greenhouse Worth It?
Absolutely. Even a tiny greenhouse can transform your gardening. You’ll harvest fresh vegetables weeks earlier than outdoor growers. You’ll enjoy salads in winter when they’re expensive in shops. You’ll start seeds successfully without cluttering up your windowsills.
A small greenhouse also lets you try crops that won’t grow outdoors in Essex. Peppers, chillies, and aubergines all need greenhouse warmth to produce well.
Getting Started
Ready to buy a small greenhouse? Start by measuring your available space carefully. Consider how much you want to grow, and be realistic about the time you can spend gardening.
At Poulton Portables, we’ve been making quality garden buildings in Essex since 1951. We can build greenhouses and potting sheds to any size you need, using top-quality redwood pine. Because we build everything to order, your greenhouse will be exactly what you want, not a compromise.
A small greenhouse isn’t just a garden building. It’s an investment in better food, year-round gardening, and hours of enjoyment.