Small greenhouses and cold frames are essential for keen gardeners, especially those who have limited outdoor space. They are also a great way to dip your toe in the water if you’re new to greenhouse gardening.
A cold frame is a small, transparent structure, built low to the ground, which performs a similar job to a mini greenhouse by protecting young, vulnerable plants from harsh weather.
Like with a greenhouse, the glazing transmits natural light and helps the interior retain heat, allowing you to plant earlier and extend the growing season.
What’s more, all cold frames and most mini greenhouses can be moved around the garden to a spot suitable for growing a particular plant or crop.
Let’s take a look at how to get the most from a mini greenhouse and cold frame throughout the year before viewing 5 fantastic cold frames/ small greenhouses for sale.
A Seasonal Guide to Using Small Greenhouses and Cold Frames
At this time of year, both can be used to overwinter young annuals and protect alpine plants.
You can put bubble wrap inside to provide additional insulation but bear in mind this will reduce both light and ventilation.
Spring Under the Cold Frame
Here, cold frames and mini greenhouses are good for protecting young vegetable plants and half-hardy annuals. They make a useful halfway house between a regular greenhouse and the unprotected outdoors.
Summer in the Greenhouse
Use your mini greenhouse to provide additional warmth for tender and exotic plants. This encourages them to ripen quicker and will help you achieve a bumper crop.
Cold Frames and Greenhouses in Autumn
Autumn is a time when they are particularly useful for protecting cuttings and younger plants from the increasingly cooler weather.
(For a seasonal guide to greenhouse gardening, click here.)
Tips for Looking After Your Greenhouse’s and Cold Frame’s Plants
Tip 1 – Cleaning Your Small Greenhouse and Cold Frame
A regular clean of your greenhouse or cold frame with soapy water will help maintain the structure.
Remember, cleaner glazing transmits more natural light, which is essential for healthy plants.
Mini Greenhouse Tip 2 – Use Potting Soil
Do not use garden soil for your newly potted plants as it is too heavy and far too dirty. It contains weed seeds, bugs and their eggs, bacteria – all the stuff you don't want in with tender plants. Make sure you use potting soil instead.
Tip 3 – The Importance of New Soil
If you are planning to replant using last year’s potting soil, stop right there. The soil’s nutrition will be depleted and it might contain fungal spores and insects. Treat you plants to new potting soil.
Greenhouse Tip 4 – What to Do with Old Soil
Use your old potting soil in the bottom third of your pots and containers, with new soil on top. Then, distribute the remaining old soil to other areas of your garden.
5 Small Greenhouses and Cold Frames for Sale
4' x 4' Halls Cotswold Birdlip Small Greenhouse (1.47m x 1.32m)
This small greenhouse is UK-made, supplied with a 12-year frame warranty and enjoys the premium design of a much larger greenhouse.
Sliding double doors with a low threshold provide easy walk-in access and can be secured by a key-operated lock to keep valuable tools safe.
The high eaves provide plenty of headroom, while the opening roof vent allows you to regulate the temperature for the benefit of your plants. An integral guttering system offers them a readymade supply of water when connected to a water butt.
4' x 2' Palram Lean-to Small Wall Mini Greenhouse (1.2m x 0.6m)
A lean-to greenhouse is ideal for gardening on a patio or balcony, and this is one of the best.
Expertly built from crystal-clear polycarbonate panels on a rust-resistant aluminium frame, it is stylish, unbreakable and very low maintenance.
You can gain easy access to your plants via both a sliding door and an adjustable lid. The lid can be propped open to control heat, humidity and airflow.
4' x 2' Forest Wooden Small Mini Lean-to Greenhouse (1.2m x 0.62m)
This luxurious mini greenhouse can be treated as both a lean-to and freestanding greenhouse, making it incredibly versatile.
The frame is constructed from pressure-treated tongue and groove cladding, backed by a 15-year anti-rot guarantee, while the glazing is made from unbreakable styrene for a longer life.
Other key features include wide double doors, a lid with props, and 2 internal slatted shelves.
6' x 2' Halls Green Wall Garden 26 Greenhouse (1.94m x 0.69m)
Built on a powder-coated green aluminium frame and backed by a 12-year guarantee, this small greenhouse is robust, durable and completely resistant to rust.
The smooth-action sliding door makes accessing your plants easy, while the integral roof vent allows you to control the internal temperature to benefit your plants.
A base, staging and an upgrade to toughened glass are all available to buy as optional extras.
4' x 2' Forest Overlap Wooden Cold Frame (1.09m x 0.63m)
This large cold frame is built from pressure-treated wood and supplied with a fantastic 15-year anti-rot guarantee, so no further treatment is required.
The glazing is made from styrene, which is virtually unbreakable and far safer than conventional glass.
The cold frame includes 2 independently opened lids, each with their own prop, so is perfect for helping you gradually acclimatise your plants to the outdoors.
Small Greenhouses for Sale
Owning a greenhouse is the perfect way to extend the growing season, making it a must for any keen gardener.
Take the first step on your journey to productive greenhouse gardening by viewing our fantastic range of small greenhouses for sale now.
Top image: 6' x 4' Palram Hybrid Grey Greenhouse