Kem Ormond’s vegetable garden: Should I get a glasshouse or a tunnel house?

Kem Ormond's insect-proof tomato house. Photo / Phil Thomsen

Kem Ormond is a features writer for The Country. She’s also a keen gardener. This week, she’s discussing the pros and cons of a glasshouse and a tunnel house.

OPINION

Have you thought about a tunnel house, a glasshouse, or a shade house in your vegetable garden?

We are now into June, and as much as I want to do a little fist pump and say, “I am still picking tomatoes”, I will refrain!

Sure, the leaves are looking a bit worse for wear, they have protected the tomatoes for months now, but those tomatoes are honestly the sweetest and most tasty treats around.

Sliced and put on top of hot buttered toast, they are just the best.

They are not in a glasshouse or hot house of any description; they are in what I call a tomato house covered with Psyllid cloth, with a door to enter.

If you have not heard of Psyllid, they are tiny sap-sucking insects that resemble miniature cicadas, and if you want to see them, you will need a magnifying glass.

The cloth prevents them from entering the tomato house and damaging the crop.

A tunnel house or a glasshouse?

Kem Ormond's winter tomatoes. Photo / Phil Thomsen

Having a glasshouse or tunnel house gives you the opportunity to plant veges early and extend their growing season.

It does take commitment, as during the hot days, there are vents to open and watering to be done.

On a rainy day, it is the most magical place to potter!

Having a shade house for orchids: come winter, there are some orchids that need a bit more warmth, and there are heat pads that you can purchase, and they are wonderful.

It’s great for raising newly planted seeds as well, but the downfall is when your cat discovers it and learns how to slide open the door to get in.

Both glasshouses (greenhouses) and tunnel houses (hoop houses or polytunnels) are used to extend the growing season and protect plants from adverse weather.

However, they differ significantly in structure, cost, and performance.

You need to sit down and work out the pros and cons of both before deciding what is going to work best for you.

Glasshouse

Pros

Glass is long-lasting and weather-resistant.

With proper care, a glasshouse can last for decades.

The bonus is that it transmits light well and doesn’t degrade like plastic, offering more stable and higher-quality light for plant growth.

I find a small glasshouse more attractive and permanent-looking than tunnel houses.

They always seem to fit well in the garden and look great with some paving and paths added around them.

When well-sealed, glasshouses can retain heat better in cold conditions, especially if double-glazed.

They are easier to integrate with automatic climate control systems (ventilation, heating, irrigation).

Cons

They are significantly more expensive to build and maintain.

You must remember that while the structure may be made from steel, most of it is glass that can break in hail, high winds, or from impact and the odd football.

You need to do it right and do it once.

Your glasshouse requires a firm foundation and professional or skilled DIY assembly.

It can heat up on sunny days, especially if there’s no ventilation.

Tunnel House

(Polytunnel or hoop house)

Pros

A tunnel house is much cheaper to build and repair than a glasshouse.

It can be easily relocated or expanded, and is so much faster and simpler to construct.

Cons

The one thing you must realise is that plastic coverings degrade over time (UV exposure), typically lasting three to five years.

They can’t retain heat like a glasshouse, especially at night or in winter and have slightly reduced light compared to glass.

You must secure your tunnel house well, otherwise you may see it flying past your kitchen window!

Summary

If you’re gardening on a budget or just getting started, a tunnel house is often the best choice.

When it comes to permanent, long-term, and you want it to merge into your garden, a glasshouse might be worth the investment.