1. Purpose
Decide whether you want early seedlings, weather protection, a longer harvest season or winter growing. Each goal asks something different of the structure.
2. Crops
Match your choices to the light, temperatures and growing time you can provide. Allow for mature plants, not just seedlings.
3. Location
Watch the sun and shade through the day and consider seasonal changes. Check drainage, convenient access and local installation requirements.
4. Working space
Sketch your beds, containers, shelves and pathways. Allow room to water, harvest and move pots through the door.
5. Structure and covering
Compare glass, polycarbonate and plastic using actual product specifications, including wind and snow ratings, foundation requirements and replacement parts.
6. Cooling
Plan ventilation, airflow and shade before hot weather. Monitor temperatures at plant level and have a plan for days you’re away. RHS ventilation guidance.
7. Heating
Decide what minimum temperature your crops need and price the energy required to maintain it. Seasonal growing may fit your budget better than winter heating.
8. Water and drainage
Make watering convenient, give containers drainage and plan how to check irrigation when you use it.
9. Pests
Inspect incoming plants and check growing crops regularly. Screens can restrict airflow, so consider ventilation as well as pest exclusion. University of Florida ventilation guidance.
10. Total cost and return
Add the base, delivery, installation, equipment and running costs. Compare realistic harvest value with that investment, and count enjoyment as part of the return when this is a hobby.
Take the checklist into your garden
Measure, observe and decide what matters most to you before heading to the garden centre. Which greenhouse would you choose—and what would you grow first?