Greenhouse Guides

Decisions you make once and live with for a decade. Orientation and glazing set how much light gets in and how much heat leaves, and no amount of equipment later compensates for getting them wrong.

• Siting and orienting a greenhouse How to choose a greenhouse site for winter sun, drainage, wind shelter, water and power, and why ridge orientation matters far less than most advice claims.
• The greenhouse glazing guide How to choose greenhouse glazing on R-value, light transmission and service life, then cut, seal and fit polycarbonate and film without cracking, clouding or losing it to wind.
• Anchoring a greenhouse against wind How much uplift a hobby greenhouse actually generates, which anchor suits which ground, and the two failure modes that destroy most structures before the frame ever gives way.
• Greenhouse snow and wind load How snow load and wind load ratings are stated, what roof pitch does to snow accumulation, and the practical steps that keep a hobby greenhouse standing through a heavy winter.
• Greenhouse flooring and paths How each greenhouse floor option affects drainage, humidity, thermal mass, weeds and pests, and why a full concrete slab is usually the wrong choice for a hobby house.

The running cost of a greenhouse is almost entirely here. Insulation and thermal mass reduce the heater you need before you buy one.

• Insulating a greenhouse Where greenhouse heat actually goes, which insulation measures pay for themselves in one winter, and how to add R-value without giving away the winter light the crop needs.
• Heating a greenhouse in winter How to decide what minimum temperature to hold, size the heater to the envelope rather than the floor area, choose between electric and propane, and control it so it runs as little as possible.
• Passive solar and thermal mass How much heat water, soil and masonry actually store in a greenhouse, how to size thermal mass to a house, and what it realistically does to the overnight minimum.
• Greenhouse electrical and safety What a 15 amp circuit can actually run in a greenhouse, why GFCI protection is non-negotiable in a wet structure, and where the line falls between a job you can do and a job for a licensed electrician.
• Winter greens in an unheated greenhouse Which crops actually produce through winter without heat, why the autumn sowing window matters more than any other date, and how the double-cover method extends the range by about a zone and a half.

A sealed greenhouse in summer cooks the crop. Airflow does more than temperature control: it moves humidity off leaves, which is what prevents most fungal disease.

• Greenhouse ventilation basics Why a greenhouse needs one complete air change per minute, how much passive vent area that requires, when a fan becomes necessary, and how to place intake and exhaust so the air actually moves.
• Cooling a greenhouse in summer Why shade comes before ventilation, how much each cooling stage is worth in degrees, and the order to apply them so you never buy a fan to solve a problem shade would have fixed.
• Greenhouse humidity and disease control Why relative humidity is the wrong number to manage, what vapour pressure deficit tells you instead, and the daily routine that prevents botrytis, downy mildew and damping off under cover.

The systems that turn a warm box into somewhere plants actually grow.

• Watering in a greenhouse How much water a greenhouse crop actually uses, why morning watering matters, the difference between bed and container schedules, and the salt problem that only exists under cover.
• Raised beds inside a greenhouse When beds beat benches in a greenhouse, how deep they need to be by crop, how to lay them out around a working path, and the salt and disease problems a permanent indoor bed develops.
• Greenhouse soil and growing media Why seed starting mix, potting mix and bed fill are three different products, what each one is made of, and how air-filled porosity decides whether a medium works under cover.
• Hardening off seedlings What actually changes in a plant during hardening off, a workable day-by-day ramp, how a greenhouse or cold frame shortens it, and the four mistakes that undo a season of propagation.

Season extension, seed starting and what to do with the space when the main crop is out.

• Building a seed starting schedule How to build a sowing calendar backwards from your own last frost date, crop by crop, with the propagation temperatures, light levels and succession intervals that make the dates achievable.
• Greenhouse pest management Why greenhouse pests build up faster than outdoor ones, how to monitor before damage shows, and what actually works against aphids, whitefly, spider mite, thrips and fungus gnats under cover.
• Extending the season with row cover How much frost protection each weight of row cover actually provides, how to support it so it does not crush a crop, and why a second layer inside a greenhouse outperforms a heavier one outside.
• Greenhouse cleaning and the season reset Why an annual clear-out is disease control rather than housekeeping, what to clean and with what, how much light a dirty greenhouse loses, and the order to do it in.

Everything else that comes up once the greenhouse is standing.

• Pollination in a greenhouse Why a closed structure removes both wind and insects, which crops that matters for, how to hand pollinate tomatoes and cucurbits, and the temperature limits that make pollen non-viable.