The greenhouse accessories you need most are the ones that control temperature, air and water. Start with automatic vent openers, a fan, shade and a right-sized heater. Then add shelves, watering and flooring to make daily care easy. The rest are nice extras you can add over time.
✅ Quick answer
- Buy first: automatic vent openers, a min/max thermometer and a way to move air. Overheating harms more plants than cold.
- Before winter: a heater sized to your coldest night, plus tight door and base seals.
- Before summer: shade cloth and an exhaust fan. A glass greenhouse can get hot fast on a sunny day.
- For easy care: shelves, a misting or drip system and a drainable floor.
- Nice extras: raised beds, a cold frame, a solar shed light and a water fountain.
We are a small, woman-owned greenhouse business in Georgia. We help customers choose accessories every day, and we answer every question personally. Here are the 12 we suggest most often, with real specs from the product pages and simple math where it helps.
Which greenhouse accessories do you need first?
Think of accessories in three groups. Each group solves a different problem.
- Climate control: heaters, vent openers, fans and shade. These protect your plants.
- Growing space: shelves, raised beds and cold frames. These help you fit more plants.
- Easy care and comfort: watering, flooring, doors, lighting and decor. These save you time and make the space a pleasure.
| Accessory | Problem it solves | Good to know | Approx. price* |
|---|---|---|---|
| Greenhouse heaters | Frost and cold nights | Size it for your coldest night | from about $150 |
| Riga Automatic Window Opener | Overheating on sunny days | No power needed | about $40 |
| Exhaust Fan for Riga and Victorian | Stale, damp, hot air | 12", 16" and 20" sizes | from about $325 |
| Royal Victorian Shade Cloths | Scorching sun and heat | 60% shade, sized per model | from about $360 |
| Royal Victorian Shelves or Seed Trays | Not enough bench space | Best ordered with the greenhouse | from about $250 |
| Misting System | Daily watering chores | 14 ft, 5 misters, cut to fit | about $150 |
*Prices checked in October 2026. Prices can change and sales may apply, so click the model name to see today's price.
1. Greenhouse heaters: how big should yours be?
A heater keeps your plants alive on the coldest nights. The most common mistake we see is buying one that is too small. Use this formula to size yours.
📐 Heater size formula
Watts = (Surface area × U-value × Temperature gap) ÷ 3.412 × 1.2
Surface area = walls + roof in sq ft · U-value = 0.7 for twin-wall polycarbonate, 1.25 for single glass · Gap = inside °F minus coldest outside °F · × 1.2 = 20% safety margin
🧮 Worked example: a Riga 4 kept at 40°F on a 10°F night
- Surface area: about 390 sq ft (our rough estimate from its dimensions)
- U-value for 8mm twin-wall polycarbonate: 0.7
- Temperature gap: 40 − 10 = 30°F
390 × 0.7 × 30 = 8,190 BTU per hour. Divide by 3.412 = about 2,400 watts. Add 20% = about 2,900 watts. A single 1,500-watt plug-in heater would fall short. A 240V heater like the 5,600-watt Dr. Infrared DR-988 covers it with room to spare.
For small greenhouses in mild areas, a 120V heater such as the Bio Green Palma (1,500 watts) or the Milkhouse heater can be enough. Our guide to the cost to heat a greenhouse in winter has full numbers by size.
💡 Pair your heater with a min/max thermometer. It records the lowest and highest temperature since you last checked. One look in the morning tells you if your heater kept up overnight.
2. Shelving: how do you fit more plants in a greenhouse?
Shelves turn wall space into growing space. They also lift plants into better light and air, and keep seedlings away from the cold floor.
The Royal Victorian shelves and seed trays come in green or black. The top shelf is a narrow 4 inches, and the bottom seed tray is 20 inches wide and 4 inches deep. Lengths match each model, from the Junior Victorians to the VI46.
One tip from experience: order shelves with your greenhouse. Shipped alone, they travel by freight, which costs much more. For other options, see our guide to the best shelves for a greenhouse kit.
3. Automatic vent openers: do you really need them?
Yes. If you only buy one accessory, make it this one. A closed greenhouse can overheat quickly on a sunny day, even in spring.
Automatic openers use a cylinder of paraffin oil. As the air warms, the oil expands and pushes the window open. As it cools, a spring pulls it shut. No electricity is needed.
- The Riga Automatic Window Opener starts opening around 72°F and lifts the window up to about 14 inches. It has a quick-release arm for stormy days.
- The Exaco Janssens Automatic Roof Window Opener does the same job on Royal and Junior Victorian greenhouses.
4. Shade cloths: how much shade does a greenhouse need?
Too much sun can scorch leaves and cook a greenhouse in summer. Shade lowers the heat and the light, and it cuts how fast plants dry out.
Our Royal Victorian shade cloths are cream polyester curtains that give 60% shade. They are cut for each model and hang from built-in loops. They are easiest to install while the greenhouse is being built.
Should shade go inside or outside? Outside shade blocks heat before it gets in. Inside shade is easier to open and close. Our article on internal vs. external shade cloths compares both.
5. Fans: why does a greenhouse need air circulation?
Still, damp air invites mold and leaf disease. A fan keeps air moving, evens out hot and cold spots and pushes out hot air on sunny days.
- The Exaco exhaust fan plugs into 110V and comes in three sizes. The 12-inch suits the Riga 2 to 4, the 16-inch suits the Riga 5 and larger Royal Victorians, and the 20-inch suits the Riga XL 7 to 9.
- No power at the greenhouse? A solar fan, like the MONT Solar Powered Ventilation System, runs from its own panel.
⚠️ Glass greenhouse owners: a fan needs an opening in the wall, and glass cannot be cut. The fix is to replace one pane with a Lexan panel. For Exaco Victorian greenhouses, we can cut that panel for you. Just ask.
6. Lighting: do you need lights in a greenhouse?
For work after dark, yes. The Gama Sonic Light My Shed IV is a solar shed light with two lamp heads. It gives 500 lumens for up to 2 hours, with no wiring. It is meant for seeing what you are doing, not for growing plants.
If you want to boost plant growth in short winter days, you need a true LED grow light. Those need a power source, so plan your wiring first.
7. Raised beds: are they worth it inside a greenhouse?
Raised beds give you deep, loose soil and drain well. They also mean less bending. They suit larger greenhouses where you want to grow in the ground year after year.
The Exaco Ergo Quadro stacking raised beds clip together without tools. Each set is 10 inches high, and you can stack them for more depth. They are made of UV- and moisture-resistant recycled plastic, with a five-year warranty.
8. Flooring: what is the best floor for a greenhouse?
A good floor drains water, stops weeds and is safe to walk on when wet. It also keeps your shoes out of the mud.
The Riverstone Interlocking Flooring System uses 22-inch panels made from recycled polypropylene. Water and air flow right through. The panels snap together, come in kits from 8x8 to 8x24 feet and hose clean. For a permanent base, start with our practical guide to a greenhouse foundation.
9. Watering systems: how do you water a greenhouse automatically?
A simple misting or drip line saves time and keeps watering steady. Add an inexpensive hose timer and it runs while you are away.
Our greenhouse misting system is 14 feet long with 5 misters. It works in greenhouses up to about 20 feet long and can be cut shorter for smaller ones. To learn how much water your plants need, read how much water do plants need in a greenhouse.
10. Doors and seals: where does a greenhouse lose the most heat?
Gaps around doors and the base let warm air escape fast. Check them each fall. Replace worn weatherstripping and fill gaps at the foundation.
Royal Victorian owners can swap the standard sliding door for a hinged door with a lock. Hinged doors are also the best fit if your greenhouse sits on a stem wall with a drop door kit. They ship only with a greenhouse order, so decide before you buy.
11. Cold frames: why use one with a greenhouse?
A cold frame is a mini greenhouse. It is perfect for hardening off seedlings before they go into the garden. It also gives you extra space when the greenhouse is full in spring.
The Exaco Juwel Year-Round Cold Frame is about 4 by 2 feet. It has a 4mm twin-wall polycarbonate cover for cold weather and an insect-netting cover for summer. It is made in Austria with a 2-year warranty.
12. Water fountains: a finishing touch
If your greenhouse is also a place to relax, a fountain adds the sound of moving water. The Exaco Eclipse Water Fountain is a large statement piece. It stands 45 inches tall, is made of fiberglass-reinforced concrete and weighs 531 pounds, so plan a solid spot for it. It includes curbside liftgate delivery in the lower 48 states.
How do you match accessories to your greenhouse?
Not every accessory fits every greenhouse. Here is where we usually start with our customers:
- Glass greenhouses (Royal Victorian, Junior Victorian): focus on vents, shade and airflow first. Glass heats up quickly in the sun.
- Insulated polycarbonate (Riga and Riga XL): add auto openers and a right-sized heater for winter growing.
- Insulated glass (Livingten): roof window openers, shade curtains and an LED light bar come included, so you can spend more on growing gear.
- Greenhouses far from power: choose a solar fan, automatic openers and a solar shed light.
Want to go further with free energy? Our guide to active vs. passive solar greenhouse systems explains how to use the sun for heat and airflow.
💡 Save on shipping: some large items cost much more to ship on their own. Shelves bought without a greenhouse go by freight, and hinged doors ship only with a greenhouse. Ordering them together saves money. We also offer optional assembly crews, so your accessories can go in while the greenhouse goes up.
📌 About prices: manufacturers update their prices during the year, and we often run sales and promotions. The price on the product page is always the current one. Prices in this article are a guide from when we wrote it (October 2026), not a quote or guarantee. Found a lower price for the same model at an authorized retailer? We offer a Price Match Guarantee - please check the rules first. Call us and we will confirm today's price and any current deals.
You can browse everything in our greenhouse accessories collection. Shipping is free to the continental US on our greenhouse kits.
Frequently asked questions
What accessories does a greenhouse need?
At minimum: automatic vent openers, a thermometer, a way to move air and some shade for summer. In cold areas, add a heater sized for your coldest night. Shelves and a watering system make daily care much easier.
What is the most important greenhouse accessory?
For most people, it is automatic vent openers. Overheating on a sunny day can damage plants quickly, and openers work with no power and no one home.
What size heater do I need for my greenhouse?
Multiply your walls-and-roof area by the glazing's U-value and by the temperature gap you need. Divide by 3.412 for watts and add 20%. Our worked example above shows the steps for a Riga 4.
Do I need a fan in my greenhouse?
Yes, in most cases. Moving air cuts condensation and disease and helps even out temperatures. In summer, an exhaust fan removes hot air much faster than vents alone.
Can I add accessories after my greenhouse is built?
Most of them, yes. Shade curtains and some shelves are easier to fit during assembly, though. Hinged doors for Royal Victorian greenhouses ship only with a greenhouse order.
Are greenhouse accessories universal?
Some are, like heaters, misting lines and flooring. Others, like openers, shelves and shade cloths, are made for one brand or model. Tell us your greenhouse and we will confirm the fit.
Not sure which accessories fit your greenhouse?
Tell us your model, your climate and what you grow. We will help you pick the accessories that matter most, and let you know about any current sales.
