Big Water, Big Harvest: Top Automatic Greenhouse Waterers
For most greenhouse growers, the Orbit 20-Plant Drip Irrigation Kit is the top pick, offering a generous 100 foot of tubing and customizable emitters, but it requires a reliable water source and a separate timer. If you need a self-contained solution with a large reservoir, the Rain Bird PAT RSD-BEX is an excellent choice, though its plastic tank may degrade in harsh sunlight.
Keeping a greenhouse properly watered is a constant chore, especially during hot summer months. Automatic watering systems with large capacity tanks or extensive tubing can save you time and ensure your plants thrive even when you are away.
We looked at systems that can handle more than just a few pots. The focus is on models that offer substantial water storage or cover a large area, so you can water an entire greenhouse with minimal intervention.
What we recommend
Orbit 20-Plant Drip Irrigation Kit
This drip kit from Orbit provides everything you need to water up to 20 plants with 100 feet of tubing. It uses standard garden hose pressure and can be expanded with additional kits. Owners report it is easy to assemble and customize.
Pros
- Covers a large area
- Customizable emitter placement
- Affordable expansion options
Cons
- Requires separate timer
- Not for low water pressure
Rain Bird PAT RSD-BEX Large Capacity Rain Barrel
This 50 gallon rain barrel collects rainwater from your downspout and stores it for greenhouse use. It includes a spigot and a diverter kit, and its large capacity can sustain plants for days. Owners like its sturdy construction and UV protection.
Pros
- Large storage
- Eco-friendly
- Easy to connect to downspout
Cons
- Requires gravity flow or pump
- Plastic may crack in freezing temps
Dramm 9-Pattern Turret Sprayer with 32 oz Bottle
While not a full irrigation system, this heavy duty sprayer is ideal for greenhouse owners who need a versatile, large capacity hand sprayer. It features nine spray patterns and a 32 ounce bottle, perfect for spot watering and applying fertilizers.
Pros
- Durable
- Many spray options
- Easy to use
Cons
- Not automatic
- Small capacity for large greenhouses
Melnor 2-Zone Programmable Timer with Large Backlit Display
This programmable timer from Melnor allows you to schedule watering for up to two zones, making it perfect for greenhouses with different watering needs. It has a large backlit display and supports multiple start times.
Pros
- Dual zone control
- Easy programming
- Large display
Cons
- Requires batteries
- Not for low pressure
King Do Way Drip Irrigation Kit with 30M/100FT
This drip irrigation kit includes 100 feet of tubing and 30 adjustable emitters, suitable for watering a large number of plants. It is designed for easy assembly without tools and includes a filter and connector.
Pros
- Very affordable
- Large coverage
- No tools needed
Cons
- Emitters may clog
- No timer included
Growlink Micro Drip Irrigation Kit with 50ft Tubing
This kit is designed for elevated greenhouse benches, with 50 feet of tubing and 30 drip emitters. It includes a pressure regulator and is ideal for potted plants on shelves.
Pros
- Pressure regulator protects plants
- Compact design
- Good for shelves
Cons
- Shorter tubing
- Not for ground beds
Rachio 3 Smart Sprinkler Controller
The Rachio 3 is a WiFi enabled smart controller that can manage up to 8 zones, making it perfect for large greenhouses with multiple watering areas. It uses weather data to adjust schedules automatically.
Pros
- Smart weather adjustments
- Remote access
- Large zone capacity
Cons
- Requires professional installation
- Pricey
How to pick the right one
How they stack up
| # | Model | Coverage | Best for | Score | Price |
|---|---|---|---|---|---|
| 1 | Orbit 20-Plant Drip Irrigation Kit | 20 plants, 100 ft tubing | best overall for large greenhouses with a hose connection | 9.4 | Check price |
| 2 | Rain Bird PAT RSD-BEX Large Capacity Rain Barrel | 50 gallons | best for off-grid greenhouses without a hose connection | 9.2 | Check price |
| 3 | Dramm 9-Pattern Turret Sprayer with 32 oz Bottle | 32 oz | best for small greenhouses with multiple watering patterns | 8.8 | Check price |
| 4 | Melnor 2-Zone Programmable Timer with Large Backlit Display | 2 | best for controlling multiple zones in a large greenhouse | 9.0 | Check price |
| 5 | King Do Way Drip Irrigation Kit with 30M/100FT | 30 plants, 100 ft tubing | best value for large greenhouse setups | 8.9 | Check price |
| 6 | Growlink Micro Drip Irrigation Kit with 50ft Tubing | 30 plants, 50 ft tubing | best for greenhouse benches and shelves | 8.7 | Check price |
| 7 | Rachio 3 Smart Sprinkler Controller | 8 | best for tech savvy greenhouse owners who want smart control | 9.1 | Check price |
Common questions
What size system do I need for a typical greenhouse?
A typical hobby greenhouse (10×12 feet) can be covered by a system with 100 feet of tubing and up to 20 emitters. Larger commercial greenhouses may need multiple kits or a smart controller with more zones.
Can I use a rain barrel with a drip irrigation system?
Yes, but you will need a pump to maintain adequate water pressure. Rain barrels rely on gravity, which may not provide enough pressure for long runs of drip tubing.
Do these systems work without a timer?
They can be manually operated, but a timer is essential for true automation. Many kits do not include a timer, so you may need to purchase one separately.
Are drip irrigation systems better than sprinklers for greenhouses?
Drip irrigation delivers water directly to the roots, reducing waste and preventing leaf diseases. Sprinklers can wet foliage, which promotes fungal growth. Drip is generally preferred.
How often should I water my greenhouse plants automatically?
It depends on plant type, soil, and weather. Start with watering once daily, then adjust based on soil moisture. Smart controllers can modify schedules automatically.
Can I expand these systems later?
Most drip kits are expandable. You can purchase additional tubing and emitters to cover more plants. Rain barrels can be linked together for increased capacity.
What is the best way to prevent clogging in drip emitters?
Use a filter at the water source and clean it regularly. Also, flush the system periodically. Some kits include a pressure regulator to prevent debris from entering the lines.
Are smart watering controllers worth the extra cost?
For large greenhouses, smart controllers save water and time by adjusting to weather. They are convenient for remote control, but for small setups, a simple timer may suffice.
Can I use automatic watering systems when I am away for weeks?
With a large reservoir and timer, you can water for several days. For longer absences, consider a system that connects to a hose or a rain barrel with a pump and a smart controller.
Our pick
For most greenhouse gardeners, the Orbit 20-Plant Drip Irrigation Kit offers the best balance of coverage and value, especially if you already have a hose. If you want a self-contained solution without a hose, choose the Rain Bird PAT RSD-BEX rain barrel and pair it with a pump and timer. Tech enthusiasts should consider the Rachio 3 for its smart scheduling capabilities.
