How to Grow Pot with Drip Irrigation

How to Grow Pot with Drip Irrigation

Pot has become legal in many states. With that new legality, cultivating cannabis has turned into more than a pastime for many. It now offers a way to make a living, creating thousands of new businesses and jobs and filling state coffers with newfound tax revenues.

Growing marijuana doesn't have to be difficult. There's a reason it is called weed. It grows like one, after all. But to produce the choicest bud, pot needs TLC and a regular supply of nutrients and water. Whether you are growing a few plants for your personal stash or have a commercial operation to produce medical marijuana or recreational bud, your plants will be healthier, happier and more potent if you use the proper cultivation and watering techniques.

Fortunately, there is no mystery to growing good weed. By using irrigation methods honed over the last 50 years, you can grow the best bud ever.

DripWorks has extensive experience designing irrigation systems. Our visits to many legally licensed grows from setup to harvest show that the right products and the grower's daily attention to detail make the difference between a merely good harvest and a hugely successful one. Here are some watering tips to show you how to grow pot for the best results.

With the advent of modern drip irrigation, efficient and effective products and techniques are available. Easy to install, drip systems save precious water and money and direct water precisely to each plant. Cannabis loves a drip system that offers a slow, even delivery of water throughout its growth cycle. Top-quality drip systems will result in a premium-quality harvest.

Water: you will want to water your plants every couple of days, allowing the soil to drain but remain moist. If your plants are outside, this schedule might vary depending on rainfall or how often you want to fertigate with a fertilizer injector as your drip system operates.

A good rule of thumb is to water your plants when the soil feels dry a few inches down. Be careful not to overdo your irrigation, though. Over-watering can suffocate the roots, because the water takes the place of oxygen the roots also need.

Droopy or yellowing leaves on your plants can be another sign your plants need water. Again, take care not to overwater to compensate. Using a battery or AC timer will allow you to schedule watering without any guesswork. It will also give you freedom of movement since you don't have to be on-hand when watering takes place.

Soil: If you are going to use emitters (drippers) or sprayers, you need to know what kind of soil you have, how water-retentive it is and what kind of saturation profile it will provide. Ideally, you will have a loam-type soil that has been amended with organic nutrients to keep your crop healthy and help your cannabis plants maximize their growth. Applied slowly to loam, water will spread fairly wide and deep as it gets absorbed. Loamy soil tends to hold water well too, because it contains a lot of organic matter.

Sandy soil is made up of broken-down, crushed rock that don't absorb water well. With sandy soil, you'll need to water daily for short periods, usually with a small sprayer that disperses water over a fairly wide area. Soil with a lot of shale or rock also doesn't absorb water well and needs to be watered daily.

Clay absorbs water slowly and spreads out in a wide pattern. Drippers are best used on clay soils. When using drip irrigation on clay soil, you shouldn't need to water as often as with loam or sandy soil.

If your soil is either sandy or has a lot of clay, you should amend it with compost or a loam-type bulk or bagged soil. You should also feed your ganja plants by top-dressing the soil with a powdered fertilizer or through a fertilizer injector using a water-soluble fertilizer.

Recommended Drip Irrigation Products: Cannabis loves a slow delivery of water throughout its growth cycle. When it comes to even water distribution, long product life and near-zero maintenance, a drip system is best. Here are the most highly rated and popular products used to grow pot:

Down-Spray Sprinklers (Full Circle) – After having visited many licensed grows over the last few years, I can easily see the advantage of using the Down-Spray Sprinkler. Growers use these sprinklers to give their plants a full-circle diameter spray pattern that will water in nutrients and allow top dressing during the growing season. Here are some of the main advantages:

  • 20" to 24" diameter circular spray pattern
  • Choose either a high-flow or low-flow model
  • Wets evenly, with minimal surface disturbance
  • Used on large or small plants
  • Comes with a shutoff clip to stop the flow
  • No moving parts – minimal maintenance

1/2" Emitter Tubing – Emitter Tubing has factory-installed, pressure-compensating emitters inside the tubing spaced 9", 12", 18", 24" or 36" apart, according to your choice. Many growers run their 1/2" or 3/4" mainline past each plant or Smart Pot and then “T" off the mainline to circle each plant a few times with emitter tubing. Other growers run straight lines of emitter tubing on either side of a row of plants to get an even flow of water to every plant, even if the rows are 100' long or more. Here are some facts about 1/2" emitter tubing:

  • Greatly reduces installation time, because emitters are factory-installed
  • Perfect for hilly or uneven terrain or long rows
  • Choice of 1/2 gallon per hour or 1 gallon per hour emitters for 9" or 12" spacing
  • This tubing is the same diameter as the 1/2" mainline
  • Pressure range of 10 to 50 psi

Aqua-Traxx Drip Tape – This is the economically perfect tape for even water distribution over long rows either outdoors or indoors, in a greenhouse/high tunnel or raised beds. Even though this product is extremely clog-resistant, we recommend using a filter to eliminate debris and sediment large enough to affect the performance of a drip system. We have even seen CO2 injected through drip tape in enclosed high tunnels to effectively grow bigger plants.

  • Low-cost and effective watering product for long rows
  • Ideal for above ground, mulched or buried applications
  • Great for low-pressure systems down to four psi
  • Superb watering efficiency and uniform delivery of water
  • Typically lasts up to seven years if mulched or buried, two to five years above ground
  • Uses drip-tape fittings

1/4" Soaker Dripline – Soaker Dripline is so versatile it can be used almost anywhere. It is ideal in small and medium garden beds or in containers such as oak barrels or Smart Pots.

  • Flexible and easy to use
  • Emitters pre-installed every 6", 9" or 12"
  • Great for low-pressure gravity systems, raised beds or containers
  • Works well down to two psi
  • Maximum operating pressure 30 psi
  • Uses standard 1/4 " fittings
  • Not pressure-compensating

1/8" Spot Spitters – We have been designing Spot Spitters in drip systems for marijuana gardens for almost 30 years. It's an old-school product still used for areas that have very low water pressure but where growers want a sprayer.

Used with 1/8" tubing that comes off the mainline, these stake sprayers put out a 160-degree, 10" to 24" cone-shaped spray pattern. Spot Spitters work very well from 15 to 25 psi, but they will work well at a higher pressure too. I've seen two or three sprayers used around a plant in a bed of container or up to six of them around a large plant. They offer a uniform spray pattern, come in three flow rates and are inexpensive.

MixRite Fertilizer Injector – Powered entirely by the water flowing through it, the MixRIte Injector is the best injector for organic fertilizers. This brand has versions perfect for chemical fertilization too. Its four models come in mix ratios of 1, 2, 4 or 10%. The 10% unit is best for organic fertilizers, because it takes a higher concentration of organic fertilizer to do an adequate job. Choose your MixRite Injector according to the fertilizer concentration you want to add.

  • Simple to install, operate and clean
  • Pressure loss at max flow: 14.5 psi
  • Shutoffs on all models except IMR1
  • UV-resistant plastic body
  • See our online video

We hope these tips help you grow the best crop possible. Whether you are a beginner or a veteran, a commercial grower or an individual user, following these simple techniques can help you grow a better, more potent crop.

How long does it take to grow pot? It depends on conditions, but generally you should expect to be reaping the rewards of your careful cultivation and hard work in three or four months.

Visit for more information about what products are best for your situation, including how-to guides, an online chat and cannabis blog articles. An entire category of our website is dedicated to hemp and cannabis cultivation too. And if you need to speak to our friendly and knowledgeable staff, they are here to help you with your crop at (800) 522-3747.

← Previous Post Next Post →