Advances in greenhouse and nursery irrigation are so good no one in a greenhouse or nursery should hand water a plant ever again. The biggest issue today is too many options of how to water and what emitters to use. The list of choices is long. Starting with spray stakes, splitters, emitters, twist weights, sticks, manifolds, octa-bubblers, and more. The options are many.
Preferences are a crucial consideration in irrigation selection. It is good to be familiar with devices used for watering. However, evaluating the technology, you are selecting to ensure it meets your application is just as important. Ideally, the right solution meets both criteria.
Two main factors drive our decision on what emitters to use in our nursery and greenhouse applications. They are the size of the container and the soil media. Most plants from nurseries and greenhouses end up elsewhere, replanted in something different from where they started growing. We must get the entire container watered evenly—side to side, top to bottom. The water you put there is all the water the plants get. So, how big of a pattern do you need to wet the container, and how fast does it have to put water to water from top to bottom?
What are the emission device characteristics are we looking for?
Nursery growers have their proprietary blends of soil media. But, first, evaluate how tight or loose the soil media is to best match the irrigation emitter to the soil type. An easy test is to pour a known amount of water into a pot with the soil media and see how fast and how much comes out the bottom. The faster it drains, the looser the media.
The most forgiving situation is the top right quadrant—tight media with a small container. Lots of emitters will work with this situation. Some of the best solutions include Octa bubblers and a multioutlet dripper assembly.
When dealing with small containers and loose media, the octa bubbler works well here, too, and so does the multioutlet dripper assembly. Don’t be afraid to use two stakes per pot to ensure you wet the entire area. Another product that works well here is the spray stick.
Tight media with a large container spray sticks or spray stakes will make a big difference in covering more area. We need more water because we have more growing media. The flow rate needs to be higher – 3, 5, and 7 gph work well in this situation.
Loose media and a large container are one of the most challenging situations. Again a higher flow rate works well. A multioutlet dripper works well here with multiple stakes per pot.
Michael Pippen provides a few more alternatives in the nursery and greenhouse irrigation webinar below.