Misting Systems

What is a misting system

A misting system is an automated way to keep cuttings moist and cool. It is also known as intermittent mist.

Rooting cuttings is quite easy when using a misting system. Prior to misting systems, nursery owners and plant propagators had to use other methods such as wooden boxes with glass or plastic covers over them. These covers kept the cuttings in a moist environment which allowed them to root. A few drawbacks to this method is the length of time and possibility of creating the right conditions for diseases and fungus.

Intermittent mist allows the propagator more control over the conditions the cuttings are in. The frequency and duration of the mist can be controlled to allow the cutting to get the correct amount of moisture to keep them hydrated and cool. Hydration and temperature control around the cutting are vital to the cutting’s ability to form roots.

Keeping the cuttings hydrated is essential to successfully root softwood cuttings. The moisture that is deposited on the cuttings leaves and rooting medium allows the cutting to live without roots. The moisture is drawn up into the cutting through the stem where it supplies the plant with moisture. Too much water in the rooting medium can cause the stems to rot. A misting system is a great way to control the amount of moisture in the rooting medium.

The moisture deposited on a cutting also keeps it cool. Plants go through a process called transpiration. This transpiration process is quite similar to our perspiring because it allows the plant to release water through its leaves which cools the plant off. This transpiration process is what actually draws the water up the cutting’s stem and the incorrect amount of water on and around the cutting can greatly affect the process.

Using intermittent mist to root cuttings of woody ornamentals and perennials is one of the most efficient means of asexually reproducing large quantities of plants. Intermittent mist offers a means of automatically supplying moisture during the critical periods of propagation by using timers that control the delivery of the misting water on a precise schedule. Without intermittent mist, cuttings need to be kept in a humidity and temperature controlled environment to keep them from wilting and dying from overheating and transpiration.

The link above told us that transpiration is the evaporation of moisture from a plants leaves, stems, flowers, and roots. Intermittent mist raises the humidity level around the cuttings, which lessens the transpiration process and allows the cuttings to form a callus and root, and reduces the temperature around the cuttings. All this can be accomplished without the need of an expensive greenhouse which requires temperature and humidity controls.

Under ideal conditions, certain softwood cuttings can root under intermittent mist in as little as 2-3 weeks, allowing you to root multiple batches of cuttings in a single growing season.

Here is a picture of a generic misting system that shows some of the components required and a typical setup:

10 reasons you should own a misting system

1. Intermittent mist keeps the cuttings moist, minimizing transpiration from the leaves.

2. Intermittent mist keeps the cuttings and the immediate area cool.

3. A misting system allows you to produce multiple crops per year.

4. Once set up, the system runs with minimal supervision.

5. You can concentrate on other tasks, knowing the misting system is taking care of your cuttings.

6. In the event a batch of cuttings fail, intermittent mist allows you to immediately start another.

7. You can produce 10's, 100's, 1000's, or even 100,000's of cuttings at a time with a misting system.

8. With intermittent mist, certain cuttings like hydrangeas form roots in as little as 3 weeks.

9. Using an intermittent mist system reduces the amount of labor involved over other propagation methods.

10. An intermittent mist system will allow you to produce rooted cuttings that you can plant in your own landscape, give away as gifts, or sell.

And how about the best reason you should be using an intermittent mist system?

11. Selling rooted cuttings produced under intermittent mist can be quite profitable!

I believe intermittent mists systems are so important, I occasionally give them away!

To read more detailed explanations of why you should be using intermittent mist, download this free ebook.

Why a misting system is important when rooting softwood cuttings

A misting system controls the environment two ways.

It controls the amount of mist the cuttings receive.

It controls how often the cuttings receive the mist.

The amount of mist a cutting receives is called the duration. This duration can be anywhere from a few seconds to a few minutes depending on the environment and conditions the cuttings are being rooted in. If your misting beds are located outside, the sun and wind will cause the moisture on the cuttings to evaporate much quicker so the duration and interval will be more that if your misting system were located inside a structure like a greenhouse or other propagation house. Typically the duration would be between 6 and 14 seconds when rooting woody ornamentals.

How often the cuttings receive mist is called the frequency or interval. This frequency can be between 2 to 10 minutes, again, depending on the specifics of the rooting environment. Typically the frequency would be 5 or 10 minutes for woody ornamentals.

Properly setting up the misting system to deliver the correct amount of moisture to the cuttings ensures they are in an environment that is suitable for rooting.

Misting beds

Types of plant propagation structures

To propagate plants you will need propagation beds. Propagation beds are areas of sand or other rooting media used specifically to propagate plants. These structures can be loosely broken down into a few categories:

Greenhouses

Misting Beds

Cold Frames

Hotbeds

Misting beds, coldframes and hotbeds are what most individuals will start off with when propagating plants. Some will have the pleasure of owning a greenhouse, but greenhouse propagation won’t be covered here.

For greenhouse growing I recommend the following:

How to Build Your Own Greenhouse

Greenhouse Gardener's Companion, Revised: Growing Food & Flowers in Your Greenhouse or Sunspace

Greenhouse Gardening: Step by Step to Growing Success (Crowood Gardening Guides)

What is a misting bed?

A misting bed has a misting system installed to keep the cuttings moist and cool.

What is a coldframe?

A cold frame is a box that holds your rooting media and has no means of producing or retaining heat to aid the rooting of the cuttings. Moisture is added to the soil and the cover of the frame keeps the moisture from evaporating too quickly.

What is a hotbed?

A hot bed is nothing more than a coldframe with bottom heat. The bottom heat aids in the cuttings ability to form roots. Moisture is added to the soil and the cover of the frame keeps the moisture from evaporating too quickly.

Did you notice the one common theme among the different types of beds? The coldframe and hot bed have covers that helps retain moisture. The misting system is designed to do it automatically whereas the others must be manually watered to make sure the cuttings have adequate moisture.

How are the beds made?

There are many ways to build your beds, too many to actually cover. However, I will give you a basic layout that you can use or adapt for your particular application. These beds should be made from good sturdy lumber to ensure years of service.

Here is a diagram of a simple propagation bed that uses mist to keep the cuttings cool and moist. The sides should be 6 to 8 inches high. The bed can be any length you choose, but a 4 foot width has been found to be the most manageable. Later on I will go into more detail about how to choose a good length for your bed.

The bed can filled with the rooting media to a depth between 4 to 6 inches. This can be sand or a mixture of peat/perlite. A better option is to fill the bed with sand and use propagation trays filled with sand or peat and perlite. This allows you to easily move the rooted cuttings from the mist.

Rooting media

Peat and Perlite are great rooting media for softwood cuttings. Successful plant propagation begins with understanding the strengths and weaknesses of each rooting media as well as the advantages of mixing the two.

Peat

To Quote Wikipedia:

Peat is an accumulation of partially decayed vegetation matter. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests.

So essentially it is decaying plant material has been forming for 360 million years. Plant propagators use peat as a rooting media because it is sterile, holds moisture, and is Ph neutral. These three qualities are one of the best reasons to use peat when rooting cuttings. One disadvantage is that straight Peat may hold too much water against the stem of the cutting that is being rooted which may cause it to rot.

Perlite