Propagation




How to Take Aeroponic Cuttings: A Step by Step Guide to Caring for Clones in Aeroponics

Aeroponic cuttings offer lots of advantages to growers. They root quicker, are less prone to disease, and they don't require any propagation media making them ideal to transfer into both aeroponic systems and other 'media-less' systems such as NFT or DWC. Here we take a look at how to take aeroponic cuttings using an EZ-Clone aeroponic cloning machine.

So What Exactly is an Aeroponic Cloning Machine?

Instead of rooting your cuttings in rooting media like rockwool, coc coir, vermiculite, or Jiffy Plugs, or Rapid Rooters, an aeroponic cloning machine allows your cuttings to root in a fine mist-thus freeing you up from the regular expense of buying media (and often the time necessary to prepare pre-soak it.) Typically, a submerged pump drives nutrient solution into low pressure misters.

EZ-Clone Aeroponic Cloning MachineMany growers are amazed when they hear that no humidity dome is required to maintain super high relative humidity levels. This is because the fine mist allow cuttings to uptake any moisture they need directly-even without roots! How cool is that?

Aeroponic cloning machines don't do everything for you though. As with all equipment you use for taking cuttings, you absolutely need tomake sure your cloning machine is kept clean!

Okay, Let's Get Started!

Step 1: Fill the Machine

Fill the machine to the indicated level with water that is at 65-68°F (18-20°C).

This low pressure mister attaches directly onto a submersible pump, creating an even mist for the cuttings. Be sure to install it so the misters point upwards.

There's no need to add any nutrients because your cuttings don't have roots yet! Saying this, some growers still prefer to add some hydroponic nutrients at this stage, so that as soon as the cuttings develop roots of their own, they have some immediate food available.  Hydroponic (mineral-based) nutrients are preferable over organic nutrients as they can be immediately assimilated by your cuttings and they don't foul up your reservoir. Many growers use a very dilute version of their standard 'bloom formulation' because the phosphorus encourages further root development. Others prefer to use a specialist product for young plants so that the ratios of micro and macro elements are kept in balance. If you add nutrients, adjust to pH 6.0-6.3 with dilute phosphoric acid and shoot for an EC of between 0.4 and 0.6.

Step 2: Check Your Environment

While aeroponic cloning machines don't require humidity domes, that's not to imply you don't need to pay attention to your indoor garden's environment. Your cuttings will be happiest when located in a room kept around a steady 70°F (21°C) and relative humidity around 60% or more. If the relative humidity in your room is less than this, you should consider misting or using a propagation dome to help increase the relative humidity directly around your cuttings. Try to keep room temperatures below 75°F (24°C) as excess heat just adds transpirational stress, and more stress is the last thing your cuttings need at this early, crucial stage!

Tomato cuttings in an EZ Clone aeroponic propagator rooting in ambient natural light near a patio window.

Another crucial factor is the temperature of your nutrient solution-ideally this should be around 68°F (20°C); if it is much warmer this will decrease levels of dissolved oxygen in your nutrients and increase the likelihood of pathogens and stem / root rot. If your room (or nutrient solution) is too cold this will slow metabolism, shock your cuttings and inhibit that all important root development.

Take note: The submerged pump in your aeroponic propagator will heat the nutrient solution slightly so you definitely need to keep an eye on nutrient solution temperatures. Use a nutrient thermometer to keep on top of things. If you find that the pump is warming up your nutrient solution excessively, try relocating your cloning machine on to a stone floor, lower ambient temperatures in your room if you can through extra ventilation or AC, or run the pump on a timer, five minutes on, five minutes off, rather than letting it run constantly. 

Step 3: Check Your Light Levels

Cuttings don't require much light; in fact, high light levels are to be avoided. Remember, you want your cuttings to concentrate their energy on creating roots, not coping with an intense growing environment-all that will come in time! Ambient light levels on a window-sill may be adequate-just try to avoid direct sunlight. Alternatively, a pair of two-foot, 55 watt, T5 fluorescent tubes hung five to eight inches away will provide more than enough light to keep 30 or 40 cuttings very happy. Other growers will simply relegate their cloning machine to the corner of the veg chamber so that it receives the diffused, distant light of a metal halide grow lamp. Just be sure the lights are not too intense and keep them on for 18 hours a day. Some growers prefer a 24-hour lights on approach as it makes temperatures easier to regulate, but all plants benefit from a little time out. There's no need to overwork them. Make sure temperatures do not drop too low during the lights out period. Use a Min/Max thermometer and a thermostatically controlled heater if required, but don't blow warm air directly on to your cuttings … ever! This will dry them out and cause them untold stress.

Step 4: Switch Cloning Machine on and Start Inserting Cuttings

If you are not sure how to take a stem cutting, check out our easy guide first. Insert each cutting into the center of the foam discs supplied with your cloning machine so that at least two inches of stem dangles in the misting chamber below the lid. Remember, there should not be any leaves in the misting chamber-just bare stem.

Step 5: Maintenance and Care

Day 1 - Settling In

You shouldn't worry if your cuttings wilt a little immediately after being inserted into your cloning machine. This is perfectly normal. After all, they've just been separated from their life-support system! After an hour or so you should see them perk up. If they continue to appear limp you should try applying a very light spray with water or a dilute foliar solution with a wetting agent to help the moisture cling to the leaves. Make sure there are no oscillating fans pointing at the cuttings as excessive air movement can dry out cuttings in no time! Keep an eye out for any pronounced signs of wilting, especially during the first 24 hours. After all, if any cuttings look particularly unhappy, you've still got plenty of time to make a replacement.

Aeroponic cuttings - day 1 - viewed from bottom up in the rooting chamber.

Day 3 - Roots start to develop

Cuttings tend to root faster in aeroponic cloning machines. It won't be long until you see the beginning of root development. Typically this starts with the formation of small white calluses on the stem. Keep an especially watchful eye over your cuttings during the next few days. Roots should be bright white. If you observe brown or discolored roots, this could be a sign that your nutrient solution is too warm. If you haven't done so already, it's definitely a good idea to add some mineral nutrition to your cloning machine's reservoir at this point as your cuttings can certainly derive benefit from it. Some growers change out the reservoir at this stage.

Aeroponic cuttings - day 3. Small nodules are starting to develop and the beginnings of roots quickly follow.

Day 7 - Root Explosion!

Just seven days after being taken, these cuttings suddenly appear to be bursting with root development.

With such prolific root growth at this early stage, it's tempting to think the job is done, but it pays to be a little more patient before removing your cuttings from the cloning machine. This is just the 'first generation' of roots.

Aeroponic cuttings - day 7 - explosive root development!

Days 8, 9, 10: Secondary roots begin to develop

As secondary roots begin to emerge, we are fast approaching the time when the cuttings will leave the cloning machine and begin life as young plants!

Aeroponic cuttings - day 10 - secondary roots visible

Day 11: We're Ready!

Wow! It took just 11 days and these cuttings are ready for life on their own. There is lots of secondary root development and root hairs too-clearly these puppies are ready for transplanting.

Why now?

The emergence of more secondary roots and root hairs is a sure sign that your cuttings are developed enough to handle life outside of the cloning machine. If you're not quite ready though, don't worry; the cuttings will be quite happy to bathe in their nutrient mist for days, even weeks if required! Just be sure to change out the nutrients once a week and keep an eye on pH levels. If roots become very long you can always trim them -they won't mind!

Transplanting

A net pot is an ideal next stage for an aeroponic cutting. This gives you a chance to establish your cutting in the growth media of your choice. One common question about aeroponic clones is how to handle transplanting them into a pot of loose-fill media or hydroponic system. For instance, there is a common myth that aeroponic clones don't do well in soil or coco coir. This is simply not the case; you just need to take care. Ensure your chosen media is at room temperature and fairly moist. Also, remember roots hate light, so be kind to your cuttings and transplant them away from bright lights. Partially fill the pot with media, make a hole just big enough to insert the rooted cutting, and gently back fill around it so all the roots are covered and your cutting is well supported. They will need a few days to adjust, so don't go whacking them straight under your 1000W metal halides just yet. Ease them in gently under a 6500K T5 fluorescent or a 250W metal halide. Some growers foliar spray with sea kelp products which help to reduce stress levels. Other growers use a Victorian Bell Cloche to increase humidity levels for the first few days as the cuttings settle in.