Growing Carnations Hydroponically
pH 6.0 EC 2.0-3.5 PPM 1260-2450
Although the plants are sometimes perennial, if you plan on growing them in hopes of turning a profit they should only be kept for 1 to 1.5 years, after that their quality and productivity wanes and they should be replaced.
Starting Carnations from Cuttings
Tip cuttings should be harvested from a healthy plants or acquired from a reputable supplier. They should be between 3 and 5 inches long. If they are too large they are harder to root. A dry, aged and Desiccated cutting does not allow for the process of cellular regeneration that takes place in cuttings.
Cuttings can be rooted in the hydroponic media as soon as harvested or can also be cold stored for up to 2 weeks before rooting. Perlite, vermiculite, coconut coir, sphagnum moss will all work. My personal preference is a 50/50 perlite/vermiculite blend. Some growers use oasis cubes or root cubes.
Do not use any nutrient solution for the first 7 to 10 days, after that a very mild nutrient solution, 1/4 strength to start out with gradually bumping it up to full strength when the cuttings are complete. Rooting should be complete in about 3 weeks.
During the rooting process the air temperature should be a few degrees above the norm for growing mature plants. So 75 to 80 F is optimal for the day cycle and 4 to 5 degrees less at night.
Starting Carnations From Seed
Carnations used in hydroponic systems are generally from cuttings, however it is possible to start from seeds. In fact if you are using a deep water system it is advisable, it also works well with Ebb and flow.
Mediums such as rock wool, coconut fiber, peat and oasis cubes or other rapid rooter plugs serve as a seed starting medium, keep in mind that when the seedlings emerge they should be transplanted to a complete hydroponic setup.
Oasis cubes are sterile and light weight and they have a good air to water ratio. Rock-wool is also popular for seed starting. Rock-wool requires more diligence as it is alkaline. Maintaining watering and nutrients with a more acidic pH level rectifies this.
Although the seed itself naturally contains all the nutrients it will need to start life. Pre-treating the hydroponic media with a 1/4 strength nutrient solution is helpful as the seeds germinate.
Do not over water the seeding medium, moderate amounts of water combined with misting works best. If the medium is too wet, particularly in the case of rock wool the seeds will fail to germinate.
Place your media, be it cubes, pellets or what have you in a shallow tray, I like to save the clear dome topped containers from rotisserie chickens and other take out foods for this purpose. Put about 3/4 inch of water [preferable distilled or Reverse Osmosis] in the bottom, leave the lid on and keep it in a warm dark location till sprouts appear.
1. Pacific Northwest Plant Disease Management Handbook
2. New additions to fusarium resistance carnation program.