Germinating Seeds & Growing Seedlings with Hydroponics

Growing Plumeria from Seeds > 2018 Projects > Germinating Seeds & Growing Seedlings with Hydroponics

Germinating Seeds & Growing Seedlings in water saturated plugs using Hydroponics

First off, I have to admit I’m not a fan for water rooting for plumeria cuttings.

Usually, I started plumeria seeds in FlexiPlugs in a flat tray without drain holes and filled with water for the first day or so. Then I transfer the FCN FlexiPlug tray to a flat tray with drainage holes. I then keep the plugs moist by watering several times a day. This year, by accident I started using flat trays without drainage holes, planted my seeds, and the next day I had an issue with my health that lasted a week or so. When I was up to check on my new seedlings, I realized they were still in the flat trays without holes, and because we had rain almost every day, the trays were full of water.

To my surprise, all the seedlings looked great, better than the ones I’m growing without saturating the plugs. So, I started researching and learning as much as possible about hydroponics. I’ve was intrigued by the explosion of new products coming out for the cannabis industry. Lighting technology, grow room automation, soil amendments and grow nutrients are seeing significant overhauls. From my research, I’ve decided to test a few products from Advanced Nutrients without adding any NPK.


  1. Germination Plumeria Seeds
    1. Germinating Plumeria seeds in water saturated plugs. (control)
    2. Germinating Plumeria seeds in water soaked plugs with corrected pH.
  2. Growing Plumeria Seedlings
    1. Growing Plumeria seedlings in water saturated plugs. (control)
    2. Growing Plumeria Seedlings in water with corrected ph, Vitazyme, and Root Activator. 

I am adding nutrients with corrected pH technology to keep the pH around 7.0 or below.

The seedling will be grown in the water mix until transplanted into the soil. It is estimated to be 2-3 months, depending on the production of roots. Each cultivar is a little different.

Starting 2/2019

I’ve started a couple of new experiments and of course with a control group: I’ll be trying out some new products to correct the pH, with my previously proven germination and growing methods to hopefully improve both.

Seeds will be started and grow for 2-3 months in 2″x 3″ FCN FlexiPlugs saturated in nutrients until transplanted into soil.

Materials Needed:
CONTROL GROUP: Plumeria Seeds, 2” x 3” FCN FlexiPlugs and flat trays without drain holes, Vitazyme, Carl Pool’s Root ActivatorMetal Labels or plastic plant markers and permanent felt tip marker. And of course Excalibur VI.

EXPERIMENT 1: Plumeria Seeds, 2” x 3” FCN FlexiPlugs and flat trays without drain holes, Vitazyme, Carl Pool’s Root Activator, correct pH, BioblastMetal Labels or plastic plant markers and permanent felt tip marker. Pro-Mix BX with Mycorrhizae and of course Excalibur VI.

EXPERIMENT 2: Plumeria Seeds, 2” x 3” FCN FlexiPlugs and flat trays without drain holes, pH Perfect Grow, Micro Additive. Metal Labels or plastic plant markers and permanent felt tip marker. Pro-Mix BX with Mycorrhizae and of course Excalibur VI

EXPERIMENT 3: Plumeria Seeds, 2” x 3” FCN FlexiPlugs and flat trays without drain holes, Vitazyme, Carl Pool’s Root Activator, correct pH, Bioblast, pH Perfect Grow, Micro Additive. Metal Labels or plastic plant markers and permanent felt tip marker. Pro-Mix BX with Mycorrhizae and of course Excalibur VI.

The goal is to determine benefits to seed germination and seedling growth by correcting the pH with automated nutrients. Integrating into from my existing germination and growing methods to find a better way to keep the pH correct. 

I plan on monitoring and controlling the pH levels, keeping the plugs saturated with water and nutrients. Water and Ambient Temperature may need to be controlled with heat mats if it gets too cold. (Too cold being below 40 degrees at night, to be controlled by heating mats and possibly covers) Why is pH so important?

  • If necessary, the water temperature will be controlled by heating mates under the plug trays. The ideal water temperature should be around 85 to 90 degrees. If it gets too cold (below 40 degrees at night), the heating mats and possibly covers will be used.
  • PH products will hopefully control the pH levels, but I will manually adjust if necessary. The pH, I prefer is between 6.7-7.0 
  • The weather will control ambient Temperature unless I decide to put a cover on the trays. Nighttime temps are expected to be in the 60s and 70s during Springtime. (I’m in Zone 10b)
  • Saturation of the plugs will start by filling the tray full and after germination reduced to 1/2 full. The design of the plugs allows the moisture to be wicked up through the plugs while allowing ample airflow and maintaining air pockets.

Nutrients & Fertilizing

From the beginning, I correct the pH, use Root Activator and Vitazyme to soak the plugs in and drench the soil when I transplant into pots. When I see 3-4 real leaves, I start fertilizing with Bioblast at 1/2 strength for the first month then full strength every two weeks.

When I transplant into pots, I add Excalibur VI at a rate of 1 tablespoon per 1 gal pot and drench the soil with Root Activator and Vitazyme.


For the soil, I prefer to use Pro-Mix BX with Mycorrhizae for many years for my seedlings, and the Mycorrhizae is very beneficial to new seedlings.

We also have soil custom mixed.

  • Canadian peat: partially decomposed organic matter. It decays slowly and aids in aeration and drainage. It also lowers media ph.
  • Sand: a non-organic component of media. It provides aeration and structure to media and weight; therefore the particle size is the critical factor in selection. We recommend sharp sand (builders’ sand).
  • Florida peat: partially decomposed organic matter. It decomposes slowly and aids in aeration and drainage. It also lowers media ph.
  • Cyprus Mulch: organic material is providing water retention and structure.
  • Cyprus Sawdust: organic material is providing water retention and structure.
  • Soil conditioner: contains processed pine bark, limestone, and gypsum. This substance adds organic matter to the soil, helping retain moisture.
  • Dolomite: a soil amendment used to slowly raise the ph.

Getting started:

  • Of course select as fresh as possible quality plumeria seeds. I only grow named cultivars, and I figure if I’m going to spend the time and money, I want my best chances of getting a quality plumeria. Even if you are growing seedlings for grafting rootstock is better if you know the cultivar.
  • Use 2″x 3″ FCN FlexiPlugs, a 10″x 20″ 36 compartment plug tray, and a 10″x 20″ flat tray without holes to hold the plug tray.
  • Place the plug tray in the flat tray.
  • Place 36 plugs in the plug tray.
  • Mix a gallon of water and a pH correction product.
  • Fill the flat tray all the way full, with the mix. Allow the plugs to soak up as much of the mix as possible and keep adding mix until the level is stable at 3/4 full to full. 
  • Use a case knife or similar to place a slice into each plug, and the slice should be about 2″ deep and 1/2″ wide.
  • Plant seeds directly into the saturated plugs, with the flag facing up.
    • If you are not sure about the viability of your seeds, then pre-soak by placing them in a bowl full of water for about 4 hours. You can also use the paper towel method to get them started. Either way, plant the seed in the plug as soon as you see they have plumped up.
  • Check the pH, but the pH product should correct the pH, so the seeds have a better chance of germinating and roots should be able to absorb more nutrients.
    • For me, the reason for the pH correction is our water comes from a well and is near 8.0. It may not be as necessary if your water is around 6.7 – 7.0
    • The high pH doesn’t seem to affect our mature plumeria in soil much but growing seedling in saturated plugs with a high pH will make it more difficult for the seedling to absorb nutrients, especially the micro-nutrients.
  • If needed, I’m planning on using heating mats, placing the heating mats in a location that get full sun. Day time air temps will vary as it cools over winter. If needed, I use 25′ commercial mats. Be sure to follow manufacturer recommendations and safety precautions when using Heating Mats.
    • The reason I place in full sun right away is mainly for the heat. All seeds need to germinate is moisture and warmth, they do not need light to germinate. As soon as you see the green of the seed leaves, the seed  The full sun and airflow lessen the chance of damping off. Damping off typically occurs when seedlings are grown in cool or too moist conditions it further increases poor soil drainage and poor airflow.
  • Add the nutrient mix as needed to keep the level about 3/4 full to full until the seeds germinate then about 1/2 full after that. It doesn’t hurt to allow the mix to go down as long as the plugs do not dry out. The plugs will act as a wick and keep ample air pockets.
  • Every month it’s a good idea, to rinse the flat tray to get rid of any contaminants that may have built up.

Notes: Cotyledon or the seed leaf is involved in the storage of food reserves. In plumeria, the seed leaf usually exists in pairs and show above the ground and do perform photosynthesis, a function similar to a real leaf. A new seedling can and will take up nutrients even while seeds leaves are still present. Soaking the plugs with a nutrient mix will assure the seedlings get all the nutrients they need when they are required.

Plants make sugars by absorbing carbon dioxide (CO2) from the atmosphere through small pores in their leaves called stomata. However, when stomata open, water is lost to the atmosphere at a prolific rate relative to the small amount of CO2 absorbed; across plant species, losing an average of 400 water molecules for each CO2 molecule gained. The balance between transpiration and photosynthesis forms an essential compromise in the existence of plants, and the stomata must remain open to build sugars but risk dehydration in the process. Windy days can contribute to dehydration — the FlexiPlugs aid in the balance of water and carbon dioxide to the plants.

When most people think of hydroponics, they think of plants grown with their roots suspended near or directly into the water with no growing medium, one type of hydroponic gardening known as N.F.T. (nutrient film technique). There are several variations of N.F.T. used around the world and it is a very popular method of growing hydroponically. What most people don’t realize is that there are countless methods and variations of hydroponic gardening.

Why I’m Trying Hydroponics?

If you give a plumeria precisely what it needs, when it needs it, in the amount that it needs, the plant will be as healthy as is genetically possible. I used this premise when developing Excalibur Plumeria Fertilizers. With hydroponics this is an easy task, in the soil it is far more difficult.

With this hydroponic experiment, the plumeria seeds germinate and the seedlings grown in FlexiPlugs. FlexiPlugs are created by blending the highest quality peat with other organics and a foamed binder. The result is a stabilized propagation medium that promotes faster rooting for seedlings while providing the consistent moisture needed for seed germination. FlixiPlugs are pH balanced and contain micronutrients and active biologicals providing the necessary elements to promote healthy seed germination, root growth, and youthful plant vigor. I also add additional nutrients and fertilizers to my seedlings as soon as they can use photosynthesis allowing the seedlings to uptake its food at an early stage with minimal effort as opposed to the soil where the roots must search out the nutrients and extract them. Correct even when using rich, organic soil and top of the line nutrients. The energy expended by the roots in this process is energy better spent on growth.

The growing medium is the material in which the roots of the plant are growing, in this case for the first few months it’s FlexiPlugs. Additional nutrition comes from nutrient solutions (water and fertilizer combined). If you wish, you can easily control everything the plants receive. The strength and pH of the nutrient solution are easy to adjust so that the plants receive just the right amount of food. The watering/feeding cycles can be controlled by an inexpensive timer so that the plants get watered on a schedule, as needed.