Tips from Olle Garden Bed: How to Start Bottom Water Seeds (5 Simple Steps)

Pouring the bottom of the seedling tray is a wonderful thing, but many people are struggling with it! But there is a way to make it work every time, which is a specific combination of the right tray, the right growth medium, and the right watering plan. Read here are some things that you should know when It comes to Olle Garden Beds!

With just a few simple tips, you can reliably and easily transition from seeds to healthy seedlings. It does require a bit of attention to finer details. But once you put it down, it's easy to repeat and you'll be able to plant all the seeds waiting to be planted!

Step 1: Start with the correct tools

What does seed germination require? For most seeds, this is warmth and moisture. In a few cases, it also requires light, but this is not very common. Water is necessary to penetrate the seed coat and stimulate embryonic plant growth. Warmth is another way to help indicate to dormant embryonic plants that it is time to grow.

Having the right tools at hand to provide warmth and moisture is crucial. There are many different ways to start seeding. But they all rely on these two factors, because without them, no seed would germinate.

Growth medium

Having the right tools at hand to provide warmth and moisture is crucial. There are many different ways to start seeding. But they all rely on these two factors, because without them, no seed would germinate.

To provide moisture, the best choice is to use a growth medium for seed initiation. In most cases, the seed initiation medium uses peat moss or coconut shell, as both can absorb moisture and retain it.

A little bit of worm casting can also help. They can withstand moisture up to 10 times their weight. But you need to ensure that your seed starting mixture is good in particle size and it is not clay or muddy.

Most seed starting mixtures are well designed; The smaller particle size reduces the opportunity for air pockets in the growth medium, which means that the seeds are more likely to be constantly surrounded by water.

In most cases, when we plant seeds, they are not as deep (usually no more than twice the width of the seeds themselves. In some cases, they do not need to be buried at all). But we need this kind of soil to keep water from damaging the seed coating, so that it can penetrate.

Ensure that it is not clay or muddy, and also ensure that very young roots can easily penetrate the soil. This will enable plants to grow.


But what about warmth? The vast majority of seeds planted in residential gardens will begin to sprout at around 60 degrees Fahrenheit (15.55 degrees Celsius). Some products that are more suitable for warm temperatures, such as tomatoes that are planned to grow in summer, prefer to be warmer - such as around 70 degrees Fahrenheit (21.11 degrees Celsius).

You can provide warmth by leaving plants indoors. Most modern families maintain a perfect temperature range for good germination (because we humans seem to prefer around 70 degrees!

However, if you cannot start planting plants in a warm and comfortable house, there are other ways to do so. The greenhouse or greenhouse setting is very effective. The same goes for the seedling heating pad, which is a device designed to provide the best warmth for your seed tray.

Seed cell tray

Finally, you need something that can accommodate the growth medium. You also need a tray that can be placed underneath; If you only start planting a few plants, we have germination domes and bottom trays that can be used for all of our cell trays, but you can also use larger trays, such as our universal bottom tray. Ensure that the bottom tray has no holes - it must be filled with water!

Therefore, to review here, you need the following content:

Seed initial culture medium (no material containing large pieces of wood, rock, large perlite or fragments - it must be fine particles, and must be able to absorb and maintain moisture)

A warm place (indoor, greenhouse, or using seedling heating pads)

Some form of cell tray to accommodate growth medium, as well as a bottom tray that can accommodate water.

Step 2: Planting something

Let's talk about how you want to plant these seeds - because there is also a process here.

As I mentioned earlier, most seed initiation media are made from peat moss or coconut shell. But there is one drawback: these media become hydrophobic when completely dry.

When the seed initial culture medium is hydrophobic, it will repel water. This is what happens to many new gardeners who miss too much watering. As the material dries, the surface becomes harder and water is less likely to penetrate.

To avoid this situation, you need to start fully moisturizing the growth medium before planting. Then, you need to keep it moist.


Replenishing the initial culture medium for most seeds is easy, but it takes some time to complete. I personally enjoy using warm water for this process. First, place the seed starting mixture into a large container. You can use old concrete mixing plates or large drums. Add warm water to hot water, stir, and then walk away for about ten minutes.

Within these ten minutes, the heat of water will soften the external fibers, allowing them to absorb water. By the time you come back after waiting for such a short time, there should be no water left.

But you haven't finished yet. Add more hot water, mix again, and then walk for another ten to fifteen minutes. If you do not see any moisture in the container when you return, please repeat this process.

Continue this operation until the water is returned and found in the tray. Now it has completely replenished water; If you grab a handful, you should be able to squeeze water out of it, that's great! Your soil should feel a bit warm to the touch, but not scorching, and it will also be very damp.

Fill your seed tray

Now is the time to fill your seed initiation tray with growth medium. You will find that it should be easy to place there, if it's a bit more messy than handling dry things.

After filling the tray, gently press on the surface of each cell. You didn't put anything there, but make sure you have filled the tray. Then, fill any remaining space with more seed starting mixtures.

Now is the time to sow the seeds. Earlier, I mentioned that most seeds should be planted approximately twice the width. Check your seed package to ensure, but this is a good general rule of thumb that applies to most seeds.

Smaller seeds usually require larger seeds to be closer to the soil surface. Gently cover the seed, then gently press down with your fingers to remove any air pockets around the seed. This ensures that your seed is now in complete contact with the seed starting mixture.

Step 3: Keep moist

This is where the bottom watering process begins - it also includes some top watering.

Do you remember I said that if coconut shells and peat were allowed to completely dry, they would become hydrophobic? You need to keep them moist to prevent this hydrophobic tendency. If you touch the surface of the tray with your fingertips and it looks dry, you need to provide moisture to the surface of the dry battery. You may also need to water the rest of the cells.

This continuous moisture, combined with warmth, will tell the seeds that it is time to sprout. But you also don't want to accidentally flush small seeds out of the cell tray by overloading them with water.

I like to use a narrow nozzle indoor spray bottle to carefully apply water to the surface of the cell tray. If you are really worried about overuse, use the spray bottle several times a day to keep the top moist.

One thing to note here is that if you use our 4-inch deep Epic4 cell trays, these trays usually need additional top watering, usually a little more than the spray bottle can provide. At this point, narrow nozzle watering is indeed a benefit; The slender nozzle allows you to pour very carefully onto the cell tray without disturbing the soil.

Germinating dome

The germination dome can help slow down the evaporation of water in the cell tray. This dome only needs to be opened until your plant sprouts. Therefore, if you are using our 6-cell tray, we suggest that you use the 6-cell germination dome with them - so that each tray has its own dome.

Due to the different types of seeds germinating at different speeds, once the plant pops up and reaches a height of approximately one inch, you can pop out from the dome of each cell tray.

In addition to keeping the surface moist, it is also necessary to keep the rest of the cells moist. This is where bottom watering works!

Bottom watering

Watch the actual effect of bottom watering by moving to 10:24 in the video above.

When watering at the bottom, you apply a small amount of water to the bottom and sides of the cell tray. Let the small medium inside drain the water into the cell tray.

In most cases, this requires less than an inch of water. However, if there are many cells in the bottom tray, it may be necessary to use up to one inch. This water should be at room temperature, not hot. You keep your cells hydrated, but you don't want to damage your seeds by replenishing them with water.

Bottom watering is a time limited matter. You don't want your cells to sit in the pool all the time. Excessive bottom watering may be negative and lead to many fungal pathogens utilizing wet conditions. Damping and other conditions are common in excessively humid soil.

Let your cell tray stand in water for about half an hour, but after that, you should discard any excess water from the tray. This allows the growth medium to absorb urgently needed water, but it does not become overly saturated.

If the tray does absorb too much, they can allow it to freely drain into the empty bottom tray, ensuring that they have the necessary amount of moisture. By avoiding the continuous puddle below, you will have happy seedlings!

Step 4: Monitor the pallet

There are two methods to test whether you need watering: touch and weight.

Touch testing is the fastest so far. Just walk to the tray, lift the sprouting dome, and touch the top. Does it feel damp to the touch? That may not be a problem.

But touch testing can only tell you if the top is damp. It won't tell you if the entire tray has water. To do this, you need to undergo a weight test.

A dry soil tray weighs much less when picked up than a moderately moist soil tray. You can quickly test for differences by filling one tray with a dry seed starting mixture and another tray with a completely hydrated seed starting mixture. Adequate hydration is your goal in terms of weight.

This is unscientific; You don't need to measure the exact weight of a fully hydrated tray to achieve the best watering effect. But you get used to lifting the tray and saying, 'Well, it seems a bit light,' or 'It feels great, I don't need to water it now. By monitoring these two things - touch and weight - you will be able to ensure that you have a well watered tray.'.

One last thing to note here. If it rains and your tray is placed outside, you will want to continue cleaning your seed tray. This can ensure that you pour out the rainwater as soon as possible after the rain.

Try not to leave a plate of seedlings in water for too long. Even placing them outdoors under cover during inclement weather is better than sitting them in the water for a long time.

Step 5: Water after germination

Your plant has sprouted, and the new seedlings are in the tray. They have reached a height of approximately one inch, and you have removed your sprouting dome. What now?

Before you need to potted plants into larger pots or transplanted them into the garden, you need to continue monitoring like touch and weight testing. But you also want to do it more frequently.

As the plant takes root and begins to grow, it will require more and more water. This means that you may water more frequently. If you have a whole plate of tomatoes, you may water them twice a day when they are ready for transplantation. This is because your thirsty little plant will suck up all the water.

Usually, once your plant has grown its first "true leaf" instead of its seed leaf, which is the cotyledon, and has reached a height of a few inches, you will see an increase in watering frequency. At this point, pouring half an inch of water into the tray and leaving it there is actually very tempting. Your seedlings will drink it faster.

This is great for slightly mature plants 3 inches or higher as they can handle it. However, it is best to be cautious between heights of 1 inch to 3 inches. Watering multiple times a day for half an hour is better than accidentally drowning plants with too much water!

Besides, your seedlings are still very tender. Before their stems begin to thicken, they are easily affected by damping. As someone who has lost multiple seedlings due to shock absorption, I can tell you that this is not fun.

In summary, this is a very simple process. But most new gardeners usually have one or more of these things that are abnormal. Perhaps they used the wrong soil to start sowing, which did not absorb moisture well, or they did not use trays that allowed good water infiltration (or drainage). Alternatively, they provided too much water and the seedlings drowned.

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