How to Grow the Perfect Tower Garden Seedling
You received your Tower Garden, you started some seeds and you sit back and wait. After 1-2 weeks you go ahead and put them in your Tower Garden, the next day they look like this! A long way from the perfect Tower Garden seedling you had imagined.
What went wrong? Why are they suddenly droopy, lifeless and lacking that deep, rich vibrant color? Why do you have weak Tower Garden seedlings?
Lack of sunlight!
The most common mistake I see Tower Garden growers all over the country make is this. Tower Gardeners are not starting their seeds out in the sun, or they don’t move them out there as soon as the seed splits (germinates). Nature has a great way of dealing with things. When seedlings are started with insufficient UV light, they stretch in an attempt to find the UV light they so desperately need. This results in weak, stringy seedlings like you see below.
You can see the seedlings above have very long stems and are all growing toward the little light they are exposed to.
So now you know what seedlings shouldn’t look like, let’s take a look at what they should look like.
Notice the difference? They are a rich, vibrant color. They are also short and stocky versus long and stringy.
Let’s go over the 3 steps involved so you can grow the perfect seedling too!
1. Soak the Rockwool
Mix a gallon (or thereabouts) of water and 10ml of each (this is half strength) A and B Mineral Solution. Place the rockwool sheet/cubes in the mixed mineral solution for approximately 20 minutes. After 20 minutes has passed, carefully remove the rockwool. The rockwool shouldn’t be submerged when you add seeds as too much moisture can cause the seeds to rot.
Soaking the rockwool serves two purposes. The rockwool is wet, giving the seed the moisture it needs to germinate (split and sprout) while also neutralizing the pH of the rockwool.
2. Add the Seed(s)
Add the seed(s) to each rockwool cube. The number of seeds you add will depend on the crop. Use this Seeding Cheat Sheet to determine how many seeds you will add. If your seeds are not germinating, this post, “Why Didn’t My Seeds Germinate?” goes over the possible causes.
3. Put the Rockwool in the Sun or Under Grow Lights
This is the most important step when growing the perfect seedling!
Seeds germinate (sprout and split open) at different rates. Some germinate in a day or two, others three or four days while some can take weeks. They need moisture and heat in order to germinate. The temperature window that a particular seed germinates in will be shown on the seed packet and it will usually match the season that crop is grown. For example, cooler-weather crops will germinate in cooler temperatures whereas warmer-weather crops will germinate in warmer temperatures.
The thing is, they NEED light as soon as germination occurs. Just a day or two without light will cause the seedlings to become “leggy”, and that is irreversible. Ensure the seedlings have at least 8 hours of sunlight if they are outside in the sun. If they are under grow lights they will need between 14-16 hours of exposure to grow lights. A set of tabletop Grow Lights can be used for seedlings. Just ensure they are about 4 inches or so from the seedlings. Having the lights too far away is just as bad as not having them on long enough.
That’s it! It’s as simple as that. Moisture, seeds and sufficient light is all you need to grow the perfect seedling.
Frequently Asked Questions
Can I start seedlings in front of a window?
Most windows have a UV filter on them. This UV filter filters out the very UV light the plants NEED. If you have a purpose-built sun room the windows probably don’t have filters on them. The only way to know would be to try it and see. HOWEVER, bear in mind that the sun will only shine through the window for a few hours a day, regardless of whether you have filters on them or not.
There’s a good chance that you will not be getting enough sunlight through those windows. Many make this same mistake by placing their tower in front of a sunny window. Half of your Tower gets 4 hours or so of sunlight. The other half gets nothing. Can you see why your Tower and/or seedlings are not doing so well inside the house?
For best results, give your seedlings as much sunlight as possible, or at least 14 hours under grow lights. Ensure the grow lights are close enough to the seedlings. If the lights are too far away the seedlings will look just like those that are not getting enough hours of direct sun/grow light exposure.
You will never have a perfect seedling if you don’t have enough light. PERIOD!
It’s freezing outside. What should I do with my seedlings?
If daytime temperatures are not too cold (above 50 or so) put them outside during the day. If your nighttime temperatures are dropping into the 30s I’d bring them in overnight. Just put them back out the following morning. If your day temperatures are below about 50 degrees you may want to consider purchasing a seedling heating mat. These mats warm the bottom of the rockwool by approximately 10 to 20 degrees above the ambient temperature.
Be sure you’re attempting to grow the right crops for your season. Cool-weather crops tend to be leafy greens, lettuces, other brassicas (cabbage, kale, broccoli etc) and some herbs.
If you’re growing inside because you have a foot of snow on the ground, or you simply don’t have an area outside to put your Tower or seedlings, you may want to consider a set of tabletop Grow Lights. Adjust the height so it’s just 4 inches or so from your rockwool and away you go!
My Tower Garden seedlings were fine until I put them in my Tower Garden. Now they have wilted and look like they’re dying. Why is this happening?
If you had strong, healthy, perfect seedlings before transplanting to the Tower Garden and they are now wilting, the problem could be your water source. My guess is your water is chlorinated. Many cities are now adding Chloramine to our water.  You can learn more about that by reading “What Water Source should I use in my Tower Garden?”.
Do I need to water them with Tower Tonic?
No. Â Initially, you can use half-strength water to neutralize the pH of the rockwool. Â After that just use plain water. Â The seedling gets all the nutrients it needs from the seed itself for the first couple of weeks.
I planted too many seeds. Â Should I thin them out?
It depends on what it is.  Most lettuce and herbs should be fine.  However, if you find you have ten tomato plants growing from one rockwool cube I would definitely thin them to no more than two. Our Seeding Cheat Sheet will help you with how many seeds to use next time. You can also use these numbers when deciding whether to thin them out.
