Tower Garden Growing Guide

While growing produce in a Tower Garden is a fairly simple process, there are a few things you need to know in order to have the best growing experience possible. From starting your seedlings in rockwool cubes to transferring them into your Tower Garden and beyond, you'll find the answers here!

What is Rock Wool

Rockwool is a lightweight hydroponic growing medium made from molten basaltic rock which has been spun into fine fibers, and then formed into growing cubes, blocks, and slabs.

Rockwool is a perfect growing material for hydroponic gardens because of its ability to hold water while also retaining more oxygen than typical soil mediums, thus encouraging more rapid, healthy growth.

Seed Starting Supplies

The Seedling Starter Kit included with your Tower Garden contains a seedling tray, rockwool cubes, vermiculite, and a variety of seeds. In addition, you will need some or all of the following items:

Grow Light (if the outdoor temperature is too cold to place seedlings outside); Small Fan (to prepare plants for the outdoors); Outlet Timer (optional); Heating Mat (if needed); Mineral Solution A and B (comes with Tower Garden; also sold separately)

Best Grow Light for Seedlings

When it comes to grow lights, there are basically two choices: Fluorescent and LED. Be sure to look for lights designated as "full" spectrum or "broad" spectrum since they are most effective for growing seedlings.

If you need to purchase grow lights and are looking for a recommendation, I prefer the Germinator by Tower Garden (see image). It includes a tabletop LED grow light as well as a heating pad to create an ideal environment for seedlings to grow.

Starting Seeds in Rockwool

To get started, prepare your rockwool cubes by soaking them in water for 30-60 minutes. Then place the appropriate number of seeds into each rockwool cube. For lettuce and greens, add 6-12 seeds to each cube. For herbs, add up to 6 seeds per cube. And for vegetables with larger seeds, add 1-2 seeds per cube.

Finally, lightly fill each rockwool cube with vermiculite (for smaller seeds, like lettuces, fill only half-way) and spritz a little water on the vermiculite in each cube. Place cubes in seedling tray or a glass baking dish. Be sure to label seedlings for identification purposes since they all look the same at this point.

Keep seeds moist by adding 1/4 inch of water to the seedling tray each morning.

Light Schedule for Seedlings

As soon as you see sprouts starting to peek out from the vermiculite, remove your new seedlings from the heat mat, if using, and give them plenty of light (window light will most likely not be enough at this stage).

If it's warm enough, you can place them outdoors in full sun for 6-8 hours a day (be sure to protect them from the wind). If it's too cold outside, place a grow light within inches of the seedlings indoors for 14-16 hours a day (the outlet timer comes in handy here). In addition to light, continue to keep your rockwool cubes moist, but not oversaturated (same as before they sprouted).

When to Fertilize Seedlings

After a couple weeks, once your seedlings have true leaves (not the initial ones from inside the seed) and the seedlings are 1-2 inches tall, start adding diluted Mineral Blend A and B to the water in the tray every other day. In a glass container, add 4 cups of water and 1/2 tsp each Mineral Blend A and Mineral Blend B and mix well. Use 1/4 cup of this solution in the seedling tray each morning in place of water, or place the mineral solution in a spray bottle and mist the seedlings with it to keep them moist.

Continue this process until your seedlings are ready to move to their permanent home. In the meantime, follow the suggestions that follow.

How to Thin Seedlings

About the same time you start fertilizing your seedlings, it's also a good idea to thin them out to reduce competition for water and nutrients and improve air circulation around the plant. This is especially important for heartier, fruiting crops such as tomatoes, peppers, and squash. Greens and herbs, on the other hand, are usually fine with multiple plants per cube.

To thin them out, use a pair of sharp shears to cut the stem of the weaker seedlings at the base, leaving only the strongest seedling to survive and thrive. Do NOT pull the seedlings out, as this can damage the roots of the remaining plant.

Harden Off Seedlings

If you started your seedlings indoors and plan to transplant them outdoors, you will need to give them time to acclimate to their new environment before transplanting them into the garden. This adjustment process, called "hardening off," will prevent young seedlings from going into shock which could delay plant growth or even cause your seedlings to die.

Start introducing your seedlings to outdoor conditions gradually over the course of a week. For example, place seedlings in a mostly shaded location protected from the elements for one hour on Day 1 and two hours on Day 2; then expose them to morning or afternoon sun for 3 hours on Day 3, etc. Increase the sun intensity and hours of exposure each day until your seedlings are in full sun all day on Day 7.

When to Transplant Seedlings into Tower

Finally, after hardening off, your seedlings are ready to be placed into your Tower Garden; get ready for a growth explosion! Place one rockwool cube into each growing port, making sure to press it down until it touches the bottom of the net pot (a black plastic insert that holds that seedling in place).

Special Note: For the first month or so, you'll need to reduce the recommended dose of nutrients in the Tower Garden reservoir by 50% until your plants are large enough to handle the full amount (refer to the growing guide that came with your garden). In addition, be sure to maintain a PH level of between 5.5 and 6.5 by testing the water 1-2 times per week and adding PH + or PH - as necessary.

HAPPY GROWING!!!