How to Plant Garden Centre Seedlings in a FlowGrow Tower
Garden centre seedlings are one of the quickest ways to get a FlowGrow tower planted and growing.
You do not need to start everything from seed. Lettuce, herbs, leafy greens and strawberries can often move from a seedling punnet into your tower, which means you can skip the germination stage and get growing sooner.
For many new growers, this is the easiest place to start. Choose healthy seedlings, rinse the roots thoroughly, settle them into a FlowGrow planting sponge or rockwool cube, and give them a little time to adjust to growing without soil.
Why start with seedlings?
Garden centre seedlings give you a head start. Instead of waiting for seeds to germinate and establish, you begin with a young plant that is already actively growing.
Seedlings are often several weeks ahead of seed-grown plants, so your first harvest can arrive sooner.
Starting with visible plants can make your first tower feel easier and more rewarding.
You can still start seeds later if you want to. Seedlings are simply a practical shortcut, especially for your first planting.
Which seedlings work best?
The easiest seedlings to start with are plants naturally suited to compact growing and regular harvesting.
Great beginner choices
- loose leaf lettuce
- mesclun salad mix
- buttercrunch lettuce
- cos or romaine lettuce
- basil
- parsley
- chives
- thyme
- mint
Also worth trying
- strawberries
- coriander
- rocket
- baby spinach
- compact herbs
- edible flowers
Larger leafy crops can become bulky in a tower and may shade neighbouring plants. For a first planting, smaller leafy greens, herbs, strawberries and compact plants are usually the better fit.
Check seedlings before planting
Before planting, spend a minute looking over each seedling. Most pest issues arrive in hydroponic systems through new plants rather than appearing inside the tower.
- Check the underside of leaves for pests.
- Look for fresh, healthy new growth.
- Avoid seedlings with yellowing, mouldy or badly damaged leaves.
- Avoid plants that look heavily pest affected.
- Choose seedlings that are not too woody, stretched or stressed.
For more on this, read Do FlowGrow Towers Get Bugs?.
Why rinsing roots matters
This is the biggest difference between traditional gardening and hydroponic growing.
A FlowGrow tower continuously recirculates water through the reservoir, pump and tower. Soil and potting mix do not belong in that system.
Soil in the system can cause problems
- mud can settle in the reservoir
- potting mix can clog the pump intake
- debris can restrict water flow
- the tower can become messier than it needs to be
Take the time to rinse roots thoroughly before planting. You do not need laboratory-clean roots, but you do want virtually all soil and potting mix removed before the seedling enters the system. A few tiny particles left behind are not a problem. Large clumps of soil are.
Option 1: Planting with a FlowGrow sponge
This is the quickest and simplest method for most garden centre seedlings.
Good to know: FlowGrow planting sponges sit directly into the tower and do not require a net cup.
Remove the seedling from its punnet and rinse away as much soil and potting mix as possible.
Use scissors or a knife to cut a slit from the outside edge of the sponge into the centre.
Open the sponge gently, lay the roots inside, then close the sponge around the plant. Keep the crown above the sponge.
Insert the sponge directly into the tower planting site and let the roots hang downward.
Option 2: Planting with rockwool and a net cup
Some growers prefer to use rockwool for transplanting, especially if they already germinate seeds in rockwool. Rockwool works well, but it needs a net cup for support.
Good to know: unlike FlowGrow sponges, rockwool cubes need a net cup before going into the tower.
Remove soil and potting mix before placing the seedling into the rockwool.
Using a clean knife, cut a slit from the outside edge of the rockwool cube into the centre.
Open the cube gently and lay the roots inside. Avoid forcing roots through the rockwool.
Place the rockwool cube into the net cup and make sure roots feed through the bottom openings.
What should you expect afterwards?
A short settling period is normal after transplanting. The plant has moved from soil into water-based growing, so it may take a few days to adjust.
- a little drooping during the first couple of days can happen
- older leaves may look tired
- growth may pause while roots adapt
- new growth is the best sign that the plant has settled
Starting nutrients after planting
Many healthy garden centre seedlings can begin on the normal FlowGrow tower mix, especially leafy greens and herbs that already have a reasonable root system.
Once seedlings have their first true leaves and are starting to grow actively, they can begin using nutrients. Start with the gentle mix, then move to the recommended mix as growth strengthens.
For very young plants or seedlings that need a softer start after rinsing and planting, use the gentle mix first. This gives plants time to adjust before moving to the everyday tower mix.
| Use | Grow A | Grow B | When to use |
|---|---|---|---|
| For very young plants | 40 ml | 40 ml | A gentle starting mix while young plants settle in and begin growing. |
| Everyday tower growing | 75 ml | 75 ml | Most healthy garden centre seedlings once settled and growing well. |
Good to know: always add Part A and Part B separately to the water, not directly together. Top up with fresh water first, then adjust nutrients as needed.
For more detail, read the FlowGrow Feeding Guide.
Common mistakes to avoid
- planting the whole soil plug straight into the tower
- leaving muddy roots or loose potting mix around the plant
- burying the crown inside the sponge or rockwool
- forcing roots through rockwool instead of opening the cube gently
- using rockwool without a net cup
- pushing very young plants too hard with nutrients straight away
- expecting instant growth during the adjustment period
Frequently asked questions
Can I use seedlings from Mitre 10 or a garden centre?
Yes. Garden centre seedlings can be a great way to plant your FlowGrow tower quickly. Choose healthy seedlings, check for pests, and rinse the roots thoroughly before planting.
Do I need to remove all the soil?
Remove virtually all soil and potting mix without shredding the roots. A few tiny particles are fine, but mud and soil clumps should not go into the tower because they can settle in the reservoir and affect the pump.
Do FlowGrow sponges need a net cup?
No. FlowGrow planting sponges sit directly into the tower planting sites.
Can I use rockwool instead?
Yes. Rockwool works well, but it should be placed inside a net cup before going into the tower.
Why is my seedling drooping?
This is common after planting into a tower. Give the plant good light, steady water, suitable nutrients and a few days to settle. New growth is the best sign that it has adjusted.
What is the easiest seedling to start with?
Loose leaf lettuce, buttercrunch lettuce, mesclun salad mix and basil are usually easy first choices. Strawberries can also work well in bright conditions.
Helpful next steps
These guides will help you keep your seedlings growing well after planting.
Start seeds for your tower
Learn how to germinate seeds in rockwool before moving young plants into your FlowGrow tower.
Do FlowGrow towers get bugs?
Learn why soil-free growing reduces pest pressure and what to check before adding new plants.
Care and maintenance
The simple routines that keep your tower clean, topped up and growing well.
Ready to plant your tower?
Start with healthy seedlings, clean roots and good light. The tower does the rest.
