Over the coming weeks and months Dish, our Head Farmer, is going to share his experiences of moving our urban farm to his home and provide tips and guidance on how you can also grow at home to help you learn, clear your mind, and grow your own fresh produce.
In this blog Dish will explain how to sow seeds using various methods. This will include sowing seeds for a conventional herb/vegetable garden and for our indoor, hydroponic system.
In last week’s blog, I mentioned that I planned to grow lots of vegetable and herb seedlings while we are on lockdown. I am going to show you how we normally sow seeds to go into our hydroponic system and how you can sow your own at home with easily obtainable equipment.
Choosing your seeds
So, to get started we need to decide which seeds to plant.
One of the benefits of controlled environment agriculture (CEA) is that we can sow our seeds at any time of the year. This is because our vertical, hydroponic systems supply the light, nutrients and ideal climate for our seedlings to grow. Essentially, we are creating the optimal growing environment for these plants all year round, whereas conventionally we would need to wait for nature to supply this.
When we’re thinking about growing outdoors, we do need to consider which seeds are suitable to plant at this time. It’s April and I know I can sow my Cabbage, Lettuce, Radish, French Bean and Pumpkins seeds right now. It’s also a great time to sow fast growing herbs like Parsley, Dill and Coriander: you can sow them every couple of weeks throughout spring and summer to ensure that you have constant supply available. If you want to know more about when to plant which vegetables the RHS have a printable veg planner, accessible here.
Some of the seeds I chose to plant, including Pumpkin, Coriander and Scarlet Kale.
Sowing for the hydroponic system
Our seeds need a medium to grow in and there are many types that you can use. The medium should hold moisture and also provide adequate drainage.
When growing in hydroponic systems with recirculating water it is best to choose a medium which will not disintegrate and clog up the irrigation system. Our favourite choice are rockwool plugs. Here’s how I use them:
Add rockwool plugs into a bucket and fill it with water.
Unlike soil, rockwool is an inert material so you’ll need to add nutrients to give the plants a boost after germination. I added ‘Propagation Solution’ at a concentration of 10ml/litre and mixed the water thoroughly.
After soaking, place your plugs in a plug-tray.
Using a folded piece of card, carefully sow kale seeds into the hole of each plug.
Cover with a humidity dome and place it in a dark, warm location to germinate. Kale will take around a week to germinate.
Once I see the first signs of green leaves I will uncover them and place the tray into our Flood and Drain system to provide additional nutrients and light.
Sowing for the container garden and vegetable bed
When sowing for a container garden or vegetable bed it is simplest to use soil as your growing medium. You can use any container with drainage holes at the bottom. I recommend using deeper containers for larger seeds such as runner beans or pumpkins seeds to accommodate their vigorous root systems. Here’s the method I used:
Firstly, I found a variety of containers to use, I found small plant pots, shallow trays and a plug tray.
I sowed some of the seeds directly into my outdoor vegetable bed, so I prepared it by removing any leaf litter and making sure the soil surface was flat and ready for seeds.
I used a premade seedling mix, you can do the same or make one yourself. Ideally you want a mixture of materials that hold moisture (like peat or coco coir) and some that encourage drainage (perlite or sand).
Fill all of the pots and trays to about 80% full. In the plug tray, plant pots and vegetable bed I poked holes for the seeds to go into.
In the wider containers, I made long gullies to scatter multiple seeds. This works well for herbs that can grow bunched together like dill, coriander or parsley.
For larger seeds, like french beans or pumpkin, I sowed them one by one into deep pots and directly into the vegetable bed (I’m experimenting with propagation by starting some indoors and some outside).
For smaller seeds, like kale and radish, I used a folded piece of cardboard to carefully scatter seeds into the holes. A rule of thumb is to plant the seed as deep as it is large, for example plant a 1cm bean, 1cm deep into the soil.
A fine layer of soil is necessary to cover the holes and gullies.
Lastly I thoroughly watered all of the containers. If you don’t have a watering can, you can improvise by making some holes in an old water bottle lid, as I’ve demonstrated here!
I placed all of the pots and trays into the conservatory to keep them warm and humid. Placing them in the dark is not necessary since the soil layer will shade the seeds.
The finished product, now they just need to germinate!
Equipment you will need
Here’s a recap on the equipment and materials you will need:
Seeds (there are many places to source seeds, this is my favourite for small quantities)
For Hydroponic Systems:
For Container Garden and Vegetable Bed: