Indoor Seed Starting for the Urban Gardener

Good morning permies!

As an urban/surburban gardener, I am very limited for space.

I don't yet have a greenhouse, so I have had to improvise.


I first started by making my own seed starting mix.

I made this from compost coco coir, and sand/clay subsoil leftover from the well drilled. About equal parts of each.

Then I used a hydro water tank I got on sale from growersupply for about 50 bucks.

I then got a full sheet of lexan and used this to keep the chamber humid.

I am using a 1000W LED, 2 full spectrum CFL's leftover from 5 or more years ago, and a 175W HPS that I added later.

I have learned that you have to water potted plants from the bottom for the best results, so I made a tub and hooked an aerator to the water to keep it aerobic.

I was watering with Aquarium water and a little added liquid kelp.

Check out the timeline of pictures I have attached, they can tell the story as well as I can!


What other tips and tricks do y'all have to share for starting seeds indoors?

Thanks!



Some new things I have learned this year.

Peat pots work great for peppers.

Peat pots are not so great for tomatoes.

Plastic pots are great for Tomatoes.

Plastic pots are not so great for peppers.

If I had only one to choose, it would have to be plastic pots. To make it economical, you need to reuse them as many times as possible.

Humidity is crucial early on with the nightshades and basil.

Kale does not need as much humidity.

That is an impressive setup!

I have less space for my seeds inhouse. German houses are usually much smaller, but the difference I see from the picture is that we have proper inside (and outside) window sills.
So all my pepper and tomato production starts inside on the two south-facing window sills I have.

I keep seeding space reduced and when the little plants are big enough for transplant there is sometimes a short time when things get really crowded inhouse. But ideally at that stage they can move to the (unheated) greenhouse already. I keep fleece/bubble wrap/newspapers at hand for really cold nights, but usually this works fine.
I have to add that I am a stay-at-home mum most of the time which allows me to move the seedlings around as the sun moves, or put them outside for hardening off on nice days.
Our last frost date is mid May, and even if this is not the case in all years I have to be prepared.

One more thing to consider: Most seeds need warmth to germinate, but not light. So I keep the pots/trays warm and only move them to a lighter location when they emerge. The bigger ones will move out by the time, so ideally I have a kind of rotation going on.

Anita Martini wrote:That is an impressive setup!

I have less space for my seeds inhouse. German houses are usually much smaller, but the difference I see from the picture is that we have proper inside (and outside) window sills.
So all my pepper and tomato production starts inside on the two south-facing window sills I have.

I keep seeding space reduced and when the little plants are big enough for transplant there is sometimes a short time when things get really crowded inhouse. But ideally at that stage they can move to the (unheated) greenhouse already. I keep fleece/bubble wrap/newspapers at hand for really cold nights, but usually this works fine.
I have to add that I am a stay-at-home mum most of the time which allows me to move the seedlings around as the sun moves, or put them outside for hardening off on nice days.
Our last frost date is mid May, and even if this is not the case in all years I have to be prepared.

One more thing to consider: Most seeds need warmth to germinate, but not light. So I keep the pots/trays warm and only move them to a lighter location when they emerge. The bigger ones will move out by the time, so ideally I have a kind of rotation going on.

Thank you for your response. It is so nice to hear how others do things, especially in other parts of the world.

I am extremely jealous of your "proper window sills," and proper South Facing windows, neither of which I really have.  

What is the coldest outside temperature your plants will survive in this unheated greenhouse?

I may have to make a slight investment for a cheap one for next year so I can keep the office in my house functional!

Hamilton Betchman wrote:

What is the coldest outside temperature your plants will survive in this unheated greenhouse?

I may have to make a slight investment for a cheap one for next year so I can keep the office in my house functional!

I usually keep my tomato and pepper plants in the greenhouse when the temperature does not go down further than 0 centigrade (32 F), but will use an additional cover and maybe some candles (called grave candles) and I also have a tube of black plastic which can be filled with water and will heat up during the day so that the temps does not drop to freezing.

But even with all that help, the plants are not too happy if it is that cold. The temperature range 5-20 centigrade (40-70 F) is preferrable, but not always possible. The plants grow slower in those cold days but speed up when the weather gets better.
Very seldom did I have problems with frost killing my plants in the greenhouse.

Our greenhouse thermometer broke or got lost so I can't check at the moment. Usually temperatures in the greenhouse are 3-5 C warmer than outside, when the sun is shining the difference is bigger.

Even a small greenhouse (like a covered shelf on the porch/terrace) makes a difference, as does a hoop tunnel.
Good luck!