u/Flabberingfrog

I have studied biology and plant physiology as part of my education, and I like to play around with growing plants, both indoors and in the garden.

I have now managed to grow cucumber, sweet melon, zucchini, and more for very little money, and I want to share how I did it, how it is going, and what my next step is:

First, I started the sweet melon in early March, as it is a very slow grower at the beginning. Then I started the zucchini in mid-March, and finally the cucumber in late March. I have other plants as well, but I want to focus on these as they are "special".

What these plants have in common is a "tap root" system. This means that they will, early on, create a long, single root that goes straight down and very deep to "anchor" them. It is important that these roots do not "hit the bottom" too early, and they will begin to curl and essentially "tell the plant" that it is not to grow into a big plant.

The seeds need humidity, and a warm environment to sprout/germinate (21-29°C). I used empty milk cartons, punched holes in the bottom and along the sides to let excess water out and prevent rot. These plants hates water clogged roots, and the roots will begin to rot away really fast.

I placed the milk cartons with soil and plastic wrappers around the top, which had small holes, on top of the CV-kettle inside the closet where it is. Since it is cold outside, and one showers, etc., it is nice, warm, and humid in there.

Once you see some "greed" coming up, it immediately needs both air and light. If the wrapper is on too long, you will have fungus growing there. I also "cheated" a little bit as I found a cheap lamp for €20 online that emits red, blue, or both, so they could stay in there with some light.

It is not that much light this early in the year, so it is good to give them extra light when it gets dark. Plants need darkness, as this is when they use the energy from the day to build their root systems.

The initial "infant" stage can last a long time as the plant is now focusing on building roots (you will only have the cotyledons, or the two initial leaves). The tap root is created. A rule of thumb is that the tap root is probably 3-4 times as long as the stem of the plant. They also need more than 20°C to grow. Having them next to a window can be risky if they are old, as a cold draft from the window can make the area colder than the room temperature.

Once they start to grow their first "true leaf", I then transplant them into the next pot. I bought two very cheap plant pots, drilled four holes in them in the bottom as instructed on the pot (to let excess water out), drilled and tore off the bottom on one of them, and put tape around the edge for protection, as the plastic bits that remained can be sharp and cut you or someone else. I also drilled four holes near the bottom and near the middle to let some air in later on.

The pots were like €1,50 euro each, and the saucer at the bottom was €0,50. I then used hypoxy glue to combine them into a tall pot. It is a very strong glue; you need very little, and you are completely stuck together after 24 hours. The glue can be used for other things as well. This was €2,50.

I bought a pack or two of dried coconut soil, which you mix with water. It was €2,50 (you get 25L of soil from it), and I also bought 40L of regular soil (€9 online, but you can use it for more, or buy even less at a much lower price). I mixed this 50% to use in the milk carton and the pots. I made sure to properly compress the soil, then gently watered it, since it might compress further before I used it.

I then put up the milk cartons and put them into the pots (this is a messy and "scary" operation, as you can easily kill the plants if everything just dissolves in your hands. I actually recommend transplanting them as soon as you see something green "sticking up", but the tap root will already be far down. You need a warm place for it to continue growing, though.

The sweet melon and cucumber plants are "climbers", and their tendrils need something to grab onto as they grow. I just used some sticks. Once the nighttime temperature is consistently above 12°C, you can start moving them outdoors. Please do it gently, as they need to adjust to the outside, which is my next step. Start by putting them outside in the shade for 1-2 hours, but make sure there is only a light breeze, as they need to "move" and strengthen themselves. Too much wind will kill them as they are too fragile after being "spoiled" growing indoors. Then you do the same the following day, but set it in the sun for 1/2 hour. Then you increase outdoor time while steadily increasing time in direct sunlight. After 5-7 days, they are ready.

Plant them outside. The "climbers" need a wall or something for the tendrils to "grab on to". They also need a spot with a lot of sun. The sweet melon needs a spot that gets extra warm (like a brick wall), and very little wind. The cucumbers can be picked as they grow, but the sweet melons should be capped at 4-6. They need support by using a net (you can use the one they sell with the vegetables at your local store).

NB!:
When they grow indoors, always remove the flower buds as they form; otherwise, the plant will expend energy on them when you want it to focus on growing. Also keep totating the pots when they are growing by the window, as they will grow towards the light.
And there you have it.

The total price was about €17, but it can be lower if you buy less regular potting soil. ("cheat lamp was €20)

It was a little long, but I made it detailed.

The pictures show the "incubation", the pots, and how the plants are today.

Edit: Remember that once you have the soil, glue, and such, you can just buy more pots, which cost nothing. The idea is not to save money by not buying a cucumber, but rather how to cultivate them without investing a lot of money into it.

Edit 2: I was so obsessed with getting everything written right that I forgot to check the headline for mistakes -_-