I was talking to Jesse about gardening and growing food and was inspired to try growing something in my apartment. I had a few ideas, but I settled on trying to grow some baby spinach. I have recently been making a lot of smoothies with baby spinach as a green ingredient, so I thought it would be a good one to attempt. Also, the internet told me it’s not too tough to grow.

Getting set up

To get myself started, I went over to the local garden store and picked up this packet of seeds:

Spinach seed packet front Spinach seed packet back

The packet came with some fairly detailed growing instructions which I did my best to follow. I picked up some shallow containers and this seed starter mix as a medium. I am not sure what makes one medium meanignfully different from another or why this one is (or claims to be) “excellent” for “seed germination and growth of young seedlings”. I’d like to learn more about this.

I am not sure the best setup for watering and drainage, but I drilled some holes in the bottom of one of my containers and then nested it in another:

Drilled holes

In the future, I’d like to figure out a nice system to do my watering and drainage. I will have to experiment a bit to see what works.

A few accumulated bits of gardening lingo in my own words:

  • Medium: the material that the plants grow in – i.e. the soil (or whatever else).
  • Sowing: Sowing seeds means planting them. I really like this word for some reason. I like that there is a special word for this.

December 13

I sowed my first set of seeds. Here is a picture:

Sewn seeds Covered seeds

A few notes:

  • I tried for a bit over 2” of the seed mix, and put paper towels down on the bottom in hopes of keeping the soil from leaking out the holes.
  • The packet suggested sowing the seeds about a 1/2” down which I tried to do; I planted them an inch or so apart. I’m not sure if I got the seeds deep enough, but we will see.

After covering the seeds, I watered them. I started by trying to bottom-water them, pouring about half my watering can into the container below and then letting it soak up through the holes for about 20-30 minutes. However, I am not sure how well this worked; it didn’t seem like the top of the soil got damp. To be sure things got thoroughly watered, I also thoroughly sprayed the top of the soil with a spray bottle. I’m not sure the best way to make sure that things are thoroughly and appropriately watered.

December 14

Checking in this morning. The soil still feels damp so I will not water. I stuck my finger in a few inches and it seems to be damp throughout which I think is the goal.

Maybe someday I will invest in a better way to tell if the soil is moist throughout. For now I’ll just stick with my fingers I guess.

Some more words:

Bolting: “Bolting occurs when a plant begins to flower and set seed too early” (source). The idea is that the plant is choosing to focus on seeding and reproduction rather than growing leaves. In the case of spinach this apparently means that the leaves become more bitter. According to the internet, plants “bolt as a response to stressful situations” like when it’s too hot or there is not enough water. Once bolting starts it is “irreversible”. Here is another link about bolting.

Succession planting: As described by this link:

Succession planting, or successive sowing as it’s also called by many gardeners, basically means to plant continuous rounds of seeds in the kitchen garden. I like to think of it as “never stop sowing”.

December 15

Still slightly damp on top, but I think it’s time for another watering. I don’t want to risk things drying out.

I am trying bottom-watering again, and did a full watering can in the bottom container (+ a bit of a second). Going to give it about 20 minutes. I may also spray the top again to be safe. The bottom-watering seemed to work better at getting things thoroughly moist throughout; I could see it on the top this time, so I think it’s just about the amount of water needed. This amount seemed to work well.

I am thinking about getting a moisture meter so I can test more confidently. The internet also suggests that testing weight is another approach (wet soil is heavier), which is an interesting idea.

Some people online seem to recommend using a humidity dome for seedlings. This creates a “mini greenhouse” for seedlings, trapping moisture and keeping the soil from drying out. They are good for just the very beginning (germination), then need to be removed so that light can get to the leaves.

Words:

Germination: the development of a plant from a seed or spore after a period of dormancy. Seems to be mostly used to describe the step of going from full seed to a seedling / first sprout.

Seedling: a young plant, especially one raised from seed and not from a cutting.

Imbition: a special type of diffusion that takes place when liquid is absorbed by solids-colloids causing an increase in volume. This is the name of the process by which seeds take up water; they swell in size until they break the seed coat. The seed “imbibes” water.

Radicle: the first part of a seedling to emerge from the seed, during the process of germination. Appearance of the radicle is sometimes considered the end of germination?

As an aside, it’s funny how many plant terms (sowing, seedling, germinate etc.) are deeply set metaphors in general speech; easy to forget they have plant meanings.

December 16

Quick check in this morning. Soil surface feels damp so no watering today. Still would like a better way to check moisture levels deeper in soil without disturbing seeds.

Some more terms and things:

Capillary action: the process of a liquid flowing in a narrow space without the assistance of external forces like gravity. Here is a link.

Why does capillary action happen? It seems to depend on the forces of “cohesion” (Water sticks to itself; it’s a polar molecule), and “adhesion” (whater sticks to other things). Here is what the source says:

Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact. Capillary action occurs when the adhesion to the walls is stronger than the cohesive forces between the liquid molecules. The height to which capillary action will take water in a uniform circular tube (picture to right) is limited by surface tension and, of course, gravity.

The image shows basically that there is more capillary action “climbing” when the tube is narrower, because the ratio of adhesion to cohesion is greater?

Here is more about adhesion and cohesion.

Cohesion is related to surface tension of water. I don’t fully understand though, and how these things give rise to capillary action.

Here is a guy talking about capillary action in different types of soils. It’s not the most clear, but he generally suggests that the amount of capillary action depends on the size of the “pores” and the volume of “pore space” in the soil. His suggestion is generally that small pores is associated with more capillary migration, but that’s not the only factor (e.g. clay has small pores, but they swell shut, limiting migration of water). He shows that there is more migration in a “silt textured” soil than in a sand or clay, because it “has a nice combination of large and small pores”.

There’s a lot more to learn about soil and soil pores. Related to the porosity of a material – or what percentage of the volume of a thing is void space.

In the context of soil, silt is a specific size of granular material, between a sand (larger granules) and a clay (smaller granules).

The internet notes also that there is a relation between the amount of capillary action and the rate of drainage (and the amount of aeration for roots?) in different types of soils. Roots need oxygen for respiration.

Loam is another good word. Mostly a mix of sand, silt and a small amount of clay. According to wiki:

Loam is considered ideal for gardening and agricultural uses because it retains nutrients well and retains water while still allowing excess water to drain away

December 17

The soil still feels damp to the touch, so not going to water. I guess that from what I know from yesterday, seed starting mix is meant to be good at water retention with less drainage.

Checking for dampness on the soil reminds me of debating whether brownies (or whatever) are done baking in the oven. Similar kind of ambiguity, and incidentally some of the same tricks – just stick a toothpick in there and see if it comes out clean. In one case you want clean (clean=brownies done), in other you don’t (clean=needs water). In my case, they kind of look similar too – damp brown mixture in a rectangular brownie-sized container.

In any case, I always have trouble with the brownie decision; the only way to get good at it is through lots of experience. In the plant case, the feedback arc seems quite long. How do you know if you made the right decision about how damp the soil was?

December 18

Watered this morning. A full watering can from the bottom; maybe too much. The water soaks up through very quickly and is visible on the top with that amount. I only let it sit for 10 minutes or so, then drained.