Starting Seeds

March is the time of year when winter starts really giving way to spring. The days get longer and the soil starts to warm, triggering the germination of many seeds. That means its also time to start planting seeds so that they’ll be ready to go outside by the time the last really hard frosts are gone.

I was a little overexcited perhaps this year and actually starting planting things up in February because I wanted them to be really ready to go out. Unfortunately I don’t have a greenhouse or anything so they’ve had to make do in a very sunny window. We’ll see how that turns out when they go out later on. At the moment I’m a little concerned that their growth appears to be stalling, and a few leaves on the seedlings are starting to go a little yellow.

Looking into the problem it is possible that their soil has been too wet or compacted, preventing the roots from establishing properly. Another possibility is that the compost I’m using doesn’t have enough nutrients to keep them going. It’s also possible that the soil has been getting too alkaline, which again reduces the plant’s ability to take up and use nutrients. The other possibility it that they haven’t been getting enough sunlight, a strong possibility given hot cloudy it’s been lately.

In order to try and save my seedlings I poked around in the soil a bit to see if that might give me any clues. It didn’t seem to be compacted, nor was it particularly wet feeling, just damp. So I’ve given them a dose of very weak general fertilizer and coffee in a effort to make more nutrient available and acidify the soil a bit. I’ve also put them under some bright light in the evening to boost the amount of light they’re getting. Fortunately we have LED bulbs so there isn’t much heat so I don’t have to worry about cooking their leaves.

Hopefully all that will have revitalize them, but I’ll also be planting a few more seeds just in case.

To Do and Make: Paper pots and Planting Seeds

A good way to get plants started while not spending tons on tiny pots is to just make your own. Not only are they free (any non-shiny scrap paper will do), once the plants are ready to go outside you can just plant the whole pot. No squidging of pots or seed trays necessary. The newspaper or other paper will pretty quickly get broken down enough for the roots to get out into the rest of the soil. If you’re like me, planting in containers, and worried about if the lack of worms, you can just tear off the paper and plant normally but the roots will break their way out on their own.

There are a few methods of making the pots. You can buy a wooden paper potter, many of which can make different sizes, but you can also just use any cylinder. Keep in mind however that they larger you try to make it, the more likely it is to fall apart, particularly when wet from watering.

The  other way is to make a folded paper pot. These I find hold together a bit better than the ones from the previous method. Here’s a link to some excellent instructions for these.

Once you have your little pots it’s time to plant them up. Most seeds just need warmth and moisture to germinate.  Check the individual packets for specific requirements and germination time, but good general rules are that bigger seeds need to be planted deeper than smaller ones. Also check to see if the seeds need a period of cold before they will germinate. For these either plant them outside in the autumn, where winter will do the job for you, or put them in a moist newspaper in the fridge for around a month before planting.

The Science

Seeds are pretty darn amazing. Specially adapted capsules to keep an embryonic plant safe until conditions are right for them to sprout. Most will have a hard seed coat which prevents the embryo from drying out. As the weather warms the seed coat starts to break down and absorb moisture. This triggers germination and the seed begins to sprout.

First a tap root is send down into the soil. This begins to grow small hair-like feeder roots which start to pull in more moisture from the soil. Using the energy stored as starches or sugars inside the cotyledon the plants them send up a shoot.  This shoot will emerge from the soil with one or two small starter leaves and start photosynthesizing. As long as conditions are right, the plant will not be able to use sunlight to manufacture more food to use as energy for growth.

If you want to see these parts soak a bean for a few days and very carefully pull it apart. You’ll find what looks like a tiny baby plant at the ‘eye’ of the bean. The rest of the bean, the fleshy part is the cotyledon, the baby plant’s food source. On a kidney or lima bean you can clearly see this part as the plant grows because it brings them with the plant out of the soil sometimes with the remnant of the seed coat as well. Eventually as this energy store is used up you can see the starter leaves shrink and eventually fall off.


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