Repotting Tomato Seedlings

 

Tomato seedlings... can I even call them seedlings anymore? They seem like they deserve to be called plants now, but until they are physically in the soil of my garden I will have a hard time not forcing a diminutive on these cute little ones. Regardless, these babies need to be transplanted. Read on to learn how.

 

You will probably read about several suggestions about when to transplant or repot your tomatoes. My intuition is to begin the process once they have several 'true leaves'.

 

What the heck am I talking about? Is there such a thing as fake leaves? Botanically speaking the first green projections you see from a germinated seed are actually embryonic leaves called cotyledons. True leaves are all the leaves that develop on the plant from then on out after the cotyledons.

 

The development of true leaves should be your sign to begin fertilizing. Past the cotyledon, the seed will have used up all its stored energy and will begin to need to get its nutrition from other sources... like the soil. However, in the simulated environment of seed starting indoors... the seed starting soil you use is typically 'soil-less', meaning it will do fine for giving your plants a medium to spread their roots in, but not much as far as nutrition.

 

I used to buy larger pots to transplant my tomato seedlings into, but then last year I had a eureka moment in which I realized that a plastic drinking cup was essentially all that was needed. This is such a more economical alternative to the more official plant pots you would find at a garden center.

 

Here I used red solo cups with holes drilled into the bottom for drainage (that's pretty important). The deciding factor in choosing these cups was their depth as you will see why in a moment.

 

For starters you have to get the plant out of its old container. Water the plants well beforehand, don't transplant with your plants in dry soil- that is bad. The soil should be nicely spongy and moist. Next, I gently squeeze the bottom of the container to loosen it up and allow the soil to release from it better. Do not, for heaven's sake, pull on the stem of the plant to pull it out. I tip the container upside down and it should slide right out with the aid of gravity. You can see above that I supported the soil surface by placing a finger on either side of the plant's stem.

 

As a general rule you want the transplant to be emerged in soil up to or past its cotyledon. Tomatoes LOVE being transplanted... wherever soil touches its stem, roots will grow! This is thanks to a hormone called auxin in the stems of these plants. Light will destroy auxin... so now you can imagine that by submerging the stem deeply in the soil... the auxin will now go to town! Later on when you transplant your seedlings out into the garden you will essentially just be repeating this process again, each time your plant will grow more and more roots.

 

Since you will be repotting your seedlings into a larger container... the plants will now take up more room. This is a drawback to the whole process if you do not have a lot of space like me (this is where a gardener dreams of greenhouses). So when you begin your whole seed starting operation factor in that at some point these plants will take up twice the space that they did before.