Skip to main content

In the Beginning

Leggy Stem Problems

Part 2 of 8

“How do I grow my tomatoes from seed without the stems getting leggy?” This is a question I hear a lot this time of year, either that or I see people posting photos who are in a state of panic because their seedlings have already grown leggy. There are several things that can be done to prevent or help correct this problem.

First of all, there are several ways to start your own tomatoes from seed, and none of them are the “wrong” way. I am going to share one way, the way that works best for me. I start my seeds in little plastic containers with lids- this could be a margarine or some type of disposable container, anything with a lid will do, I prefer clear so that I can see if I have new sprouts. I add about an inch of soil to the container, then I add more seeds than what I truly need, cover with a thin layer of soil, spray until damp with water, put the cover on, and place it on my heat mat. Some might ask why I am so wasteful with extra seeds. If you think about it, you are probably going to be saving seeds from your garden in the coming season anyway, which will give you fresh seeds for the following year. But the most important reason why I sow several extra seeds is to get the strongest seedlings. Sow many- select the strongest seedlings to move forward.

In about 5 days from the time you have sown your seeds, you will begin to see your seedlings emerge. At this time, you can remove the lid, add water until the soil softens, and carefully transplant them into their own individual cells. I take this extra germination step before placing them into cells because it gives me a chance to plant them deep once in the cells. Plant the small seedlings all the way up to the cotyledons, everything that is now beneath the soil level will grow more roots.

Lighting is another important step in keeping your seedlings at a steady growth rate. Unless you plan on growing year-round indoors, you don’t need the fancy full-spectrum lighting. An inexpensive shop light or even a daylight light bulb with a reflective aluminum shade will work. The trick is a bright light (1,000 lumens/ 5,000 kelvin or higher) and keeping the light source around two inches from the top of the seedlings. The light needs to be strong enough so that they do not “reach” for light and become lanky.

So what happens if you have already learned the hard way and are now struggling with leggy plants? You can pot up to a bigger container and gently ease the excess stem length into the soil. Again, this will simply give you a stronger root system. Many will use a Solo-type drinking cup with holes drilled in the bottom for drainage. This is the perfect size for individual tomato plants.

One last little trick I have for keeping stems strong and healthy during the seedling growth stage is the use of a fan. In nature, the wind strengthens the stems of seedlings as they grow causing them to develop stronger roots and support cells through the main stem. A fan will replicate this process indoors, once a week for a few minutes is all that is needed.


Reader Comments

No comments yet
About The Author
  • Chief Operating Officer, Director of Research and Innovation
Also in this series

Try it

Sign up for a free membership and set up your dashboard. Get a taste of our rich content and view up to 12 tomatoes, recipes, bugs, articles, and videos on us!