I’m at it again… transplanting tomatoes. They began their lives in seed starting newspaper rolls, outgrew their 4-inch pots, and are now moving into gallon-size containers. I could have graduated them to the garden by now, but I prefer to transplant into larger pots one more time — it’s really worth the extra effort.
If you started your tomatoes early from seed and have some time before they go in the ground, it’s a good idea to repot them two or three times as they develop. Doing so builds up a bigger and stronger root system, as their vigorous taproots can grow up to 1 inch per day.
So why wouldn’t you simply start your tomatoes in large pots, and let the roots grow unbound? Because every time you transplant your tomato, you sink the lower portion of its stem deeper into the soil — thus allowing more roots to form along the newly buried stem.
While tomatoes do suffer a little transplant shock, they recover quickly and transplanting ultimately stimulates root growth.
Generally, the right time to transplant is when your tomato reaches three times the height of its pot. I use gallon pots as the final containers before planting my tomatoes in the garden.
Start with clean pots. Mix together a well-draining potting medium of soil and compost. Choose your healthiest plants to transplant.
Pinch off the lowest two or three branches of leaves, especially if they are wilting or yellowing. You will end up with a tall skinny stem with only a few branches on top.
Gently loosen the root ball and place the transplant in an empty pot.
While it’s true that the roots are sensitive, they are not the most vital part of a tomato plant — the stem is. New branches, leaves and roots continue to grow throughout its lifespan, but a tomato plant usually only has one main stem. The plant cannot sustain damage to its stem, which should be treated with care during transplant. Handle the plant by its leaves or root ball only — never by its stem.
Fill the pot with well-amended potting mix, all the way up to its lowest branches.
I like to give the pot a good final shake to settle everything in.
Your newly transplanted tomato should have several inches of its stem sunk below the surface. Water deeply down to the lowest roots and only water again when the first inch or two of the soil feels dry. With a deep-rooted plant, the key is to water less frequently, but more thoroughly.
Over the next few weeks, your tomatoes will develop new roots along the buried stems. Feed your hungry plants with an organic fertilizer as needed.
When your plants have grown a considerable size, you can transplant them into the garden, again pinching off the lowest branches and sinking the stems deeper into the soil.
By repotting a second time, I’ve found that I’ve given my tomatoes a head start on the season and they flower much sooner… bringing me that much closer to those scrumptious summer globes!