When to Transplant Your Spring Vegetable Seedlings

By David Wall
Guest Columnist

This time of year, desires to plant a garden exponentially expand. Onions, cabbage, lettuce and other cool season vegetables are already in the ground, and gardeners are itching to transplant warm season vegetable seedlings (tomatoes, peppers, cucumbers, etc.). Though it’s still early, vendors have already begun providing such seedlings. While the urge to buy/plant is strong, one should consider whether doing such so early is a wise move.

Seedlings are highly vulnerable and should be hardened for the garden, meaning made ready to face the outside world. Hardening involves sun and wind. Seedlings should be gradually introduced to harsh sunlight, i.e., placing them outside in the sun for a short time, gradually increasing the amount of time daily, so that by the time they’re transplanted, they can stand 8 hours of direct sun a day.

Seedlings should also be hardened for windy days. This can be accomplished by daily moving (gently) something like a broom handle over 4”+ seedlings to get them used to swaying in the wind (not for peppers).  Alternatively, especially for peppers, seedlings can be mist-sprayed so they gently sway as they are watered.

There’s a long-standing rule that says, “Don’t violate the double 55.”  When temperatures fall below 55°, a pepper seedling in your garden can be permanently stunted. The same rule applies to soil temperature. Cool soil temps slow down the growth of many seedlings. Use a soil temperature gauge to check soil temperatures at least 6” deep in the soil.

The earlier seedlings are bought, the longer one must care for them. Easter this year is 01 April, and the NETSEO area historically has a freeze after Easter. The date for buying seedlings is, of course, your choice, but the earlier you buy, the longer you must protect, water, and harden them before transplanting.