Potting Up, Hardening Off, and Transplanting

 

Potting Up (or "up-potting" or “potting on”) is the process of moving plants or seedlings from their current container to a larger one, providing more room for roots to expand and access nutrients. Potting up is important for thriving, root-bound plants to prevent stunted growth.  Depending on when you started your seedlings and your growing conditions, potting up is often needed for seedlings before they are ready to transplant into the garden.

When to Pot Up: When seedlings are root-bound in their small cells or have at least two sets of true leaves, it’s time to consider potting up

Even if you purchased seedlings, hoping to get an early start, and find you need to maintain them for a while before it’s time to put them in the garden, they may need potting up.  The grower may have started seeds a good bit earlier in order to get them to market,  making the possibility of crowded roots more likely.  To determine if a seedling needs potting up, pick it up from its cell by the leaves, and check the root system. If the roots extend throughout the soil medium, it’s time to pot up.  If you need help getting the plant out of the cell, we find a butter knife works well.  Insert it between the edge of the cell and the potting medium and carefully pry up the entire contents of the cell while gently squeezing the outside of the cell from the bottom.

Transfer seedlings gently into larger pots with fresh potting mix.  Handle plants by their leaves, not their stems, to avoid breaking them. They can grow new leaves if you break one off, but they can’t grow new stems.

Hardening Off should begin 1–2 weeks before your last frost date, currently calculated as mid-March in our north Florida area (9A).

Days 1-3: Place plants in a sheltered, shady, and wind-protected spot (e.g., under a tree or against a north-facing wall) for 1–2 hours.

Days 4-7: Gradually increase direct sun exposure by 1 hour each day.

Days 8-14: Start exposing them to cooler, windy conditions and, if temperatures are above 45 degrees, leave them out overnight.  Be sure to bring them inside if the forecast is for temperatures below 45°.  Pay attention to watering. Plants dry out faster outside, so check soil daily.

 Transplanting your baby plants into the garden. Leon County Sustainable Agriculture and Community Food Systems Extension Agent Molly Jameson gives all the necessary details for transplanting in this short article.  She also gives tips for what to look for when buying transplants.

Transplant late in the afternoon or ideally on a cloudy day. After transplanting, keep a close eye on your garden, particularly for the first week or so, to make sure your plants don’t need special care, such as extra watering or protection from sun or cold.  New tender plants are also fair game for garden pests, so they need your attention. It’s usually a lovely time to be out in the garden anyway, and watching your carefully tended plants grow and thrive is a special pleasure.