It’s great to start flowers and vegetables from seed. You get more varieties and often an earlier vegetable harvest than waiting for seedlings to show up at the store. Your homegrown seedlings, though, are sown and begin their lives growing in the ambient climate of your late winter home. They receive light from a window or plant-light and it’s likely that the only air movement they experience is from a ceiling fan or heating vent. They receive water regularly and they generally live a healthy, pampered life. But eventually the time comes when it’s time to transplant your seedlings into the world outdoors.
Moving plants and seedlings directly outdoors in the spring can be a shock to their systems, even to the point of causing damage or death. “Hardening off” is the safe way to introduce plants to the outdoors. This is a process that gradually introduces seedlings to outdoor conditions, such as wind, stronger sunlight and cooler night temperatures.
Hardening off should begin about two weeks before you plan to plant. (See our article, Garden Planting Schedule, to determine the date). Once you’ve determined when you’ll be planting, here’s the schedule for hardening off seedlings:
Day 1 – For two hours, set outside in a location that is out of direct sun and away from strong wind – maybe on a porch or balcony.
Day 2 – For two hours, set outside in a location that is out of direct sun.
Day 3 – For four hours, set outside in a location that is out of direct sun.
Day 4 – For four hours, set outside in a location that is out of direct sun.
Day 5 – For four hours, set outside in a location that is out of direct sun. For two hours, move to a sunny location.
Day 6 – For four hours, set outside in a location that is out of direct sun. For four hours, move to a sunny location.
Day 7 – On a cloudy day, take the seedlings to the garden bed for a full day.
Day 8 – Plant the now sturdy seedlings in the garden on a cloudy day.
Water well and protect the seedlings for a few days with a shade cloth if needed. Then water daily until the seedlings settle and are growing well. If you forget one day, all is not lost, simply pick the schedule back up the next day. At the end of the week the seedlings are adjusted to living outdoors and are ready to transplant.
Use this same process in spring for frost tender patio plants that you may have overwintered indoors, such as a citrus tree or hibiscus. You should also follow these steps for any houseplants you may want to bring outdoors for the summer.
Reverse the process in fall for tender patio plants by watering them well and bringing onto the porch or into a shady location for a few days before bringing indoors. Check the plants for insects. Repot and refresh the potting soil if needed, before placing them in their permanent winter location inside.
Seeds aren’t the only way to start new plants. Check out our article, The Garbage Garden, to learn about ways to use vegetable scraps from your kitchen to grow new plants for your garden.