How to Grow Salad Greens in a Container
Salad greens, like lettuce and spinach, grow quickly, and when you cut them, new ones form. Instead of sowing several seeds at the same time, plant a row every two weeks to provide a steady supply. Salad greens grow in full sun and most soil types are suitable. The seeds germinate in 1 week and the leaves are ready to harvest from 3 weeks. This project takes four weeks to complete.
- potting soil
- salad greens seeds, like lettuce and spinach
- kid-safe scissors
- plastic milk jug
Week 1: Prepare your planter
Put a thin layer of gravel in the base. Fill it with potting soil and water it well, then wait for the water to drain through, leaving the soil moist.
Plant the seeds
Make a 1/2-inch-deep trench along the back of the planter and sow seeds thinly along it. Brush soil over them lightly with your fingertips. Water using a watering can.
Keep your greens organized
Label each row with a marker made from one side of a plastic milk bottle and write the date on it when the row was sown.
Cover your planter with fine mesh netting to protect the seedlings from pests such as birds, slugs and snails. This netting will also prevent butterflies from laying their eggs, which hatch into hungry caterpillars. To keep your planter away from slugs and snails, place it on a tabletop, a windowsill or even a couple of bricks, rather than putting it on the ground.
Week 2: Maintain the seedlings
Two weeks later, thin the first seedlings so your plants have room to grow. Make another trench in the middle of the planter and sow more seeds thinly, then cover them lightly with soil.
Week 3: Harvest your salad greens
The first leaves will be ready to eat after about three weeks. Use scissors to cut about one inch (2.5 cm) above the base of the stem, leaving a stump that will grow into more leaves.
Week 4: Sow more seeds
After a further week, make another trench along the front of the planter and sow a third row. Thin the seedlings of the second row and continue to cut the leaves from the first row of plants. Keep the relay going, cutting small leaves when they're three or four weeks old, or, if you want larger leaves, cutting from four weeks onward.
Harvest lettuce all year round
For a continuous supply through the summer, start a second planter. After a few croppings, replace the soil from the first planter so the relay can continue. It is important to keep your crops well watered, especially when the weather is dry, to prevent the plants from bolting (flowering and producing seeds).