Planting

Many vegetables and flowers are usually planted as seeds or as young transplants. Beginning Vegetable Gardening provides a wealth of information, including suggested planting dates for different areas in San Diego County.

Planting Seeds

Radishes, peas, spinach, marigolds and sunflowers are among the many plants that are easy to grow from seeds. You may choose to plant seeds directly in the garden or start them earlier in pots in the classroom.

Planting Directly in the Garden

Keep in mind:

        • Not every seed in a packet will germinate. Some seed packets and catalogs provide the percentage of germination that you can expect. It helps to discuss this ahead of time to save disappointment for the children. Germination decreases as seeds age. Plan to plant more seeds than needed. Then compensate by removing extra seedlings.
        • Some seeds are more difficult and take longer to germinate than others. For example: radish and broccoli seeds sprout quickly, but carrots and parsley are slow to germinate. Seed packets will give you information on germination time.

If you plan to sow the seeds directly in the garden, thoroughly soak the bed one or more days prior to planting day. On planting day guide the students as they:

        • Lightly rake the area to loosen the soil to a depth of one inch.
        • Use stakes and string to identify the location of each row and then make shallow furrows.
        • Sprinkle the seeds thinly in the furrows.
        • Lightly cover the seeds with compost or a small amount of soil. Seed packets will tell you the correct depth for covering.
        • Gently pat the soil to ensure the seeds are in good contact with the soil.
        • Water gently so the seeds are not dislodged.
        • Keep the seeds moist until germination, but the soil should not be soggy.

If there is an area of the garden where you are not planting in rows (e.g., Square Foot Gardens), you can simply broadcast the seeds over the bed, then cover, pat, and water as you would if planting in rows.

Some seeds (e.g., lettuce and carrots) require light to germinate, therefore they should be very lightly covered with soil – just enough to keep them from washing away when watered.

Some seeds, such as peas or beans, will rot if they are kept too moist. Planted in moist soil, they often do not need to be watered again until they sprout. Poke a finger into the soil to feel if it is moist at the depth seeds were planted. If needed, mist them lightly until they sprout.

Starting Seeds Indoors

If you want to get a head start on the growing season, you can have the class plant seeds in containers 4 to 8 weeks before time to plant them in the garden. Keep them in the classroom or greenhouse, and transplant them into the garden when the recommended planting date arrives.

Guidelines for the Best Results

        • Good germination requires a sterile soil medium, constant moisture, air, proper soil temperature and correct light. Soggy wet conditions may cause the seed to rot or seedlings to die (damping-off disease).
        • Do not mix a fertilizer into the seed-starting medium as it will hinder germination.
        • Good seedling growth requires correct moisture, moderate temperature, and correct light intensity (bright), and duration (8-16 hours).
        • Apply the first light feeding (1/2 strength liquid fertilizer) when the plants have their first set of “true” leaves. True leaves are the second pair of leaves to appear. The first pair are called “seedling leaves” or cotyledons.
        • Thin the seedlings when they begin to crowd one another. Carefully cut off extras with a pair of scissors. Many of the thinned plants, but not tomatoes, can be eaten as micro-greens.

Seedlings grown indoors need time to become accustomed to the variation in outdoor temperature and light before being planted in the garden. This is called “hardening off”. When the hardened-off seedlings are transplanted, they will experience less shock.

        • First expose the seedlings to a sunny location in the classroom or greenhouse.
        • Then move them outside each day and expose them to increasingly longer periods of sun over a period of a week or more.
        • Expand the time outside to include overnight to help them adjust to the temperature variation.

Some seeds, such as carrots, need to be planted directly into the garden because they do not transplant easily. The seed packet will indicate whether the seeds can be sown indoors or whether they should be sown directly into the garden.

Transplants

Transplants, or seedlings, get the garden off to a faster start. They can be plants purchased from a nursery or plants from seeds planted earlier in the classroom. When you are ready to put transplants in the garden:

    • Water the garden a day or two before you want to plant, so the soil will be moist but not saturated.
    • Dig a hole about the size of the seedling root ball with a trowel.
    • Remove the seedling from the container, keeping the root ball intact.
    • Place the transplant in the hole, add the dirt and firm the soil around the roots. Then pull soil into the hole and gently firm it around the root ball. For most plants, the top of the root ball should be even with the soil surface (Tomatoes can be planted more deeply).
    • Make a small ridge of soil around the plant to create a basin to hold water in the root zone area.
    • “Water in” the new plants to make sure the roots are in contact with the soil. Include a half-strength solution of plant food or starter fertilizer in this watering to get the plants off to a good start. Always check the directions on the plant-food container.
    • Keep a close watch for pests such as snails and slugs, cutworms and other insects. Pick off and destroy them.

No “hardening off” is required for seedlings purchased from a nursery because this was done before they were shipped.

Next: Maintaining the Garden