Starting seeds may seem intimidating to a beginner, but it's a reasonably straightforward process. This guide discusses the supplies you’ll need, teaches you how to prepare for planting, gives you step-by-step instructions for sowing, explains how to care for seedlings, and helps troubleshoot common problems.
Some seeds take longer to germinate than others, and all seeds have varying germination success rates. To hasten germination and improve the number of seeds that sprout, there are two ways you can prep the seeds before planting. Soaking and cold stratification are helpful for some seeds in the Herb Variety Pack.
Often known as pre-soaking, soaking seeds in water before planting is a common way to improve germination. The water softens the hard seed coat, exposing the embryo to moisture and kickstarting growth. It is best to soak seeds overnight and then plant them the next day when they start to swell.
Don’t soak seeds longer than overnight or you risk drowning the seed and halting germination completely. Out of the Herb Variety Pack you can pre-soak basil, chives, cilantro, dill, and parsley.
Sage, lavender, and parsley benefit from cold stratification before sowing. Place these seeds on a damp paper towel inside a plastic storage bag, then leave them in your refrigerator for three weeks.
Pre-moisten the potting soil by putting some in a large basin or bucket and adding lukewarm water. Use a clean trowel or your hands to mix thoroughly. The potting soil should feel damp or moist but not overly saturated or soggy. The potting soil should form a clump and hold together if you squeeze a handful, but excess water shouldn’t drain out.
It is okay to reuse used potting soil, but it needs to be sterilized before starting your seeds.To sterilize your potting soil, thoroughly moisten it and place it in an oven-safe dish no more than three inches deep. Cover with aluminum foil and place in an oven preheated to 200°F. When the soil's internal temperature reaches 180°F, bake for thirty minutes without opening the oven door. Shut the oven off and leave the soil inside until it reaches room temperature.
It’s perfectly acceptable to reuse old containers or growing trays as long as they are properly cleaned and disinfected to kill any possible fungal spores, mold, or pathogens. This is extremely important if you have had trouble with damping off in the past.
Scrub the containers with soapy water and a soft-bristled brush to remove any potting soil and rinse well. In a large bucket or a sink, mix one part bleach with nine parts water. Submerge the containers and let them soak for 15 minutes, then set them aside to dry.
When grown outdoors, most herbs require a location classified as full sun, where they receive a minimum of six hours of sunlight daily. Indoors, they prefer a spot that gets ten to twelve hours of daylight to grow as they do outside. There is a high likelihood the light inside your house isn’t adequate for good growth, especially in the winter when days are shorter.
Plants that don’t get enough light will grow tall and spindly, lacking robust flavor. To compensate for low light and prevent legginess, purchase a simple and inexpensive grow light for your herbs.
The best locations in your home for your herbs are by south- or west-facing windows because they have the best sun exposure. South-facing windows get the most sun; they typically have light streaming through them for most if not all of the day. West-facing windows stream direct sunlight for a good portion of the day and are often shaded from the intense sun in the late afternoon.
The temperature inside most homes is ideal for growing herbs. Most herbs prefer daytime air temperatures between 65°F and 75°F and can withstand nighttime temperatures as low as 50°F. This fluctuation mimics the drop in temperatures outdoors once the sun goes down.
Beware extreme temperature variations when growing plants indoors. These variations cause internal stress, which may hinder plant growth and yields. To minimize variations, avoid putting your herbs where they can feel cold drafts from a door or window, or register vents that blow cool air during the summer and heat during the winter. If you are growing plants near windows, periodically check the temperature when it’s especially hot or cold outside.
Most herbs are native to tropical or semi-tropical regions where the relative humidity is high, so they don’t grow as well indoors where the air is dry. Indoors, you need to find a balance between high humidity and good air movement to keep plants happy and minimize or prevent fungal problems.
You can increase the relative humidity around your herbs by grouping plants together, misting them periodically with a spray bottle, or setting containers atop a pebble tray that holds water. Ensure there is some space between the plants for air to circulate, or set up a small fan nearby to move air through the foliage.
Once seedlings have sprouted, keep the growing medium moist without overwatering. The preferred method is to water containers from the bottom. To do this, place the seed tray or container(s) in a shallow pan of water. The growing medium will only wick up the water it needs to fill the pore spaces. This helps prevent overwatering and won’t dislodge the seeds or seedlings like overhead watering may.
Tap water is usually fine for your plants, but there are a few things to keep in mind:
There is no need to fertilize your seeds before they sprout. Inside every seed is an endosperm that stores food—usually starch and some nutrients—for the developing embryo. This is enough to get the seedling started, especially since the plant’s needs are low because of its size. However, you’ll need to fertilize your herbs once their growth takes off.
When your seedlings are four to six weeks old, give them a small dose of a balanced liquid fertilizer. Dilute the concentrated formula at half the rate listed on the package directions, then use this to water your plants once. Most herbs only need a dose of fertilizer once or twice a year.
Damping off is a problem in seedlings caused by fungus or mold that thrives in cool, damp conditions, resulting in seedling death. The most effective way to avoid damping off is to increase air circulation by setting up a small fan nearby. Keep the potting soil moist but take care not to overwater it and keep containers in a warm location.
When seedlings grow tall and spindly, it’s a sign they aren’t getting enough light. If you are using natural light, try moving the plants to a spot that gets more sun or supplement the lighting with a grow light. If you are using grow lights, they may be positioned too far from the plants. Place shims (books work well) under the trays so the plants are closer to the light source. Ideally, the lights should be four to six inches above the tops of the herbs. Some seedlings grow faster than others, so stacking smaller shims works well, making it easy to maintain the proper spacing.
Because the seed contains only a small amount of food, young plants can discolor when they use up these reserves. A lack of phosphorus results in leaves with a reddish-purple hue. To fix discolored leaves, apply a dose of diluted plant food.
Indoor plants have fewer pest problems than outdoor plants, but fungus gnats are problematic indoors. You may have problems with aphids and spider mites, but they typically prefer larger plants with bigger leaves. Pest problems can be discouraged with increased air circulation and by avoiding overwatering; insecticidal soap can also be used as a treatment.